Effectiveness of Strategy-Focused Training in Colorectal Endoscopic Submucosal Dissection: A Retrospective Observational Study

Effectiveness of Strategy-Focused Training in Colorectal Endoscopic Submucosal Dissection: A Retrospective Observational Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Effectiveness of Strategy-Focused Training in Colorectal Endoscopic Submucosal Dissection: A Retrospective Observational Study Hideyuki Chiba, Ken Ohata, Keiichi Ashikari, Jun Tachikawa, Naoya Okada, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3990882/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 25 Apr, 2024 Read the published version in Digestive Diseases and Sciences → Version 1 posted 7 You are reading this latest preprint version Abstract Background Colorectal ESD, an advanced minimally invasive treatment, presents technical challenges, with globally varying training methods. We analyzed the learning curve of ESD training, emphasizing preoperative strategies, notably gravity traction, to guide ESD instructors and trainee programs. Method This retrospective study included 881 cases guided by an experienced supervisor. Six trainees received “strategy-focused” instruction. To evaluate the number of ESD experiences in steps, the following phases were classified based on ESD experiences of each trainees: Phase 0 (0–50 ESD), Phase 1 (51–100 ESD), Phase 2 (101–150 ESD), and Phase 3 (151–200 ESD). Lesion background, outcomes, and safety were compared across phases. Factors contributing to technical difficulty in early (Phase 0 and 1) and late phases (Phase 2 and 3) were identified, along with the utility of traction ESD with device assistance. Result Treatment outcomes were favorable, with 99.8% and 94.7% en bloc resection and curative resection rates, respectively. Approximately 90% self-completion rate could be achieved after experiencing about 50 cases (92.7% in Phase 1), signifying proficiency growth despite increased case difficulty. In early phases, factors such as right-sided colon, LST-NG morphology, and mild and severe fibrosis pose challenges. In late phases, mild and severe fibrosis remained significant. Traction-assisted ESD, utilized in 3% of cases, comprised planned (1.1%) and rescue (1.9%) methods. Planned traction aided specific lesions, while rescue traction was common in the right colon. Conclusion "Strategy-focused" ESD training consistently yields successful outcomes, effectively adapting to varying difficulty factors in different proficient stages. Figures Figure 1 Figure 2 Figure 3 Introduction Colorectal endoscopic submucosal dissection (ESD) has progressed as a minimally invasive treatment for colorectal tumors due to improved endoscopic equipment and appropriate training methods. Recent reports also validated ESD in Western countries [ 1 – 3 ]. Colorectal ESD is widely acknowledged as technically challenging, primarily due to endoscopic maneuverability issues to the colon and higher complication rates related to the thin colonic wall. Traditionally, the fundamental technique of ESD involves mucosal flap creation, advancing the scope behind the lesion, and guiding resection primarily via natural traction, predominantly gravity. The European Society of Gastrointestinal Endoscopy (ESGE) Technical Review outlines gravity-assisted ESD as a representative of traction techniques without device assistance in the technical aspects section [ 4 ]. Other similar methods such as tunneling, pocket creation method, and tissue traction are also described (ESD without devise assistance). Meanwhile, external or internal traction-devise assisted ESD (TA-ESD) techniques, such as ring-thread traction or clip and line etc., have shown favorable outcomes by facilitating easier resection [ 5 – 8 ]. Recently, TA-ESD are often compared to conventional ESD; however, the definition of conventional ESD remains unclear. Particularly, the preference for TA-ESD in all cases remains unclear. Upon initial training for colorectal ESD, familiarity with traction devices is often necessary when using TA-ESD. To provide effective traction, including traction direction and strength, it is very useful to have experience in daily ESD, wherein traction by natural gravity and optimal treatment strategy are considered while performing the procedure. TA-ESD may occasionally lead to unexpected directions or even interfere with the procedure. ESD is mainly performed without device assistance by simulating the treatment strategy simulated preoperatively and sometimes flexibly intraoperatively to preserve effective traction force until the end of treatment while giving awareness to tissue traction. To date, however, few comprehensive reports exist on the safety and validity of strategy-focused ESD training. Additionally, information on the necessary case volume is limited to allow sufficient proficiency and experience for a practitioner and consistently achieve stable results using this instructional approach. This study aims to examine the validity and educational effectiveness of “strategy-focused” ESD training at our institution. Method This single-center, retrospective, observational study analyzed 1532 colorectal ESD cases performed between April 2012 and October 2023. ESD was initiated by the same supervising physician who had experienced about 500 ESD cases as of 2012 and performed by six trainee physicians with at least 50 cases of strategy-focused ESD training. ESD trainees included a total of 6 physicians with less than 30 ESD cases at their previous institution (JA, HK, and MN), including those without colorectal ESD experience (KA, JT, and NA). To evaluate the number of ESD experiences in steps, the following phases were classified based on the number of ESD experiences of each trainee in our institution: Phase 0 (0–50 ESD experiences), Phase 1 (51–100 ESD experiences), Phase 2 (101–150 ESD experiences), and Phase 3 (151–200 ESD experiences) (Fig. 1 ). The initial investigation compared lesion backgrounds, outcomes including en bloc resection and self-completion rates, and safety across each phase to determine the number of cases that the trainees underwent under the similar instruction needed for a stable ESD outcome. Second, cases with lower dissection speed were compared in the early phase (Phase 0,1: ESD < 100) and late phase (Phase 2,3: ESD 101–200) to identify their associated factors. Furthermore, cases with devise assistance in planned or rescue were examined. All ESDs were planned based on the Japanese guidelines for ESD and endoscopic mucosal resection of colorectal cancer [ 9 ]. Antithrombotic and anticoagulant agents were stopped prior the procedure in accordance with current guidelines [ 10 ]. If the tumor showed obvious expanded change with white light imaging, deep depressed surfaces, or was clearly Vi high or VN irregular with magnifying endoscopy, it was diagnosed as SM invasive carcinoma (SM2; >1000 µm) and was not an indication for ESD [ 11 ]. The technical prerequisite for training The technical prerequisite for colorectal ESD training was an endoscopist who could accurately perform stable colonoscopy, colonic endoscopic mucosal resection, and magnified endoscopic observation using narrow band imaging and other techniques. About 30 cases of gastric ESD were experienced as a physician, while more than 20 cases of colorectal ESD were experienced as an assistant during the same period. Colorectal ESD procedures (Fig. 2 ) For all cases, ESD operators were chosen by the supervising physician according to the trainee's experience and performance. Training initially focused on rectal or ascending colon lesions with a tumor diameter of approximately 2 cm and good scope maneuverability, followed by gradually targeting more difficult lesions. Colorectal ESD utilized a single-channel endoscope (PCF-Q260JI, GIF-Q260J, GIF-H290T; Olympus, Tokyo, Japan) with carbon dioxide insufflation. Intravenous sedation was administered using a combination of midazolam or flunitrazepam and pethidine according to each endoscopist's judgment. After injecting undiluted 0.4% sodium hyaluronate (Mucoup, Boston Scientific, Tokyo, Japan; ksmart, Olympus) and indigo carmine with diluted epinephrine, one or two ESD knives were primarily utilized for procedures. A Dual knife (KD-650L; Olympus, Tokyo, Japan), A TechKnife (Micro-Tech, Nanjing, China) was primarily utilized for mucosal incision and submucosal dissection. We used an ERBE electrosurgical unit, VIO300D or VIO3 (Erbe, Tübingen, Germany). The ESD strategy for standard lesions was as follows: Initially, a mucosal flap was created from the proximal side using mainly cutting waves of sufficient size, allowing the scope to dive behind the lesion (effect 2, duration 2, interval 2). Afterwards, a sufficient endpoint was created distal to the lesion. The direction of fluid was taken as the direction of gravity, and incisional dissection was performed along that side. The submucosal layer on the gravity side was thoroughly dissected by re-entering behind the mucosal flap. Finally, the procedure was completed with the remaining gravity contralateral mucosal incision and dissection of the remaining submucosa. Prophylactic coagulation was not performed for remaining small vessels on the ulcer surface. The tunnel method was employed for large lesions larger than half circumference. The decision to perform TA-ESD depends on the physician's judgment; however, planned TA-ESD (pTA-ESD) is often done primarily for recurrent lesions after endoscopic treatment, diverticular extension lesions, and appendiceal orifice extension lesions, and sometimes rescue TA-ESD (rTA-ESD) is performed on short notice due to procedural difficulties. For high-frequency device settings, EndoCutI was utilized for mucosal incisions. Submucosal dissection primarily employed Effect I mode, with swift or forced coagulation mode (Effect 2, 45W) occasionally applied for vascular-rich submucosal areas. Endoscopic hemostasis was achieved using the knife tip in coagulation mode, while resorting to hemostatic forceps if hemostasis could not be achieved with the knife alone. During ESD by trainees, the procedure was switched to the supervising physician with the following conditions: (1) procedural difficulty (situations where the procedure did not proceed for a long time, uncontrolled intraoperative perforation, difficulty in controlling hemostasis), (2) instructive switching (when teaching a better or more appropriate procedure), and (3) for time management (when the procedure time was expected to exceed 2 hours). Making the preoperative ESD strategy (Strategy-focused ESD) The trainee developed a preoperative ESD strategy and discussed it with the supervising physician. This strategy covered not only the endoscopic device, injection needle, and solution, but also the most challenging lesion locations, initial mucosal incision sites, and which incision should be made last, considering the direction of gravity. Additionally, the overall strategy was described as specific as possible (scope manipulation, controlled amount of local injection or air in the lumen, device placement, concrete cutting technique, etc.), as well as the predicted procedure time, which the supervising physician revised as needed (Fig. 3 ). Regarding video recording during ESD from October 2018, both endoscopic videos and actual endoscopic procedures were recorded to facilitate better understanding of the endoscopic hand and scope operation. After synchronizing with the endoscopic video, a two-screen video of the case was generated, including the voice of the supervising physician providing advice and the sounds of the incision and coagulation of the high-frequency device. Reviewing this video post-ESD helped the trainee identify strengths and areas for improvement (video). Recently, our online platform has been developed for learning by using two and three screens of actual ESD videos, which can also be one of the learning by watching them before and after ESD (Ohata Endosalon https://www.jamtea.org/endosalon/ ). Data analysis and evaluations The primary outcome was the self completion rate between phases, with comparisons made regarding lesion difficulty and treatment outcome. Dissection speed (DS) was