Analysis of risk factors for postoperative delayed perforation following endoscopic submucosal dissection in the treatment of gastrointestinal stromal tumors

Analysis of risk factors for postoperative delayed perforation following endoscopic submucosal dissection in the treatment of gastrointestinal stromal tumors | 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 Analysis of risk factors for postoperative delayed perforation following endoscopic submucosal dissection in the treatment of gastrointestinal stromal tumors Ling Lei, Ping Wang, Lihong Gan, Li Zheng, Mengqi Kuang, Bin Li This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8485481/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objective We aimed to identify independent risk factors for delayed perforation following endoscopic submucosal dissection (ESD) in gastrointestinal stromal tumors (GISTs). Methods This study was a retrospective case-control study that included 113 patients with GIST who underwent ESD treatment. Among them, 13 patients who developed postoperative delayed perforation constituted the perforation group, while 100 patients without such a complication formed the control group. The differences in demographics, clinical characteristics, and surgical details between the two groups were analyzed and compared. Independent risk factors for delayed perforation were identified through univariate and multivariate logistic regression analyses. Meanwhile, the occurrence time, management, and outcomes in the perforation group were recorded, and the postoperative gastrointestinal function recovery times of the two groups were compared. Results Univariate analysis revealed significant differences between the perforation and control groups in four factors: tumor diameter, growth pattern, degree of submucosal fibrosis, and intraoperative muscular layer injury ( p 2.0 cm, extraluminal growth, severe submucosal fibrosis, and intraoperative muscular layer injury were independent risk factors for delayed perforation after ESD ( p < 0.05). Kaplan-Meier analysis showed that the median time to diagnosis of delayed perforation in the 13 patients was 10 hours postoperatively, with the majority of perforations occurring within 24 hours postoperatively. The median hospital stay in the perforation group (16 days) was longer than that in the control group (7.5 days). After treatment, the first flatus time, first oral intake time, and first bowel movement time were longer in the perforation group than in the control group ( p 2.0 cm, extraluminal growth, severe submucosal fibrosis, and intraoperative muscular layer injury are independent risk factors for delayed perforation after ESD in the treatment of GISTs. Perforations predominantly occur within 24 hours postoperatively, necessitating enhanced postoperative monitoring in high-risk patients. Gastrointestinal stromal tumor Endoscopic submucosal dissection Postoperative delayed perforation Risk factors Gastrointestinal function Figures Figure 1 Figure 2 Introduction Endoscopic submucosal dissection (ESD) emerged in 2003 as an innovative therapeutic approach for gastrointestinal lesions, bridging the technical gap between endoscopic mucosal resection (EMR) and surgical intervention [ 1 ]. Owing to its ability to completely resect larger gastrointestinal lesions while obtaining high-quality pathological specimens, ESD has become one of the standard methods for treating early-stage gastrointestinal cancers and precancerous lesions [ 1 – 3 ]. In recent years, its indications have gradually expanded to include gastrointestinal submucosal tumors, particularly for the diagnostic resection of gastrointestinal stromal tumors (GISTs) with potential malignant risk, where ESD also demonstrates unique advantages [ 4 – 6 ]. ESD typically starts with lesion marking, followed by submucosal injection to elevate the mucosa. The raised mucosa is then incised to expose the tumor, which is carefully dissected along its capsule for complete en bloc removal [ 7 , 8 ]. The resulting wound is closed with clips or advanced techniques to reduce complications. In parallel, endoscopic submucosal excavation involves resecting the overlying mucosa and enucleating the lesion. However, perforation is common when the lesion involves deeper muscle layers [ 7 , 8 ]. As a time-consuming procedure, ESD is associated with a higher risk of complications such as bleeding and perforation, often requiring the participation of two or more assistants [ 1 ]. ESD-related perforations can be classified into intraoperative perforations and postoperative delayed perforations. In most cases, intraoperative perforations can be successfully managed conservatively through endoscopic closure alone [ 9 ]. Compared to intraoperative perforations, delayed perforation is a severe adverse event. Upon diagnosis, it is often associated with life-threatening complications such as peritonitis, prolonging hospital stays, increasing healthcare burdens, and even endangering patient lives [ 9 – 11 ]. Currently, research on postoperative complications following ESD for epithelial-derived tumors, such as early gastric cancer [ 10 ] and colorectal cancer [ 11 ], is relatively abundant. However, systematic studies on the risk factors and clinical characteristics of delayed perforation after ESD for GISTs, a specific type of submucosal tumor, are relatively scarce. Given that GISTs often exhibit unique biological behaviors, such as a tendency for extraluminal growth [ 12 ] and a close relationship with the muscularis propria [ 13 ], the risk profile for delayed perforation after ESD may differ from that of epithelial-derived tumors. This study aims to investigate the relevant risk factors for delayed perforation after ESD in patients with GISTs, with the goal of providing evidence-based guidance for clinical practice. Materials and methods Ethical approval This study protocol was reviewed and approved by The First Hospital of Nanchang’s ethics committee, and informed consent was waived for the retrospective study. Patients and g rouping A retrospective case-control study design was adopted. Patient data were consecutively collected from the electronic medical record system of The First Hospital of Nanchang for all individuals who underwent ESD for GISTs at the Endoscopy Center of the Department of Gastroenterology between January 2022 and June 2025, with postoperative pathological confirmation of GIST. A total of 13 patients who developed delayed perforation after ESD were identified (delayed perforation was defined as the absence of perforation during ESD, no symptoms or free gas immediately postoperatively, followed by sudden onset of peritoneal irritation symptoms or chest pain, or the presence of free gas on postoperative abdominal plain films or chest-abdominal CT scans). From the cohort of GIST patients treated with ESD during the same period without delayed perforation, 100 patients were randomly selected as the control group based on study requirements. Inclusion and exclusion criteria Inclusion criteria: ① Patients aged ≥18 years; ② those preoperatively diagnosed with a submucosal tumor of the gastrointestinal tract via imaging (endoscopic ultrasonography or CT) and highly suspected of having GIST; ③ those who underwent standard ESD treatment with postoperative pathological confirmation of GIST [ 14 ]; ④ those with clear indications for ESD (e.g., tumor diameter ≤5 cm, considered very low/low/intermediate risk, patient desire for organ preservation); ⑤ those with complete clinical records, endoscopic reports, surgical records, imaging data, and pathological reports; ⑥ those with a smooth surgical procedure meeting technical requirements for complete lesion resection and with clear follow-up records for at least 1 month post-discharge. Exclusion criteria: ① Patients assessed preoperatively as advanced with distant metastasis or severe local tumor invasion (e.g., serosal involvement, severe adhesion to surrounding tissues) where curative resection via ESD was not feasible; ② those with multiple primary GISTs or concurrent gastrointestinal malignancies requiring simultaneous surgical treatment; ③ those undergoing emergency ESD for acute tumor-related complications (e.g., obstruction, bleeding, perforation); ④ those with active gastrointestinal bleeding, infection, or perforation within 1 week preoperatively; ⑤ those with severe coagulopathy or long-term use of anticoagulant/antiplatelet agents without standardized perioperative management or bridging therapy; ⑥ those with a history of major resection surgery involving the target organ (stomach or intestines); ⑦ pregnant or lactating women; ⑧ those with intraoperative perforation during ESD (detected immediately and managed endoscopically); ⑨ those lost to follow-up or with incomplete follow-up data preventing confirmation of delayed perforation; ⑩ those whose final postoperative pathological diagnosis was not GIST (e.g., leiomyoma, neuroendocrine tumor). Surgical m ethods All ESD procedures in this study adhered to standardized protocols and were performed by experienced endoscopists. Patients underwent comprehensive preoperative evaluation and preparation. Intraoperatively, the Olympus CV-290 electronic endoscopy system with matching GIF-HQ290 therapeutic endoscopes [Olympus (Beijing) Sales & Service Co., Ltd.] was primarily used. The submucosal injection solution consisted of a mixture of glycerol fructose injection (Dalian Tianyu Pharmaceutical Co., Ltd., State Drug Administration: H20064034) containing epinephrine hydrochloride injection (Beijing Yongkang Pharmaceutical Co., Ltd., State Drug Administration: H11020584) and indigo carmine (Southwest Pharmaceutical Co., Ltd., State Drug Administration: H50021944) (ratio: glycerol fructose:indigo carmine:epinephrine = 100 mL:1 mL:0.5 mL). Key surgical steps included lesion marking, submucosal injection for lifting, marginal incision, and submucosal dissection, with carbon dioxide insufflation used throughout. Specialized instruments such as the Dual Knife (Olympus KD-650Q/U) and IT Knife 2 (Olympus KD-611L) were employed for precise dissection and electrocoagulation hemostasis. After complete lesion resection, the wound was carefully inspected and treated with metallic hemostatic clips (Olympus HX-610 series) as needed. Specimens