Retrospective Cohort Study on 3D Printing Technology for Preoperative Rehearsal and Intraoperative Navigation in Laparoscopic Rectal Cancer Surgery with Left Colic Artery Preservation

Retrospective Cohort Study on 3D Printing Technology for Preoperative Rehearsal and Intraoperative Navigation in Laparoscopic Rectal Cancer Surgery with Left Colic Artery Preservation | 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 Retrospective Cohort Study on 3D Printing Technology for Preoperative Rehearsal and Intraoperative Navigation in Laparoscopic Rectal Cancer Surgery with Left Colic Artery Preservation Zongxian Zhao, Zongju Hu, Rundong Yao, Xinyu Su, Shu Zhu, Sun Jie, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4763568/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 3 You are reading this latest preprint version Abstract Background Previous studies have shown that preserving the left colic artery (LCA) during laparoscopic radical resection for rectal cancer (RC) can maintain the blood supply to the remaining colon without compromising the oncological outcomes. However, anatomical variations in the branches of the inferior mesenteric artery (IMA) and LCA present significant surgical challenges. Here, we construct a 3D printing IMA model for preoperative rehearsal and intraoperative navigation to analyze its positive impact on surgical safety. Methods We retrospectively collected clinical dates from patients with RC who received laparoscopic radical resection from January 2022 to May 2024 at Fuyang City People's Hospital. Patients were divided into 3D printing group and control group and their perioperative characteristics were statistically analyzed. Results 172 patients who underwent laparoscopic radical resection for RC were included in the study. Among them, a total of 32 patients were excluded due to exclusion criteria. Finally, observe group (3D printing group) was comprised of 72 patients, while control group consisted of 68 patients. Operating time (196.7 ± 44.5 vs. 233.3 ± 44.3 min, p < 0.001), intraoperative blood loss (43.9 ± 31.3 vs. 58.2 ± 30.8 ml, p = 0.005), duration of hospitalization (14.3 ± 5.1 vs. 18.7 ± 9.2 days, p < 0.001), and postoperative recovery time (9.1 ± 5.1 vs. 11.9 ± 7.1 days, p = 0.007) were significantly lower in observe group than in control group. There were no significant differences in the number of lymph node dissections, presence of lymph vessel invasion, postoperative intestinal obstruction and anastomotic leakage between the two groups. Conclusions Utilization of a 3D-printed IMA model in laparoscopic radical resection of RC can assist the surgeon in understanding the LCA anatomy preoperatively, reducing intraoperative bleeding, shortening operating time. Rectal cancer Three-dimensional printing Inferior mesenteric artery Left colic artery Preoperative Rehearsal Intraoperative Navigation Figures Figure 1 Figure 2 Figure 3 Introduction Rectal cancer (RC) is a common malignant tumor of the digestive tract, accounting for one-third of all morbidity and mortality due to bowel cancer, with significant implications for patient health and survival[ 1 , 2 ]. Alongside the increase in life expectancy, morbidity due to RC has risen gradually. Therefore, therapeutic strategies against RC have attracted growing attention. To date, treatment for RC has involved a surgery-based multidisciplinary approach, with contributions from the fields of gastroenterology, medical oncology, radiation oncology, and radiology[ 3 , 4 ]. In clinical practice, the standardization of total mesorectal excision, adoption of neoadjuvant chemoradiotherapy and total neoadjuvant therapy (TNT) implementation of rectal magnetic resonance imaging, advancements in mechanical stapling technology, and improvements in operating techniques (transanal total mesorectal excision, TaTME; intersphincteric resection, ISR) have significantly augmented the success rates of anus-preserving surgeries for low-lying RC[ 5 – 7 ]. With the enhancement of surgical techniques and the completion of numerous clinical trials, preservation of the left colic artery (LCA) has been observed to significantly mitigate the occurrence of anastomotic leakage (AL) following surgery[ 8 , 9 ]. During the surgical procedure, the surgeon needs to perform a lymphadenectomy at the root of the inferior mesenteric artery (NO.253). Subsequently, the surgeon needs to open the vascular sheath along the inferior mesenteric artery (IMA), preserve the LCA, and then cuts the sigmoid artery (SA) and the superior rectal artery (SRA)[ 10 ]. However, this approach is technically demanding and time-consuming, especially for the less experienced surgeon. The increased surgical difficulty is attributed to the uncertain anatomical relationship between the branches of the IMA, including the LCA, SA, and SRA[ 10 – 12 ]. Studies have identified four vascular types, namely. Type I, LCA arising independently form IMA; type II, LCA and SA branching from a common trunk of the IMA; type III, LCA, SA, and SRA branching at the same location; Type IV, LCA is absence, with only SA and SRA (Fig. 2 A) [ 10 , 12 , 13 ]. In addition, the distance at which the LCA emanates from the IMA differs among RA patients[ 14 , 15 ]. The preoperative identification of the location of the LCA and the precise types of branches of the IMA are crucial for ensuring successful surgical intervention. Three-dimensional (3D) printing technology can be utilized for medical, including preoperative simulation and intraoperative navigation, assisting surgeons in selecting the appropriate surgical plan[ 16 , 17 ]. In addition, 3D printing can build personalized implants, such as hip joints and knee joints, as well as customized dental crowns, bridges, orthodontic appliances, and implants[ 18 ]. Additionally, 3D printing can build precise anatomical models for medical education and training, customize 3D-printed surgical guides to help doctors with accurate positioning and cutting, and create personalized drug doses and combinations based on patient needs, enhancing treatment effectiveness and patient compliance[ 19 , 20 ]. To date, 3D printing technology has been extensively applied in orthopedics, stomatology, neurosurgery, hepatobiliary surgery, and other fields[ 21 , 22 ]. However, its application in RC surgery is still at an early stage. In previous studies, researchers printed entire models of the pelvic cavity to guide surgery; however, this was costly and time-consuming, and therefore not convenient for clinical application[ 23 ]. Besides, although a monolithic 3D-printed pelvic cavity is helpful to the surgeon in understanding pelvic structure, it provides relatively little information on the local vascular anatomy. In this study, we constructed a 3D-printed IMA model to clarify the morphology of IMA branches and locate the origin of the LCA before surgery. Furthermore, we assessed the role of the 3D-printed model in preoperative rehearsal and intraoperative navigation in laparoscopic RC surgery. Materials and Methods Patients and study design In this cohort study, participants with RC scheduled for laparoscopic radical resection were divided into a 3D printing group (observation group) and a control group based on their willingness to receive 3D printing-assisted treatment. The study was conducted at Fuyang City People's Hospital from January 2022 to May 2024. Inclusion criteria were as follows: (1) patients > 18 years old; (2) RC confirmed by histopathology; (3) patients provided informed and written consent for surgery; (4) patients received laparoscopic radical resection of RC with reconstruction of the digestive tract (Dixon); (5) R0 resection was achieved; (6) patients exhibited optimal cardiac and pulmonary function; and (7) all patients underwent an abdominal double-phase enhanced scan before surgery. Exclusion criteria were as follows: (1) occurrence of distant metastasis; (2) presence of other concurrent malignancies; (3) surgical procedures without reconstruction of the digestive tract (Miles or Hartmann); (4) co-morbidity with autoimmune disease; (5) co-morbidity with severe heart and lung disease; (6) co-morbidity with schizophrenia or other mental health disorders, lack of independent behavior ability, or inability to cooperate with treatment. If the patient's IMA type is type IV (absence of the LCA), the IMA is directly ligated at its root during surgery. The study design and flow chart is depicted in Fig. 2 . This study was approved by the Ethics Committee of Fuyang City People's Hospital. Construction of 3D IMA model The enhanced CT images were imported into 