Usefulness of transanal approach for lower rectal cancer: a propensity score-matched analysis

Usefulness of transanal approach for lower rectal cancer: a propensity score-matched analysis | 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 Usefulness of transanal approach for lower rectal cancer: a propensity score-matched analysis Daichi Ishikawa, Takuya Tokunaga, Hideya Kashihara, Toshiaki Yoshimoto, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7089219/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Aim: Transanal approaches, such as transanal total mesorectal excision and transperineal abdominoperineal resection, have been developed to improve surgical quality for lower rectal cancer. However, international concerns have been raised about higher local recurrence rates. We investigated the usefulness of the transanal approach with respect to short- and long-term outcomes. Methods: In total, 291 patients who underwent laparoscopic or robotic surgery for rectal cancer were enrolled. Clinical, pathological, surgical, and follow-up data were retrospectively collected. Patients were divided into a transanal approach group (n = 139) and a conventional total mesorectal excision group (n = 152). A 1:1 propensity score-matched analysis was performed to compare surgical outcomes between the two groups. Results: After matching, 65 patients were included in each group. In the transanal group, intersphincteric resection was performed more frequently and abdominoperineal resection was performed less frequently, resulting in a higher rate of anus preservation (72.3% vs. 53.8%). The operative time was shorter (278 [240–343] min vs. 317 [259–373] min, p = 0.030), and blood loss was lower (29 [10–50] mL vs. 50 [10–119] mL, p = 0.033) in the transanal group. Major complications (Clavien–Dindo ≥ III) were less frequent in the transanal group. Overall survival was also better in the transanal group. No significant difference was observed in the total recurrence rate, including local recurrence. Conclusions: The transanal approach may be a promising surgical option for lower rectal cancer, contributing to higher rates of anus preservation and improved short- and long-term outcomes. Rectal cancer Transrectal approach Transanal total mesorectal excision Transperineal abdominoperineal resection Figures Figure 1 Figure 2 Introduction Recent data have shown that rectal cancer (RC) accounts for 3.8% of all new cancer cases and 3.4% of cancer-related deaths worldwide ( 1 ). The standard treatment for resectable RC is radical surgery with total mesorectal excision (TME) ( 2 ). TME has been shown to reduce the local recurrence rate and provide survival benefits ( 3 ). Laparoscopic TME was introduced in the early 2000s. Comparable oncological outcomes to those of conventional open surgery can be achieved by experienced surgeons using the laparoscopic approach ( 4 ). However, laparoscopic surgery is more complex and technically demanding, with an increased risk of positive circumferential resection margins and anastomotic leakage ( 5 ). Transanal TME (taTME), which combines an abdominal and transanal approach, was first described in 2010 ( 6 ). The transanal approach offers improved visualization of the mesorectal plane in the lower pelvis, which may lead to a negative circumferential resection margin, improved specimen quality, a lower frequency of anastomotic leakage, and comparable short- and long-term oncological outcomes compared with conventional abdominal TME ( 7 , 8 ). However, studies by Wasmuth et al. and van Oostendorp et al. revealed a higher rate of local recurrence with multifocal growth patterns, increased mortality, and a lower disease-free survival rate ( 9 , 10 ). Additionally, the Norwegian Colorectal Cancer Group imposed a moratorium on taTME because of the elevated rate of local recurrence ( 11 ). To date, the true benefit of the transanal approach for lower RC remains controversial. Therefore, the present study was performed to investigate the usefulness of the transanal approach compared with the conventional abdominal TME using a propensity score-matched analysis. Methods Patients and design This single-institution, retrospective cohort study included 291 consecutive patients who underwent curative laparoscopic or robotic surgery for mid- to low RC at Tokushima University Hospital between January 2017 and December 2023. Of these, 139 patients underwent the transanal approach and 152 underwent the conventional transabdominal approach. The transanal approach for RC was introduced at our institution in January 2017. The median follow-up time was 22.4 (10.0–49.1) months in the transanal group and 43.3 (12.4–60.8) months in the conventional group. A CONSORT diagram is shown in Fig. 1 . Patients who underwent palliative surgery, underwent combined resections (hepatectomy, colectomy), or were diagnosed with conditions other than rectal adenocarcinoma were excluded. The procedure and hospitalization costs were covered by insurance for all patients. All patients provided written informed consent for surgery after receiving a detailed explanation of the procedures and associated risks. Clinical data, including medical history and treatment details, were retrospectively collected from the patients’ medical records. Postoperative morbidity was classified according to the Clavien–Dindo classification ( 12 ). This study was approved in advance by the Institutional Review Board of the University of Tokushima Graduate School of Medical Science (TOCMS: 3215-4). Postoperative follow-up was conducted in accordance with international guidelines, including regular measurements of tumor markers (carcinoembryonic antigen and carbohydrate antigen 19 − 9), clinical examinations, computed tomography scans every 6 months, and annual endoscopy ( 13 ). For patients with Stage III disease, postoperative adjuvant chemotherapy was administered using the CAPOX regimen: oxaliplatin (130 mg/m 2 ) on day 1 and capecitabine (2000 mg/m 2 /day) from days 1 to 14, repeated for 6 months. Propensity score matching For propensity score matching, 1:1 matching was performed using a caliper width of 0.02. Independent variables included in the model were age, sex, body mass index, American Society of Anesthesiologists physical status, pT, pN, pStage, lymphatic vessel invasion (ly), venous invasion (v), tumor location, distance from the anal verge, and neoadjuvant chemoradiotherapy. The matched cohort consisted of 65 patients in each group. Short- and long-term surgical and oncological outcomes were compared between the transanal group and the conventional group. Surgical procedure The stage and extent of lymphadenectomy were classified according to the Japanese Classification of Colorectal Carcinoma ( 14 ). In all 291 cases, a surgeon certified by the Endoscopic Surgical Skill Qualification System of the Japan Society for Endoscopic Surgery participated in the surgery as either an operator or supervisor. The operators were board-certified surgeons of the Japan Surgical Society, board-certified gastroenterological surgeons of the Japan Society of Gastroenterological Surgery, and/or colorectal surgeons qualified by the Endoscopic Surgical Skill Qualification System. All robotic surgeries were performed using the Da Vinci Xi Surgical System (Intuitive Surgical Inc., Sunnyvale, CA, USA). In both the transanal and conventional groups, the procedure was performed as previously described ( 15 ). Statistical analysis Values are presented as median (interquartile range). Statistical analyses were performed using JMP 10 software (SAS Institute, Cary, NC, USA). The Mann–Whitney U test was used to compare continuous variables, and the chi-square test was used to analyze relationships among clinical characteristics. Prognostic data were plotted using the Kaplan–Meier method and analyzed with the log-rank test to assess differences between survival curves. A p-value of < 0.05 was considered statistically significant. Results Patient and tumor characteristics Before propensity score matching, there were no significant differences between the two groups in patient-related factors such as age, sex, body mass index, American Society of Anesthesiologists physical status, or history of laparotomy (Table 1 ). However, among tumor-related factors, the location of the tumor was lower and the distance from the anal verge to the inferior margin of the tumor was shorter in the transanal group than in the conventional group (5 [3–6] cm vs. 8 [5–10] cm, p < 0.001). Neoadjuvant chemoradiotherapy was also administered more frequently in the transanal group (40.3% vs. 27.6%, p = 0.020). After propensity score matching, 130 patients were included in the analysis, and no significant differences in patient or tumor characteristics were observed between the two groups. Table 1 Patient and tumor characteristics before and after propensity score matching Before matching After matching Variables Transanal n = 139 Conventional n = 152 p value Transanal n = 65 Conventional n = 65 p value Patient-related factors Age, years 68 (60.8–74) 67.5 (60–75) 0.944 68 (62.5–74) 69 (60.5–77.5) 0.709 Sex, male/female 92/47 94/58 0.468 37/28 42/23 0.369 BMI, kg/m 2 22.6 (20.7–25.0) 22.6 (20.2–24.9) 0.551 23.1 (21.2–24.6) 23.7 (21.2–25.7) 0.336 ASA-PS, 1/2/3 50/77/12 75/66/11 0.078 30/30/5 31/30/4 0.938 History of laparotomy 38 45 0.697 16 22 0.247 Tumor-related factors pT, CR/1/2/3/4 4/25/37/65/8 5/33/39/69/6 0.955 4/11/17/30/3 2/13/15/31/4 0.889 pN, 0/1/2/3 98/27/6/8 106/28/15/3 0.109 46/11/5/3 48/11/3/3 0.910 ly, −/+ 67/71 80/68 0.281 35/30 39/26 0.479 v, −/+ 52/86 66/84 0.427 35/30 39/26 0.479 fStage, 0/I/II/III/IV † 6/51/36/37/8 7/56/41/34/14 0.879 4/24/17/18/2 2/24/20/15/4 0.759 Location, Ra/Rb/P 19/118/2 97/54/1 < 0.001** 17/48/0 16/48/1 0.493 Distance from anal verge to inferior margin of tumor, cm 5 ( 3 – 6 ) 8 ( 5 – 10 ) < 0.001** 5 ( 4 – 6 ) 5 ( 3 – 7 ) 0.796 Neoadjuvant