were fixed and sent for pathological examination. Postoperatively, patients were fasted, given acid suppression, prophylactic antibiotics, and closely monitored, with gradual dietary resumption and standardized follow-up to monitor for complications. Collection of relevant factors and observational indicators (1) Demographic characteristics included gender, age, body mass index, educational level, and medical insurance type. (2) Comorbidities and preoperative conditions included chronic histories of hypertension, diabetes, coronary heart disease; smoking history (defined as cumulative smoking ≥10 pack-years) and alcohol history (defined as regular drinking ≥1 year with alcohol intake ≥30 g/day); American Society of Anesthesiologists (ASA) classification. (3) Tumor characteristics: ① Tumor location was classified as stomach (cardia, fundus, body, antrum), duodenum, or colorectum based on endoscopic and imaging findings; ② Tumor diameter was measured as the maximum diameter (cm) on endoscopic ultrasonography or CT images; ③ Growth pattern was classified as intraluminal, extraluminal, or mixed based on endoscopic ultrasonography results; ④ Preoperative risk assessment: Risk stratification (very low, low, intermediate, high) was performed according to the Chinese GIST diagnosis and treatment consensus, combining tumor diameter and mitotic count (based on postoperative pathology); ⑤ Degree of submucosal fibrosis was classified as F0 (no fibrosis), F1 (mild fibrosis), or F2 (severe fibrosis). (4) Surgical procedures: ① Surgical duration was defined as the time from submucosal injection to complete lesion resection (minutes); ② Intraoperative muscular layer injury was defined as exposure or electrocoagulation injury to the muscular layer during dissection without transmural perforation; ③ Wound management was recorded whether metallic clips or other closure techniques were used for wound suturing; ④ Surgeon experience was classified based on the total number of ESD procedures independently performed by the primary surgeon (≥500 cases defined as high experience, <500 as low experience). (5) Postoperative management included the dosage form of prophylactic proton pump inhibitors used postoperatively (intravenous/oral). (6) Temporal distribution of perforation events was documented by recording in detail the interval time (in hours) from the conclusion of surgery to the emergence of typical clinical symptoms, such as sudden severe abdominal pain and abdominal muscle rigidity, as well as the radiological confirmation (via abdominal CT or upright abdominal plain film) of the perforation. (7) Management approaches and clinical outcomes of perforation: ① Management approaches was classified as conservative treatment (fasting, gastrointestinal decompression, intensified anti-infection), endoscopic treatment (endoscopic clipping, suturing, or covered stent placement), percutaneous interventional drainage, or surgical treatment; ② Clinical outcomes involved the recording of the treatment success rate (which was defined as the healing of perforation without the necessity for reintervention), complications (such as intra-abdominal infection and abscess), the total duration of postoperative hospital stay, and cases of ICU admission. (8) Postoperative gastrointestinal functional recovery time: Key time points for gastrointestinal functional recovery were recorded, all calculated from the end of surgery: ① First flatus time: Time of first spontaneous anal flatus postoperatively; ② First oral intake time: Time when patients were permitted by the attending physician to resume oral intake of liquid or semi-liquid diets; ③ First bowel movement time: Time of first spontaneous defecation postoperatively. These time points were obtained by reviewing postoperative nursing records, progress notes, and discharge summaries. Statistical m ethods Statistical analysis was performed using SPSS 27.0. Categorical data were expressed as [n (%)] and compared using the χ² test or Fisher’s exact test. Temporal distribution characteristics in the perforation group were analyzed using Kaplan-Meier curves. Continuous data were tested for normality using the Shapiro-Wilk test; skewed distributions were expressed as [M (P25, P75)] and compared using the Mann-Whitney U test, while normally distributed data were expressed as (mean ± standard deviation). Homogeneity of variance was verified using Levene’s test, with independent samples t-tests used for comparisons between two groups when variance was homogeneous and Welch’s t-test when variance was not homogeneous. A p -value <0.05 indicated statistical significance. Results Univariate analysis of delayed perforation after ESD Univariate analysis revealed statistically significant differences between the perforation group and the control group in four factors: tumor diameter, growth pattern, degree of submucosal fibrosis, and intraoperative muscular layer injury ( p 2.0 cm [19.836 (2.631~149.532)], extraluminal growth type [15.741 (2.027~122.246)], severe submucosal fibrosis [8.244 (1.018~66.761)], and intraoperative muscular layer injury [9.022 (1.424~56.747)] were independent risk factors for delayed perforation after ESD ( p < 0.05) (Tables 2-3; Figure 1) Temporal distribution characteristics of the perforation group Kaplan-Meier analysis revealed that the median time to diagnosis of delayed perforation in 13 patients was 10 hours postoperatively (range: 3~26 hours; 95% CI: 6.477~13.523). As shown in Figure 2, the vast majority of perforation events (92.31%, 12/13) occurred within 24 hours postoperatively, suggesting that the first 24 hours postoperatively is a high-risk window period for delayed perforation, necessitating enhanced clinical monitoring (Figure 2). Management approaches and clinical outcomes in the perforation group Among the 13 patients with delayed perforation, all cases were diagnosed by imaging examination after symptom onset and immediately initiated targeted treatment. Management Approaches: Treatment plans were individualized based on the size of the perforation, degree of abdominal contamination, and overall patient condition. Seven patients (53.8%) underwent endoscopic treatment as the primary option (including direct closure with metal clips in 5 cases and Over-The-Scope Clip closure in 2 cases); four patients (30.8%) underwent direct surgical treatment (perforation repair) due to large perforation defects or concomitant diffuse peritonitis; two patients (15.4%) opted for conservative management (absolute fasting, gastrointestinal decompression, intensive anti-infection, and nutritional support) due to small, localized perforations. Clinical Outcomes: After the above treatments, 12 patients (92.3%) were cured (perforation healed without further intervention). One patient who underwent endoscopic treatment required conversion to surgical treatment for cure due to incomplete closure and secondary abdominal infection. In terms of complications, three patients (23.1%) developed postoperative abdominal infection or abscess, which were controlled after anti-infection and puncture drainage. The median total hospital stay for patients in the perforation group was 16 days (range: 12~25 days), significantly longer than the median total hospital stay of 7.5 days (range: 5~13 days) for patients with conventional recovery, with a statistically significant difference (Z = 5.844, p < 0.05). Among them, three patients (23.1%) required transfer to the ICU for monitoring and treatment due to their condition. There were no deaths. Postoperative gastrointestinal function recovery time The first flatus time, first feeding time, and first defecation time were all longer in the perforation group than in the control group (Table 4) ( p < 0.05). Discussion This study employed univariate and multivariate logistic regression analyses to identify four independent risk factors for delayed perforation following ESD for GIST: tumor diameter > 2.0 cm, extraluminal growth type, severe submucosal fibrosis, and intraoperative muscular layer injury. Firstly, a tumor diameter > 2.0 cm was associated with an increased risk of perforation. Larger tumors typically entail a more extensive dissection area, longer operative time, and greater dissection difficulty [15, 16]. During the dissection process, the cumulative thermal and mechanical trauma from electrocoagulation and traction more significantly compromises the integrity of the muscular layer, increasing the risk of delayed perforation due to postoperative tissue necrosis or tearing at weakened sites. Previous studies have identified larger tumor size as risk factors for delayed perforation [17, 18]. Additionally, it has been reported that risk factors for intraoperative perforation include tumor diameter exceeding 20 mm, lesions in the U-region, the presence of ulcer scars, and lesions on the greater curvature [16]. Moreover, extraluminal growth type GIST represents another key risk factor. These tumors often breach the muscular layer boundary and grow outward [19], which may bring the ESD dissection plane closer to or even into the muscular layer [20]. This not only increases the risk of intraoperative perforation but also undermines the stability of the postoperative wound base, making it more susceptible to delayed perforation triggered by gastrointestinal motility or pressure changes postoperatively. Severe submucosal fibrosis also increases the technical difficulty and risk of perforation. Fibrosis leads to blurred tissue layers and increased dissection resistance [21], often necessitating increased electrocoagulation intensity or more frequent sharp dissection during surgery [22], which can easily result in uncontrollable muscular layer damage. Even if immediate perforation does not occur, the damaged muscular layer may undergo delayed necrosis and perforation postoperatively. Existing evidence supports that submucosal fibrosis is associated with prolonged operative time, an increased risk of complications such as perforation, and a reduced rate of complete en bloc resection [21]. Naohisa et al. further confirmed that severe fibrosis and long ESD operative time are important risk factors for delayed perforation [18]. Finally, intraoperative muscular layer injury is also a clearly defined independent risk factor. Even if the