3D modeling software (3D slicer 5.2.2, mimics 19.0) in DICOM format for 3D reconstruction. The abdominal aorta (AA), left iliac artery, right iliac artery, IMA, LCA, SA, SRA, and mesenterica inferior vein (IMV) were examined and chosen for 3D reconstruction. Using the ‘multiple slice edit’ function, the required arteries and veins were marked in the transverse, sagittal, and coronal planes. The surface of the 3D virtual model was subsequently refined through a smoothing process. After ensuring the absence of any structural deformation or deviation, the resin white material was 3D-printed using a high-precision SLA photocuring process (CHUNLEI SLA 600 or Prismlab RP-400D). The entire 3D model reconstruction took 25 minutes approximately, and the printing time was about 150 minutes. The 3D models were then cured, polished, and colored. Red was used to color the arteries and blue was used to color the veins. The completed model was submitted to the surgeon prior to surgery for preoperative assessment and surgical planning. Before entering the operating room, the model was disinfected with 75% alcohol. The model was positioned adjacent to the laparoscopic television monitor for intraoperative navigation of the location of origin and course of the LCA and types of IMA. A comparison between photos obtained during operation and the 3D printing IMA model is shown in Fig. 3 . We confirmed the successful preservation of the LCA based on intraoperative findings and postoperative CT evaluations. Observation index The general characteristics of the two groups were comprehensively evaluated based on five factors, namely, gender, age, clinical stage, diverting stoma, and IMA types. The factors selected for further analysis included the operating time, intraoperative blood loss, number of lymph node dissections, lymph vessel invasion and nerve invasion, depth of tumor invasion (T stage), presence of lymph node metastasis (N stage), duration of stay in the hospital, postoperative recovery time, cost, and occurrence of postoperative complications (AL and intestinal obstruction). Postoperative recovery time is defined as the period from surgery to discharge from the hospital. Duration of hospital stay is defined as the time from be hospitalized to discharge. Statistical analysis Using GraphPad Prism 8 software for statistical analysis, the measurement data were analyzed by Student’s t test or Mann–Whitney U test. The enumeration data were analyzed by chi-square test or Fisher's exact test. Values of p < 0.05 were considered to indicate statistical significance. Results IMA types and 3D printing models We performed 3D reconstruction and printed 3D models based on the patients' preoperative enhanced CT images, as shown in Fig. 1 and Supplementary Table 1. Clinical characteristics Between January 2022 and May 2024, 172 RC patients with laparoscopic radical resection were included (Fig. 1 ). Among them, 3 patients with liver metastasis who underwent laparoscopic radical resection of RC and partial hepatectomy were excluded. And then, 29 patients who underwent abdominoperineal resection (Miles) or laparoscopic radical resection of RC without digestive tract reconstruction (Hartmann) were excluded. Finally, a total of 140 eligible patients were selected and randomly divided into two groups. The control group (n = 68) did not receive 3D printing model for preoperative rehearsal and intraoperative navigation, while the observe group (n = 72) used 3D printing model. The two groups had similar clinical characteristics, including sex, age, clinical stage, diverting stoma, and IMA types ( p > 0.05). Their clinical characteristics are detailed in Table 1 . Table 1 Baseline Characteristics of Included RC Patients Characteristic The control group The observe group t/χ 2 P value (n = 68) (n = 72) Age (years) Mean (SD) 64.9 ± 12.4 66.2 ± 10.5 0.636 0.513 Median (IQR) 67.0 (59.0, 73.0) 69.0 (60.0, 72.0) 0.644 Gender 0.759 0.448 Male 43 41 Female 25 31 Clinical stage 0.752 0.687 I 25 23 II 20 26 III 23 23 Diverting stoma 1.703 0.192 Yes 46 41 No 22 31 IMA types 1.947 0.584 I 28 35 II 19 16 III 21 20 IV 0 1 The primary surgeon* 0.660 0.719 A 22 28 B 38 36 C 8 8 *In the primary surgery, A and B were experienced surgeons, while C was a less experienced surgeon. Perioperative characteristics Patient perioperative characteristics were shown in Table 2 . Operating time (196.7 ± 44.5 min in observe group vs. 233.3 ± 44.3 min in control group, p < 0.001) and intraoperative blood loss (43.9 ± 31.3 mL in observe group vs. 58.2 ± 30.8 ml in control group, p < 0.005) were significantly lower in observe group than in control group. There were no significant differences between the two cohorts in number of lymph node dissections, lymph vessel invasion and nerve invasion, depth of tumor invasion, presence of lymph node metastasis, the occurrence of AL and intestinal obstruction. Duration of hospitalization (14.3 ± 5.1 days observe group vs. 18.7 ± 9.2 min in control group, p < 0.001), postoperative recovery time (9.1 ± 5.1 days observe group vs. 11.9 ± 7.1 min in control group, p < 0.007), and cost (35.1 ± 5.9 thousand RMB in observe group vs. 40.1 ± 10.1 thousand RMB in control group, p < 0.001) were significantly lower for observe group than for control group. Table 2 Perioperative Characteristics of RC Patients Characteristic The control group The observe group t/χ 2 P value (n = 68) (n = 72) Operating time (min) Mean (SD) 233.3 ± 44.3 196.7 ± 44.5 3.810 0.001 Median (IQR) 230 (195.0, 255.0) 190 (170, 228.8) 0.001 Intraoperative blood loss (ml) 58.2 ± 30.8 43.9 ± 31.3 2.857 0.005 Number of lymph node dissections 14.5 ± 5.1 14.8 ± 5.5 0.336 0.738 Lymph vessel invasion 0.776 0.438 Yes 21 18 No 47 54 Nerve invasion 1.582 0.554 Yes 15 13 No 53 59 T 0.416 0.677 T1/T2 24 28 T3/T4 44 44 N 0.237 0.813 N0 45 49 N+ 23 23 Postoperative recovery time (days) Mean (SD) 11.9 ± 7.1 9.1 ± 5.1 2.758 0.007 Median (IQR) 8.0 (7.0, 9.0) 9.0 (8.0, 12.8) 0.001 Duration of stay in the hospital (days) Mean (SD) 18.7 ± 9.2 14.3 ± 5.1 3.541 0.001 Median (IQR) 15.0 (13.0, 22.8) 13.0 (12.0, 15.8) 0.001 Cost (thousand RMB) Mean (SD) 40.1 ± 10.1 35.1 ± 5.9 2.105 0.001 Median (IQR) 38.7 (34.7, 42.7) 35.1 (31.4, 38.6) 0.001 Postoperative complications 0.150 Yes 9 4 No 59 68 Intestinal obstruction 0.432 Yes 4 2 No 64 70 Anastomotic leakage 0.265 Yes 5 2 No 63 70 Supplement Table 1 . Four types of IMA branching patterns and their 3D reconstruction link address. Discussion In clinical practice, preservation of the anus and reconstruction of the digestive tract have consistently been pivotal aspects of RC surgery. With the advancement and implementation of neoadjuvant therapy, total neoadjuvant therapy, anal preservation techniques (ISR, TaTME), and minimally invasive techniques, the rate of organ preservation is improving gradually[ 5 , 24 ]. However, AL as a common and serious postoperative complication, has become a major concern for surgeons. Further studies have found that preserving the LCA can increase blood supply to the anastomosis and reduce the risk of AL. However, the LCA exhibits a high rate of anatomical variation, posing significant challenges in surgical procedures. The preoperative identification of the location and variations of the LCA are therefore critical. There are four common types of anatomical variations of the IMA. In Type I, the LCA branches off from the IMA early and separately, followed by the SA and SRA branching together from the IMA. In type II, the LCA and SA initially branch together from the IMA, then after traveling a certain distance, the LCA branches off separately from their common trunk. And the SRA branches off independently from the IMA. In type III, In Type III, the LCA, SA, and SRA branch together from the IMA. In type IV, LCA is absence, with only SA and SRA[ 10 , 13 ]. Preoperative identification of the IMA types and LCA anatomical variations is crucial for the successful completion of laparoscopic RC resection with LCA preservation. In this article, we propose utilizing 3D printing technology to preoperatively identify IMA types and LCA anatomical variations and to conduct preoperative rehearsals. During surgery, the 3D model serves as a navigational aid, thereby reducing the difficulty of LCA-preserving procedures. According to the result, operating time (196.7 ± 44.5 min in observe group vs. 233.3 ± 44.3 min in control group, p < 0.001) and intraoperative blood loss (43.9 ± 31.3 mL in observe group vs. 58.2 ± 30.8 ml in control group, p < 0.005) were significantly lower in 3D printing group than in control group. Therefore, the