chemoradiotherapy 56 (40.3) 42 (27.6) 0.020* 23 (35.4) 28 (43.1) 0.369 Data are expressed as number (percentage) of patients within a given group or as median (interquartile range). M, male; F, female; BMI, body mass index; ASA-PS, American Society of Anesthesiologists physical status; CR, complete response; Ra, rectum above the peritoneal reflection; Rb, rectum below the peritoneal reflection; P, anal canal *Statistically significant. † UICC classification, 8th edition Operative details and outcomes As shown in Table 2 , there were significant differences in operative procedures between the two groups, both before and after propensity score matching. After matching, intersphincteric resection was performed more frequently in the transanal group (29.2% vs. 6.2%), while abdominoperineal resection (APR) was less common (26.1% vs. 46.2%) than in the conventional group. The anus preservation rate was significantly higher in the transanal group (72.3% vs. 53.8%, p = 0.029). In terms of surgical approach, robotic surgery was much more frequently used in the transanal group than in the conventional group (72.3% vs. 16.9%, p < 0.001), replacing laparoscopic surgery. Lateral lymph node dissection was also performed more often in the transanal group (33.8% vs. 9.2%, p < 0.001). Both the operative time and blood loss were greater in the transanal group before matching. However, after matching, the trends reversed: the operative time was shorter and blood loss was lower in the transanal group (278 [240–343] min vs. 317 [259–373] min, p = 0.030; 29 [10–50] mL vs. 50 [10–119] mL, p = 0.033, respectively). Stoma was created more frequently in the transanal group, both before (98.6% vs. 46.1%, p < 0.001) and after matching (96.9% vs. 69.2%, p < 0.001). Before matching, one patient in the conventional group required conversion to open surgery because of severe pelvic adhesions; however, no conversions occurred in either group after matching. Table 2 Operative details before and after propensity score matching Before matching After matching Variables Transanal n = 139 Conventional n = 152 p value Transanal n = 65 Conventional n = 65 p value Procedure < 0.001** 0.001** LAR 56 (40.2) 115 (75.7) 28 (43.1) 31 (47.7) ISR 37 (26.6) 4 (2.6) 19 (29.2) 4 (6.2) APR 45 (32.4) 32 (21.1) 17 (26.1) 30 (46.2) Hartmann procedure 1 (0.7) 1 (0.7) 1 (1.5) 0 (0.0) Anus preservation 93 (66.9) 119 (78.2) 0.037* 47 (72.3) 35 (53.8) 0.029* Approach < 0.001** < 0.001** Laparoscopic 38 (27.3) 107 (70.4) 18 (27.7) 54 (83.1) Robotic 101 (72.7) 45 (29.6) 47 (72.3) 11 (16.9) Lymph node dissection D2/D3 21/118 42/110 < 0.001** 12/53 20/45 0.102 LLND 57 (41.0) 6 (3.9) < 0.001** 22 (33.8) 6 (9.2) < 0.001** Duration of operation, min 332 (263–412) 283 (240–348) < 0.001** 278 (240–343) 317 (259–373) 0.030* Blood loss, mL 40 (16–91) 15 (5–50) < 0.001** 29 (10–50) 50 (10–119) 0.033* Stoma creation 137 (98.6) 70 (46.1) < 0.001** 63 (96.9) 45 (69.2) < 0.001** Conversion to laparotomy 0 (0.0) 1 (0.7) 0.256 0 (0.0) 0 (0.0) NA Data are expressed as number (percentage) of patients within a given group or as median (interquartile range). LAR, low anterior resection; ISR, intersphincteric resection; APR, abdominoperineal resection; LLND, lateral lymph node dissection; NA, not applicable *Statistically significant. Postoperative complications and pathological outcomes Table 3 presents the postoperative and pathological outcomes after propensity score matching. Major postoperative complications (Clavien–Dindo classification ≥ III) occurred less frequently in the transanal group than in the conventional group (9.2% vs. 21.5%, p = 0.049). There were no significant differences between the groups in the rates of anastomotic leakage, wound dehiscence, neurogenic bladder, ileus, parastomal hernia, wound infection, or bowel perforation. Pelvic cellulitis and intraabdominal abscess were not observed in any patients in the transanal group, whereas these complications occurred in four and three patients, respectively, in the conventional group (p = 0.017 and p = 0.040). No 30-day postoperative mortality was observed in either group. The postoperative hospital stay did not differ significantly between the groups (15 [12–20] days vs. 17 [12.5–26] days, p = 0.100). Pathological findings showed no significant differences in the rate of positive circumferential resection margins (defined as < 1 mm) (9.2% vs. 13.8%, p = 0.409) or in the distal resection margin length (15 [11–26] mm vs. 20 [12–30] mm, p = 0.400). However, the transanal group had a higher lymph node yield from TME (12 [8–18.5] vs. 10 [4–14], p = 0.011). Table 3 Postoperative and pathological results after matching Variables Transanal n = 65 Conventional n = 65 p value Morbidity Complications CD ≥ III 6 (9.2) 14 (21.5) 0.049* Anastomotic leakage 1 (1.5) 2 (3.1) 0.555 Pelvic cellulitis 0 (0.0) 4 (6.2) 0.017* Intra-abdominal abscess 0 (0.0) 3 (4.6) 0.040* Wound dehiscence 2 (3.1) 2 (3.1) NA Neurogenic bladder 0 (0.0) 1 (1.5) 0.119 Ileus 2 (3.1) 0 (0.0) 0.094 Parastomal hernia 1 (1.5) 0 (0.0) 0.119 Wound infection 0 (0.0) 1 (1.5) 0.119 Bowel perforation 0 (0.0) 1 (1.5) 0.119 30-day postoperative mortality 0 (0.0) 0 (0.0) NA Postoperative hospital stay, days 15 ( 12 – 20 ) 17 (12.5–26) 0.100 Radial margin positivity 6 (9.2) 9 (13.8) 0.409 LN yield from TME, n 12 (8–18.5) 10 ( 4 – 14 ) 0.011* Distal margin, mm 15 ( 11 – 26 ) 20 ( 12 – 30 ) 0.400 Data are expressed as number (percentage) of patients within a given group or as median (interquartile range). CD, Clavien–Dindo classification; TME, total mesorectal excision; LN, lymph node; NA, not applicable *Statistically significant. Long-term outcomes Long-term survival outcomes in propensity matched cohort are shown in Fig. 2 . The transanal group demonstrated better overall survival than the conventional group (3-year overall survival: 97.5% vs. 80.9%, p < 0.001) (Fig. 2 A). There was no significant difference in disease-free survival between the two groups (3-year disease-free survival: 71.5% vs. 62.3%, p = 0.186) (Fig. 2 B). Regarding recurrence patterns, there were no statistically significant differences in overall recurrence rates or in the distribution of recurrence sites, including local recurrence (Table 4 ). However, lung metastasis tended to be more frequent in the conventional group (10.8% vs. 21.5%, p = 0.091). Table 4 Recurrence details after matching Variables Transanal n = 65 Conventional n = 65 p value Total recurrence 14 (21.5) 19 (29.2) 0.311 Recurrence site Local (in the pelvic space) 3(4.6) 5 (7.7) 0.462 Liver metastasis 3 (4.6) 6 (9.2) 0.303 Lung metastasis 7 (10.8) 14 (21.5) 0.091 Lymph node metastasis 2 (3.1) 3 (4.6) 0.654 Dissemination 1 (1.5) 0 (0.0) 0.119 Data are expressed as number (percentage) of patients. Discussion In the present study, the transanal approach for lower RC, compared with conventional abdominal TME, was associated with higher rates of anus preservation and improved short- and long-term outcomes. Transanal approach contributed to a higher rate of intersphincteric resection and a lower rate of APR, resulting in a higher frequency of anus preservation. We previously reported the feasibility of combined robotic rectal surgery and taTME (hybrid robotic surgery), although that study did not include a comparison with conventional transabdominal TME ( 15 ). Li et al. also demonstrated a decreased rate of APR with taTME and an increase in low anterior resection ( 16 ). However, their study did not specifically address the impact of taTME on anus preservation. Avoiding a permanent colostomy may contribute significantly to patient satisfaction and improve quality of life. Previous reports primarily compared taTME and conventional TME without including cases of transperineal or conventional APR. To the best of our knowledge, the present study is the first to highlight this finding. Before matching, the operative time was longer and blood loss was greater in the transanal group. This was likely due to differences in tumor characteristics. Specifically, tumors were located lower in the rectum, and the distance from the anal verge to the inferior tumor margin was shorter in the transanal group than in the conventional group. Additionally, neoadjuvant chemoradiotherapy was more frequently administered in the transanal group, which may have further complicated the surgical procedure. After matching, however, the operative time was shorter and blood loss was less in the transanal group. Previous studies have reported varying results regarding operative time. Li et al. and Ammann et al. found that taTME was associated with a shorter operation duration than conventional TME ( 8 , 16 ), whereas Lin et al. and Ye et al. reported the opposite ( 17 , 18 ), particularly in cases performed using a one-team approach. As for blood loss, most publications have shown no significant difference between the transanal and conventional approaches ( 7 , 16 – 18 ). Major complications (Clavien–Dindo classification ≥ III) were observed less frequently in the transanal group than in the conventional group. In particular, the incidence of pelvic cellulitis and intraabdominal abscess was lower in the transanal group. These complications may have been reduced because of the lower rate of APR, a procedure that often leaves a postoperative dead space prone to infection. The rate of anastomotic leakage was similar between the groups in the present study. Previous reports have been mixed: some studies demonstrated that taTME offers an advantage in reducing intraoperative and postoperative complications, including anastomotic leakage ( 19 , 20 ), while others reported higher complication rates with taTME than with the conventional approach ( 21 ). Conversely, several studies and meta-analyses have indicated that overall morbidity is comparable between the two procedures ( 7 , 22 , 23 ). Regarding long-term outcomes, few retrospective studies have focused on