muscular layer laceration is closed or sutured during surgery, this site remains a postoperative weak point that may rupture due to tension or blood supply issues during the process of functional recovery. Delayed perforation is believed to be caused by thermal injury, meaning that excessive electrocoagulation can damage the submucosa and muscular layer, leading to small perforations over time [22]. This study further clarifies this viewpoint. Existing evidence indicates that delayed perforation after gastric ESD typically occurs 1-2 days postoperatively [16]. In this study, the median onset time of delayed perforation was 10 hours postoperatively, with 92.3% of cases occurring within 24 hours after surgery, suggesting that enhanced monitoring should be implemented for at least 24 to 48 hours postoperatively in such patients. Perforation significantly prolonged hospital stays, with nearly one-fourth of patients requiring transfer to the intensive care unit (ICU), all of whom also experienced delayed recovery of gastrointestinal function. After active multidisciplinary collaborative intervention, all patients were cured, with no fatalities reported. The choice of treatment approach should be individualized based on the characteristics of the perforation, the degree of abdominal contamination, the patient's overall condition, and the availability of endoscopic technical resources. The limitations of this study lie in its single-center retrospective design and limited sample size, particularly the small number of cases in the perforation group, which may lead to the failure to identify certain potential risk factors or affect the precision of effect estimates in multivariate analysis. Future multicenter, large-sample prospective studies are needed to further validate and refine these risk factors and explore more effective preventive strategies. In conclusion, a large tumor diameter (> 2.0 cm), extraluminal growth, severe submucosal fibrosis, and intraoperative muscular layer injury are key independent risk factors for delayed perforation following ESD for GIST. The findings provide a basis for optimizing the perioperative management of ESD for GIST. It is recommended that clinicians identify high-risk patients through preoperative imaging assessment, perform meticulous intraoperative procedures to protect the muscular layer, and extend postoperative monitoring to at least 24 hours for high-risk cases. In the event of delayed perforation, timely initiation of multidisciplinary collaboration should be implemented, and treatment options such as endoscopic, surgical, or conservative approaches should be selected based on the patient's condition to improve their prognosis. Declarations Funding This work was supported by the Science and Technology Project of Health Commission of Jiangxi Province (202210085, 202311202, 202510682). Conflict of interest The authors declare no competing interests. References Pal, S. and G. Bhaduri, Endoscopic submucosal dissection for early gastrointestinal malignancies: Current state and future perspectives. World J Gastrointest Endosc, 2025. 17 (9): p. 109144. 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Tables Table 1 Univariate analysis of delayed perforation after ESD Indicator Perforation group (n = 13) Control group (n = 100) χ 2 p Gender 0.081 0.776 Male 7 (53.85) 58 (58.00) - - Female 6 (46.15) 42 (42.00) - - Age * 0.554 <65 years 7 (53.85) 63 (63.00) - - ≥65 years 6 (46.15) 37 (37.00) - - Body mass index 0.425 0.906 24.0 kg/m 2 4 (30.77) 24 (24.00) - - Education level 0.161 1.000 Primary school 6 (46.15) 42 (42.00) - - Junior high school-high school 6 (46.15) 48 (48.00) - - College and above 1 (7.69) 10 (10.00) - - Medical insurance type 1.274 0.725 None 1 (7.69) 4 (4.00) - - Urban employee 3 (23.08) 29 (29.00) - - Urban and rural residents 9 (69.23) 65 (65.00) - - Commercial insurance 0 (0.00) 2 (2.00) - - Comorbidities Hypertension 4 (30.77) 22 (22.00) * 0.492 Diabetes 1 (7.69) 9 (9.00) * 1.000 Coronary heart disease 1 (7.69) 3 (3.00) * 0.391 Others 2 (15.38) 10 (10.00) * 0.627 Smoking history 4 (30.77) 23 (23.00) * 0.507 Drinking history 3 (23.08) 25 (25.00) * 1.000 ASA grade * 1.000 Grade I-II 12 (92.31) 93 (93.00) - - Grade III 1 (7.69) 7 (7.00) - - Tumor location 3.213 0.221 Stomach 5 (38.46) 62 (62.00) - - Duodenum 5 (38.46) 20 (20.00) - - Rectum 3 (23.08) 18 (18.00) - - Tumor diameter * 0.008 ≤2.0 cm 6 (46.15) 82 (82.00) - - >2.0 cm 7 (53.85) 18 (18.00) - - Growth pattern 9.387 0.005 Intraluminal growth type 4 (30.77) 68 (68.00) - - Mixed type 3 (23.08) 20 (20.00) - - Extraluminal growth type 6 (46.15) 12 (12.00) - - Risk stratification * 0.241 Very low/low risk 9 (69.23) 84 (84.00) - - Moderate risk 4 (30.77) 16 (16.00) - - Degree of submucosal fibrosis 10.923 0.003 F0 3 (23.08) 45 (45.00) - - F1 3 (23.08) 43 (43.00) - - F2 7 (53.85) 12 (12.00) - - Surgical duration * 0.110 ≤90 min 6 (46.15) 71 (71.00) - - >90 min 7 (53.85) 29 (29.00) - - Intraoperative muscular layer injury 8 (61.54) 16 (16.00) * <0.001 Wound management method 1.084 0.605 Unclosed/simple hemostasis 4 (30.77) 21 (21.00) - - Metal clip technique 8 (61.54) 72 (72.00) - - Other techniques 1 (7.69) 7 (7.00) - - Surgeon's experience * 0.752 Less experienced 5 (38.46) 31 (31.00) - - More experienced 8 (61.54) 69 (69.00) - - Proton pump inhibitor type * 0.338 Oral 2 (15.38) 32 (32.00) - - Intravenous 11 (84.62) 68 (68.00) - - Note: * indicates Fisher's exact test. Table 2 Assignment table No. Factor Assignment X1 Tumor diameter ≤2.0 cm = 0，>2.0 cm = 1 X2 Growth pattern Intraluminal growth type = 0, Mixed type = 1, Extraluminal growth type = 2 X3 Degree of submucosal fibrosis F0 = 0, F1 = 1, F2 = 2 X4 Intraoperative muscular layer injury No = 0, Yes = 1 Table 3 Multivariate logistic regression analysis of delayed perforation after ESD Variable β SE Wald p OR (95% CI ) Tumor diameter (1) 2.987 1.031 8.402 0.004 19.836 (2.631~149.532) Growth pattern 6.996 0.030 Mixed type 1.106 1.084 1.042 0.307 3.022 (0.361~25.267) Extraluminal growth type 2.756 1.046 6.946 0.008 15.741 (2.027~122.246) Degree of submucosal fibrosis 4.049 0.132 F1 0.835 1.064 0.615 0.433 2.304 (0.286~18.560) F2 2.109 1.067 3.907 0.048 8.244 (1.018~66.761) Intraoperative muscular layer injury (1) 2.200 0.938 5.496 0.019 9.022 (1.424~56.747) Table 4 Comparison of postoperative gastrointestinal function recovery time between the two groups (h) Indicator Perforation group (n = 13) Control group (n = 100) Welch t p First flatus time 86.77 ± 27.88 25.24 ± 7.45 7.919 <0.001 First feeding time 133.77 ± 38.13 48.88 ± 13.48 7.964 <0.001 First defecation time 158.54 ± 40.83 72.83 ± 17.14 7.484 <0.001 Additional Declarations No competing interests reported. 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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-8485481","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":592503078,"identity":"f71a1f75-d7ff-4401-980d-8ab710bc4b05","order_by":0,"name":"Ling Lei","email":"","orcid":"","institution":"First Affiliated Hospital of Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Ling","middleName":"","lastName":"Lei","suffix":""},{"id":592503080,"identity":"52ea6edf-1b9f-4d33-8af5-e8bf89dbe3f1","order_by":1,"name":"Ping Wang","email":"","orcid":"","institution":"First Affiliated Hospital of Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Ping","middleName":"","lastName":"Wang","suffix":""},{"id":592503081,"identity":"3a9a1ae3-821a-4615-873f-4b709e967d18","order_by":2,"name":"Lihong Gan","email":"","orcid":"","institution":"First Affiliated Hospital of Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Lihong","middleName":"","lastName":"Gan","suffix":""},{"id":592503082,"identity":"045f0125-6034-4fff-ab28-15b22e420013","order_by":3,"name":"Li Zheng","email":"","orcid":"","institution":"First Affiliated Hospital of Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Li","middleName":"","lastName":"Zheng","suffix":""},{"id":592503084,"identity":"e808b3d6-79ff-456c-8125-0c99ff93972d","order_by":4,"name":"Mengqi Kuang","email":"","orcid":"","institution":"First Affiliated Hospital of Nanchang University","correspondingAuthor":false,"prefix":"","firstName":"Mengqi","middleName":"","lastName":"Kuang","suffix":""},{"id":592503085,"identity":"9fb36a3d-771d-41e4-8756-ae3b4de1c898","order_by":5,"name":"Bin Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAxklEQVRIiWNgGAWjYBACA2b+AwcYKv7L8bM3Nj78QJwWnoQDDGeYjSV7DjcbSxClhYHHgIGxjTlxw430NgEeorSw8yQeLjjDxjhz5sM2BgkGOzndBoIO4z9weEYFDzO/dGLbgwKGZGOzA0T45TDPGQk2ydmJ7QYSDAcStxGhxeAwb5sBj8HNg20SPCRoSZAwuMFIvBaQww4YSPYkAgPZgAi/2PefP/yZp+JAfT/78YcPP1TYyRHUgm4pacpHwSgYBaNgFOAAAEnkQjSrEc4fAAAAAElFTkSuQmCC","orcid":"","institution":"First Affiliated Hospital of Nanchang University","correspondingAuthor":true,"prefix":"","firstName":"Bin","middleName":"","lastName":"Li","suffix":""}],"badges":[],"createdAt":"2025-12-31 03:38:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8485481/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8485481/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":103210598,"identity":"7319bd66-0d13-4623-b37c-4457f23371d3","added_by":"auto","created_at":"2026-02-23 08:29:01","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":95706,"visible":true,"origin":"","legend":"\u003cp\u003eForest plot of influencing factors\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8485481/v1/469fb29d5231c7f815629186.jpg"},{"id":103210599,"identity":"ab82061a-3d7f-4079-9082-5ea90ab0516c","added_by":"auto","created_at":"2026-02-23 08:29:01","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":101868,"visible":true,"origin":"","legend":"\u003cp\u003eKaplan-Meier curve of temporal distribution characteristics in the perforation group\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8485481/v1/ccf5e901d66cd392527fb3a5.jpg"},{"id":109252396,"identity":"b3812d16-0dee-43a7-9518-d78c1e2e68ba","added_by":"auto","created_at":"2026-05-14 09:25:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":545166,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8485481/v1/0fa4c137-b04b-451e-a194-e6bd0df55013.