present 3D printed model can reduce surgical complexity and enhance operative safety. Some researchers have also suggested that the utilization of 3D printing models could enhance the comprehension and assessment of blood vessels, thereby effectively mitigating intraoperative hemorrhage. This notion is consistent with the findings of our study[ 23 , 25 ]. Although contrast-enhanced CT scan can detect the LCA, it is difficult for surgeons to mentally visualize in the form of accurate 3D images. Furthermore, it is easy to forget the specific location of the LCA based on CT scans because surgeons tend to direct their focus to the surgical procedure being carried out. In this study, we 3D-printed accurate IMA models before surgery and placed the 3D models next to the laparoscopic television monitor during the operation. This enabled the LCA to be readily identified by comparing the anatomical features of the IMA with the 3D model during the surgical procedure. The IMA model was precisely 3D printed at a 1:1 scale. During surgery, we measured and compared the size of the 3D model with the actual vascular anatomy of the patients using aseptic silk, and found the differences to be negligible. Consequently, the IMA model holds greater potential for clinical application. In this study, we found that the duration of hospitalization (14.3 ± 5.1 vs. 18.7 ± 9.2 days p < 0.001), postoperative recovery time (9.1 ± 5.1 vs. 11.9 ± 7.1 days p < 0.007), and cost (35.1 ± 5.9 vs. 40.1 ± 10.1, p < 0.05) for the observe group were significantly lower than for the control cohort. Identification of the location of LCA and IMA branches before operation allows the surgeon to formulate a personalized and specific surgical plan, avoid excessive traction of the LCA during surgery, and reduce the thermal injury to the LCA from the ultrasonic and electric scalpels, in accordance with the concept of enhanced recovery after surgery (ERAS)[ 26 ]. However, we acknowledge that there may be some biases in our results. With ongoing healthcare reforms, the centralized procurement of drugs and medical devices has reduced hospitalization costs, and the implementation of pre-admission protocols has shortened hospital stays. Most of the cases in our 3D printing group were enrolled in recent years, which could introduce some inaccuracies in our analysis. Therefore, we plan to conduct a randomized controlled clinical trial in the future to further investigate this issue. However, we acknowledge that there may be some biases in our results. Recent healthcare reforms, including the centralized procurement of drugs and medical devices, have reduced hospitalization costs. And the implementation of the pre-admission system has shortened hospital stays. As most of the cases in our 3D printing group were enrolled in recent years, this could introduce some inaccuracies in our analysis. Furthermore, our analysis did not reveal a significant reduction in the incidence of postoperative complications (AL and intestinal obstruction) in observe group, which can be attributed to the limited sample size across the included studies. In this study, we only collected AL and postoperative intestinal obstruction as indicators of postoperative complications, neglecting other complications such as pneumonia, deep vein thrombosis, gastroparesis, and wound infection et al. Therefore, we plan to conduct a prospective randomized controlled clinical trial in the future to further investigate those questions. During the course of our study, we found that the 3D IMA model was more useful for less experienced surgeons than experienced surgeons. We speculate that this is because the model might shorten the learning curve for surgeons, although this requires further study. However, this study still has some limitations: (1) this study is a retrospective analysis conducted at a single center with a limited sample size; (2) the printing material is inelastic and cannot be pulled or valgus as in the operation; (3) the models only focus on the branches of IMA and LCA, and other concerns during the operation are not addressed. Conclusion The utilization of a 3D printed IMA model in laparoscopic radical resection of RC can greatly aid the surgeon in comprehending the intricate anatomy of the LCA prior to surgery, thereby reducing intraoperative bleeding, shortening operating time, and facilitating rapid postoperative recovery of patients. Abbreviations RC rectal cancer LCA left colic artery IMA inferior mesenteric artery IMV inferior mesenteric vein SA sigmoid artery SRA superior rectal artery AA abdominal aorta 3D Three-dimensional AL anastomotic leakage TNT total neoadjuvant therapy TaTME transanal total mesorectal excision ISR intersphincteric resection Declarations Conflicts of Interest The authors declare that they have no conflict of interest Funding This study was funded by the Scientific Research Department of Fuyang People's Hospital, the General Surgery Department of Fuyang People's Hospital, the Health Commission of Fuyang City, Anhui Provence, China (FY2021-18 to Zongxian Zhao, NO. FY2023-45 to Zongju Hu) and Bengbu Medical College of Bengbu City, Anhui, China (NO.2023byzd215 to Rundong Yao), and the Health Commission Anhui Provence, China (NO.AHWJ2023BAa20164 to Zongxian Zhao). Funding This study was funded by the Scientific Research Department of Fuyang People's Hospital, the General Surgery Department of Fuyang People's Hospital, the Health Commission of Fuyang City, Anhui Provence, China (FY2021-18 to Zongxian Zhao, NO. FY2023-45 to Zongju Hu) and Bengbu Medical College of Bengbu City, Anhui, China (NO.2023byzd215 to Rundong Yao), and the Health Commission Anhui Provence, China (NO.AHWJ2023BAa20164 to Zongxian Zhao). Author Contribution Z.Z. and Z.H. wrote the main manuscript text and R.Y. prepared the Tables. X.S. and S.Z. and Z.Z. collected the clinical data. Z.H. and S.J. and Y.Y. completed the operating procedure . Acknowledgement Grateful thanks to the Fuyang People's Hospital 3D Printing Center for their selfless assistance. Data Availability The data that support the findings of this study are available from the corresponding author upon reasonable request. References Siegel RL, Miller KD, Fuchs HE, Jemal A. Cancer statistics, 2022. 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Role of CT angiography with three-dimensional reconstruction of mesenteric vessels in laparoscopic colorectal resections: a randomized controlled trial. Surg Endosc. 2013;27:2058–67. Aarts MA, Okrainec A, Glicksman A, Pearsall E, Victor JC, McLeod RS. Adoption of enhanced recovery after surgery (ERAS) strategies for colorectal surgery at academic teaching hospitals and impact on total length of hospital stay. Surg Endosc. 2012;26:442–50. Additional Declarations No competing interests reported. Supplementary Files SupplementaryTable1.docx Cite Share Download PDF Status: Under Review Version 1 posted Editor assigned by journal 18 Jul, 2024 Submission checks completed at journal 18 Jul, 2024 First submitted to journal 18 Jul, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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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-4763568","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":329202982,"identity":"74899c7a-c8f0-42f1-a2b8-e6c1365085d2","order_by":0,"name":"Zongxian Zhao","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAzUlEQVRIiWNgGAWjYBACxvbGxgcJBv/k2NgbiNTC3HO42eBDwQFjfp4DRGphn+HeJjnjw4HEmTMSiNTCO4OxTZrH4I6xwc3HG28w1NhEE9QiObux2ZrH4Jmcwe20YguGY2m5DYS0GM452Hibx4DZ2OB2jpkEY8NhwlrsbyQ2AB3GnLjh5hkitTDOSGySnGFwGOh9HmK19BwEBrJBGjCQgX5JIMYvjO3tDx8k/LEBRuXhjTc+1NgQ1oIMDCQSSFEO0UKqjlEwCkbBKBgZAABQvUXxBaCj4wAAAABJRU5ErkJggg==","orcid":"","institution":"Fuyang People's Hospital","correspondingAuthor":true,"prefix":"","firstName":"Zongxian","middleName":"","lastName":"Zhao","suffix":""},{"id":329202985,"identity":"c6cc5224-3ba8-462a-a8e3-34216693a065","order_by":1,"name":"Zongju Hu","email":"","orcid":"","institution":"Fuyang People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Zongju","middleName":"","lastName":"Hu","suffix":""},{"id":329202986,"identity":"2c43c7bd-601c-4d06-a022-c34547607732","order_by":2,"name":"Rundong Yao","email":"","orcid":"","institution":"Fuyang People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Rundong","middleName":"","lastName":"Yao","suffix":""},{"id":329202988,"identity":"7ed990c6-6abe-4eb1-a8fa-f9cd065f2df1","order_by":3,"name":"Xinyu Su","email":"","orcid":"","institution":"Fuyang People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Xinyu","middleName":"","lastName":"Su","suffix":""},{"id":329202989,"identity":"7892e0f7-e14f-499b-8b83-d8fb4e7d953c","order_by":4,"name":"Shu Zhu","email":"","orcid":"","institution":"Fuyang People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Shu","middleName":"","lastName":"Zhu","suffix":""},{"id":329202990,"identity":"7a1b1444-d87c-40dd-bb9c-3a8cfa6e6225","order_by":5,"name":"Sun Jie","email":"","orcid":"","institution":"Fuyang People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Sun","middleName":"","lastName":"Jie","suffix":""},{"id":329202992,"identity":"cbd39a1d-5e1b-4ade-8154-32226d61473a","order_by":6,"name":"Yuan Yao","email":"","orcid":"","institution":"Fuyang People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yuan","middleName":"","lastName":"Yao","suffix":""}],"badges":[],"createdAt":"2024-07-18 15:10:41","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4763568/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4763568/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":62660320,"identity":"c385d624-3ad5-4ed5-a2a7-811ccac011bf","added_by":"auto","created_at":"2024-08-17 02:33:26","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":444749,"visible":true,"origin":"","legend":"\u003cp\u003eThe flowchart of this retrospective study. RC: rectal cancer.