comparing taTME with conventional TME. Most of these studies reported no significant prognostic differences between the two approaches ( 22 , 24 ). In the present study, the transanal group demonstrated better overall survival than the conventional group, while no significant difference was observed in disease-free survival. However, given the difference in median follow-up durations between the two groups, the significance of these findings should be further investigated in future prospective studies. Before the concerning results reported by Wasmuth et al. and van Oostendorp et al., many studies had shown that the recurrence rate did not differ after taTME ( 25 , 26 ). Following these worrisome publications, further research intensified to investigate the issue. Fortunately, an increased local recurrence rate was not observed in several subsequent studies, including a retrospective multicenter study by Roodbeen et al. ( 27 ), national database surveys from Denmark and the international taTME registry ( 28 , 29 ), a nationwide multicenter cohort study in Japan by Matsuda et al. ( 30 ), and a meta-analysis ( 22 ). In the present study, there was no significant difference in the overall recurrence rate. However, there was a trend toward a higher frequency of lung metastases in the conventional group (10.8% vs. 21.5%, p = 0.091). The present study had several limitations. First, it was a single-center, retrospective study with no randomization, a relatively short follow-up period, and differing proportions of laparoscopic and robotic surgeries between the two groups. Second, the surgical approach was selected by the operating surgeon, which may have introduced selection bias. However, most baseline differences were adjusted for using propensity score matching, allowing for a more balanced comparison. Third, the sample size after matching was relatively small because a considerable number of patients had to be excluded to maintain the quality of the matching process. Conclusion The transanal approach may be a promising surgical option for lower RC, offering a higher rate of anus preservation and potentially improved short- and long-term outcomes. Abbreviations RC rectal cancer taTME transanal total mesorectal excision TME total mesorectal excision APR abdominoperineal resection Declarations Ethics approval and consent to participate: The study protocol was approved by the Institutional Review Board of the University of Tokushima Graduate School of Medical Science (TOCMS: 3215-4). Consent for publication: Informed consent was obtained from all participating patients. In cases where the patient was deceased, consent was obtained from a consanguineous family member or legal guardian. Competing interests: The authors declare that they have no competing interest. Funding: None. Authors’ contributions: Ishikawa D designed the study, acquired and analyzed the data, and wrote the initial draft of the manuscript. 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J Natl Compr Cancer Network: JNCCN 19(11):1232–1240 Klein MF, Seiersen M, Bulut O, Bech-Knudsen F, Jansen JE, Gögenur I (2021) Short-term outcomes after transanal total mesorectal excision for rectal cancer in Denmark - a prospective multicentre study. Colorectal disease: official J Association Coloproctology Great Br Irel 23(4):834–842 Matsuda T, Takemasa I, Endo H, Mori S, Hasegawa S, Hida K et al (2024) Local Recurrence of Rectal Cancer After Transanal Total Mesorectal Excision and Risk Factors: A Nationwide Multicenter Cohort Study in Japan. Annals of surgery open: perspectives of surgical history, education, and clinical approaches. 5(1):e369 Cite Share Download PDF Status: Posted Version 1 posted 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-7089219","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":485423394,"identity":"dbf0313a-29b2-4250-ac2a-bd3d0985e48c","order_by":0,"name":"Daichi Ishikawa","email":"data:image/png;base64,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","orcid":"","institution":"Tokushima University Hospital: Tokushima Daigaku Byoin","correspondingAuthor":true,"prefix":"","firstName":"Daichi","middleName":"","lastName":"Ishikawa","suffix":""},{"id":485423395,"identity":"84def069-17a4-4537-81b8-8d74e29506f4","order_by":1,"name":"Takuya Tokunaga","email":"","orcid":"","institution":"Tokushima University Hospital: Tokushima Daigaku Byoin","correspondingAuthor":false,"prefix":"","firstName":"Takuya","middleName":"","lastName":"Tokunaga","suffix":""},{"id":485423396,"identity":"9d0c31a3-9f40-41cf-974e-aec46c4105e0","order_by":2,"name":"Hideya Kashihara","email":"","orcid":"","institution":"Tokushima University Hospital: Tokushima Daigaku Byoin","correspondingAuthor":false,"prefix":"","firstName":"Hideya","middleName":"","lastName":"Kashihara","suffix":""},{"id":485423397,"identity":"21f0d568-cd3e-44d6-b29c-03211c5c2e40","order_by":3,"name":"Toshiaki Yoshimoto","email":"","orcid":"","institution":"Tokushima University Hospital: Tokushima Daigaku Byoin","correspondingAuthor":false,"prefix":"","firstName":"Toshiaki","middleName":"","lastName":"Yoshimoto","suffix":""},{"id":485423398,"identity":"1d783239-ea9d-4dc9-aaa0-558f3d8131f2","order_by":4,"name":"Yuma Wada","email":"","orcid":"","institution":"Tokushima University Hospital: Tokushima Daigaku Byoin","correspondingAuthor":false,"prefix":"","firstName":"Yuma","middleName":"","lastName":"Wada","suffix":""},{"id":485423399,"identity":"42a3dd12-cc55-4c3e-aaca-1943fc5a07a1","order_by":5,"name":"Chie Takasu","email":"","orcid":"","institution":"Tokushima University Hospital: Tokushima Daigaku Byoin","correspondingAuthor":false,"prefix":"","firstName":"Chie","middleName":"","lastName":"Takasu","suffix":""},{"id":485423400,"identity":"f096add0-c218-4616-872f-c7227409e844","order_by":6,"name":"Masaaki Nishi","email":"","orcid":"https://orcid.org/0000-0003-3845-457X","institution":"Tokushima University Hospital: Tokushima Daigaku Byoin","correspondingAuthor":false,"prefix":"","firstName":"Masaaki","middleName":"","lastName":"Nishi","suffix":""},{"id":485423401,"identity":"1ec2f2c2-c46f-4d2b-9494-73984b3448a5","order_by":7,"name":"Mitsuo Shimada","email":"","orcid":"","institution":"Tokushima University Hospital: Tokushima Daigaku Byoin","correspondingAuthor":false,"prefix":"","firstName":"Mitsuo","middleName":"","lastName":"Shimada","suffix":""}],"badges":[],"createdAt":"2025-07-10 05:44:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7089219/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7089219/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":87269695,"identity":"acd761c1-1eb4-4f9f-9d1f-2b46dc187d0c","added_by":"auto","created_at":"2025-07-22 08:16:20","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":14875,"visible":true,"origin":"","legend":"\u003cp\u003eCONSORT diagram of the present study.\u003c/p\u003e\n\u003cp\u003eMIS, minimally invasive surgery.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7089219/v1/125a0d76e846ce7136f168be.png"},{"id":87269696,"identity":"34d89d2e-1c5e-4b77-8e71-2c43c7d580b9","added_by":"auto","created_at":"2025-07-22 08:16:20","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":17816,"visible":true,"origin":"","legend":"\u003cp\u003ePrognosis of patients in the transanal and conventional groups after propensity score matching.\u003c/p\u003e\n\u003cp\u003eA: Overall survival in the transanal and conventional groups. The number at risk is shown below the graph.\u003c/p\u003e\n\u003cp\u003eB: Disease-free survival in the transanal and conventional groups. The number at risk is shown below the graph.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7089219/v1/23e4c1f67de32e4460086bbf.png"},{"id":88835293,"identity":"8cd568da-fef0-432e-b12a-badb9ffc2f22","added_by":"auto","created_at":"2025-08-12 00:58:39","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":837225,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7089219/v1/89ca7e28-dae8-4116-9914-8ddfea30e467.pdf"}],"financialInterests":"","formattedTitle":"Usefulness of transanal approach for lower rectal cancer: a propensity score-matched analysis","fulltext":[{"header":"Introduction","content":"\u003cp\u003eRecent data have shown that rectal cancer (RC) accounts for 3.8% of all new cancer cases and 3.4% of cancer-related deaths worldwide (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). The standard treatment for resectable RC is radical surgery with total mesorectal excision (TME) (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). TME has been shown to reduce the local recurrence rate and provide survival benefits (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). Laparoscopic TME was introduced in the early 2000s. Comparable oncological outcomes to those of conventional open surgery can be achieved by experienced surgeons using the laparoscopic approach (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). However, laparoscopic surgery is more complex and technically demanding, with an increased risk of positive circumferential resection margins and anastomotic leakage (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eTransanal TME (taTME), which combines an abdominal and transanal approach, was first described in 2010 (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). The transanal approach offers improved visualization of the mesorectal plane in the lower pelvis, which may lead to a negative circumferential resection margin, improved specimen quality, a lower frequency of anastomotic leakage, and comparable short- and long-term oncological outcomes compared with conventional abdominal TME (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eHowever, studies by Wasmuth et al. and van Oostendorp et al. revealed a higher rate of local recurrence with multifocal growth patterns, increased mortality, and a lower disease-free survival rate (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Additionally, the Norwegian Colorectal Cancer Group imposed a moratorium on taTME because of the elevated rate of local recurrence (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eTo date, the true benefit of the transanal approach for lower RC remains controversial. Therefore, the present study was performed to investigate the usefulness of the transanal approach compared with the conventional abdominal TME using a propensity score-matched analysis.