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Analysis of risk factors for postoperative delayed perforation following endoscopic submucosal dissection in the treatment of gastrointestinal stromal tumors","fulltext":[{"header":"Introduction","content":"\u003cp\u003eEndoscopic submucosal dissection (ESD) emerged in 2003 as an innovative therapeutic approach for gastrointestinal lesions, bridging the technical gap between endoscopic mucosal resection (EMR) and surgical intervention [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Owing to its ability to completely resect larger gastrointestinal lesions while obtaining high-quality pathological specimens, ESD has become one of the standard methods for treating early-stage gastrointestinal cancers and precancerous lesions [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. In recent years, its indications have gradually expanded to include gastrointestinal submucosal tumors, particularly for the diagnostic resection of gastrointestinal stromal tumors (GISTs) with potential malignant risk, where ESD also demonstrates unique advantages [\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eESD typically starts with lesion marking, followed by submucosal injection to elevate the mucosa. The raised mucosa is then incised to expose the tumor, which is carefully dissected along its capsule for complete en bloc removal [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. The resulting wound is closed with clips or advanced techniques to reduce complications. In parallel, endoscopic submucosal excavation involves resecting the overlying mucosa and enucleating the lesion. However, perforation is common when the lesion involves deeper muscle layers [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. As a time-consuming procedure, ESD is associated with a higher risk of complications such as bleeding and perforation, often requiring the participation of two or more assistants [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. ESD-related perforations can be classified into intraoperative perforations and postoperative delayed perforations. In most cases, intraoperative perforations can be successfully managed conservatively through endoscopic closure alone [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Compared to intraoperative perforations, delayed perforation is a severe adverse event. Upon diagnosis, it is often associated with life-threatening complications such as peritonitis, prolonging hospital stays, increasing healthcare burdens, and even endangering patient lives [\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eCurrently, research on postoperative complications following ESD for epithelial-derived tumors, such as early gastric cancer [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] and colorectal cancer [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], is relatively abundant. However, systematic studies on the risk factors and clinical characteristics of delayed perforation after ESD for GISTs, a specific type of submucosal tumor, are relatively scarce. Given that GISTs often exhibit unique biological behaviors, such as a tendency for extraluminal growth [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] and a close relationship with the muscularis propria [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], the risk profile for delayed perforation after ESD may differ from that of epithelial-derived tumors. This study aims to investigate the relevant risk factors for delayed perforation after ESD in patients with GISTs, with the goal of providing evidence-based guidance for clinical practice.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study protocol was reviewed and approved by The First Hospital of Nanchang\u0026rsquo;s ethics committee, and informed consent was waived for the retrospective study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePatients and\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eg\u003c/strong\u003e\u003cstrong\u003erouping\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA retrospective case-control study design was adopted. Patient data were consecutively collected from the electronic medical record system of The First Hospital of Nanchang for all individuals who underwent ESD for GISTs at the Endoscopy Center of the Department of Gastroenterology between January 2022 and June 2025, with postoperative pathological confirmation of GIST. A total of 13 patients who developed delayed perforation after ESD were identified (delayed perforation was defined as the absence of perforation during ESD, no symptoms or free gas immediately postoperatively, followed by sudden onset of peritoneal irritation symptoms or chest pain, or the presence of free gas on postoperative abdominal plain films or chest-abdominal CT scans). From the cohort of GIST patients treated with ESD during the same period without delayed perforation, 100 patients were randomly selected as the control group based on study requirements.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInclusion and exclusion criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInclusion criteria: ① Patients aged \u0026ge;18 years; ② those preoperatively diagnosed with a submucosal tumor of the gastrointestinal tract via imaging (endoscopic ultrasonography or CT) and highly suspected of having GIST; ③ those who underwent standard ESD treatment with postoperative pathological confirmation of GIST\u0026nbsp;[\u003ca href=\"#_ENREF_14\" title=\"Casali, 2022 #23\"\u003e14\u003c/a\u003e];\u0026nbsp;④\u0026nbsp;those\u0026nbsp;with clear indications for ESD (e.g., tumor diameter \u0026le;5 cm, considered very low/low/intermediate risk, patient desire for organ preservation);\u0026nbsp;⑤\u0026nbsp;those\u0026nbsp;with complete clinical records, endoscopic reports, surgical records, imaging data, and pathological reports;\u0026nbsp;⑥\u0026nbsp;those\u0026nbsp;with a smooth surgical procedure meeting technical requirements for complete lesion resection and with clear follow-up records for at least 1 month post-discharge.\u003c/p\u003e\n\u003cp\u003eExclusion criteria: ① Patients assessed preoperatively as advanced with distant metastasis or severe local tumor invasion (e.g., serosal involvement, severe adhesion to surrounding tissues) where curative resection via ESD was not feasible; ② those with multiple primary GISTs or concurrent gastrointestinal malignancies requiring simultaneous surgical treatment; ③ those undergoing emergency ESD for acute tumor-related complications (e.g., obstruction, bleeding, perforation); ④ those with active gastrointestinal bleeding, infection, or perforation within 1 week preoperatively; ⑤ those with severe coagulopathy or long-term use of anticoagulant/antiplatelet agents without standardized perioperative management or bridging therapy; ⑥ those with a history of major resection surgery involving the target organ (stomach or intestines); ⑦ pregnant or lactating women; ⑧ those with intraoperative perforation during ESD (detected immediately and managed endoscopically); ⑨ those lost to follow-up or with incomplete follow-up data preventing confirmation of delayed perforation; ⑩ those whose final postoperative pathological diagnosis was not GIST (e.g., leiomyoma, neuroendocrine tumor).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSurgical\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003em\u003c/strong\u003e\u003cstrong\u003eethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll ESD procedures in this study adhered to standardized protocols and were performed by experienced endoscopists. Patients underwent comprehensive preoperative evaluation and preparation. Intraoperatively, the Olympus CV-290 electronic endoscopy system with matching GIF-HQ290 therapeutic endoscopes [Olympus (Beijing) Sales \u0026amp; Service Co., Ltd.] was primarily used. The submucosal injection solution consisted of a mixture of glycerol fructose injection (Dalian Tianyu Pharmaceutical Co., Ltd., State Drug Administration: H20064034) containing epinephrine hydrochloride injection (Beijing Yongkang Pharmaceutical Co., Ltd., State Drug Administration: H11020584) and indigo carmine (Southwest Pharmaceutical Co., Ltd., State Drug Administration: H50021944) (ratio: glycerol fructose:indigo carmine:epinephrine = 100 mL:1 mL:0.5 mL). Key surgical steps included lesion marking, submucosal injection for lifting, marginal incision, and submucosal dissection, with carbon dioxide insufflation used throughout. Specialized instruments such as the Dual Knife (Olympus KD-650Q/U) and IT Knife 2 (Olympus KD-611L) were employed for precise dissection and electrocoagulation hemostasis. After complete lesion resection, the wound was carefully inspected and treated with metallic hemostatic clips (Olympus HX-610 series) as needed. Specimens were fixed and sent for pathological examination. Postoperatively, patients were fasted, given acid suppression, prophylactic antibiotics, and closely monitored, with gradual dietary resumption and standardized follow-up to monitor for complications.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCollection of relevant factors and observational indicators\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(1) Demographic characteristics included gender, age, body mass index, educational level, and medical insurance type.\u003c/p\u003e\n\u003cp\u003e(2) Comorbidities and preoperative conditions included chronic histories of hypertension, diabetes, coronary heart disease; smoking history (defined as cumulative smoking \u0026ge;10 pack-years) and alcohol history (defined as regular drinking \u0026ge;1 year with alcohol intake \u0026ge;30 g/day); American Society of Anesthesiologists (ASA) classification.\u003c/p\u003e\n\u003cp\u003e(3) Tumor characteristics: ① Tumor location was classified as stomach (cardia, fundus, body, antrum), duodenum, or colorectum based on endoscopic and imaging findings; ② Tumor diameter was measured as the maximum diameter (cm) on endoscopic ultrasonography or CT images; ③ Growth pattern was classified as intraluminal, extraluminal, or mixed based on endoscopic ultrasonography results; ④ Preoperative risk assessment: Risk stratification (very low, low, intermediate, high) was performed according to the Chinese GIST diagnosis and treatment consensus, combining tumor diameter and mitotic count (based on postoperative pathology); ⑤ Degree of submucosal fibrosis was classified as F0 (no fibrosis), F1 (mild fibrosis), or F2 (severe fibrosis).