\u003c/p\u003e","description":"","filename":"F1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4763568/v1/a848b4361da0ebe84033d032.jpg"},{"id":62660317,"identity":"022bfcec-47b7-49bb-bbd1-8172a0e39b7b","added_by":"auto","created_at":"2024-08-17 02:33:26","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":404218,"visible":true,"origin":"","legend":"\u003cp\u003eFour types of IMA classification display. A, Diagram illustration. B, Based on enhanced CT display. C. Display using 3D printing models. AA, abdominal aorta, IMA: LCA: left colic artery; IMA: inferior mesenteric artery; SA: sigmoid artery; SRA: superior rectal artery.\u003c/p\u003e","description":"","filename":"F2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4763568/v1/f281c519fdce61238e853f35.jpg"},{"id":62661512,"identity":"000c3ad3-c835-437b-a62c-0137a24d4bef","added_by":"auto","created_at":"2024-08-17 02:41:26","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":237016,"visible":true,"origin":"","legend":"\u003cp\u003eClinical application of 3D IMA model in laparoscopic radical resection with preservation of LCA: A, Patient A. B, Patient B. AA, abdominal aorta, IMA: LCA: left colic artery; IMA: inferior mesenteric artery; IMV: inferior mesenteric vein; SA: sigmoid artery; SRA: superior rectal artery.\u003c/p\u003e","description":"","filename":"F3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4763568/v1/837291c178dd0f724ec1dc01.jpg"},{"id":62661768,"identity":"b22972a4-0dfd-4601-bc58-4a3f4c82c57a","added_by":"auto","created_at":"2024-08-17 02:49:26","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1679952,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4763568/v1/11805a4b-52b5-477f-b967-8793ed0ee76c.pdf"},{"id":62660318,"identity":"88b597d4-3929-464b-b712-90db466ead45","added_by":"auto","created_at":"2024-08-17 02:33:26","extension":"docx","order_by":7,"title":"","display":"","copyAsset":false,"role":"supplement","size":15653,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryTable1.docx","url":"https://assets-eu.researchsquare.com/files/rs-4763568/v1/ae0bc7ea7f41a43e8529edb3.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Retrospective Cohort Study on 3D Printing Technology for Preoperative Rehearsal and Intraoperative Navigation in Laparoscopic Rectal Cancer Surgery with Left Colic Artery Preservation","fulltext":[{"header":"Introduction","content":"\u003cp\u003eRectal cancer (RC) is a common malignant tumor of the digestive tract, accounting for one-third of all morbidity and mortality due to bowel cancer, with significant implications for patient health and survival[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Alongside the increase in life expectancy, morbidity due to RC has risen gradually. Therefore, therapeutic strategies against RC have attracted growing attention. To date, treatment for RC has involved a surgery-based multidisciplinary approach, with contributions from the fields of gastroenterology, medical oncology, radiation oncology, and radiology[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. In clinical practice, the standardization of total mesorectal excision, adoption of neoadjuvant chemoradiotherapy and total neoadjuvant therapy (TNT) implementation of rectal magnetic resonance imaging, advancements in mechanical stapling technology, and improvements in operating techniques (transanal total mesorectal excision, TaTME; intersphincteric resection, ISR) have significantly augmented the success rates of anus-preserving surgeries for low-lying RC[\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. With the enhancement of surgical techniques and the completion of numerous clinical trials, preservation of the left colic artery (LCA) has been observed to significantly mitigate the occurrence of anastomotic leakage (AL) following surgery[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. During the surgical procedure, the surgeon needs to perform a lymphadenectomy at the root of the inferior mesenteric artery (NO.253). Subsequently, the surgeon needs to open the vascular sheath along the inferior mesenteric artery (IMA), preserve the LCA, and then cuts the sigmoid artery (SA) and the superior rectal artery (SRA)[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. However, this approach is technically demanding and time-consuming, especially for the less experienced surgeon. The increased surgical difficulty is attributed to the uncertain anatomical relationship between the branches of the IMA, including the LCA, SA, and SRA[\u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Studies have identified four vascular types, namely. Type I, LCA arising independently form IMA; type II, LCA and SA branching from a common trunk of the IMA; type III, LCA, SA, and SRA branching at the same location; Type IV, LCA is absence, with only SA and SRA (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003eA) [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. In addition, the distance at which the LCA emanates from the IMA differs among RA patients[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. The preoperative identification of the location of the LCA and the precise types of branches of the IMA are crucial for ensuring successful surgical intervention.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThree-dimensional (3D) printing technology can be utilized for medical, including preoperative simulation and intraoperative navigation, assisting surgeons in selecting the appropriate surgical plan[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. In addition, 3D printing can build personalized implants, such as hip joints and knee joints, as well as customized dental crowns, bridges, orthodontic appliances, and implants[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Additionally, 3D printing can build precise anatomical models for medical education and training, customize 3D-printed surgical guides to help doctors with accurate positioning and cutting, and create personalized drug doses and combinations based on patient needs, enhancing treatment effectiveness and patient compliance[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. To date, 3D printing technology has been extensively applied in orthopedics, stomatology, neurosurgery, hepatobiliary surgery, and other fields[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. However, its application in RC surgery is still at an early stage. In previous studies, researchers printed entire models of the pelvic cavity to guide surgery; however, this was costly and time-consuming, and therefore not convenient for clinical application[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Besides, although a monolithic 3D-printed pelvic cavity is helpful to the surgeon in understanding pelvic structure, it provides relatively little information on the local vascular anatomy. In this study, we constructed a 3D-printed IMA model to clarify the morphology of IMA branches and locate the origin of the LCA before surgery. Furthermore, we assessed the role of the 3D-printed model in preoperative rehearsal and intraoperative navigation in laparoscopic RC surgery.