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cb\u003ePatients and design\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThis single-institution, retrospective cohort study included 291 consecutive patients who underwent curative laparoscopic or robotic surgery for mid- to low RC at Tokushima University Hospital between January 2017 and December 2023. Of these, 139 patients underwent the transanal approach and 152 underwent the conventional transabdominal approach. The transanal approach for RC was introduced at our institution in January 2017. The median follow-up time was 22.4 (10.0–49.1) months in the transanal group and 43.3 (12.4–60.8) months in the conventional group. A CONSORT diagram is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Patients who underwent palliative surgery, underwent combined resections (hepatectomy, colectomy), or were diagnosed with conditions other than rectal adenocarcinoma were excluded. The procedure and hospitalization costs were covered by insurance for all patients. All patients provided written informed consent for surgery after receiving a detailed explanation of the procedures and associated risks. Clinical data, including medical history and treatment details, were retrospectively collected from the patients’ medical records. Postoperative morbidity was classified according to the Clavien–Dindo classification (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). This study was approved in advance by the Institutional Review Board of the University of Tokushima Graduate School of Medical Science (TOCMS: 3215-4). Postoperative follow-up was conducted in accordance with international guidelines, including regular measurements of tumor markers (carcinoembryonic antigen and carbohydrate antigen 19 − 9), clinical examinations, computed tomography scans every 6 months, and annual endoscopy (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). For patients with Stage III disease, postoperative adjuvant chemotherapy was administered using the CAPOX regimen: oxaliplatin (130 mg/m\u003csup\u003e2\u003c/sup\u003e) on day 1 and capecitabine (2000 mg/m\u003csup\u003e2\u003c/sup\u003e/day) from days 1 to 14, repeated for 6 months.\u003c/p\u003e\u003cp\u003e\u003cb\u003ePropensity score matching\u003c/b\u003e\u003c/p\u003e\u003cp\u003eFor propensity score matching, 1:1 matching was performed using a caliper width of 0.02. Independent variables included in the model were age, sex, body mass index, American Society of Anesthesiologists physical status, pT, pN, pStage, lymphatic vessel invasion (ly), venous invasion (v), tumor location, distance from the anal verge, and neoadjuvant chemoradiotherapy. The matched cohort consisted of 65 patients in each group. Short- and long-term surgical and oncological outcomes were compared between the transanal group and the conventional group.\u003c/p\u003e\u003cp\u003e\u003cb\u003eSurgical procedure\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe stage and extent of lymphadenectomy were classified according to the Japanese Classification of Colorectal Carcinoma (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). In all 291 cases, a surgeon certified by the Endoscopic Surgical Skill Qualification System of the Japan Society for Endoscopic Surgery participated in the surgery as either an operator or supervisor. The operators were board-certified surgeons of the Japan Surgical Society, board-certified gastroenterological surgeons of the Japan Society of Gastroenterological Surgery, and/or colorectal surgeons qualified by the Endoscopic Surgical Skill Qualification System. All robotic surgeries were performed using the Da Vinci Xi Surgical System (Intuitive Surgical Inc., Sunnyvale, CA, USA). In both the transanal and conventional groups, the procedure was performed as previously described (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e).\u003c/p\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eValues are presented as median (interquartile range). Statistical analyses were performed using JMP 10 software (SAS Institute, Cary, NC, USA). The Mann–Whitney U test was used to compare continuous variables, and the chi-square test was used to analyze relationships among clinical characteristics. Prognostic data were plotted using the Kaplan–Meier method and analyzed with the log-rank test to assess differences between survival curves. A p-value of \u0026lt; 0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cb\u003ePatient and tumor characteristics\u003c/b\u003e\u003c/p\u003e\u003cp\u003eBefore propensity score matching, there were no significant differences between the two groups in patient-related factors such as age, sex, body mass index, American Society of Anesthesiologists physical status, or history of laparotomy (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). However, among tumor-related factors, the location of the tumor was lower and the distance from the anal verge to the inferior margin of the tumor was shorter in the transanal group than in the conventional group (5 [3\u0026ndash;6] cm vs. 8 [5\u0026ndash;10] cm, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Neoadjuvant chemoradiotherapy was also administered more frequently in the transanal group (40.3% vs. 27.6%, p\u0026thinsp;=\u0026thinsp;0.020). After propensity score matching, 130 patients were included in the analysis, and no significant differences in patient or tumor characteristics were observed between the two groups.\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\u003ePatient and tumor characteristics before and after propensity score matching\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\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=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e\u003cp\u003eBefore matching\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e\u003cp\u003eAfter matching\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariables\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eTransanal\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;139\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eConventional\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;152\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eTransanal\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eConventional\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePatient-related factors\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\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\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\u003cp\u003e68 (60.8\u0026ndash;74)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e67.5 (60\u0026ndash;75)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.944\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e68 (62.5\u0026ndash;74)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e69 (60.5\u0026ndash;77.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.709\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex, male/female\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e92/47\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e94/58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.468\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e37/28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e42/23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.369\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI, kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e22.6 (20.7\u0026ndash;25.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e22.6 (20.2\u0026ndash;24.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.551\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e23.1 (21.2\u0026ndash;24.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e23.7 (21.2\u0026ndash;25.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.336\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eASA-PS, 1/2/3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e50/77/12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e75/66/11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.078\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e30/30/5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e31/30/4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.938\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHistory of laparotomy\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\u003e45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.697\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.247\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTumor-related factors\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\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003epT, CR/1/2/3/4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e4/25/37/65/8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5/33/39/69/6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.955\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4/11/17/30/3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2/13/15/31/4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.889\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003epN, 