\u003c/p\u003e\n\u003cp\u003e(4) Surgical procedures: ① Surgical duration was defined as the time from submucosal injection to complete lesion resection (minutes); ② Intraoperative muscular layer injury was defined as exposure or electrocoagulation injury to the muscular layer during dissection without transmural perforation; ③ Wound management was recorded whether metallic clips or other closure techniques were used for wound suturing; ④ Surgeon experience was classified based on the total number of ESD procedures independently performed by the primary surgeon (\u0026ge;500 cases defined as high experience, \u0026lt;500 as low experience).\u003c/p\u003e\n\u003cp\u003e(5) Postoperative management included the dosage form of prophylactic proton pump inhibitors used postoperatively (intravenous/oral).\u003c/p\u003e\n\u003cp\u003e(6) Temporal distribution of perforation events was documented by recording in detail the interval time (in hours) from the conclusion of surgery to the emergence of typical clinical symptoms, such as sudden severe abdominal pain and abdominal muscle rigidity, as well as the radiological confirmation (via abdominal CT or upright abdominal plain film) of the perforation.\u003c/p\u003e\n\u003cp\u003e(7) Management approaches and clinical outcomes of perforation: ① Management approaches was classified as conservative treatment (fasting, gastrointestinal decompression, intensified anti-infection), endoscopic treatment (endoscopic clipping, suturing, or covered stent placement), percutaneous interventional drainage, or surgical treatment; ② Clinical outcomes involved the recording of the treatment success rate (which was defined as the healing of perforation without the necessity for reintervention), complications (such as intra-abdominal infection and abscess), the total duration of postoperative hospital stay, and cases of ICU admission.\u003c/p\u003e\n\u003cp\u003e(8) Postoperative gastrointestinal functional recovery time: Key time points for gastrointestinal functional recovery were recorded, all calculated from the end of surgery: ① First flatus time: Time of first spontaneous anal flatus postoperatively; ② First oral intake time: Time when patients were permitted by the attending physician to resume oral intake of liquid or semi-liquid diets; ③ First bowel movement time: Time of first spontaneous defecation postoperatively. These time points were obtained by reviewing postoperative nursing records, progress notes, and discharge summaries.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003em\u003c/strong\u003e\u003cstrong\u003eethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStatistical analysis was performed using SPSS 27.0. Categorical data were expressed as [n (%)] and compared using the \u0026chi;\u0026sup2; test or Fisher\u0026rsquo;s exact test. Temporal distribution characteristics in the perforation group were analyzed using Kaplan-Meier curves. Continuous data were tested for normality using the Shapiro-Wilk test; skewed distributions were expressed as [M (P25, P75)] and compared using the Mann-Whitney U test, while normally distributed data were expressed as (mean \u0026plusmn; standard deviation). Homogeneity of variance was verified using Levene\u0026rsquo;s test, with independent samples t-tests used for comparisons between two groups when variance was homogeneous and Welch\u0026rsquo;s t-test when variance was not homogeneous. A \u003cem\u003ep\u003c/em\u003e-value \u0026lt;0.05 indicated statistical significance.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eUnivariate analysis of delayed perforation after ESD\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUnivariate analysis revealed statistically significant differences between the perforation group and the control group in four factors: tumor diameter, growth pattern, degree of submucosal fibrosis, and intraoperative muscular layer injury (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05) (Table 1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMultivariate logistic regression analysis of delayed perforation after ESD\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMultivariate logistic regression analysis showed that tumor diameter \u0026gt;2.0 cm [19.836 (2.631~149.532)], extraluminal growth type [15.741 (2.027~122.246)], severe submucosal fibrosis [8.244 (1.018~66.761)], and intraoperative muscular layer injury [9.022 (1.424~56.747)] were independent risk factors for delayed perforation after ESD (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05) (Tables 2-3;\u0026nbsp;Figure 1)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTemporal distribution characteristics of the perforation group\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eKaplan-Meier analysis revealed that the median time to diagnosis of delayed perforation in 13 patients was 10 hours postoperatively (range: 3~26 hours; 95% CI: 6.477~13.523). As shown in Figure 2, the vast majority of perforation events (92.31%, 12/13) occurred within 24 hours postoperatively, suggesting that the first 24 hours postoperatively is a high-risk window period for delayed perforation, necessitating enhanced clinical monitoring (Figure 2).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eManagement approaches and clinical outcomes in the perforation group\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAmong the 13 patients with delayed perforation, all cases were diagnosed by imaging examination after symptom onset and immediately initiated targeted treatment. Management Approaches: Treatment plans were individualized based on the size of the perforation, degree of abdominal contamination, and overall patient condition. Seven patients (53.8%) underwent endoscopic treatment as the primary option (including direct closure with metal clips in 5 cases and Over-The-Scope Clip closure in 2 cases); four patients (30.8%) underwent direct surgical treatment (perforation repair) due to large perforation defects or concomitant diffuse peritonitis; two patients (15.4%) opted for conservative management (absolute fasting, gastrointestinal decompression, intensive anti-infection, and nutritional support) due to small, localized perforations. Clinical Outcomes: After the above treatments, 12 patients (92.3%) were cured (perforation healed without further intervention). One patient who underwent endoscopic treatment required conversion to surgical treatment for cure due to incomplete closure and secondary abdominal infection. In terms of complications, three patients (23.1%) developed postoperative abdominal infection or abscess, which were controlled after anti-infection and puncture drainage. The median total hospital stay for patients in the perforation group was 16 days (range: 12~25 days), significantly longer than the median total hospital stay of 7.5 days (range: 5~13 days) for patients with conventional recovery, with a statistically significant difference (Z = 5.844, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05). Among them, three patients (23.1%) required transfer to the ICU for monitoring and treatment due to their condition. There were no deaths.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePostoperative gastrointestinal function recovery time\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe first flatus time, first feeding time, and first defecation time were all longer in the perforation group than in the control group (Table 4) (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study employed univariate and multivariate logistic regression analyses to identify four independent risk factors for delayed perforation following ESD for GIST: tumor diameter \u0026gt; 2.0 cm, extraluminal growth type, severe submucosal fibrosis, and intraoperative muscular layer injury. \u003c/p\u003e\n\u003cp\u003eFirstly, a tumor diameter \u0026gt; 2.0 cm was associated with an increased risk of perforation. Larger tumors typically entail a more extensive dissection area, longer operative time, and greater dissection difficulty [15, 16]. During the dissection process, the cumulative thermal and mechanical trauma from electrocoagulation and traction more significantly compromises the integrity of the muscular layer, increasing the risk of delayed perforation due to postoperative tissue necrosis or tearing at weakened sites. Previous studies have identified larger tumor size as risk factors for delayed perforation [17, 18]. Additionally, it has been reported that risk factors for intraoperative perforation include tumor diameter exceeding 20 mm, lesions in the U-region, the presence of ulcer scars, and lesions on the greater curvature [16].\u003c/p\u003e\n\u003cp\u003eMoreover, extraluminal growth type GIST represents another key risk factor. These tumors often breach the muscular layer boundary and grow outward [19], which may bring the ESD dissection plane closer to or even into the muscular layer [20]. This not only increases the risk of intraoperative perforation but also undermines the stability of the postoperative wound base, making it more susceptible to delayed perforation triggered by gastrointestinal motility or pressure changes postoperatively. \u003c/p\u003e\n\u003cp\u003eSevere submucosal fibrosis also increases the technical difficulty and risk of perforation. Fibrosis leads to blurred tissue layers and increased dissection resistance [21], often necessitating increased electrocoagulation intensity or more frequent sharp dissection during surgery [22], which can easily result in uncontrollable muscular layer damage. Even if immediate perforation does not occur, the damaged muscular layer may undergo delayed necrosis and perforation postoperatively. Existing evidence supports that submucosal fibrosis is associated with prolonged operative time, an increased risk of complications such as perforation, and a reduced rate of complete en bloc resection [21]. Naohisa et al. further confirmed that severe fibrosis and long ESD operative time are important risk factors for delayed perforation [18]. \u003c/p\u003e\n\u003cp\u003eFinally, intraoperative muscular layer injury is also a clearly defined independent risk factor. Even if the muscular layer laceration is closed or sutured during surgery, this site remains a postoperative weak point that may rupture due to tension or blood supply issues during the process of functional recovery. Delayed perforation is believed to be caused by thermal injury, meaning that excessive electrocoagulation can damage the submucosa and muscular layer, leading to small perforations over time [22]. This study further clarifies this viewpoint.