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePatients and study design\u003c/h2\u003e \u003cp\u003eIn this cohort study, participants with RC scheduled for laparoscopic radical resection were divided into a 3D printing group (observation group) and a control group based on their willingness to receive 3D printing-assisted treatment. The study was conducted at Fuyang City People's Hospital from January 2022 to May 2024. Inclusion criteria were as follows: (1) patients\u0026thinsp;\u0026gt;\u0026thinsp;18 years old; (2) RC confirmed by histopathology; (3) patients provided informed and written consent for surgery; (4) patients received laparoscopic radical resection of RC with reconstruction of the digestive tract (Dixon); (5) R0 resection was achieved; (6) patients exhibited optimal cardiac and pulmonary function; and (7) all patients underwent an abdominal double-phase enhanced scan before surgery. Exclusion criteria were as follows: (1) occurrence of distant metastasis; (2) presence of other concurrent malignancies; (3) surgical procedures without reconstruction of the digestive tract (Miles or Hartmann); (4) co-morbidity with autoimmune disease; (5) co-morbidity with severe heart and lung disease; (6) co-morbidity with schizophrenia or other mental health disorders, lack of independent behavior ability, or inability to cooperate with treatment. If the patient's IMA type is type IV (absence of the LCA), the IMA is directly ligated at its root during surgery. The study design and flow chart is depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003e. This study was approved by the Ethics Committee of Fuyang City People's Hospital.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eConstruction of 3D IMA model\u003c/h2\u003e \u003cp\u003eThe enhanced CT images were imported into 3D modeling software (3D slicer 5.2.2, mimics 19.0) in DICOM format for 3D reconstruction. The abdominal aorta (AA), left iliac artery, right iliac artery, IMA, LCA, SA, SRA, and mesenterica inferior vein (IMV) were examined and chosen for 3D reconstruction. Using the \u0026lsquo;multiple slice edit\u0026rsquo; function, the required arteries and veins were marked in the transverse, sagittal, and coronal planes. The surface of the 3D virtual model was subsequently refined through a smoothing process. After ensuring the absence of any structural deformation or deviation, the resin white material was 3D-printed using a high-precision SLA photocuring process (CHUNLEI SLA 600 or Prismlab RP-400D). The entire 3D model reconstruction took 25 minutes approximately, and the printing time was about 150 minutes. The 3D models were then cured, polished, and colored. Red was used to color the arteries and blue was used to color the veins. The completed model was submitted to the surgeon prior to surgery for preoperative assessment and surgical planning. Before entering the operating room, the model was disinfected with 75% alcohol. The model was positioned adjacent to the laparoscopic television monitor for intraoperative navigation of the location of origin and course of the LCA and types of IMA. A comparison between photos obtained during operation and the 3D printing IMA model is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003e. We confirmed the successful preservation of the LCA based on intraoperative findings and postoperative CT evaluations.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eObservation index\u003c/h2\u003e \u003cp\u003eThe general characteristics of the two groups were comprehensively evaluated based on five factors, namely, gender, age, clinical stage, diverting stoma, and IMA types. The factors selected for further analysis included the operating time, intraoperative blood loss, number of lymph node dissections, lymph vessel invasion and nerve invasion, depth of tumor invasion (T stage), presence of lymph node metastasis (N stage), duration of stay in the hospital, postoperative recovery time, cost, and occurrence of postoperative complications (AL and intestinal obstruction). Postoperative recovery time is defined as the period from surgery to discharge from the hospital. Duration of hospital stay is defined as the time from be hospitalized to discharge.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eUsing GraphPad Prism 8 software for statistical analysis, the measurement data were analyzed by Student\u0026rsquo;s t test or Mann\u0026ndash;Whitney U test. The enumeration data were analyzed by chi-square test or Fisher's exact test. Values of \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 were considered to indicate statistical significance.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eIMA types and 3D printing models\u003c/h2\u003e \u003cp\u003eWe performed 3D reconstruction and printed 3D models based on the patients' preoperative enhanced CT images, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e1\u003c/span\u003e and Supplementary Table\u0026nbsp;1.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eClinical characteristics\u003c/h2\u003e \u003cp\u003eBetween January 2022 and May 2024, 172 RC patients with laparoscopic radical resection were included (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Among them, 3 patients with liver metastasis who underwent laparoscopic radical resection of RC and partial hepatectomy were excluded. And then, 29 patients who underwent abdominoperineal resection (Miles) or laparoscopic radical resection of RC without digestive tract reconstruction (Hartmann) were excluded. Finally, a total of 140 eligible patients were selected and randomly divided into two groups. The control group (n\u0026thinsp;=\u0026thinsp;68) did not receive 3D printing model for preoperative rehearsal and intraoperative navigation, while the observe group (n\u0026thinsp;=\u0026thinsp;72) used 3D printing model. The two groups had similar clinical characteristics, including sex, age, clinical stage, diverting stoma, and IMA types (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05). Their clinical characteristics are detailed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eBaseline Characteristics of Included RC Patients\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eThe control group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eThe observe group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003et/χ\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;68)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e64.9\u0026thinsp;\u0026plusmn;\u0026thinsp;12.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e66.2\u0026thinsp;\u0026plusmn;\u0026thinsp;10.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.636\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.513\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e67.0 (59.0, 73.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e69.0 (60.0, 72.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.644\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.759\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.448\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eClinical stage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.752\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.687\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIII\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDiverting stoma\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.703\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.192\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIMA types\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.947\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.584\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eI\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eII\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIII\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe primary surgeon*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.660\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.719\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e*In the primary surgery, A and B were experienced surgeons, while C was a less experienced surgeon.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003ePerioperative characteristics\u003c/h2\u003e \u003cp\u003ePatient perioperative characteristics were shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Operating time (196.7\u0026thinsp;\u0026plusmn;\u0026thinsp;44.5 min in observe group vs. 233.3\u0026thinsp;\u0026plusmn;\u0026thinsp;44.3 min in control group, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and intraoperative blood loss (43.9\u0026thinsp;\u0026plusmn;\u0026thinsp;31.3 mL in observe group vs. 58.2\u0026thinsp;\u0026plusmn;\u0026thinsp;30.8 ml in control group, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.005) were significantly lower in observe group than in control group. There were no significant differences between the two cohorts in number of lymph node dissections, lymph vessel invasion and nerve invasion, depth of tumor invasion, presence of lymph node metastasis, the occurrence of AL and intestinal obstruction. Duration of hospitalization (14.3\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1 days observe group vs. 18.7\u0026thinsp;\u0026plusmn;\u0026thinsp;9.2 min in control group, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), postoperative recovery time (9.