Learning Curve for Transanal Total Mesorectal Excision for Low Rectal Malignancy.

Previous studies have demonstrated the advantages of short-term histopathological outcomes and complications associated with transanal total mesorectal excision (TME) compared with laparoscopic TME. However, the long-term oncological outcomes of transanal TME remain ambiguous. This study aims to compare 3-year disease-free survival of transanal TME with laparoscopic TME. To evaluate 3-year disease-free survival between transanal TME and laparoscopic TME in patients with rectal cancer. This randomized, open-label, noninferiority, phase 3 clinical trial was performed in 16 different centers in China. Between April 2016 and June 2021, a total of 1115 patients with clinical stage I to III mid-low rectal cancer were enrolled. The last date of participant follow-up was in June 2024. Participants were randomly assigned in a 1:1 ratio before their surgical procedure to undergo either transanal TME (n = 558) or laparoscopic TME (n = 557). The primary end point was 3-year disease-free survival, with a noninferiority margin of -10% for the comparison between transanal TME and laparoscopic TME. Secondary outcomes included 3-year overall survival and 3-year local recurrence. In the primary analysis set, the median patient age was 60 years. A total of 692 male and 397 female patients were included in the analysis. Three-year disease-free survival was 82.1% (97.5% CI, 78.4%-85.8%) for the transanal TME group and 79.4% (97.5% CI, 75.6%-83.4%) for the laparoscopic TME group, with a difference of 2.7% (97.5% CI, -3.0% to 8.1%). The lower tail of a 2-tailed 97.5% CI for the group difference in 3-year disease-free survival was above the noninferiority margin of -10 percentage points. Furthermore, the 3-year local recurrence was 3.6% (95% CI, 2.0%-5.1%) for transanal TME and 4.4% (95% CI, 2.6%-6.1%) for laparoscopic TME. Three-year overall survival was 92.6% (95% CI, 90.4%-94.8%) for transanal TME and 90.7% (95% CI, 88.3%-93.2%) for laparoscopic TME. In patients with mid-low rectal cancer, 3-year disease-free survival for transanal TME was noninferior to that of laparoscopic TME. ClinicalTrials.gov Identifier: NCT02966483.

Total mesorectal excision has become the standard treatment for rectal cancer, and several investigators have shown that a transanal approach is a feasible option. This study aimed to evaluate the efficacy of transanal endoscopic total mesorectal excision in patients with rectal cancer. This study was a prospective, single-arm phase II trial. It was registered on clinicaltrials.gov under identifier NCT02406118. Inpatients at a hospital specializing in oncology were selected. This prospective study enrolled 49 patients with rectal cancer located 3 to 12 cm from the anal verge who were scheduled to undergo radical surgery. Laparoscopy-assisted transanal total mesorectal excision was performed. The primary end point was total mesorectal excision quality and circumferential resection margin. Secondary end points included the number of harvested lymph nodes, operation time, and 30-day postoperative complications. From March 2015 to April 2016, 32 men and 17 women with rectal cancer were enrolled. The mean age was 61.2 years, and mean BMI was 23.3 kg/m. The mean operating time was 158 minutes, and the mean estimated blood loss was 89.3 mL. There were no intraoperative complications and no conversions to open surgery. Successful treatment based on total mesorectal excision quality and circumferential resection margin was achieved in 45 patients (91.8%). Fifteen patients (30.6%) had 30-day postoperative complications, including 7 (14.3%) with anastomotic dehiscence, 5 (10.2%) with urinary retention, 2 (4.1%) with abdominal wound complications, and 1 (2.0%) with ileus. There was no postoperative mortality. This was a noncomparative single-arm trial conducted at a single institution. Transanal endoscopic total mesorectal excision showed acceptable results based on perioperative and short-term oncologic outcomes. Further investigations are necessary to show the benefits and long-term outcomes of this procedure. See Video Abstract at http://links.lww.com/DCR/A563.