0/1/2/3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e98/27/6/8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e106/28/15/3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.109\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e46/11/5/3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e48/11/3/3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.910\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ely, \u0026minus;/+\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e67/71\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e80/68\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.281\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e35/30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e39/26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.479\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ev, \u0026minus;/+\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e52/86\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e66/84\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.427\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e35/30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e39/26\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.479\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003efStage, 0/I/II/III/IV\u003csup\u003e\u0026dagger;\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6/51/36/37/8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7/56/41/34/14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.879\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4/24/17/18/2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e2/24/20/15/4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.759\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLocation, Ra/Rb/P\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e19/118/2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e97/54/1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e17/48/0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e16/48/1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.493\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDistance from anal verge to inferior margin of tumor, cm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5 (\u003cspan additionalcitationids=\"CR4 CR5\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8 (\u003cspan additionalcitationids=\"CR6 CR7 CR8 CR9\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e5 (\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e5 (\u003cspan additionalcitationids=\"CR4 CR5 CR6\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.796\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNeoadjuvant chemoradiotherapy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e56 (40.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e42 (27.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.020*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e23 (35.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e28 (43.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.369\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eData are expressed as number (percentage) of patients within a given group or as median (interquartile range).\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eM, male; F, female; BMI, body mass index; ASA-PS, American Society of Anesthesiologists physical status; CR, complete response; Ra, rectum above the peritoneal reflection; Rb, rectum below the peritoneal reflection; P, anal canal\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e*Statistically significant. \u003csup\u003e\u0026dagger;\u003c/sup\u003eUICC classification, 8th edition\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eOperative details and outcomes\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAs shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, there were significant differences in operative procedures between the two groups, both before and after propensity score matching. After matching, intersphincteric resection was performed more frequently in the transanal group (29.2% vs. 6.2%), while abdominoperineal resection (APR) was less common (26.1% vs. 46.2%) than in the conventional group. The anus preservation rate was significantly higher in the transanal group (72.3% vs. 53.8%, p\u0026thinsp;=\u0026thinsp;0.029). In terms of surgical approach, robotic surgery was much more frequently used in the transanal group than in the conventional group (72.3% vs. 16.9%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), replacing laparoscopic surgery. Lateral lymph node dissection was also performed more often in the transanal group (33.8% vs. 9.2%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Both the operative time and blood loss were greater in the transanal group before matching. However, after matching, the trends reversed: the operative time was shorter and blood loss was lower in the transanal group (278 [240\u0026ndash;343] min vs. 317 [259\u0026ndash;373] min, p\u0026thinsp;=\u0026thinsp;0.030; 29 [10\u0026ndash;50] mL vs. 50 [10\u0026ndash;119] mL, p\u0026thinsp;=\u0026thinsp;0.033, respectively). Stoma was created more frequently in the transanal group, both before (98.6% vs. 46.1%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) and after matching (96.9% vs. 69.2%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Before matching, one patient in the conventional group required conversion to open surgery because of severe pelvic adhesions; however, no conversions occurred in either group after matching.\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\u003eOperative details before and after propensity score matching\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\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=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e\u003cp\u003eBefore matching\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e\u003cp\u003eAfter matching\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariables\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eTransanal\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;139\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eConventional\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;152\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eTransanal\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003eConventional\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;65\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003ep value\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProcedure\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\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.001**\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLAR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e56 (40.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e115 (75.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e28 (43.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e31 (47.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eISR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e37 (26.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (2.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e19 (29.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e4 (6.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAPR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e45 (32.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e32 (21.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e17 (26.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e30 (46.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHartmann procedure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (0.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (0.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1 (1.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAnus preservation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e93 (66.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e119 (78.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.037*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e47 (72.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e35 (53.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.029*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eApproach\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\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLaparoscopic\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e38 (27.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e107 (70.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e18 (27.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e54 (83.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRobotic\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e101 (72.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e45 (29.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e47 (72.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e11 (16.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLymph node dissection\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\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eD2/D3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e21/118\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e42/110\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e12/53\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e20/45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.102\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLLND\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e57 (41.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6 (3.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e22 (33.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e6 (9.