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1 days observe group vs. 11.9\u0026thinsp;\u0026plusmn;\u0026thinsp;7.1 min in control group, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.007), and cost (35.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.9 thousand RMB in observe group vs. 40.1\u0026thinsp;\u0026plusmn;\u0026thinsp;10.1 thousand RMB in control group, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) were significantly lower for observe group than for control group.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePerioperative Characteristics of RC Patients\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCharacteristic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eThe control group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eThe observe group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003et/χ\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eP value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;68)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;72)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOperating time (min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e233.3\u0026thinsp;\u0026plusmn;\u0026thinsp;44.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e196.7\u0026thinsp;\u0026plusmn;\u0026thinsp;44.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.810\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e230 (195.0, 255.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e190 (170, 228.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntraoperative\u003c/p\u003e \u003cp\u003eblood loss (ml)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e58.2\u0026thinsp;\u0026plusmn;\u0026thinsp;30.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e43.9\u0026thinsp;\u0026plusmn;\u0026thinsp;31.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.857\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNumber of lymph node dissections\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14.5\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14.8\u0026thinsp;\u0026plusmn;\u0026thinsp;5.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.336\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.738\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLymph vessel invasion\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.776\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.438\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNerve invasion\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.582\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.554\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.416\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.677\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1/T2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT3/T4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.237\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.813\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eN+\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003ePostoperative recovery time (days)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11.9\u0026thinsp;\u0026plusmn;\u0026thinsp;7.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.758\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.0 (7.0, 9.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.0 (8.0, 12.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eDuration of stay in the hospital (days)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18.7\u0026thinsp;\u0026plusmn;\u0026thinsp;9.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14.3\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.541\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e15.0 (13.0, 22.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.0 (12.0, 15.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003eCost (thousand RMB)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean (SD)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40.1\u0026thinsp;\u0026plusmn;\u0026thinsp;10.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.105\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMedian (IQR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38.7 (34.7, 42.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35.1 (31.4, 38.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003ePostoperative complications\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.150\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntestinal obstruction\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.432\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnastomotic leakage\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.265\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eSupplement Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Four types of IMA branching patterns and their 3D reconstruction link address.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn clinical practice, preservation of the anus and reconstruction of the digestive tract have consistently been pivotal aspects of RC surgery. With the advancement and implementation of neoadjuvant therapy, total neoadjuvant therapy, anal preservation techniques (ISR, TaTME), and minimally invasive techniques, the rate of organ preservation is improving gradually[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. However, AL as a common and serious postoperative complication, has become a major concern for surgeons. Further studies have found that preserving the LCA can increase blood supply to the anastomosis and reduce the risk of AL. However, the LCA exhibits a high rate of anatomical variation, posing significant challenges in surgical procedures. The preoperative identification of the location and variations of the LCA are therefore critical. There are four common types of anatomical variations of the IMA. In Type I, the LCA branches off from the IMA early and separately, followed by the SA and SRA branching together from the IMA. In type II, the LCA and SA initially branch together from the IMA, then after traveling a certain distance, the LCA branches off separately from their common trunk. And the SRA branches off independently from the IMA. In type III, In Type III, the LCA, SA, and SRA branch together from the IMA. In type IV, LCA is absence, with only SA and SRA[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Preoperative identification of the IMA types and LCA anatomical variations is crucial for the successful completion of laparoscopic RC resection with LCA preservation. In this article, we propose utilizing 3D printing technology to preoperatively identify IMA types and LCA anatomical variations and to conduct preoperative rehearsals. During surgery, the 3D model serves as a navigational aid, thereby reducing the difficulty of LCA-preserving procedures. According to the result, operating time (196.7\u0026thinsp;\u0026plusmn;\u0026thinsp;44.5 min in observe group vs. 233.3\u0026thinsp;\u0026plusmn;\u0026thinsp;44.3 min in control group, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and intraoperative blood loss (43.9\u0026thinsp;\u0026plusmn;\u0026thinsp;31.3 mL in observe group vs. 58.2\u0026thinsp;\u0026plusmn;\u0026thinsp;30.8 ml in control group, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.005) were significantly lower in 3D printing group than in control group. Therefore, the present 3D printed model can reduce surgical complexity and enhance operative safety. Some researchers have also suggested that the utilization of 3D printing models could enhance the comprehension and assessment of blood vessels, thereby effectively mitigating intraoperative hemorrhage. This notion is consistent with the findings of our study[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAlthough contrast-enhanced CT scan can detect the LCA, it is difficult for surgeons to mentally visualize in the form of accurate 3D images. Furthermore, it is easy to forget the specific location of the LCA based on CT scans because surgeons tend to direct their focus to the surgical procedure being carried out. In this study, we 3D-printed accurate IMA models before surgery and placed the 3D models next to the laparoscopic television monitor during the operation. This enabled the LCA to be readily identified by comparing the anatomical features of the IMA with the 3D model during the surgical procedure. The IMA model was precisely 3D printed at a 1:1 scale. During surgery, we measured and compared the size of the 3D model with the actual vascular anatomy of the patients using aseptic silk, and found the differences to be negligible. Consequently, the IMA model holds greater potential for clinical application.