calculated by dividing the area of the resected specimen into the procedure time (cm 2 /min). The area of the resected specimen was considered to be oval in shape. Hence, it was calculated as follows: 3.14 × 0.25 × long axis × minor axis. DS < 9 was defined as difficult-to-treat cases, with multivariate analysis comparing factors associated with early-stage (Phase 0,1: ESD < 100) and late-stage (Phase 2,3: ESD101-200) ESD. Second, regarding TA-ESD, two categories were investigated: planned traction-assisted ESD (pTA-ESD) and rescue traction-assisted ESD (rTA-ESD). Histopathological Assessment En bloc resection was defined as removing a tumor whole in a single piece. Patients were considered to have undergone “curative resection” when meeting all the following criteria based on the Japanese Classification for Cancer of the Colon and Rectum: lateral and vertical margins were free of tumor, well- or moderately differentiated or papillary carcinoma, no vascular invasion, submucosal invasion depth < 1,000 mm, and grade 1 budding [ 9 ]. Definitions The degree of submucosal fibrosis was classified into three types (F0–2) (F0: no fibrosis, which manifested as a blue transparent layer; F1: mild fibrosis, which appeared as a white web-like structure in the blue submucosal layer; F2: whitish submucosa or severe fibrosis, which appeared as a white muscular like structure without a blue transparent layer in the submucosal layer) [ 12 ]. Delayed bleeding was defined as the presentation of bloody stools within 14 days post-ESD, followed by an emergency colonoscopy. Intraoperative perforation was defined as the occurrence of an immediately recognizable hole in the bowel wall. Delayed perforation was defined as colon perforation occurring after the scope had been withdrawn following ESD completion without intraprocedural perforation [ 10 ]. Post-ESD coagulation syndrome (PECS) was defined as a presence of pain and fever due to inflammation of the peritoneum, which occasionally occurs after electrocoagulation despite the absence of subsequent perforation [ 14 ]. Statistical Analysis For comparing categorial variables, a two-sided χ2- or Fisher’s exact test was performed. Continuous variables (patient characteristics) were assumed to have a normal distribution according to the central limit theorem, and an ANOVA was utilized to compare the four phases. Meanwhile, other continuous variables (procedural, and lesion characteristics) were compared using the Kruskal-Wallis test. Factors significant in univariate analysis were entered into the multivariate logistic regression analysis model. The odds ratio (OR) and 95% confidence interval (CI) were calculated for each variable. All analyses were conducted using SPSS 23 for Windows, with P -values ≤ 0.05 considered statistically significant. Ethics The study was conducted in accordance with the principles in the Declaration of Helsinki. Informed consent was obtained from all patients prior the procedures. This was also approved by the institutional review board of our hospital(No.23–38). Results A total of 881 cases were included, including 6 trainees with 300 lesions in Phase 0 (0-50 ESD), 6 trainees with 286 lesions in Phase 1 (51-100 ESD), 4 trainees with 195 lesions in Phase 2 (101-150 ESD), and 2 trainees with 100 lesions in Phase 3 (150-200 ESD). Each physician were trained in the following time periods: 86 cases in 3 years and 2 months for KA (about 29 cases/year), 100 cases in 3 years and 6 months for JT (about 29 cases/year), 145 cases in 3 years and 8 months for NO (about 39 cases/year), 1 case in 5 years for JA (about 30 cases/year), 150 cases in 6 years and 3 months for HK (about 32 cases/year), and 5 years 200 cases in 3 months for MN (about 38 cases/year). Patient background is summarized in Table 1. The location, macroscopic type, and difficult situation (post-biopsy, post-endoscopic treatment, diverticulum-related lesions, and appendiceal orifice-related lesions) were similar for each phase. Overall, the outcome of treatment was favorable, with 99.8% (879/881) of cases resected en bloc and 94.7% (834/881) of cases curatively resected (Table 2). Tumor diameter was similar for all phases; however, lesions >5 cm were most common in Phase 1. Treatment time and dissection speed increased with increasing phase. The self-completion rate improved with each phase. Notably, the self-completion rate was 92.7% in Phase 1, without cases of ESD interruption. No significant difference was found in the rate of en bloc resection and curative resection between phases. Regarding adverse events, 2 cases (2%) of perforation were observed in Phase 3, which was more common than in other phases. Difficult cases were defined as DS<9 (cm 2 /min), and their associated factors were examined in the early phase (Phase 0,1: ESD<100) and late phase (Phase 2,3: ESD101-200). Results revealed that in early phase, right-sided colon (OR 3.383, 95% CI: 1.113-10.283, p =0.032), LST-NG (OR 2. 222, 95% CI 1.019-4.845, p =0.045), mild fibrosis ( F1) (OR 2.521, 95% CI: 1.364-4.661, p =0.003), severe fibrosis (F2) (OR 13.237, 95% CI: 5.203-33.674, p <0.0001), and in the late stage, mild fibrosis (F1) (OR 4.182, 95%CI: 1.398-12.511, p =0.01), severe fibrosis (F2) (OR 25.096, 95% CI: 7.437-84.685, p <0.0001) were identified (Table 3). TA-ESD was performed in 26 cases (3.0%) overall, with an increasing trend with increasing phase (Table 2). Ten cases (38.5%) were planned TA-ESD, and 16 cases (61.5%) were rescue TA-ESD (Table 4). pTA-ESD was performed in 3 cases of diverticular extension, 3 cases of supranastomotic lesions, 2 cases of large and stalked lesions, 1 case of appendiceal extension lesion, and 1 case of recurrent lesion after endoscopic treatment. Meanwhile, rTA-ESD was performed in 11 of 16 cases in the later stages (Phase 2 and 3), 12 cases in the right colon, especially in the cecum (all cases with appendiceal extension), 9 cases with fibrosis (F1: 3 cases, F2: 6 cases), and both operation time and DS took longer than in other cases, with one case of intraoperative perforation (Table 4). Discussion The study evaluated the outcomes of six trainees trained in strategy-focused colorectal ESD and the training's validity. By systematically performing a preoperative strategy simulations considering the physician's experience and treatment difficulty levels, trainees achieved favorable ESD outcomes, with 99.8% and 94.7% of cases resected en bloc and curatively, respectively. Moreover, 97% of cases could be safely resected in a short time without device assistance. This strategy-focused training method resulted in a self-completion rate of about 90% in more than 50 cases, remaining high even in challenging cases. Under this strategy-focused training method, the planned traction method with device assistance proved useful for more difficult cases. Colorectal ESD is challenging due to the thin colon wall and poor operability. While various training methods for colorectal ESD have been reported in the past, they vary depending on the country and institution [4, 13,15]. Especially in Asia, many institutions start colorectal ESD after prior experience with gastric and esophageal ESD, and certain proficiency is achieved with approximately 30 to 80 cases [15, 16]. However, training for colorectal ESD was deemed difficult in Europe and the United States due to limited experience with gastric cancer ESD and the lack of supervising physicians. Zhang et al. also reported that 280 ESD cases were necessitated to achieve colorectal ESD proficiency (en bloc resection >90%, R0 resection >80%, and resection speed >9 cm 2 /h) [13]. A national survey from Italy reported that perforation rates in the colon and rectum were significantly lower with experience of >150 compared to 80-150 cases [17]. The primary goal of any training method is to develop skills for safely and reliably completing ESD, even for challenging lesions. At our institution, a single experienced supervisor trained physicians using the similar teaching method (strategy-focused ESD), achieving a high self-completion rate of about 90% in more than 50 cases, with a DS of 14.9 cm 2 /min and a curative resection rate of 94.3%. In subsequent phases, as more difficult cases were selected, the self-completion rate improved, and speed increased to a DS of 19.6 cm 2 /min, a trend that continued to improve with each phase. Preoperative simulation and strategy creation tailored to intraoperative situations are crucial. Furthermore, the angle manipulation of the scope and endoscope is essential to ensure successful ESD completion, and we believe that simultaneous video recording on two screens (video of the inside and outside of the endoscope) is a useful educational tool. While its usefulness cannot be evaluated since it has not been compared with other training methods of ESD, this educational method is very effective given an overall median procedure time by the trainees of 30 minutes, a very high en bloc resection rate (99.7%), and relatively low complication frequency. In the present study, treatment difficulty was classified into early and late stages, anticipating variation based on operator experience. Factors identified in the early stage included right-sided colon, LST-NG, and mild/severe fibrosis, while in the late stage, only fibrosis was significant, with no notable differences in location or morphology type. Poor operability, common in the right-sided colon, poses a challenge in colorectal ESD, with Boda et al. recommending gaining scope operability experience in the first 20 cases [18]. Familiarity with operability and experience likely decreases treatment difficulty by location, possibly due to increased fibrosis in LST-NG, as previously reported. [19]. Preoperative simulation of the lesion, including its characteristics and maneuverability, contributed to this learning curve. ESD with device assistance occurred less frequently, with 26 cases (3.0%) categorized as planned traction and rescue traction for difficult cases. Planned traction was used for lesions extending into diverticula or appendiceal orifices where preoperative gravity traction was not expected [20,21]. Meanwhile, rescue traction was utilized when gravity traction was less effective, and a consistent endoscopic view could not be obtained. Since it is crucial to imagine the ideal traction direction and traction force prior the procedure, it is assumed that these factors are always imagined during the usual ESD to ensure a smooth rescue traction. This study has several limitations. This study was conducted in Japan and involved one supervising physician teaching six physicians using the similar training method. Hence, a validation study is warranted to identify whether this training method is appropriate for facilities lacking a supervising physician and whether it is equally effective for physicians starting their training with colorectal ESD. Furthermore, it remains unclear if physicians completing this training can consistently perform the procedure at other facilities. However, in more than 50 cases of colorectal ESD, a self-completion rate of about 90% was obtained, including difficult lesions, and it is expected that physicians will step up to become proficient in colorectal ESD. In conclusion, this study evaluated the effectiveness of "strategy-focused” training, emphasizing preoperative strategy development and natural traction. After conducting 881 cases by six trainee physicians, results showed a progressive improvement in self-completion rates, lesion outcomes, and safety across training phases. The strategy-focused approach achieved a 95% self-completion rate in the later phase without device assistance. The study suggests that this training method is effective in enhancing ESD skills, emphasizing preoperative simulation and strategy development for successful and safe outcomes. Declarations Author Contribution HC, KA, JT, KO, JA, HK, and MN performed the colorectal ESD. HC recruited the study participants. HC, KA, JT, KO, JA, HK, MN, AH, YE, and MK collected the clinical data of the study participants. Analysis and interpretation of the data was conducted by HC and KO. All the authors have read the final manuscript and approve of its submission for publication. References Ohata K, Kobayashi N, Sakai E et al. 