Transanal total mesorectal excision (TaTME) is positioned at the cutting edge of minimally invasive approach to mid- and low rectal cancer. This meta-analysis was to compare the short- and long-term outcomes of TaTME versus laparoscopic total mesorectal excision (LTME) and to evaluate the safety, efficacy, and possible superiority of TaTME. A comprehensive search was conducted for randomized controlled trials (RCTs) and non-RCTs (NRCTs) comparing TaTME with LTME. Inter-group differences were evaluated via standardized mean differences and relative risks (RRs). All outcomes were analyzed using fixed effects or random effects models according to the heterogeneity. Statistical analysis was performed using Stata/SE 12.0 software. Eleven studies (1 RCT and 10 NRCTs) with involving 757 patients were included. Among which, 361 patients underwent TaTME and 396 patients underwent LTME. Comparing the surgical and oncological quality of resection of TaTME with that of LTME, reports of TaTME indicated favorable outcomes considering mesorectal resection quality, circumferential resection margin involvement, intraoperative blood loss, conversions, and postoperative complications, while the differences between the two groups had no statistical significance in terms of distal resection margin, harvested lymph node, operation time, hospital stay, recurrence, 2-year overall survival (OS), and 2-year disease-free survival. TaTME is a promising surgical technique and is fully a safe, efficacious, and diffusible alternative to LTME in managing mid- and distal rectal cancer. Larger scale, national, multicentric RCTs are warranted to further verify these results and the possible superiority of TaTME.

Transanal total mesorectal excision (TaTME) is an alternative technique for rectal surgery that could facilitate the mobilization and the distal transection of the rectum. Our objective was to analyze whether the presence of factors affecting the difficulty of laparoscopic total mesorectal excision (TME) could affect surgical and oncological outcomes of TaTME for mid and low rectal cancer. 20 patients (13 male, 7 female) with a mean age of 66.5 years (range 55.5–75.7) and mid–low rectal cancer were prospectively submitted to TaTME. Every TaTME procedure was performed by two teams of experienced surgeons working simultaneously. Adverse conditions for laparoscopic TME were considered to be male gender, obesity, benign prostatic hypertrophy, low rectal cancer, pT3-T4, tumor size >5 cm, and neoadjuvant therapy. These factors were matched to surgical (morbidity, operative time, conversion rate) and pathological (quality of mesorectum, circumferential resection margin) outcomes. Male gender was associated with longer operative time (285 vs. 240 min, p = 0.031). There were no significant associations among the rest of the analyzed factors complicating laparoscopic TME and pathological and surgical outcomes of TaTME. Multivariate analysis showed that male gender was independently associated with operative time (β = 0.18 OR 1.019 CI95%:1.001–1.037; p = 0.042). TaTME seems to be more difficult in males but not in obesity, benign prostatic hypertrophy, low rectal cancer, pT3-T4, tumor size >5 cm, or neoadjuvant therapy. TaTME could be considered an alternative surgery for low rectal cancer in the presence of these factors affecting laparoscopic TME.

The aim of this study was to compare long-term oncological, functional outcomes and quality of life (QoL) after transanal total mesorectal excision (TaTME) and laparoscopic total mesorectal excision (LaTME) for rectal cancer. A systematic review and meta-analysis based on Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were conducted on PubMed and Cochrane database. Non-randomized controlled trials (NRCTs) which compared TaTME with LaTME were included. Ten non-randomized studies were identified, including a total of 638 patients (323 TaTME and 315 LaTME). Age, sex, body mass index, neoadjuvant treatment and American Society of Anesthesiologists (ASA) staging of patients in the two groups were comparable in all included studies. The follow-up period was significantly shorter in the TaTME group than in the LaTME group. No significant differences in local (p = 0.71) and distant (p = 0.23) recurrence rate, 2-year disease-free (p = 0.86) and overall (p = 0.25) survival was found. Also, no significant differences in function outcomes and QoL, including the Wexner score (p = 0.48) or the International Prostate Syndrome Score (IPSS) (p = 0.64) were found. However, the low anterior resection syndrome (LARS) score was significantly higher in the TaTME group (p = 0.04). TaTME and LaTME have similar long-term oncological and functional outcomes as well as QoL. The only exception is higher LARS scores after TaTME. The current data are based mainly on observational studies and further randomized controlled trials are required.