\u003c/p\u003e \u003cp\u003eIn this study, we found that the duration of hospitalization (14.3\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1 vs. 18.7\u0026thinsp;\u0026plusmn;\u0026thinsp;9.2 days \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), postoperative recovery time (9.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1 vs. 11.9\u0026thinsp;\u0026plusmn;\u0026thinsp;7.1 days \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.007), and cost (35.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.9 vs. 40.1\u0026thinsp;\u0026plusmn;\u0026thinsp;10.1, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) for the observe group were significantly lower than for the control cohort. Identification of the location of LCA and IMA branches before operation allows the surgeon to formulate a personalized and specific surgical plan, avoid excessive traction of the LCA during surgery, and reduce the thermal injury to the LCA from the ultrasonic and electric scalpels, in accordance with the concept of enhanced recovery after surgery (ERAS)[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. However, we acknowledge that there may be some biases in our results. With ongoing healthcare reforms, the centralized procurement of drugs and medical devices has reduced hospitalization costs, and the implementation of pre-admission protocols has shortened hospital stays. Most of the cases in our 3D printing group were enrolled in recent years, which could introduce some inaccuracies in our analysis. Therefore, we plan to conduct a randomized controlled clinical trial in the future to further investigate this issue. However, we acknowledge that there may be some biases in our results. Recent healthcare reforms, including the centralized procurement of drugs and medical devices, have reduced hospitalization costs. And the implementation of the pre-admission system has shortened hospital stays. As most of the cases in our 3D printing group were enrolled in recent years, this could introduce some inaccuracies in our analysis. Furthermore, our analysis did not reveal a significant reduction in the incidence of postoperative complications (AL and intestinal obstruction) in observe group, which can be attributed to the limited sample size across the included studies. In this study, we only collected AL and postoperative intestinal obstruction as indicators of postoperative complications, neglecting other complications such as pneumonia, deep vein thrombosis, gastroparesis, and wound infection et al. Therefore, we plan to conduct a prospective randomized controlled clinical trial in the future to further investigate those questions.\u003c/p\u003e \u003cp\u003eDuring the course of our study, we found that the 3D IMA model was more useful for less experienced surgeons than experienced surgeons. We speculate that this is because the model might shorten the learning curve for surgeons, although this requires further study. However, this study still has some limitations: (1) this study is a retrospective analysis conducted at a single center with a limited sample size; (2) the printing material is inelastic and cannot be pulled or valgus as in the operation; (3) the models only focus on the branches of IMA and LCA, and other concerns during the operation are not addressed.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe utilization of a 3D printed IMA model in laparoscopic radical resection of RC can greatly aid the surgeon in comprehending the intricate anatomy of the LCA prior to surgery, thereby reducing intraoperative bleeding, shortening operating time, and facilitating rapid postoperative recovery of patients.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eRC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003erectal cancer\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLCA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eleft colic artery\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIMA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003einferior mesenteric artery\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIMV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003einferior mesenteric vein\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003esigmoid artery\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSRA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003esuperior rectal artery\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAA\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eabdominal aorta\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e3D\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eThree-dimensional\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAL\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eanastomotic leakage\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTNT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003etotal neoadjuvant therapy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTaTME\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003etransanal total mesorectal excision\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eISR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eintersphincteric resection\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eConflicts of Interest\u003c/h2\u003e \u003cp\u003eThe authors declare that they have no conflict of interest\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis study was funded by the Scientific Research Department of Fuyang People's Hospital, the General Surgery Department of Fuyang People's Hospital, the Health Commission of Fuyang City, Anhui Provence, China (FY2021-18 to Zongxian Zhao, NO. FY2023-45 to Zongju Hu) and Bengbu Medical College of Bengbu City, Anhui, China (NO.2023byzd215 to Rundong Yao), and the Health Commission Anhui Provence, China (NO.AHWJ2023BAa20164 to Zongxian Zhao).\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis study was funded by the Scientific Research Department of Fuyang People's Hospital, the General Surgery Department of Fuyang People's Hospital, the Health Commission of Fuyang City, Anhui Provence, China (FY2021-18 to Zongxian Zhao, NO. FY2023-45 to Zongju Hu) and Bengbu Medical College of Bengbu City, Anhui, China (NO.2023byzd215 to Rundong Yao), and the Health Commission Anhui Provence, China (NO.AHWJ2023BAa20164 to Zongxian Zhao).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eZ.Z. and Z.H. wrote the main manuscript text and R.Y. prepared the Tables. X.S. and S.Z. and Z.Z. collected the clinical data. Z.H. and S.J. and Y.Y. completed the operating procedure .\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eGrateful thanks to the Fuyang People's Hospital 3D Printing Center for their selfless assistance.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e \u003cp\u003eThe data that support the findings of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSiegel RL, Miller KD, Fuchs HE, Jemal A. Cancer statistics, 2022. CA Cancer J Clin. 2022;72:7\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSiegel RL, Miller KD, Wagle NS, Jemal A. Cancer statistics, 2023. CA Cancer J Clin. 2023;73:17\u0026ndash;48.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBenson AB, Venook AP, Al-Hawary MM, Azad N, Chen YJ, Ciombor KK, et al. 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JAMA Oncol. 2022;8:e215445.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCollard M, Lefevre JH. Ultimate Functional Preservation With Intersphincteric Resection for Rectal Cancer. Front Oncol. 2020;10:297.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFan YC, Ning FL, Zhang CD, Dai DQ. Preservation versus non-preservation of left colic artery in sigmoid and rectal cancer surgery: A meta-analysis. Int J Surg. 2018;52:269\u0026ndash;77.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi Z, Zhou Y, Xu L, Xie L. Safety and efficacy of left colic artery preservation in laparoscopic anterior resection for lower rectal cancer. Future Oncol. 