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Endoscopic submucosal dissection for laterally spreading tumors involving the appendiceal orifice.Surg Endosc 2017; 31: 5444-5450 Tables Table 1 The Characteristics of the patients Phase 0 Phase 1 Phase 2 Phase 3 P value Case, n 300 286 195 100 Sex (male), n (%) 153 (51) 157 (54.9) 109 (55.9) 45 (45) 0.398 Age, mean ± SD 68.8 ± 12.6 67.1± 12.1 65.5 ± 12.9 63.5 ± 14.2 0.003 Location*, n (%) 0.584 Right colon 186 (62) 187 (65.4) 137 (70.3) 64 (64) Left colon 66 (22) 63(22.0) 35 (17.9) 20 (20) Rectum 48 (16) 36 (12.6) 23 (11.8) 16 (16) Morphology, n (%) 0.171 0-I 42 (14） 49 (17.1） 40 (20.5） 18 (18) LST-G 67 (22.3） 53 (18.5） 25 (12.8） 18 (18) LST-NG 191 (63.7) 184 (64.3) 130 (66.7) 64 (64) Difficult situation, n (%) 25 (8.3) 23 (8.0) 11 (5.6) 9 (9) 0.527 Post ER 1 5 5 1 Pre-biopsy 9 4 0 1 Diverticulum** 7 4 4 2 Appendiceal orifice*** 8 10 2 5 *The right colon refers to the transverse colon-cecum, and the left colon to the sigmoid colon-descending colon. ** The diverticulum refers to the lesion spreading to the diverticulum. *** The appendiceal orifice refers to the lesion spreading to the appendiceal orifice. LST-G; laterally spreading tumor- granular type, LST-NG: laterally spreading tumor- nongranular type, ER; endoscopic resection. Table 2 The treatment outcome per phase in six trainees ESD training ESD experience Phase 0 Phase 1 Phase 2 Phase 3 P value 0-50 51-100 101-150 151- 200 Case, n 300 286 195 100 Size (mm), median (IQR) 20.0 (18.0 - 28.0) 21.5 (18.0 - 30.0) 20.0 (16.0 - 26.0) 20.0 (18.0 - 26.5) 0.97 Time (min), median (IQR) 36 (23 - 55) 29 (19- 46) 25.0 (17.0 - 41.0) 24.5 (16.0 - 37.8) <0.001 Dissection speed (cm 2 /min), median (IQR) 14.9 (10.6 - 21.4) 19.6 (13.7 - 27.7) 20.8 (14.1 - 30.2) 23.7 (17.5 - 33.0) <0.001 Devise traction, n (%) 1 (0.3) 6 (2.1) 11 (5.6) 8 (8) <0.001 Rescue traction, n (%) 0 5 (1.7) 8 (4.1) 4 (4.0) 0.279 Tunnel method, n (%) 3 (1) 11 (3.8) 13 (6.7) 4 (4) 0.009 Fibrosis, n (%) 44 (14.7) 65 (22.7) 26 (26) 25 (25) 0.005 F1 (mild) 30 (10) 55 (19.2) 15 (7.7) 19 (19) F2 (severe) 14 (4.7) 10 (3.5) 11 (7.6) 6 (6) 0.637 Self-completion, n (%) 254 (84.7) 265 (92.7) 180 (92.3) 95 (95) 0.001 Interruption, n (%) 0 0 0 0 - Histology, n (%) 0.371 Adenoma 161 (53.7) 140 (49.0) 109 (55.9) 50 (50) Tis 115 (38.3) 123 (43.0) 70 (35.9) 40 (40) T1a 7 (2.3) 12 (4.2) 4 (2.1) 2 (2) T1b or deeper 16 (5.3) 8 (2.8) 8 (4.1) 7 (7) Others 1 (0.3) 3 (1.0) 4 (2.1) 1 (1) En bloc resection, n (%) 300 (100) 285 (99.7) 194 (99.5) 100 (100) 0.614 Curative resection, n (%) 283 (94.3) 275 (96.2) 184 (94.4) 92 (92) 0.43 Adverse events, n (%) 12 (4) 14 (4.9) 8 (4.1) 7 (7) 0.637 post bleeding 6 (2) 5 (1.7) 4 (2.1) 1 (1) 0.919 perforation 0 (0) 0 (0) 1 (0.5) 2 (2) 0.016 delayed perforation 1 (0.3) 0 (0) 1 (0.5) 0 (0) 0.63 PECS 5 (1.7) 9 (3.1) 2 (1.0) 4 (4) 0.241 ESD; endoscopic submucosal dissection, PECS; post-ESD coagulation syndrome Table 3 Risk Factors for difficult cases* in each Phase Early Phase (Phase 0 and 1) Univariate, OR (95%CI) P value Multivariate, OR (95%CI) P value Location ** Rectum 1 1 Left colon 3.486 (1.142 - 10.644) 0.028 3.116 (0.966 - 10.048) 0.057 Right colon 3.608(1.271 - 10.238) 0.016 3.383 (1.113 - 10.283) 0.032 Shape LST-G 1 1 LST-NG 2.12(1.014 - 4.430) 0.046 2.222 (1.019 - 4.845) 0.045 Protruded 2.667 (1.119 - 6.352) 0.027 2.267 (0.854 - 6.019) 0.1 Fibrosis F1 (mild) 2.396 (1.315 - 4.364) 0.004 2.521 (1.364 - 4.661) 0.003 F2 (severe) 12.483 (5.258 - 29.636) <0.001 13.237 (5.203 - 33.674) <0.001 Late Phase (Phase 2 and 3) Univariate, OR (95%CI) P value Multivariate, OR (95%CI) P value Location** Rectum 1 1 Left colon 2.043 (0.506 – 8.251) 0.316 2.083 (0.4141 – 10.468) 0.373 Right colon 1.180 (0.330 – 4.217) 0.799 1.420 (0.310 – 6.494) 0.651 Shape LST-NG 2.13 (0.838 - 5.413) 0.112 3.05 (0.983 - 9.462) 0.053 Protruded 1.074 (0.416 – 2.771) 0.883 Fibrosis F1 (mild) 3.52 (1.252 - 9.897) 0.017 4.182 (1.398 - 12.511) 0.01 F2 (severe) 18.482 (6.186 - 55.223) <0.001 25.096 (7.437 - 84.685) <0.001 *Difficult cases were defined as dissection speed <9 (cm 2 /min). **The right colon refers to the transverse colon-cecum, and the left colon to the sigmoid colon-descending colon. LST-G; laterally spreading tumor- granular type, LST-NG: laterally spreading tumor- nongranular type, ER; endoscopic resection. Table 4 Sixteen cases treated by ESD with rescue traction method No Phase Size (mm) Shape Site Difficult situation Fibrosis Time (min) DT En bloc Adverse events 1 1 33 G T - F1 70 16.1 Yes - 2 1 24 NG Ce AO F2 96 9.2 Yes - 3 1 21 I T - F2 132 3.5 Yes - 4 1 35 I S - F2 190 5.2 Yes - 5 1 25 NG Ce AO F1 58 12.3 Yes - 6 2 20 I T - - 26 18.9 Yes - 7 2 20 NG T - F2 110 2.9 No - 8 2 45 NG D - F2 120 6.5 Yes - 9 2 25 NG D - F2 120 6.5 Yes - 10 2 25 NG T - F1 123 4.8 Yes - 11 2 15 NG D - - 10 23.6 Yes - 12 2 20 NG A - - 46 9.8 Yes - 13 3 20 I T - - 12 47.1 Yes - 14 3 18 I Ce AO - 80 2.9 Yes - 15 3 28 NG Ce AO - 80 7.1 Yes Perforation 16 3 20 NG Ce AO - 35 12.9 Yes - median 22.5 80 8.2 ESD; endoscopic submucosal dissection, G; laterally spreading tumor-granular type, NG: laterally spreading tumor- nongranular type, I: protruded type, Ce; cecum, A; ascending colon, T; transverse colon, D; descending colon, S: sigmoid colon, AO: appendiceal orifice, F1: mild fibrosis, F2; severe fibrosis, DT; dissection time (cm 2 /min) Additional Declarations No competing interests reported. Supplementary Files video.mp4 Video Legends a two-screen video for ESD learning Cite Share Download PDF Status: Published Journal Publication published 25 Apr, 2024 Read the published version in Digestive Diseases and Sciences → Version 1 posted Editorial decision: Revision requested 12 Mar, 2024 Reviews received at journal 09 Mar, 2024 Reviewers agreed at journal 02 Mar, 2024 Reviewers invited by journal 28 Feb, 2024 Editor assigned by journal 28 Feb, 2024 Submission checks completed at journal 27 Feb, 2024 First submitted to journal 26 Feb, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3990882","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":275473205,"identity":"faa7f1e0-38a3-4576-8623-8ce9a01c082d","order_by":0,"name":"Hideyuki Chiba","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA20lEQVRIiWNgGAWjYBACAwYGNobEBgY5MC8ByIEAHsJajEnUwtgA0kUsMGdgfvbg4Q679H6xw8c+PGDgy+dvYD72gUHmDk4tlg1s5gaJZ5JzZ85OS54BdJjljANsyTMYeJ7hdtj9N2wSiW3MuRtu5xiD/GJgwMAD9BjPYdxaDvCAtNSnG5Cq5XACKVrYzCQSzxw3BPmFIcGAzUDiMBuQgc8vB5ifSf7cUS3PL518mPFHxTED/vbmwwwfe3CHGLoJxxgYmIF0Ys8BYrUw1EDpH8RrGQWjYBSMgmEPANfJSNGgV7xRAAAAAElFTkSuQmCC","orcid":"","institution":"Omori Red Cross Hospital","correspondingAuthor":true,"prefix":"","firstName":"Hideyuki","middleName":"","lastName":"Chiba","suffix":""},{"id":275473206,"identity":"2567e52b-722a-4ba7-bbcb-15c4a4dc2c5f","order_by":1,"name":"Ken Ohata","email":"","orcid":"","institution":"NTT Medical Center Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Ken","middleName":"","lastName":"Ohata","suffix":""},{"id":275473207,"identity":"c923c6cb-ec66-4b5c-809c-8dcdb307b3ac","order_by":2,"name":"Keiichi Ashikari","email":"","orcid":"","institution":"Ashikari Endoscopy Clinic","correspondingAuthor":false,"prefix":"","firstName":"Keiichi","middleName":"","lastName":"Ashikari","suffix":""},{"id":275473208,"identity":"6a3e0fab-8e0c-433f-a29c-d354498bfb74","order_by":3,"name":"Jun Tachikawa","email":"","orcid":"","institution":"Hiratsuka City Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jun","middleName":"","lastName":"Tachikawa","suffix":""},{"id":275473209,"identity":"82ee0765-063f-4916-ad93-33477b575abe","order_by":4,"name":"Naoya Okada","email":"","orcid":"","institution":"Yokohama Rosai Hospital","correspondingAuthor":false,"prefix":"","firstName":"Naoya","middleName":"","lastName":"Okada","suffix":""},{"id":275473210,"identity":"2fc2002c-51d2-4202-bfb3-6e41d97db60c","order_by":5,"name":"Akimichi Hayashi","email":"","orcid":"","institution":"Omori Red Cross Hospital","correspondingAuthor":false,"prefix":"","firstName":"Akimichi","middleName":"","lastName":"Hayashi","suffix":""},{"id":275473211,"identity":"a27cb8d0-357f-4346-85e7-5d17c60022dd","order_by":6,"name":"Yu Ebisawa","email":"","orcid":"","institution":"Omori Red Cross Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yu","middleName":"","lastName":"Ebisawa","suffix":""},{"id":275473212,"identity":"7bf43b84-d267-45ad-beb1-dc93e7c6f63c","order_by":7,"name":"Mikio Kobayashi","email":"","orcid":"","institution":"Omori Red Cross Hospital","correspondingAuthor":false,"prefix":"","firstName":"Mikio","middleName":"","lastName":"Kobayashi","suffix":""},{"id":275473213,"identity":"306f5678-ccbf-46b9-81d8-d7d0f8bc9e07","order_by":8,"name":"Jun Arimoto","email":"","orcid":"","institution":"Omori Red Cross Hospital","correspondingAuthor":false,"prefix":"","firstName":"Jun","middleName":"","lastName":"Arimoto","suffix":""},{"id":275473214,"identity":"eac03b81-d13b-4924-8594-8db3fcd14c68","order_by":9,"name":"Hiroki Kuwabara","email":"","orcid":"","institution":"Omori Red Cross Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hiroki","middleName":"","lastName":"Kuwabara","suffix":""},{"id":275473215,"identity":"d8468259-dff0-44a1-b96b-015ea57c22b6","order_by":10,"name":"Michiko Nakaoka","email":"","orcid":"","institution":"Omori Red Cross Hospital","correspondingAuthor":false,"prefix":"","firstName":"Michiko","middleName":"","lastName":"Nakaoka","suffix":""}],"badges":[],"createdAt":"2024-02-26 12:18:52","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3990882/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3990882/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10620-024-08430-9","type":"published","date":"2024-04-25T22:04:12+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":51822120,"identity":"92ffd04d-94a3-4730-aaf8-965fefdb386f","added_by":"auto","created_at":"2024-02-29 16:12:22","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":80250,"visible":true,"origin":"","legend":"\u003cp\u003eStudy flow\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3990882/v1/39fe16e091cd87512b905c6e.jpg"},{"id":51822683,"identity":"b0d1ba6e-4b20-41eb-8a71-b51c42c36730","added_by":"auto","created_at":"2024-02-29 16:20:23","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":372287,"visible":true,"origin":"","legend":"\u003cp\u003eEndoscopic submucosal dissection of 40mm 0-IIa lesion treated by trainee\u003c/p\u003e\n\u003cp\u003e(a) 40mm, laterally spreading tumor-non granular type lesion\u003c/p\u003e\n\u003cp\u003e(b) An initial incision was started from the oral side because the approach to the oral side of the lesion was predicted to be more difficult.\u003c/p\u003e\n\u003cp\u003e(c) Next, a mucosal flap was created from the anal side.\u003c/p\u003e\n\u003cp\u003e(d) Efficient dissection was proceeded with the use of gravity traction (the uncut mucosa remains at 2 o'clock, indicating that tissue traction is being applied).\u003c/p\u003e\n\u003cp\u003e(e) Ulcer surface immediately after ESD. The resection was completed without adverse events within 45 minutes.\u003c/p\u003e\n\u003cp\u003e(f) The histopathology revealed an intramucosal carcinoma with negative margins.\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3990882/v1/e5e3ebbd0e840223ff0fbe63.jpg"},{"id":51822121,"identity":"330b39f2-7128-438d-8711-10088215fb0a","added_by":"auto","created_at":"2024-02-29 16:12:23","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":269495,"visible":true,"origin":"","legend":"\u003cp\u003eThe strategy note\u003c/p\u003e\n\u003cp\u003eBefore ESD, the trainee simulates the target lesion in as much detail as possible and describes the simulation. The content is revised by the supervising physician before the procedure and modified as appropriate.