\u003c/p\u003e\n\u003cp\u003eExisting evidence indicates that delayed perforation after gastric ESD typically occurs 1-2 days postoperatively [16]. In this study, the median onset time of delayed perforation was 10 hours postoperatively, with 92.3% of cases occurring within 24 hours after surgery, suggesting that enhanced monitoring should be implemented for at least 24 to 48 hours postoperatively in such patients. Perforation significantly prolonged hospital stays, with nearly one-fourth of patients requiring transfer to the intensive care unit (ICU), all of whom also experienced delayed recovery of gastrointestinal function. After active multidisciplinary collaborative intervention, all patients were cured, with no fatalities reported. The choice of treatment approach should be individualized based on the characteristics of the perforation, the degree of abdominal contamination, the patient's overall condition, and the availability of endoscopic technical resources.\u003c/p\u003e\n\u003cp\u003eThe limitations of this study lie in its single-center retrospective design and limited sample size, particularly the small number of cases in the perforation group, which may lead to the failure to identify certain potential risk factors or affect the precision of effect estimates in multivariate analysis. Future multicenter, large-sample prospective studies are needed to further validate and refine these risk factors and explore more effective preventive strategies.\u003c/p\u003e\n\u003cp\u003eIn conclusion, a large tumor diameter (\u0026gt; 2.0 cm), extraluminal growth, severe submucosal fibrosis, and intraoperative muscular layer injury are key independent risk factors for delayed perforation following ESD for GIST. The findings provide a basis for optimizing the perioperative management of ESD for GIST. It is recommended that clinicians identify high-risk patients through preoperative imaging assessment, perform meticulous intraoperative procedures to protect the muscular layer, and extend postoperative monitoring to at least 24 hours for high-risk cases. In the event of delayed perforation, timely initiation of multidisciplinary collaboration should be implemented, and treatment options such as endoscopic, surgical, or conservative approaches should be selected based on the patient's condition to improve their prognosis.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Science and Technology Project of Health Commission of Jiangxi Province (202210085, 202311202, 202510682).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003ePal, S. and G. Bhaduri, \u003cem\u003eEndoscopic submucosal dissection for early gastrointestinal malignancies: Current state and future perspectives.\u003c/em\u003e World J Gastrointest Endosc, 2025. \u003cstrong\u003e17\u003c/strong\u003e(9): p. 109144.\u003c/li\u003e\n\u003cli\u003eXu, M., et al., \u003cem\u003eHydrogels in endoscopic submucosal dissection for gastrointestinal cancers.\u003c/em\u003e Acta Biomater, 2025. \u003cstrong\u003e200\u003c/strong\u003e: p. 47-66.\u003c/li\u003e\n\u003cli\u003eJiang, S., et al., \u003cem\u003eComparative study on different endoscopic submucosal dissection techniques for the treatment of superficial esophageal cancer and precancerous lesions.\u003c/em\u003e BMC Gastroenterol, 2025. \u003cstrong\u003e25\u003c/strong\u003e(1): p. 73.\u003c/li\u003e\n\u003cli\u003eShimura, T., et al., \u003cem\u003eSuccessful diagnosis and endoscopic submucosal dissection of a gastric gastrointestinal stromal tumor originating from the submucosal layer.\u003c/em\u003e VideoGIE, 2022. \u003cstrong\u003e7\u003c/strong\u003e(2): p. 65-67.\u003c/li\u003e\n\u003cli\u003eMeng, R., et al., \u003cem\u003eComparison of Modified Cap-Assisted Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection in Treating Intraluminal Gastric Gastrointestinal Stromal Tumor (\u0026lt;/=20 mm).\u003c/em\u003e Clin Transl Gastroenterol, 2023. \u003cstrong\u003e14\u003c/strong\u003e(6): p. e00589.\u003c/li\u003e\n\u003cli\u003eWu, J. and Z.D. Jin, \u003cem\u003eAdvancements in endoscopic resection of gastrointestinal stromal tumors: Techniques, outcomes, and perspectives.\u003c/em\u003e World J Gastrointest Surg, 2025. \u003cstrong\u003e17\u003c/strong\u003e(10): p. 111558.\u003c/li\u003e\n\u003cli\u003eVogli, S., et al., \u003cem\u003eExpanding the role of endoscopic resection in esophageal gastrointestinal stromal tumors: Insights and challenges.\u003c/em\u003e World J Gastroenterol, 2025. \u003cstrong\u003e31\u003c/strong\u003e(20): p. 106441.\u003c/li\u003e\n\u003cli\u003ePimentel-Nunes, P., et al., \u003cem\u003eEndoscopic submucosal dissection for superficial gastrointestinal lesions: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2022.\u003c/em\u003e Endoscopy, 2022. \u003cstrong\u003e54\u003c/strong\u003e(6): p. 591-622.\u003c/li\u003e\n\u003cli\u003eKim, T.S., et al., \u003cem\u003eDelayed Perforation Occurring after Gastric Endoscopic Submucosal Dissection: Clinical Features and Management Strategy.\u003c/em\u003e Gut Liver, 2024. \u003cstrong\u003e18\u003c/strong\u003e(1): p. 40-49.\u003c/li\u003e\n\u003cli\u003eCai, R.S., W.Z. Yang, and G.R. Cui, \u003cem\u003eAssociate factors for endoscopic submucosal dissection operation time and postoperative delayed hemorrhage of early gastric cancer.\u003c/em\u003e World J Gastrointest Surg, 2023. \u003cstrong\u003e15\u003c/strong\u003e(1): p. 94-104.\u003c/li\u003e\n\u003cli\u003eHamada, K., et al., \u003cem\u003eDelayed Perforation of Colorectal Endoscopic Submucosal Dissection Treated by Endoscopic Ultrasound-Guided Drainage.\u003c/em\u003e Case Rep Gastroenterol, 2023. \u003cstrong\u003e17\u003c/strong\u003e(1): p. 148-154.\u003c/li\u003e\n\u003cli\u003eOkano, H., et al., \u003cem\u003eBleeding From a Ruptured, Extraluminally Growing Gastric Gastrointestinal Stromal Tumor Treated by Transcatheter Arterial Embolization: A Case Report.\u003c/em\u003e Cureus, 2024. \u003cstrong\u003e16\u003c/strong\u003e(1): p. e52394.\u003c/li\u003e\n\u003cli\u003eLi, J., et al., \u003cem\u003eEfficacy and Safety of Endoscopic Resection for Gastric Gastrointestinal Stromal Tumors Originating from the Muscularis Propria.\u003c/em\u003e Dig Dis Sci, 2024. \u003cstrong\u003e69\u003c/strong\u003e(6): p. 2184-2192.\u003c/li\u003e\n\u003cli\u003eCasali, P.G., et al., \u003cem\u003eGastrointestinal stromal tumours: ESMO-EURACAN-GENTURIS Clinical Practice Guidelines for diagnosis, treatment and follow-up.\u003c/em\u003e Ann Oncol, 2022. \u003cstrong\u003e33\u003c/strong\u003e(1): p. 20-33.\u003c/li\u003e\n\u003cli\u003eSuzuki, H., et al., \u003cem\u003eManagement and associated factors of delayed perforation after gastric endoscopic submucosal dissection.\u003c/em\u003e World J Gastroenterol, 2015. \u003cstrong\u003e21\u003c/strong\u003e(44): p. 12635-43.\u003c/li\u003e\n\u003cli\u003eAkashi, T., et al., \u003cem\u003eCharacteristics and Risk Factors of Delayed Perforation in Endoscopic Submucosal Dissection for Early Gastric Cancer.\u003c/em\u003e J Clin Med, 2024. \u003cstrong\u003e13\u003c/strong\u003e(5).\u003c/li\u003e\n\u003cli\u003eGweon, T.G. and D.H. Yang, \u003cem\u003eManagement of complications related to colorectal endoscopic submucosal dissection.\u003c/em\u003e Clin Endosc, 2023. \u003cstrong\u003e56\u003c/strong\u003e(4): p. 423-432.\u003c/li\u003e\n\u003cli\u003eYoshida, N., et al., \u003cem\u003eRisk Factors, Clinical Course, and Management of Delayed Perforation After Colorectal Endoscopic Submucosal Dissection: A Large-Scale Multicenter Study.\u003c/em\u003e Dig Dis Sci, 2025. \u003cstrong\u003e70\u003c/strong\u003e(7): p. 2404-2413.\u003c/li\u003e\n\u003cli\u003eFukuda, H., N. Uedo, and S. Shichijo, \u003cem\u003eTraction-assisted endoscopic full-thickness resection for extraluminal type gastrointestinal stromal tumor.\u003c/em\u003e Endosc Int Open, 2021. \u003cstrong\u003e9\u003c/strong\u003e(8): p. E1243-E1245.\u003c/li\u003e\n\u003cli\u003e\u003cem\u003e[Regulations concerning the nurse at a treatment and prevention institution].\u003c/em\u003e Med Sestra, 1988. \u003cstrong\u003e47\u003c/strong\u003e(1): p. 7-10.\u003c/li\u003e\n\u003cli\u003eZeng, Y., et al., \u003cem\u003eDevelopment and validation of a predictive model for submucosal fibrosis in patients with early gastric cancer undergoing endoscopic submucosal dissection: experience from a large tertiary center.\u003c/em\u003e Ann Med, 2024. \u003cstrong\u003e56\u003c/strong\u003e(1): p. 2391536.\u003c/li\u003e\n\u003cli\u003eZhou, G.Y., et al., \u003cem\u003eDelayed perforation after endoscopic resection of a colonic laterally spreading tumor: A case report and literature review.\u003c/em\u003e World J Clin Cases, 2020. \u003cstrong\u003e8\u003c/strong\u003e(16): p. 3608-3615.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e Univariate analysis of delayed perforation after ESD\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"99%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eIndicator\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003ePerforation group (n = 13)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003eControl group (n = 100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eGender\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e0.081\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.776\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e7 (53.85)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e58 (58.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e6 (46.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e42 (42.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eAge\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.554\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003e\u0026lt;65 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e7 (53.85)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e63 (63.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003e\u0026ge;65 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e6 (46.