2023;19:1485\u0026ndash;94.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang KX, Cheng ZQ, Liu Z, Wang XY, Bi DS. Vascular anatomy of inferior mesenteric artery in laparoscopic radical resection with the preservation of left colic artery for rectal cancer. World J Gastroenterol. 2018;24:3671\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLuo Y, Li R, Wu D, Zeng J, Wang J, Chen X, et al. Long-term oncological outcomes of low anterior resection for rectal cancer with and without preservation of the left colic artery: a retrospective cohort study. BMC Cancer. 2021;21:171.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen J, Wang M, Chen Y, Chen S, Xiao J, Fan X, et al. A clinical study of inferior mesenteric artery typing in laparoscopic radical resections with left colonic artery preservation of rectal cancer. World J Surg Oncol. 2022;20:292.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKobayashi M, Morishita S, Okabayashi T, Miyatake K, Okamoto K, Namikawa T, et al. Preoperative assessment of vascular anatomy of inferior mesenteric artery by volume-rendered 3D-CT for laparoscopic lymph node dissection with left colic artery preservation in lower sigmoid and rectal cancer. 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Acta Biomater. 2021;122:26\u0026ndash;49.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZoabi A, Redenski I, Oren D, Kasem A, Zigron A, Daoud S et al. 3D Printing and Virtual Surgical Planning in Oral and Maxillofacial Surgery. J Clin Med. 2022; 11.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAnderson LA, Christie M, Blackburn BE, Mahan C, Earl C, Pelt CE, et al. 3D-printed titanium metaphyseal cones in revision total knee arthroplasty with cemented and cementless stems. Bone Joint J. 2021;103\u0026ndash;B:150\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQi W, Qian J, Zhou W, Li J, Mao B, Wen A, et al. 3D-printed titanium surgical guides for extraction of horizontally impacted lower third molars. Clin Oral Investig. 2023;27:1499\u0026ndash;507.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeich S, Bocklet M, Evans Z, Gutmacher Z, Renne W. 3D printed implant surgical guides with internally routed irrigation for temperature reduction during osteotomy preparation: A pilot study. J Esthet Restor Dent. 2022;34:796\u0026ndash;803.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWitowski JS, Coles-Black J, Zuzak TZ, Pedziwiatr M, Chuen J, Major P, et al. 3D Printing in Liver Surgery: A Systematic Review. Telemed J E Health. 2017;23:943\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMeng M, Wang J, Huang H, Liu X, Zhang J, Li Z. 3D printing metal implants in orthopedic surgery: Methods, applications and future prospects. J Orthop Translat. 2023;42:94\u0026ndash;112.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLu F, Qiu L, Yu P, Xu DL, Miao YC, Wang G. Application of a three-dimensional printed pelvic model in laparoscopic radical resection of rectal cancer. Front Oncol. 2023;13:1195404.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGhadimi M, Rodel C, Hofheinz R, Flebbe H, Grade M. Multimodal Treatment of Rectal Cancer. Dtsch Arztebl Int. 2022;119:570\u0026ndash;80.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMari FS, Nigri G, Pancaldi A, De Cecco CN, Gasparrini M, Dall'Oglio A, et al. Role of CT angiography with three-dimensional reconstruction of mesenteric vessels in laparoscopic colorectal resections: a randomized controlled trial. Surg Endosc. 2013;27:2058\u0026ndash;67.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAarts MA, Okrainec A, Glicksman A, Pearsall E, Victor JC, McLeod RS. Adoption of enhanced recovery after surgery (ERAS) strategies for colorectal surgery at academic teaching hospitals and impact on total length of hospital stay. Surg Endosc. 2012;26:442\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"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":"3d-printing-in-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"tdpm","sideBox":"Learn more about [3D Printing in Medicine](https://threedmedprint.biomedcentral.com/)","snPcode":"41205","submissionUrl":"https://submission.nature.com/new-submission/41205/3","title":"3D Printing in Medicine","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Rectal cancer, Three-dimensional printing, Inferior mesenteric artery, Left colic artery, Preoperative Rehearsal, Intraoperative Navigation","lastPublishedDoi":"10.21203/rs.3.rs-4763568/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4763568/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003ePrevious studies have shown that preserving the left colic artery (LCA) during laparoscopic radical resection for rectal cancer (RC) can maintain the blood supply to the remaining colon without compromising the oncological outcomes. However, anatomical variations in the branches of the inferior mesenteric artery (IMA) and LCA present significant surgical challenges. Here, we construct a 3D printing IMA model for preoperative rehearsal and intraoperative navigation to analyze its positive impact on surgical safety.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eWe retrospectively collected clinical dates from patients with RC who received laparoscopic radical resection from January 2022 to May 2024 at Fuyang City People's Hospital. Patients were divided into 3D printing group and control group and their perioperative characteristics were statistically analyzed.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003e172 patients who underwent laparoscopic radical resection for RC were included in the study. Among them, a total of 32 patients were excluded due to exclusion criteria. Finally, observe group (3D printing group) was comprised of 72 patients, while control group consisted of 68 patients. Operating time (196.7\u0026thinsp;\u0026plusmn;\u0026thinsp;44.5 vs. 233.3\u0026thinsp;\u0026plusmn;\u0026thinsp;44.3 min, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), intraoperative blood loss (43.9\u0026thinsp;\u0026plusmn;\u0026thinsp;31.3 vs. 58.2\u0026thinsp;\u0026plusmn;\u0026thinsp;30.8 ml, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.005), duration of hospitalization (14.3\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1 vs. 18.7\u0026thinsp;\u0026plusmn;\u0026thinsp;9.2 days, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and postoperative recovery time (9.1\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1 vs. 11.9\u0026thinsp;\u0026plusmn;\u0026thinsp;7.1 days, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.007) were significantly lower in observe group than in control group. There were no significant differences in the number of lymph node dissections, presence of lymph vessel invasion, postoperative intestinal obstruction and anastomotic leakage between the two groups.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eUtilization of a 3D-printed IMA model in laparoscopic radical resection of RC can assist the surgeon in understanding the LCA anatomy preoperatively, reducing intraoperative bleeding, shortening operating time.\u003c/p\u003e","manuscriptTitle":"Retrospective Cohort Study on 3D Printing Technology for Preoperative Rehearsal and Intraoperative Navigation in Laparoscopic Rectal Cancer Surgery with Left Colic Artery Preservation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-17 02:33:22","doi":"10.21203/rs.3.rs-4763568/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorAssigned","content":"","date":"2024-07-19T01:10:56+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-07-19T01:10:43+00:00","index":"","fulltext":""},{"type":"submitted","content":"3D Printing in Medicine","date":"2024-07-18T15:09:14+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"3d-printing-in-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"tdpm","sideBox":"Learn more about [3D Printing in Medicine](https://threedmedprint.biomedcentral.com/)","snPcode":"41205","submissionUrl":"https://submission.nature.com/new-submission/41205/3","title":"3D Printing in Medicine","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"aa95da72-3b9b-4b2c-9e08-c39d5071d245","owner":[],"postedDate":"August 17th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2024-08-17T02:33:22+00:00","versionOfRecord":[],"versionCreatedAt":"2024-08-17 02:33:22","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4763568","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4763568","identity":"rs-4763568","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}