\u003c/p\u003e","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-3990882/v1/a4dab23cea9572dbf12497aa.jpg"},{"id":55689495,"identity":"37898521-d7c2-48d2-b81c-ada4cf27c733","added_by":"auto","created_at":"2024-05-01 22:04:17","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1170912,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3990882/v1/b6cbbdad-3894-4b41-8770-c65e20ec9182.pdf"},{"id":51822197,"identity":"13adb873-38ee-49a0-b963-de11cc6a5b28","added_by":"auto","created_at":"2024-02-29 16:12:40","extension":"mp4","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":244502394,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eVideo Legends \u003c/strong\u003ea two-screen video for ESD learning\u003c/p\u003e","description":"","filename":"video.mp4","url":"https://assets-eu.researchsquare.com/files/rs-3990882/v1/1f7f2c156db4e1bdbaa87d3d.mp4"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effectiveness of Strategy-Focused Training in Colorectal Endoscopic Submucosal Dissection: A Retrospective Observational Study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eColorectal endoscopic submucosal dissection (ESD) has progressed as a minimally invasive treatment for colorectal tumors due to improved endoscopic equipment and appropriate training methods. Recent reports also validated ESD in Western countries [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Colorectal ESD is widely acknowledged as technically challenging, primarily due to endoscopic maneuverability issues to the colon and higher complication rates related to the thin colonic wall.\u003c/p\u003e \u003cp\u003eTraditionally, the fundamental technique of ESD involves mucosal flap creation, advancing the scope behind the lesion, and guiding resection primarily via natural traction, predominantly gravity. The European Society of Gastrointestinal Endoscopy (ESGE) Technical Review outlines gravity-assisted ESD as a representative of traction techniques without device assistance in the technical aspects section [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Other similar methods such as tunneling, pocket creation method, and tissue traction are also described (ESD without devise assistance). Meanwhile, external or internal traction-devise assisted ESD (TA-ESD) techniques, such as ring-thread traction or clip and line etc., have shown favorable outcomes by facilitating easier resection [\u003cspan additionalcitationids=\"CR6 CR7\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Recently, TA-ESD are often compared to conventional ESD; however, the definition of conventional ESD remains unclear. Particularly, the preference for TA-ESD in all cases remains unclear. Upon initial training for colorectal ESD, familiarity with traction devices is often necessary when using TA-ESD. To provide effective traction, including traction direction and strength, it is very useful to have experience in daily ESD, wherein traction by natural gravity and optimal treatment strategy are considered while performing the procedure. TA-ESD may occasionally lead to unexpected directions or even interfere with the procedure. ESD is mainly performed without device assistance by simulating the treatment strategy simulated preoperatively and sometimes flexibly intraoperatively to preserve effective traction force until the end of treatment while giving awareness to tissue traction. To date, however, few comprehensive reports exist on the safety and validity of strategy-focused ESD training. Additionally, information on the necessary case volume is limited to allow sufficient proficiency and experience for a practitioner and consistently achieve stable results using this instructional approach.\u003c/p\u003e \u003cp\u003eThis study aims to examine the validity and educational effectiveness of \u0026ldquo;strategy-focused\u0026rdquo; ESD training at our institution.\u003c/p\u003e"},{"header":"Method","content":"\u003cp\u003eThis single-center, retrospective, observational study analyzed 1532 colorectal ESD cases performed between April 2012 and October 2023. ESD was initiated by the same supervising physician who had experienced about 500 ESD cases as of 2012 and performed by six trainee physicians with at least 50 cases of strategy-focused ESD training. ESD trainees included a total of 6 physicians with less than 30 ESD cases at their previous institution (JA, HK, and MN), including those without colorectal ESD experience (KA, JT, and NA). To evaluate the number of ESD experiences in steps, the following phases were classified based on the number of ESD experiences of each trainee in our institution: Phase 0 (0\u0026ndash;50 ESD experiences), Phase 1 (51\u0026ndash;100 ESD experiences), Phase 2 (101\u0026ndash;150 ESD experiences), and Phase 3 (151\u0026ndash;200 ESD experiences) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe initial investigation compared lesion backgrounds, outcomes including en bloc resection and self-completion rates, and safety across each phase to determine the number of cases that the trainees underwent under the similar instruction needed for a stable ESD outcome. Second, cases with lower dissection speed were compared in the early phase (Phase 0,1: ESD\u0026thinsp;\u0026lt;\u0026thinsp;100) and late phase (Phase 2,3: ESD 101\u0026ndash;200) to identify their associated factors. Furthermore, cases with devise assistance in planned or rescue were examined. All ESDs were planned based on the Japanese guidelines for ESD and endoscopic mucosal resection of colorectal cancer [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Antithrombotic and anticoagulant agents were stopped prior the procedure in accordance with current guidelines [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. If the tumor showed obvious expanded change with white light imaging, deep depressed surfaces, or was clearly Vi high or VN irregular with magnifying endoscopy, it was diagnosed as SM invasive carcinoma (SM2; \u0026gt;1000 \u0026micro;m) and was not an indication for ESD [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eThe technical prerequisite for training\u003c/h2\u003e \u003cp\u003eThe technical prerequisite for colorectal ESD training was an endoscopist who could accurately perform stable colonoscopy, colonic endoscopic mucosal resection, and magnified endoscopic observation using narrow band imaging and other techniques. About 30 cases of gastric ESD were experienced as a physician, while more than 20 cases of colorectal ESD were experienced as an assistant during the same period.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eColorectal ESD procedures (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e)\u003c/h2\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFor all cases, ESD operators were chosen by the supervising physician according to the trainee's experience and performance. Training initially focused on rectal or ascending colon lesions with a tumor diameter of approximately 2 cm and good scope maneuverability, followed by gradually targeting more difficult lesions.\u003c/p\u003e \u003cp\u003eColorectal ESD utilized a single-channel endoscope (PCF-Q260JI, GIF-Q260J, GIF-H290T; Olympus, Tokyo, Japan) with carbon dioxide insufflation. Intravenous sedation was administered using a combination of midazolam or flunitrazepam and pethidine according to each endoscopist's judgment. After injecting undiluted 0.4% sodium hyaluronate (Mucoup, Boston Scientific, Tokyo, Japan; ksmart, Olympus) and indigo carmine with diluted epinephrine, one or two ESD knives were primarily utilized for procedures. A Dual knife (KD-650L; Olympus, Tokyo, Japan), A TechKnife (Micro-Tech, Nanjing, China) was primarily utilized for mucosal incision and submucosal dissection. We used an ERBE electrosurgical unit, VIO300D or VIO3 (Erbe, T\u0026uuml;bingen, Germany).\u003c/p\u003e \u003cp\u003eThe ESD strategy for standard lesions was as follows: Initially, a mucosal flap was created from the proximal side using mainly cutting waves of sufficient size, allowing the scope to dive behind the lesion (effect 2, duration 2, interval 2). Afterwards, a sufficient endpoint was created distal to the lesion. The direction of fluid was taken as the direction of gravity, and incisional dissection was performed along that side. The submucosal layer on the gravity side was thoroughly dissected by re-entering behind the mucosal flap. Finally, the procedure was completed with the remaining gravity contralateral mucosal incision and dissection of the remaining submucosa. Prophylactic coagulation was not performed for remaining small vessels on the ulcer surface. The tunnel method was employed for large lesions larger than half circumference. The decision to perform TA-ESD depends on the physician's judgment; however, planned TA-ESD (pTA-ESD) is often done primarily for recurrent lesions after endoscopic treatment, diverticular extension lesions, and appendiceal orifice extension lesions, and sometimes rescue TA-ESD (rTA-ESD) is performed on short notice due to procedural difficulties.\u003c/p\u003e \u003cp\u003eFor high-frequency device settings, EndoCutI was utilized for mucosal incisions. Submucosal dissection primarily employed Effect I mode, with swift or forced coagulation mode (Effect 2, 45W) occasionally applied for vascular-rich submucosal areas. Endoscopic hemostasis was achieved using the knife tip in coagulation mode, while resorting to hemostatic forceps if hemostasis could not be achieved with the knife alone.\u003c/p\u003e \u003cp\u003eDuring ESD by trainees, the procedure was switched to the supervising physician with the following conditions: (1) procedural difficulty (situations where the procedure did not proceed for a long time, uncontrolled intraoperative perforation, difficulty in controlling hemostasis), (2) instructive switching (when teaching a better or more appropriate procedure), and (3) for time management (when the procedure time was expected to exceed 2 hours).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e\u003cb\u003eMaking the preoperative ESD strategy (Strategy-focused ESD)\u003c/b\u003e\u003c/h2\u003e \u003cp\u003eThe trainee developed a preoperative ESD strategy and discussed it with the supervising physician. This strategy covered not only the endoscopic device, injection needle, and solution, but also the most challenging lesion locations, initial mucosal incision sites, and which incision should be made last, considering the direction of gravity. Additionally, the overall strategy was described as specific as possible (scope manipulation, controlled amount of local injection or air in the lumen, device placement, concrete cutting technique, etc.), as well as the predicted procedure time, which the supervising physician revised as needed (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Regarding video recording during ESD from October 2018, both endoscopic videos and actual endoscopic procedures were recorded to facilitate better understanding of the endoscopic hand and scope operation. After synchronizing with the endoscopic video, a two-screen video of the case was generated, including the voice of the supervising physician providing advice and the sounds of the incision and coagulation of the high-frequency device. Reviewing this video post-ESD helped the trainee identify strengths and areas for improvement (video). Recently, our online platform has been developed for learning by using two and three screens of actual ESD videos, which can also be one of the learning by watching them before and after ESD (Ohata Endosalon \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.jamtea.org/endosalon/\u003c/span\u003e\u003cspan address=\"https://www.jamtea.org/endosalon/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eData analysis and evaluations\u003c/h2\u003e \u003cp\u003eThe primary outcome was the self completion rate between phases, with comparisons made regarding lesion difficulty and treatment outcome. Dissection speed (DS) was calculated by dividing the area of the resected specimen into the procedure time (cm\u003csup\u003e2\u003c/sup\u003e/min). The area of the resected specimen was considered to be oval in shape. Hence, it was calculated as follows: 3.14 \u0026times; 0.25 \u0026times; long axis \u0026times; minor axis. DS\u0026thinsp;\u0026lt;\u0026thinsp;9 was defined as difficult-to-treat cases, with multivariate analysis comparing factors associated with early-stage (Phase 0,1: ESD\u0026thinsp;\u0026lt;\u0026thinsp;100) and late-stage (Phase 2,3: ESD101-200) ESD. Second, regarding TA-ESD, two categories were investigated: planned traction-assisted ESD (pTA-ESD) and rescue traction-assisted ESD (rTA-ESD).