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e37 (37.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eBody mass index\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e0.425\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.906\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003e\u0026lt;18.5 kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e1 (7.69)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e12 (12.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003e18.5~24.0 kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e8 (61.54)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e64 (64.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003e\u0026gt;24.0 kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e4 (30.77)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e24 (24.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eEducation level\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e0.161\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003ePrimary school\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e6 (46.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e42 (42.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eJunior high school-high school\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e6 (46.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e48 (48.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eCollege and above\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e1 (7.69)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e10 (10.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eMedical insurance type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e1.274\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.725\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eNone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e1 (7.69)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e4 (4.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eUrban employee\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e3 (23.08)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e29 (29.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eUrban and rural residents\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e9 (69.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e65 (65.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eCommercial insurance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e0 (0.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e2 (2.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eComorbidities\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eHypertension\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e4 (30.77)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e22 (22.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.492\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eDiabetes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e1 (7.69)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e9 (9.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eCoronary heart disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e1 (7.69)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e3 (3.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.391\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eOthers\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e2 (15.38)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e10 (10.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.627\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eSmoking history\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e4 (30.77)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e23 (23.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.507\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eDrinking history\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e3 (23.08)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e25 (25.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eASA grade\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eGrade I-II\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e12 (92.31)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e93 (93.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eGrade III\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e1 (7.69)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e7 (7.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eTumor location\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e3.213\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.221\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eStomach\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e5 (38.46)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e62 (62.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eDuodenum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e5 (38.46)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e20 (20.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eRectum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e3 (23.08)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e18 (18.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eTumor diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.008\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003e\u0026le;2.0 cm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e6 (46.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e82 (82.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003e\u0026gt;2.0 cm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e7 (53.85)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e18 (18.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eGrowth pattern\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e9.387\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eIntraluminal growth type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e4 (30.77)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e68 (68.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eMixed type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e3 (23.08)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e20 (20.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eExtraluminal growth type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e6 (46.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e12 (12.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eRisk stratification\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.241\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eVery low/low risk\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e9 (69.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e84 (84.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eModerate risk\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e4 (30.77)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e16 (16.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eDegree of submucosal fibrosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e10.923\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.003\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eF0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e3 (23.08)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e45 (45.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eF1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e3 (23.08)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e43 (43.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eF2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e7 (53.85)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e12 (12.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eSurgical duration\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.110\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003e\u0026le;90 min\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e6 (46.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e71 (71.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003e\u0026gt;90 min\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e7 (53.85)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e29 (29.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eIntraoperative muscular layer injury\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e8 (61.54)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e16 (16.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eWound management method\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e1.084\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.605\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eUnclosed/simple hemostasis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e4 (30.77)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e21 (21.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eMetal clip technique\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e8 (61.54)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e72 (72.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eOther techniques\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e1 (7.69)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e7 (7.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eSurgeon\u0026apos;s experience\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.752\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eLess experienced\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e5 (38.46)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e31 (31.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eMore experienced\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e8 (61.54)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e69 (69.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eProton pump inhibitor type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.338\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eOral\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e2 (15.38)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e32 (32.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eIntravenous\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 28px;\"\u003e\n \u003cp\u003e11 (84.62)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25px;\"\u003e\n \u003cp\u003e68 (68.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNote: * indicates Fisher\u0026apos;s exact test.