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDuration of operation, min\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e332 (263\u0026ndash;412)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e283 (240\u0026ndash;348)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e278 (240\u0026ndash;343)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e317 (259\u0026ndash;373)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.030*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBlood loss, mL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e40 (16\u0026ndash;91)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15 (5\u0026ndash;50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e29 (10\u0026ndash;50)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e50 (10\u0026ndash;119)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e0.033*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eStoma creation\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e137 (98.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e70 (46.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e63 (96.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e45 (69.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001**\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eConversion to laparotomy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (0.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.256\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u003cp\u003eNA\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eData are expressed as number (percentage) of patients within a given group or as median (interquartile range).\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003eLAR, low anterior resection; ISR, intersphincteric resection; APR, abdominoperineal resection; LLND, lateral lymph node dissection; NA, not applicable\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e*Statistically significant.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003ePostoperative complications and pathological outcomes\u003c/b\u003e\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e presents the postoperative and pathological outcomes after propensity score matching. Major postoperative complications (Clavien\u0026ndash;Dindo classification\u0026thinsp;\u0026ge;\u0026thinsp;III) occurred less frequently in the transanal group than in the conventional group (9.2% vs. 21.5%, p\u0026thinsp;=\u0026thinsp;0.049). There were no significant differences between the groups in the rates of anastomotic leakage, wound dehiscence, neurogenic bladder, ileus, parastomal hernia, wound infection, or bowel perforation. Pelvic cellulitis and intraabdominal abscess were not observed in any patients in the transanal group, whereas these complications occurred in four and three patients, respectively, in the conventional group (p\u0026thinsp;=\u0026thinsp;0.017 and p\u0026thinsp;=\u0026thinsp;0.040). No 30-day postoperative mortality was observed in either group. The postoperative hospital stay did not differ significantly between the groups (15 [12\u0026ndash;20] days vs. 17 [12.5\u0026ndash;26] days, p\u0026thinsp;=\u0026thinsp;0.100). Pathological findings showed no significant differences in the rate of positive circumferential resection margins (defined as \u0026lt;\u0026thinsp;1 mm) (9.2% vs. 13.8%, p\u0026thinsp;=\u0026thinsp;0.409) or in the distal resection margin length (15 [11\u0026ndash;26] mm vs. 20 [12\u0026ndash;30] mm, p\u0026thinsp;=\u0026thinsp;0.400). However, the transanal group had a higher lymph node yield from TME (12 [8\u0026ndash;18.5] vs. 10 [4\u0026ndash;14], p\u0026thinsp;=\u0026thinsp;0.011).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePostoperative and pathological results after matching\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\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=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariables\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eTransanal\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;65\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eConventional\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;65\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\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\u003cp\u003eMorbidity\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\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eComplications CD\u0026thinsp;\u0026ge;\u0026thinsp;III\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6 (9.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14 (21.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.049*\u003c/p\u003e\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\u003cp\u003e1 (1.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (3.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.555\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePelvic cellulitis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (6.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.017*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIntra-abdominal abscess\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3 (4.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.040*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWound dehiscence\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (3.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (3.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eNA\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNeurogenic bladder\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (1.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.119\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eIleus\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (3.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.094\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParastomal hernia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (1.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.119\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWound infection\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (1.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.119\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBowel perforation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (1.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.119\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e30-day postoperative mortality\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eNA\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative hospital stay, days\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e15 (\u003cspan additionalcitationids=\"CR13 CR14 CR15 CR16 CR17 CR18 CR19\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17 (12.5\u0026ndash;26)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.100\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRadial margin positivity\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e6 (9.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9 (13.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.409\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLN yield from TME, n\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e12 (8\u0026ndash;18.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10 (\u003cspan additionalcitationids=\"CR5 CR6 CR7 CR8 CR9 CR10 CR11 CR12 CR13\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.011*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDistal margin, mm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e15 (\u003cspan additionalcitationids=\"CR12 CR13 CR14 CR15 CR16 CR17 CR18 CR19 CR20 CR21 CR22 CR23 CR24 CR25\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e20 (\u003cspan additionalcitationids=\"CR13 CR14 CR15 CR16 CR17 CR18 CR19 CR20 CR21 CR22 CR23 CR24 CR25 CR26 CR27 CR28 CR29\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.400\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eData are expressed as number (percentage) of patients within a given group or as median (interquartile range).\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eCD, Clavien\u0026ndash;Dindo classification; TME, total mesorectal excision; LN, lymph node; NA, not applicable\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003e*Statistically significant.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eLong-term outcomes\u003c/b\u003e\u003c/p\u003e\u003cp\u003eLong-term survival outcomes in propensity matched cohort are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The transanal group demonstrated better overall survival than the conventional group (3-year overall survival: 97.5% vs. 80.9%, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA). There was no significant difference in disease-free survival between the two groups (3-year disease-free survival: 71.5% vs. 62.3%, p\u0026thinsp;=\u0026thinsp;0.186) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB). Regarding recurrence patterns, there were no statistically significant differences in overall recurrence rates or in the distribution of recurrence sites, including local recurrence (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). However, lung metastasis tended to be more frequent in the conventional group (10.8% vs. 21.5%, p\u0026thinsp;=\u0026thinsp;0.091).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eRecurrence details after matching\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariables\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eTransanal\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;65\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eConventional\u003c/p\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;65\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\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\u003cp\u003eTotal recurrence\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e14 (21.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e19 (29.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.311\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRecurrence site\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\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLocal (in the pelvic space)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3(4.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e5 (7.