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eHistopathological Assessment\u003c/h2\u003e \u003cp\u003eEn bloc resection was defined as removing a tumor whole in a single piece. Patients were considered to have undergone \u0026ldquo;curative resection\u0026rdquo; when meeting all the following criteria based on the Japanese Classification for Cancer of the Colon and Rectum: lateral and vertical margins were free of tumor, well- or moderately differentiated or papillary carcinoma, no vascular invasion, submucosal invasion depth\u0026thinsp;\u0026lt;\u0026thinsp;1,000 mm, and grade 1 budding [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eDefinitions\u003c/h2\u003e \u003cp\u003eThe degree of submucosal fibrosis was classified into three types (F0\u0026ndash;2) (F0: no fibrosis, which manifested as a blue transparent layer; F1: mild fibrosis, which appeared as a white web-like structure in the blue submucosal layer; F2: whitish submucosa or severe fibrosis, which appeared as a white muscular like structure without a blue transparent layer in the submucosal layer) [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Delayed bleeding was defined as the presentation of bloody stools within 14 days post-ESD, followed by an emergency colonoscopy. Intraoperative perforation was defined as the occurrence of an immediately recognizable hole in the bowel wall. Delayed perforation was defined as colon perforation occurring after the scope had been withdrawn following ESD completion without intraprocedural perforation [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Post-ESD coagulation syndrome (PECS) was defined as a presence of pain and fever due to inflammation of the peritoneum, which occasionally occurs after electrocoagulation despite the absence of subsequent perforation [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eFor comparing categorial variables, a two-sided χ2- or Fisher\u0026rsquo;s exact test was performed. Continuous variables (patient characteristics) were assumed to have a normal distribution according to the central limit theorem, and an ANOVA was utilized to compare the four phases. Meanwhile, other continuous variables (procedural, and lesion characteristics) were compared using the Kruskal-Wallis test. Factors significant in univariate analysis were entered into the multivariate logistic regression analysis model. The odds ratio (OR) and 95% confidence interval (CI) were calculated for each variable. All analyses were conducted using SPSS 23 for Windows, with \u003cem\u003eP\u003c/em\u003e-values\u0026thinsp;\u0026le;\u0026thinsp;0.05 considered statistically significant.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eEthics\u003c/h2\u003e \u003cp\u003e The study was conducted in accordance with the principles in the Declaration of Helsinki. Informed consent was obtained from all patients prior the procedures. This was also approved by the institutional review board of our hospital(No.23\u0026ndash;38).\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 881 cases were included, including 6 trainees with 300 lesions in Phase 0 (0-50 ESD), 6 trainees with 286 lesions in Phase 1 (51-100 ESD), 4 trainees with 195 lesions in Phase 2 (101-150 ESD), and 2 trainees with 100 lesions in Phase 3 (150-200 ESD). Each physician were trained in the following time periods: 86 cases in 3 years and 2 months for KA (about 29 cases/year), 100 cases in 3 years and 6 months for JT (about 29 cases/year), 145 cases in 3 years and 8 months for NO (about 39 cases/year), 1 case in 5 years for JA (about 30 cases/year), 150 cases in 6 years and 3 months for HK (about 32 cases/year), and 5 years 200 cases in 3 months for MN (about 38 cases/year).\u003c/p\u003e\n\u003cp\u003ePatient background is summarized in Table 1. The location, macroscopic type, and difficult situation (post-biopsy, post-endoscopic treatment, diverticulum-related lesions, and appendiceal orifice-related lesions) were similar for each phase. Overall, the outcome of treatment was favorable, with 99.8% (879/881) of cases resected en bloc and 94.7% (834/881) of cases curatively resected (Table 2). Tumor diameter was similar for all phases; however, lesions \u0026gt;5 cm were most common in Phase 1. Treatment time and dissection speed increased with increasing phase.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe self-completion rate improved with each phase. Notably, the self-completion rate was 92.7% in Phase 1, without cases of ESD interruption. No significant difference was found in the rate of en bloc resection and curative resection between phases. Regarding adverse events, 2 cases (2%) of perforation were observed in Phase 3, which was more common than in other phases.\u003c/p\u003e\n\u003cp\u003eDifficult cases were defined as DS\u0026lt;9 (cm\u003csup\u003e2\u003c/sup\u003e/min), and their associated factors were examined in the early phase (Phase 0,1: ESD\u0026lt;100) and late phase (Phase 2,3: ESD101-200). Results revealed that in early phase, right-sided colon (OR 3.383, 95% CI: 1.113-10.283, \u003cem\u003ep\u003c/em\u003e=0.032), LST-NG (OR 2. 222, 95% CI 1.019-4.845, \u003cem\u003ep\u003c/em\u003e=0.045), mild fibrosis ( F1) (OR 2.521, 95% CI: 1.364-4.661, \u003cem\u003ep\u003c/em\u003e=0.003), severe fibrosis (F2) (OR 13.237, 95% CI: 5.203-33.674, \u003cem\u003ep\u003c/em\u003e\u0026lt;0.0001), and in the late stage, mild fibrosis (F1) (OR 4.182, 95%CI: 1.398-12.511, \u003cem\u003ep\u003c/em\u003e=0.01), severe fibrosis (F2) (OR 25.096, 95% CI: 7.437-84.685, \u003cem\u003ep\u003c/em\u003e\u0026lt;0.0001) were identified (Table 3).\u003c/p\u003e\n\u003cp\u003eTA-ESD was performed in 26 cases (3.0%) overall, with an increasing trend with increasing phase (Table 2). Ten cases (38.5%) were planned TA-ESD, and 16 cases (61.5%) were rescue TA-ESD (Table 4). pTA-ESD was performed in 3 cases of diverticular extension, 3 cases of supranastomotic lesions, 2 cases of large and stalked lesions, 1 case of appendiceal extension lesion, and 1 case of recurrent lesion after endoscopic treatment. Meanwhile, rTA-ESD was performed in 11 of 16 cases in the later stages (Phase 2 and 3), 12 cases in the right colon, especially in the cecum (all cases with appendiceal extension), 9 cases with fibrosis (F1: 3 cases, F2: 6 cases), and both operation time and DS took longer than in other cases, with one case of intraoperative perforation (Table 4).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe study evaluated the outcomes of six trainees trained in strategy-focused colorectal ESD and the training's validity. By systematically performing a preoperative strategy simulations considering the physician's experience and treatment difficulty levels, trainees achieved favorable ESD outcomes, with 99.8% and 94.7% of cases resected en bloc and curatively, respectively. Moreover, 97% of cases could be safely resected in a short time without device assistance. This strategy-focused training method resulted in a self-completion rate of about 90% in more than 50 cases, remaining high even in challenging cases. Under this strategy-focused training method, the planned traction method with device assistance proved useful for more difficult cases.\u003c/p\u003e\n\u003cp\u003eColorectal ESD is challenging due to the thin colon wall and poor operability. While various training methods for colorectal ESD have been reported in the past, they vary depending on the country and institution [4, 13,15]. Especially in Asia, many institutions start colorectal ESD after prior experience with gastric and esophageal ESD, and certain proficiency is achieved with approximately 30 to 80 cases [15, 16]. However, training for colorectal ESD was deemed difficult in Europe and the United States due to limited experience with gastric cancer ESD and the lack of supervising physicians. Zhang et al. also reported that 280 ESD cases were necessitated to achieve colorectal ESD proficiency (en bloc resection \u0026gt;90%, R0 resection \u0026gt;80%, and resection speed \u0026gt;9 cm\u003csup\u003e2\u003c/sup\u003e/h) [13]. A national survey from Italy reported that perforation rates in the colon and rectum were significantly lower with experience of \u0026gt;150 compared to 80-150 cases [17]. The primary goal of any training method is to develop skills for safely and reliably completing ESD, even for challenging lesions. At our institution, a single experienced supervisor trained physicians using the similar teaching method (strategy-focused ESD), achieving a high self-completion rate of about 90% in more than 50 cases, with a DS of 14.9 cm\u003csup\u003e2\u003c/sup\u003e/min and a curative resection rate of 94.3%.\u0026nbsp; In subsequent phases, as more difficult cases were selected, the self-completion rate improved, and speed increased to a DS of 19.6 cm\u003csup\u003e2\u003c/sup\u003e/min, a trend that continued to improve with each phase. Preoperative simulation and strategy creation tailored to intraoperative situations are crucial. Furthermore, the angle manipulation of the scope and endoscope is essential to ensure successful ESD completion, and we believe that simultaneous video recording on two screens (video of the inside and outside of the endoscope) is a useful educational tool. While its usefulness cannot be evaluated since it has not been compared with other training methods of ESD, this educational method is very effective given an overall median procedure time by the trainees of 30 minutes, a very high en bloc resection rate (99.7%), and relatively low complication frequency.\u003c/p\u003e\n\u003cp\u003eIn the present study, treatment difficulty was classified into early and late stages, anticipating variation based on operator experience. Factors identified in the early stage included right-sided colon, LST-NG, and mild/severe fibrosis, while in the late stage, only fibrosis was significant, with no notable differences in location or morphology type. Poor operability, common in the right-sided colon, poses a challenge in colorectal ESD, with Boda et al. recommending gaining scope operability experience in the first 20 cases [18]. Familiarity with operability and experience likely decreases treatment difficulty by location, possibly due to increased fibrosis in LST-NG, as previously reported. [19]. Preoperative simulation of the lesion, including its characteristics and maneuverability, contributed to this learning curve.\u003c/p\u003e\n\u003cp\u003eESD with device assistance occurred less frequently, with 26 cases (3.0%) categorized as planned traction and rescue traction for difficult cases. Planned traction was used for lesions extending into diverticula or appendiceal orifices where preoperative gravity traction was not expected [20,21]. Meanwhile, rescue traction was utilized when gravity traction was less effective, and a consistent endoscopic view could not be obtained. Since it is crucial to imagine the ideal traction direction and traction force prior the procedure, it is assumed that these factors are always imagined during the usual ESD to ensure a smooth rescue traction.\u003c/p\u003e\n\u003cp\u003eThis study has several limitations. This study was conducted in Japan and involved one supervising physician teaching six physicians using the similar training method. Hence, a validation study is warranted to identify whether this training method is appropriate for facilities lacking a supervising physician and whether it is equally effective for physicians starting their training with colorectal ESD.\u0026nbsp;Furthermore, it remains unclear if physicians completing this training can consistently perform the procedure at other facilities. However, in more than 50 cases of colorectal ESD, a self-completion rate of about 90% was obtained, including difficult lesions, and it is expected that physicians will step up to become proficient in colorectal ESD.\u003c/p\u003e\n\u003cp\u003eIn conclusion, this study evaluated the effectiveness of \"strategy-focused” training, emphasizing preoperative strategy development and natural traction. After conducting 881 cases by six trainee physicians, results showed a progressive improvement in self-completion rates, lesion outcomes, and safety across training phases. The strategy-focused approach achieved a 95% self-completion rate in the later phase without device assistance. The study suggests that this training method is effective in enhancing ESD skills, emphasizing preoperative simulation and strategy development for successful and safe outcomes.