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e Assignment table\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"99%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003eNo.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003eFactor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003eAssignment\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003eX1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003eTumor diameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026le;2.0 cm = 0，\u0026gt;2.0 cm = 1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003eX2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003eGrowth pattern\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003eIntraluminal growth type = 0, Mixed type = 1, Extraluminal growth type = 2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003eX3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003eDegree of submucosal fibrosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003eF0 = 0, F1 = 1, F2 = 2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003eX4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 41px;\"\u003e\n \u003cp\u003eIntraoperative muscular layer injury\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003eNo = 0, Yes = 1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e Multivariate logistic regression analysis of delayed perforation after ESD\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"99%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eVariable\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026beta;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e\u003cem\u003eSE\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e\u003cem\u003eWald\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 29px;\"\u003e\n \u003cp\u003e\u003cem\u003eOR\u003c/em\u003e (95%\u003cem\u003eCI\u003c/em\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eTumor diameter (1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e2.987\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e1.031\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e8.402\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e0.004\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 29px;\"\u003e\n \u003cp\u003e19.836 (2.631~149.532)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eGrowth pattern\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e6.996\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e0.030\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 29px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eMixed type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e1.106\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e1.084\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e1.042\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e0.307\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 29px;\"\u003e\n \u003cp\u003e3.022 (0.361~25.267)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 26px;\"\u003e\n \u003cp\u003eExtraluminal growth type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e2.756\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e1.046\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e6.946\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e0.008\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 29px;\"\u003e\n \u003cp\u003e15.741 (2.027~122.246)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eDegree of submucosal fibrosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e4.049\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e0.132\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 29px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eF1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.835\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e1.064\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e0.615\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e0.433\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 29px;\"\u003e\n \u003cp\u003e2.304 (0.286~18.560)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eF2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e2.109\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e1.067\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e3.907\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e0.048\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 29px;\"\u003e\n \u003cp\u003e8.244 (1.018~66.761)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 26px;\"\u003e\n \u003cp\u003eIntraoperative muscular layer injury (1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e2.200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10px;\"\u003e\n \u003cp\u003e0.938\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e5.496\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 11px;\"\u003e\n \u003cp\u003e0.019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 29px;\"\u003e\n \u003cp\u003e9.022 (1.424~56.747)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4\u003c/strong\u003e Comparison of postoperative gastrointestinal function recovery time between the two groups (h)\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"99%\" class=\"fr-table-selection-hover\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003eIndicator\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003ePerforation group (n = 13)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003eControl group (n = 100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eWelch\u0026nbsp;\u003c/strong\u003e\u003cem\u003et\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003eFirst flatus time\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e86.77 \u0026plusmn; 27.88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e25.24 \u0026plusmn; 7.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e7.919\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003eFirst feeding time\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e133.77 \u0026plusmn; 38.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e48.88 \u0026plusmn; 13.48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e7.964\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003eFirst defecation time\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e158.54 \u0026plusmn; 40.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24px;\"\u003e\n \u003cp\u003e72.83 \u0026plusmn; 17.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e7.484\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12px;\"\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"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Gastrointestinal stromal tumor, Endoscopic submucosal dissection, Postoperative delayed perforation, Risk factors, Gastrointestinal function","lastPublishedDoi":"10.21203/rs.3.rs-8485481/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8485481/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eWe aimed to identify independent risk factors for delayed perforation following endoscopic submucosal dissection (ESD) in gastrointestinal stromal tumors (GISTs).\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis study was a retrospective case-control study that included 113 patients with GIST who underwent ESD treatment. Among them, 13 patients who developed postoperative delayed perforation constituted the perforation group, while 100 patients without such a complication formed the control group. The differences in demographics, clinical characteristics, and surgical details between the two groups were analyzed and compared. Independent risk factors for delayed perforation were identified through univariate and multivariate logistic regression analyses. Meanwhile, the occurrence time, management, and outcomes in the perforation group were recorded, and the postoperative gastrointestinal function recovery times of the two groups were compared.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eUnivariate analysis revealed significant differences between the perforation and control groups in four factors: tumor diameter, growth pattern, degree of submucosal fibrosis, and intraoperative muscular layer injury (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Multivariate logistic regression analysis confirmed that tumor diameter\u0026thinsp;\u0026gt;\u0026thinsp;2.0 cm, extraluminal growth, severe submucosal fibrosis, and intraoperative muscular layer injury were independent risk factors for delayed perforation after ESD (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Kaplan-Meier analysis showed that the median time to diagnosis of delayed perforation in the 13 patients was 10 hours postoperatively, with the majority of perforations occurring within 24 hours postoperatively. The median hospital stay in the perforation group (16 days) was longer than that in the control group (7.5 days). After treatment, the first flatus time, first oral intake time, and first bowel movement time were longer in the perforation group than in the control group (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eTumor diameter\u0026thinsp;\u0026gt;\u0026thinsp;2.0 cm, extraluminal growth, severe submucosal fibrosis, and intraoperative muscular layer injury are independent risk factors for delayed perforation after ESD in the treatment of GISTs. Perforations predominantly occur within 24 hours postoperatively, necessitating enhanced postoperative monitoring in high-risk patients.\u003c/p\u003e","manuscriptTitle":"Analysis of risk factors for postoperative delayed perforation following endoscopic submucosal dissection in the treatment of gastrointestinal stromal tumors","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-23 08:28:56","doi":"10.21203/rs.3.rs-8485481/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"216c163f-05e0-4ec5-881c-bb5256b8de8e","owner":[],"postedDate":"February 23rd, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Withdrawn","date":"2026-05-13T22:11:48+00:00","index":"","fulltext":""},{"type":"decision","content":"Revision requested","date":"2026-05-11T13:19:02+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-13T22:23:26+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-23 08:28:56","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8485481","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8485481","identity":"rs-8485481","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}