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.462\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLiver metastasis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3 (4.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e6 (9.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.303\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLung metastasis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e7 (10.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e14 (21.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.091\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLymph node metastasis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2 (3.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e3 (4.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.654\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDissemination\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1 (1.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0 (0.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.119\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eData are expressed as number (percentage) of patients.\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn the present study, the transanal approach for lower RC, compared with conventional abdominal TME, was associated with higher rates of anus preservation and improved short- and long-term outcomes. Transanal approach contributed to a higher rate of intersphincteric resection and a lower rate of APR, resulting in a higher frequency of anus preservation. We previously reported the feasibility of combined robotic rectal surgery and taTME (hybrid robotic surgery), although that study did not include a comparison with conventional transabdominal TME (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). Li et al. also demonstrated a decreased rate of APR with taTME and an increase in low anterior resection (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). However, their study did not specifically address the impact of taTME on anus preservation. Avoiding a permanent colostomy may contribute significantly to patient satisfaction and improve quality of life. Previous reports primarily compared taTME and conventional TME without including cases of transperineal or conventional APR. To the best of our knowledge, the present study is the first to highlight this finding.\u003c/p\u003e\u003cp\u003eBefore matching, the operative time was longer and blood loss was greater in the transanal group. This was likely due to differences in tumor characteristics. Specifically, tumors were located lower in the rectum, and the distance from the anal verge to the inferior tumor margin was shorter in the transanal group than in the conventional group. Additionally, neoadjuvant chemoradiotherapy was more frequently administered in the transanal group, which may have further complicated the surgical procedure. After matching, however, the operative time was shorter and blood loss was less in the transanal group. Previous studies have reported varying results regarding operative time. Li et al. and Ammann et al. found that taTME was associated with a shorter operation duration than conventional TME (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e), whereas Lin et al. and Ye et al. reported the opposite (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e), particularly in cases performed using a one-team approach. As for blood loss, most publications have shown no significant difference between the transanal and conventional approaches (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan additionalcitationids=\"CR17\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eMajor complications (Clavien\u0026ndash;Dindo classification\u0026thinsp;\u0026ge;\u0026thinsp;III) were observed less frequently in the transanal group than in the conventional group. In particular, the incidence of pelvic cellulitis and intraabdominal abscess was lower in the transanal group. These complications may have been reduced because of the lower rate of APR, a procedure that often leaves a postoperative dead space prone to infection. The rate of anastomotic leakage was similar between the groups in the present study. Previous reports have been mixed: some studies demonstrated that taTME offers an advantage in reducing intraoperative and postoperative complications, including anastomotic leakage (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e), while others reported higher complication rates with taTME than with the conventional approach (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). Conversely, several studies and meta-analyses have indicated that overall morbidity is comparable between the two procedures (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eRegarding long-term outcomes, few retrospective studies have focused on comparing taTME with conventional TME. Most of these studies reported no significant prognostic differences between the two approaches (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). In the present study, the transanal group demonstrated better overall survival than the conventional group, while no significant difference was observed in disease-free survival. However, given the difference in median follow-up durations between the two groups, the significance of these findings should be further investigated in future prospective studies.\u003c/p\u003e\u003cp\u003eBefore the concerning results reported by Wasmuth et al. and van Oostendorp et al., many studies had shown that the recurrence rate did not differ after taTME (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e). Following these worrisome publications, further research intensified to investigate the issue. Fortunately, an increased local recurrence rate was not observed in several subsequent studies, including a retrospective multicenter study by Roodbeen et al. (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e), national database surveys from Denmark and the international taTME registry (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e), a nationwide multicenter cohort study in Japan by Matsuda et al. (\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e), and a meta-analysis (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). In the present study, there was no significant difference in the overall recurrence rate. However, there was a trend toward a higher frequency of lung metastases in the conventional group (10.8% vs. 21.5%, p\u0026thinsp;=\u0026thinsp;0.091).\u003c/p\u003e\u003cp\u003eThe present study had several limitations. First, it was a single-center, retrospective study with no randomization, a relatively short follow-up period, and differing proportions of laparoscopic and robotic surgeries between the two groups. Second, the surgical approach was selected by the operating surgeon, which may have introduced selection bias. However, most baseline differences were adjusted for using propensity score matching, allowing for a more balanced comparison. Third, the sample size after matching was relatively small because a considerable number of patients had to be excluded to maintain the quality of the matching process.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe transanal approach may be a promising surgical option for lower RC, offering a higher rate of anus preservation and potentially improved short- and long-term outcomes.\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\"\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\"\u003eTME\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003etotal mesorectal excision\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eAPR\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eabdominoperineal resection\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e The study protocol was approved by the Institutional Review Board of the University of Tokushima Graduate School of Medical Science (TOCMS: 3215-4).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u003c/strong\u003e Informed consent was obtained from all participating patients. In cases where the patient was deceased, consent was obtained from a consanguineous family member or legal guardian.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no competing interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e None.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors’ contributions:\u003c/strong\u003e Ishikawa D designed the study, acquired and analyzed the data, and wrote the initial draft of the manuscript. Yoshimoto T, and Kashihara H contributed to data analysis and interpretation. Tokunaga T, Wada Y, and Takasu C assisted in the preparation of the manuscript. Nishi M and Shimada M supervised the project. All authors critically reviewed the manuscript and approved the final version of the article.