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eHC, KA, JT, KO, JA, HK, and MN performed the colorectal ESD. HC recruited the study participants. HC, KA, JT, KO, JA, HK, MN, AH, YE, and MK collected the clinical data of the study participants. Analysis and interpretation of the data was conducted by HC and KO. All the authors have read the final manuscript and approve of its submission for publication.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eOhata K, Kobayashi N, Sakai E et al. Long-term Outcomes After Endoscopic Submucosal Dissection for Large Colorectal Epithelial Neoplasms: A Prospective, Multicenter, Cohort Trial From Japan. Gastroenterology 2022; 163: 1423-1434\u003c/li\u003e\n \u003cli\u003ePimentel-Nunes P, Pioche M, Alb\u0026eacute;niz E, et al. Curriculum for endoscopic submucosal dissection training in Europe: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement.Endoscopy 2019; 51: 980-992\u003c/li\u003e\n \u003cli\u003eDraganov PV, Aihara H, Karasik MS et al.\u0026nbsp;Endoscopic Submucosal Dissection in North America: A Large Prospective Multicenter Study. Gastroenterology 2021; 160: 2317-2327\u003c/li\u003e\n \u003cli\u003e\u0026nbsp;Lib\u0026acirc;nio D, Pimentel-Nunes P, Bastiaansen B et al.\u0026nbsp;Endoscopic submucosal dissection techniques and technology: European Society of Gastrointestinal Endoscopy (ESGE) Technical Review. Endoscopy 2023; 55: 361-389\u003c/li\u003e\n \u003cli\u003eMori H, Kobara H, Nishiyama N, et al. Novel effective and repeatedly available ring-thread counter traction for safer colorectal endoscopic submucosal dissection. Surg Endosc 2017; 31: 3040-3047\u003c/li\u003e\n \u003cli\u003eYamasaki Y, Takeuchi Y, Uedo N et al. Traction-assisted colonic endoscopic submucosal dissection using clip and line: a feasibility study. Endosc Int Open 2016; 4: E51\u0026ndash;E55\u003c/li\u003e\n \u003cli\u003eTakezawa T, Hayashi Y, Shinozaki S, et al. The pocket-creation method facilitates colonic endoscopic submucosal dissection (with video).Gastrointest Endosc 2019; 89: 1045-1053\u003c/li\u003e\n \u003cli\u003eSuzuki Y, Ohata K, Sakai E et al. Palisade technique as an effective endoscopic submucosal dissection tool for large colorectal tumors. Endosc Int Open 2021; 9: E210-E215\u003c/li\u003e\n \u003cli\u003eHashiguchi Y, Muro K, Saito S, et al. Japanese Society for Cancer of the Colon and Rectum (JSCCR) Guidelines 2019 for the treatment of colorectal cancer. Int J Clin Oncol 2020; 25: 1\u0026ndash;42\u003c/li\u003e\n \u003cli\u003eTanaka S, Kashida H, Saito Y, et al. Japan Gastroenterological Endoscopy Society guidelines for colorectal endoscopic submucosal dissection/endoscopic mucosal resection. Dig Endosc 2020; 32: 219\u0026ndash;23\u003c/li\u003e\n \u003cli\u003eMatsuda T, Fujii T, Saito Y, et al. Efficacy of the invasive/non-invasive pattern by magnifying chromoendoscopy to estimate the depth of invasion of early colorectal neoplasms. Am J Gastroenterol 2008; 103: 2700-6\u003c/li\u003e\n \u003cli\u003eMatsumoto A, Tanaka S, Oba S, et al. Outcome of endoscopic submucosal dissection for colorectal tumors accompanied by fibrosis. Scand J Gastroenterol. 2010; 45: 1329-1337\u003c/li\u003e\n \u003cli\u003eZhang X, Ly EK, Nithyanand S,et al Learning Curve for Endoscopic Submucosal Dissection With an Untutored, Prevalence-Based Approach in the United States. Clin Gastroenterol Hepatol 2020; 18: 580-588\u003c/li\u003e\n \u003cli\u003eArimoto J, Higurashi T, Kato S, et al. Risk factors for post-colorectal endoscopic submucosal dissection (ESD) coagulation syndrome: a multicenter, prospective, observational study. Endosc Int Open 2018; 6: E342-E349\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eOhata K, Ito T, Chiba H, et al. Effective training system in colorectal endoscopic submucosal dissection. Digestive Endoscopy 2012; 24: 84\u0026ndash;89\u003c/li\u003e\n \u003cli\u003eK. Hotta, T. Oyama, T. Shinohara, et al. Learning curve for endoscopic submucosal dissection of large colorectal tumors Digestive Endoscopy 2010; 22: 302-306\u003c/li\u003e\n \u003cli\u003eMaselli R, Iacopini F, Azzolini F, et al. Endoscopic submucosal dissection: Italian national survey on current practices, training and outcomes.Dig Liver Dis 2020; 52: 64-71\u003c/li\u003e\n \u003cli\u003eBoda K, Oka S, Tanaka S, et al. Real-world learning curve analysis of colorectal endoscopic submucosal dissection: a large multicenter study. Surg Endosc 2020; 34: 3344-3351\u003c/li\u003e\n \u003cli\u003eChiba H, Tachikawa J, Arimoto J, et al. Predictive Factors of Mild and Severe Fibrosis in Colorectal Endoscopic Submucosal Dissection. Dig Dis Sci 2020; 65: 232-242\u003c/li\u003e\n \u003cli\u003eMuramoto T, Ohata K, Sakai E, et al. Endoscopic submucosal dissection for colorectal neoplasms in proximity or extending to a diverticulum. Surg Endosc 2021; 35: 3479-3487\u003c/li\u003e\n \u003cli\u003eTashima T, Ohata K, Nonaka K, et al. Endoscopic submucosal dissection for laterally spreading tumors involving the appendiceal orifice.Surg Endosc 2017; 31: 5444-5450\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 The Characteristics of the patients\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"576\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003ePhase 0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003ePhase 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003ePhase 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003ePhase 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003eCase, n\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e300\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e286\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e195\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003eSex (male), n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e153 (51)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e157 (54.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e109 (55.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e45 (45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\n \u003cp\u003e0.398\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003eAge, mean \u0026plusmn; SD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e68.8 \u0026plusmn; 12.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e67.1\u0026plusmn; 12.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e65.5 \u0026plusmn; 12.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e63.5 \u0026plusmn; 14.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\n \u003cp\u003e0.003\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003eLocation*, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\n \u003cp\u003e0.584\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003e\u0026nbsp;Right colon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e186 (62)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e187 (65.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e137 (70.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e64 (64)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003e\u0026nbsp;Left colon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e66 (22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e63(22.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e35 (17.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e20 (20)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003e\u0026nbsp;Rectum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e48 (16)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e36 (12.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e23 (11.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e16 (16)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003eMorphology, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\n \u003cp\u003e0.171\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003e\u0026nbsp;0-I\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e42 (14）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e49 (17.1）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e40 (20.5）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e18 (18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003e\u0026nbsp;LST-G\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e67 (22.3）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e53 (18.5）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e25 (12.8）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e18 (18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003e\u0026nbsp;LST-NG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e191 (63.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e184 (64.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e130 (66.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e64 (64)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003eDifficult situation, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e25 (8.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e23 (8.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e11 (5.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e9 (9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\n \u003cp\u003e0.527\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003e\u0026nbsp;Post ER\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003e\u0026nbsp;Pre-biopsy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003e\u0026nbsp;Diverticulum**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"27.902946273830157%\"\u003e\n \u003cp\u003e\u0026nbsp;Appendiceal orifice***\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.731369150779896%\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.17157712305026%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e*The right colon refers to the transverse colon-cecum, and the left colon to the sigmoid colon-descending colon.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e** The diverticulum refers to the lesion spreading to the diverticulum.\u003c/p\u003e\n\u003cp\u003e*** The\u0026nbsp;appendiceal orifice\u0026nbsp;refers to the lesion spreading to the appendiceal orifice.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;LST-G; laterally spreading tumor- granular type, LST-NG: laterally spreading tumor- nongranular type, ER; endoscopic resection.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Table 2 The treatment outcome per phase in six trainees ESD training\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"586\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" rowspan=\"2\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eESD experience\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003ePhase 0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003ePhase 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003ePhase 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003ePhase 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" rowspan=\"2\" valign=\"bottom\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.474254742547426%\" valign=\"bottom\"\u003e\n \u003cp\u003e0-50\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.745257452574524%\" valign=\"bottom\"\u003e\n \u003cp\u003e51-100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"25.745257452574524%\" valign=\"bottom\"\u003e\n \u003cp\u003e101-150\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.035230352303522%\" valign=\"bottom\"\u003e\n \u003cp\u003e151- 200\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eCase, n\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e300\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e286\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e195\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eSize (mm), median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e20.0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(18.0 - 28.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e21.5\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(18.0 - 30.