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgment:\u003c/strong\u003e We thank Angela Morben, DVM, ELS, from Edanz (https://jp.edanz.com/ac), for editing a draft of this manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A et al (2021) Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. Cancer J Clin 71(3):209\u0026ndash;249\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHeald RJ (1988) The 'Holy Plane' of rectal surgery. J R Soc Med 81(9):503\u0026ndash;508\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHeald RJ, Husband EM, Ryall RD (1982) The mesorectum in rectal cancer surgery\u0026ndash;the clue to pelvic recurrence? Br J Surg 69(10):613\u0026ndash;616\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBonjer HJ, Deijen CL, Haglind E (2015) A Randomized Trial of Laparoscopic versus Open Surgery for Rectal Cancer. N Engl J Med 373(2):194\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLaurent C, Leblanc F, Gineste C, Saric J, Rullier E (2007) Laparoscopic approach in surgical treatment of rectal cancer. Br J Surg 94(12):1555\u0026ndash;1561\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSylla P, Rattner DW, Delgado S, Lacy AM (2010) NOTES transanal rectal cancer resection using transanal endoscopic microsurgery and laparoscopic assistance. Surg Endosc 24(5):1205\u0026ndash;1210\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMunini M, Popeskou SG, Galetti K, Roesel R, Mongelli F, Christoforidis D (2021) Transanal (TaTME) vs. laparoscopic total mesorectal excision for mid and low rectal cancer: a propensity score-matched analysis of early and long-term outcomes. Int J Colorectal Dis 36(10):2271\u0026ndash;2279\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAmmann Y, Warschkow R, Schmied B, De Lorenzi D, Rei\u0026szlig;felder C, Bischofberger S et al (2024) Is survival after transanal total mesorectal excision (taTME) worse than that after traditional total mesorectal excision? A retrospective propensity score-adjusted cohort study. Int J Colorectal Dis 39(1):28\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWasmuth HH, Faerden AE, Myklebust T, Pfeffer F, Norderval S, Riis R et al (2020) Transanal total mesorectal excision for rectal cancer has been suspended in Norway. Br J Surg 107(1):121\u0026ndash;130\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003evan Oostendorp SE, Belgers HJ, Bootsma BT, Hol JC, Belt E, Bleeker W et al (2020) Locoregional recurrences after transanal total mesorectal excision of rectal cancer during implementation. Br J Surg 107(9):1211\u0026ndash;1220\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLarsen SG, Pfeffer F, K\u0026oslash;rner H (2019) Norwegian moratorium on transanal total mesorectal excision. Br J Surg 106(9):1120\u0026ndash;1121\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDindo D, Demartines N, Clavien PA (2004) Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg 240(2):205\u0026ndash;213\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGlynne-Jones R, Wyrwicz L, Tiret E, Brown G, R\u0026ouml;del C, Cervantes A et al (2017) Rectal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Annals oncology: official J Eur Soc Med Oncol 28(suppl4):iv22\u0026ndash;iv40\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJapanese Classification of Colorectal (2019) Appendiceal, and Anal Carcinoma: the 3d English Edition [Secondary Publication]. J anus rectum colon 3(4):175\u0026ndash;195\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKashihara H, Tokunaga T, Yoshimoto T, Wada Y, Takasu C, Nishi M et al (2025) Feasibility of hybrid robotic rectal surgery. Surg Today\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi Z, Liu H, Luo S, Hou Y, Zhou Y, Zheng X et al (2024) Long-term oncological outcomes of transanal versus laparoscopic total mesorectal excision for mid-low rectal cancer: a retrospective analysis of 2502 patients. Int J Surg (London England) 110(3):1611\u0026ndash;1619\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLin YC, Kuo YT, You JF, Chern YJ, Hsu YJ, Yu YL et al (2022) Transanal Total Mesorectal Excision (TaTME) versus Laparoscopic Total Mesorectal Excision for Lower Rectal Cancer: A Propensity Score-Matched Analysis. Cancers. ;14(17)\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYe J, Tian Y, Li F, van Oostendorp S, Chai Y, Tuynman J et al (2021) Comparison of transanal total mesorectal excision (TaTME) versus laparoscopic TME for rectal cancer: A case matched study. Eur J Surg oncology: J Eur Soc Surg Oncol Br Association Surg Oncol 47(5):1019\u0026ndash;1025\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSimo V, Tejedor P, Jimenez LM, Hernan C, Zorilla J, Arrredondo J et al (2021) Oncological safety of transanal total mesorectal excision (TaTME) for rectal cancer: mid-term results of a prospective multicentre study. Surg Endosc 35(4):1808\u0026ndash;1819\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAdamina M, Buchs NC, Penna M, Hompes R (2018) St.Gallen consensus on safe implementation of transanal total mesorectal excision. Surg Endosc 32(3):1091\u0026ndash;1103\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSylla P, Knol JJ, D'Andrea AP, Perez RO, Atallah SB, Penna M et al (2021) Urethral Injury and Other Urologic Injuries During Transanal Total Mesorectal Excision: An International Collaborative Study. Ann Surg 274(2):e115\u0026ndash;e25\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMoon JY, Lee MR, Ha GW (2022) Long-term oncologic outcomes of transanal TME compared with transabdominal TME for rectal cancer: a systematic review and meta-analysis. Surg Endosc 36(5):3122\u0026ndash;3135\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHol JC, Burghgraef TA, Rutgers MLW, Crolla R, van Geloven NAW, Hompes R et al (2021) Comparison of laparoscopic versus robot-assisted versus transanal total mesorectal excision surgery for rectal cancer: a retrospective propensity score-matched cohort study of short-term outcomes. Br J Surg 108(11):1380\u0026ndash;1387\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZeng Z, Liu Z, Luo S, Liang Z, Huang L, Ruan L et al (2022) Three-year outcomes of transanal total mesorectal excision versus standard laparoscopic total mesorectal excision for mid and low rectal cancer. Surg Endosc 36(6):3902\u0026ndash;3910\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMa B, Gao P, Song Y, Zhang C, Zhang C, Wang L et al (2016) Transanal total mesorectal excision (taTME) for rectal cancer: a systematic review and meta-analysis of oncological and perioperative outcomes compared with laparoscopic total mesorectal excision. BMC Cancer 16:380\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePenna M, Hompes R, Arnold S, Wynn G, Austin R, Warusavitarne J et al (2017) Transanal Total Mesorectal Excision: International Registry Results of the First 720 Cases. Ann Surg 266(1):111\u0026ndash;117\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRoodbeen SX, Spinelli A, Bemelman WA, Di Candido F, Cardepont M, Denost Q et al (2021) Local Recurrence After Transanal Total Mesorectal Excision for Rectal Cancer: A Multicenter Cohort Study. Ann Surg 274(2):359\u0026ndash;366\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRoodbeen SX, Penna M, van Dieren S, Moran B, Tekkis P, Tanis PJ et al (2021) Local Recurrence and Disease-Free Survival After Transanal Total Mesorectal Excision: Results From the International TaTME Registry. J Natl Compr Cancer Network: JNCCN 19(11):1232\u0026ndash;1240\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKlein MF, Seiersen M, Bulut O, Bech-Knudsen F, Jansen JE, G\u0026ouml;genur I (2021) Short-term outcomes after transanal total mesorectal excision for rectal cancer in Denmark - a prospective multicentre study. Colorectal disease: official J Association Coloproctology Great Br Irel 23(4):834\u0026ndash;842\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMatsuda T, Takemasa I, Endo H, Mori S, Hasegawa S, Hida K et al (2024) Local Recurrence of Rectal Cancer After Transanal Total Mesorectal Excision and Risk Factors: A Nationwide Multicenter Cohort Study in Japan. Annals of surgery open: perspectives of surgical history, education, and clinical approaches. 5(1):e369\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Rectal cancer, Transrectal approach, Transanal total mesorectal excision, Transperineal abdominoperineal resection","lastPublishedDoi":"10.21203/rs.3.rs-7089219/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7089219/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eAim:\u003c/strong\u003e Transanal approaches, such as transanal total mesorectal excision and transperineal abdominoperineal resection, have been developed to improve surgical quality for lower rectal cancer. However, international concerns have been raised about higher local recurrence rates. We investigated the usefulness of the transanal approach with respect to short- and long-term outcomes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e In total, 291 patients who underwent laparoscopic or robotic surgery for rectal cancer were enrolled. Clinical, pathological, surgical, and follow-up data were retrospectively collected. Patients were divided into a transanal approach group (n = 139) and a conventional total mesorectal excision group (n = 152). A 1:1 propensity score-matched analysis was performed to compare surgical outcomes between the two groups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e After matching, 65 patients were included in each group. In the transanal group, intersphincteric resection was performed more frequently and abdominoperineal resection was performed less frequently, resulting in a higher rate of anus preservation (72.3% vs. 53.8%). The operative time was shorter (278 [240–343] min vs. 317 [259–373] min, p = 0.030), and blood loss was lower (29 [10–50] mL vs. 50 [10–119] mL, p = 0.033) in the transanal group. Major complications (Clavien–Dindo ≥ III) were less frequent in the transanal group. Overall survival was also better in the transanal group. No significant difference was observed in the total recurrence rate, including local recurrence.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e The transanal approach may be a promising surgical option for lower rectal cancer, contributing to higher rates of anus preservation and improved short- and long-term outcomes.\u003c/p\u003e","manuscriptTitle":"Usefulness of transanal approach for lower rectal cancer: a propensity score-matched analysis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-22 08:16:16","doi":"10.21203/rs.3.rs-7089219/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"313be6c5-e794-49b4-9a5c-ac6b86383aeb","owner":[],"postedDate":"July 22nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-08-12T00:50:32+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-22 08:16:16","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7089219","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7089219","identity":"rs-7089219","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}