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e20.0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(16.0 - 26.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e20.0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(18.0 - 26.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.97\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eTime (min), median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e36\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(23 - 55)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(19- 46)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e25.0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(17.0 - 41.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e24.5\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(16.0 - 37.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eDissection speed\u0026nbsp;(cm\u003csup\u003e2\u003c/sup\u003e/min), median (IQR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e14.9\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(10.6 - 21.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e19.6\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(13.7 - 27.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e20.8\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(14.1 - 30.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e23.7\u003c/p\u003e\n \u003cp\u003e(17.5 - 33.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eDevise traction, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e1 (0.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e6 (2.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e11 (5.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e8 (8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eRescue traction, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e5 (1.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e8 (4.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e4 (4.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.279\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eTunnel method, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e3 (1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e11 (3.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e13 (6.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e4 (4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.009\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eFibrosis, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e44 (14.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e65 (22.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e26 (26)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e25 (25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;F1 (mild)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e30 (10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e55 (19.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e15 (7.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e19 (19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;F2 (severe)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e14 (4.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e10 (3.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e11 (7.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e6 (6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.637\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eSelf-completion, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e254 (84.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e265 (92.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e180 (92.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e95 (95)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eInterruption, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eHistology, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.371\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;Adenoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e161 (53.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e140 (49.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e109 (55.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e50 (50)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;Tis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e115 (38.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e123 (43.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e70 (35.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e40 (40)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;T1a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e7 (2.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e12 (4.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e4 (2.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e2 (2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;T1b or deeper\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e16 (5.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e8 (2.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e8 (4.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e7 (7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;Others\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e1 (0.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e3 (1.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e4 (2.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e1 (1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eEn bloc resection, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e300 (100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e285 (99.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e194 (99.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e100 (100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.614\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eCurative resection,\u0026nbsp;\u003c/p\u003e\n \u003cp\u003en (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e283 (94.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e275 (96.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e184 (94.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e92 (92)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.43\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003eAdverse events, n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e12 (4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e14 (4.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e8 (4.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e7 (7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.637\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;post bleeding\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e6 (2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e5 (1.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e4 (2.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e1 (1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.919\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;perforation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e0 (0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e0 (0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e1 (0.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e2 (2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.016\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;delayed perforation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e1 (0.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e0 (0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e1 (0.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e0 (0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.63\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"25.7679180887372%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;PECS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.040955631399317%\" valign=\"bottom\"\u003e\n \u003cp\u003e5 (1.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e9 (3.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.21160409556314%\" valign=\"bottom\"\u003e\n \u003cp\u003e2 (1.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.505119453924914%\" valign=\"bottom\"\u003e\n \u003cp\u003e4 (4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.262798634812286%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.241\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eESD; endoscopic submucosal dissection, PECS; post-ESD coagulation syndrome\u003c/p\u003e\n\u003cp\u003eTable 3 Risk Factors for difficult cases* in each Phase\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"576\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003eEarly Phase\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(Phase 0 and 1)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003eUnivariate,\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eOR (95%CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003eMultivariate,\u003c/p\u003e\n \u003cp\u003eOR (95%CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003eLocation **\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;Rectum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;Left colon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e3.486 (1.142 - 10.644)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.028\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e3.116 (0.966 - 10.048)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.057\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;Right colon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e3.608(1.271 - 10.238)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.016\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e3.383 (1.113 - 10.283)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.032\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003eShape\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;LST-G\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;LST-NG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e2.12(1.014 - 4.430)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.046\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e2.222 (1.019 - 4.845)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.045\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;Protruded\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e2.667 (1.119 - 6.352)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.027\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e2.267 (0.854 - 6.019)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003eFibrosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;F1 (mild)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e2.396 (1.315 - 4.364)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.004\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e2.521 (1.364 - 4.661)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.003\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.618055555555557%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;F2 (severe)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e12.483 (5.258 - 29.636)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.11111111111111%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.125%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.95138888888889%\" valign=\"bottom\"\u003e\n \u003cp\u003e13.237 (5.203 - 33.674)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.243055555555555%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"576\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u003cstrong\u003eLate Phase\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(Phase 2 and 3)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003eUnivariate,\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eOR (95%CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"bottom\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003eMultivariate,\u003c/p\u003e\n \u003cp\u003eOR (95%CI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003eP value\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\n \u003cp\u003eLocation**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;Rectum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;Left colon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e2.043 (0.506 \u0026ndash; 8.251)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.316\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e2.083 (0.4141 \u0026ndash; 10.468)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.373\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;Right colon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e1.180 (0.330 \u0026ndash; 4.217)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.799\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e1.420 (0.310 \u0026ndash; 6.494)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.651\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\n \u003cp\u003eShape\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;LST-NG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"top\"\u003e\n \u003cp\u003e2.13 (0.838 - 5.413)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"top\"\u003e\n \u003cp\u003e0.112\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e3.05 (0.983 - 9.462)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.053\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;Protruded\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"top\"\u003e\n \u003cp\u003e1.074 (0.416 \u0026ndash; 2.771)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"top\"\u003e\n \u003cp\u003e0.883\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\n \u003cp\u003eFibrosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;F1 (mild)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e3.52 (1.252 - 9.897)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.017\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e4.182 (1.398 - 12.511)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.584055459272097%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;F2 (severe)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e18.482 (6.186 - 55.223)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.43847487001733%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"3.292894280762565%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"27.902946273830157%\" valign=\"bottom\"\u003e\n \u003cp\u003e25.096 (7.437 - 84.685)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.878682842287695%\" valign=\"bottom\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e*Difficult cases were defined as dissection speed \u0026lt;9 (cm\u003csup\u003e2\u003c/sup\u003e/min).\u003c/p\u003e\n\u003cp\u003e**The right colon refers to the transverse colon-cecum, and the left colon to the sigmoid colon-descending colon.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eLST-G; laterally spreading tumor- granular type, LST-NG: laterally spreading tumor- nongranular type, ER; endoscopic resection.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Table 4 Sixteen cases treated by ESD with rescue traction method\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"586\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003ePhase\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eSize\u003c/p\u003e\n \u003cp\u003e(mm)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eShape\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eSite\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003eDifficult situation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eFibrosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eTime\u003c/p\u003e\n \u003cp\u003e(min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eDT\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eEn bloc\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003eAdverse events\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003eF1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e16.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eNG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eCe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eAO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003eF2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e9.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003eF2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e132\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e3.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003eF2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e190\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e5.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eNG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eCe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eAO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003eF1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e12.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e18.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eNG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003eF2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e110\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e2.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eNG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003eF2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e120\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e6.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eNG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003eF2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e120\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e6.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eNG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003eF1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e123\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e4.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eNG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eD\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e23.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eNG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e9.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eT\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e47.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eCe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eAO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e2.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eNG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eCe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eAO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e7.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003ePerforation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003eNG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003eCe\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003eAO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e12.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"5.47945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.616438356164384%\" valign=\"top\"\u003e\n \u003cp\u003emedian\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e22.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.561643835616438%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.335616438356165%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.301369863013699%\" colspan=\"2\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"10.95890410958904%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e8.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.047945205479452%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.554794520547945%\" valign=\"top\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eESD; endoscopic submucosal dissection, \u0026nbsp;G; laterally spreading tumor-granular type, NG: laterally spreading tumor- nongranular type, I: protruded type, Ce; cecum, A; ascending colon, T; transverse colon, D; descending colon, S: sigmoid colon, AO: appendiceal orifice, F1: mild fibrosis, F2; severe fibrosis, DT; dissection time (cm\u003csup\u003e2\u003c/sup\u003e/min)\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"digestive-diseases-and-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ddsj","sideBox":"Learn more about [Digestive Diseases and Sciences](http://link.springer.com/journal/10620)","snPcode":"10620","submissionUrl":"https://submission.nature.com/new-submission/10620/3","title":"Digestive Diseases and Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-3990882/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3990882/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eColorectal ESD, an advanced minimally invasive treatment, presents technical challenges, with globally varying training methods. We analyzed the learning curve of ESD training, emphasizing preoperative strategies, notably gravity traction, to guide ESD instructors and trainee programs.\u003c/p\u003e\u003ch2\u003eMethod\u003c/h2\u003e \u003cp\u003eThis retrospective study included 881 cases guided by an experienced supervisor. Six trainees received \u0026ldquo;strategy-focused\u0026rdquo; instruction. To evaluate the number of ESD experiences in steps, the following phases were classified based on ESD experiences of each trainees: Phase 0 (0\u0026ndash;50 ESD), Phase 1 (51\u0026ndash;100 ESD), Phase 2 (101\u0026ndash;150 ESD), and Phase 3 (151\u0026ndash;200 ESD). Lesion background, outcomes, and safety were compared across phases. Factors contributing to technical difficulty in early (Phase 0 and 1) and late phases (Phase 2 and 3) were identified, along with the utility of traction ESD with device assistance.\u003c/p\u003e\u003ch2\u003eResult\u003c/h2\u003e \u003cp\u003eTreatment outcomes were favorable, with 99.8% and 94.7% en bloc resection and curative resection rates, respectively. Approximately 90% self-completion rate could be achieved after experiencing about 50 cases (92.7% in Phase 1), signifying proficiency growth despite increased case difficulty. In early phases, factors such as right-sided colon, LST-NG morphology, and mild and severe fibrosis pose challenges. In late phases, mild and severe fibrosis remained significant. Traction-assisted ESD, utilized in 3% of cases, comprised planned (1.1%) and rescue (1.9%) methods. Planned traction aided specific lesions, while rescue traction was common in the right colon.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003e\"Strategy-focused\" ESD training consistently yields successful outcomes, effectively adapting to varying difficulty factors in different proficient stages.\u003c/p\u003e","manuscriptTitle":"Effectiveness of Strategy-Focused Training in Colorectal Endoscopic Submucosal Dissection: A Retrospective Observational Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-02-29 16:12:18","doi":"10.21203/rs.3.rs-3990882/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-03-13T03:53:47+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-03-09T16:50:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"bb47df5c-62cd-4aa8-9b09-d30943300547","date":"2024-03-02T06:21:30+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-02-28T21:10:30+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-02-28T19:27:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-02-28T04:12:24+00:00","index":"","fulltext":""},{"type":"submitted","content":"Digestive Diseases and Sciences","date":"2024-02-26T12:13:33+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"digestive-diseases-and-sciences","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ddsj","sideBox":"Learn more about [Digestive Diseases and Sciences](http://link.springer.com/journal/10620)","snPcode":"10620","submissionUrl":"https://submission.nature.com/new-submission/10620/3","title":"Digestive Diseases and Sciences","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"9d390de7-5c40-4988-9956-aafc678a50be","owner":[],"postedDate":"February 29th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-05-01T22:04:12+00:00","versionOfRecord":{"articleIdentity":"rs-3990882","link":"https://doi.org/10.1007/s10620-024-08430-9","journal":{"identity":"digestive-diseases-and-sciences","isVorOnly":false,"title":"Digestive Diseases and Sciences"},"publishedOn":"2024-04-25 22:04:12","publishedOnDateReadable":"April 25th, 2024"},"versionCreatedAt":"2024-02-29 16:12:18","video":"","vorDoi":"10.1007/s10620-024-08430-9","vorDoiUrl":"https://doi.org/10.1007/s10620-024-08430-9","workflowStages":[]},"version":"v1","identity":"rs-3990882","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3990882","identity":"rs-3990882","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}