Total mesorectal excision has evolved from open to minimally invasive techniques. To overcome difficulties in the lowest part of the pelvis, transanal total mesorectal excision was introduced and has gained acceptance in the recent years. The results of transanal total mesorectal excision seem to be comparable to laparoscopic total mesorectal excision. Whether or not transanal total mesorectal excision has changed the pattern of defects in the retrieved mesorectal specimens is yet to be clarified. To determine the pattern of mesorectal defects following transanal total mesorectal excision, compared to laparoscopic total mesorectal excision. The primary end-point was the location of defects in the part of the mesorectum below the peritoneal reflection, as it is this part, which is dissected from below in the transanal total mesorectal excision procedure. From our transanal total mesorectal excision database that includes all transanal total mesorectal excision procedures performed at our institution since 2013, we have included 29 patients who originally had defects in their retrieved specimens. Another 29 patients who underwent laparoscopic total mesorectal excision with mesorectal defects served as a control group. All specimen photos and pathology reports were reviewed systematically; sites and pattern of defects were defined. A higher ratio of the defects in the laparoscopic total mesorectal excision group was located below the peritoneal reflection (P = 0.043). The distribution of defects by anatomical quadrant was not statistically different between the groups. The ratio of defects below the peritoneal reflection was lower in the transanal total mesorectal excision group. Whether this is due to a lower incidence of defect in transanal total mesorectal excision is not part of our study.

The best approach for total mesorectal excision (TME) remains controversial. Two recently described approaches are robotic TME (RTME) and transanal TME (TaTME). This systematic review and meta-analysis aimed to compare the outcomes between robotic surgery and TaTME in patients undergoing rectal cancer resection. We structured this systematic review and meta-analysis according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines 2020 and Assessing the Methodological Quality of Systematic Reviews (AMSTAR) guidelines. An electronic search of relevant literature was conducted on 20 May 2023. The protocol was registered in PROSPERO (CRD42023435259). Eleven eligible nonrandomised studies were included in this study. The study included 2796 patients (RTME = 1800; TaTME = 996). The RTME group had a higher rate of complete TME. However, no significant differences were observed in mortality, morbidity, severe complications, operative time, conversion rate, anastomotic leak, hospital stay, CRM-positive resection margin, distal resection margin, number of harvested lymph nodes, abdominoperineal resection (APR) rate, or local recurrence between the RTME and TaTME groups. The RTME technique may ensure a higher rate of complete TME than TaTME. However, no significant differences were observed in most postoperative outcomes and oncological safety between the RTME and TaTME groups. Evidence does not conclusively favor one technique over the other, highlighting the need for additional randomized controlled trials to better define their roles in rectal cancer surgery.

Comparing efficacy and safety of transanal vs. laparoscopic total mesorectal excision for middle and low rectal cancer: Updated meta-analysis.

Natural orifice translumenal endoscopic surgery (NOTES) has always made more sense in the colorectal field where the target organ for entry houses the pathology. To address the question whether an adequate total mesorectal excision (TME) for rectal cancer can be performed from a transanal bottoms-up approach, we performed a case-matched study. Starting in 2009, transanal TME (taTME) surgery was selectively used for rectal cancer after neoadjuvant therapy and prospectively entered into a database. Between March 2012 and February 2014, 17 consecutive taTME rectal cancer patients were identified and case-matched to multiport laparoscopic TME (MP TME) based on age, body mass index, uT stage, radiation dose, level in the rectum, and procedure. Perioperative outcomes, morbidity, mortality, local recurrence, completeness of TME, and radial and distal margins were analyzed. Statistically significant differences were identified using Student's t test. There were 12 transanal abdominal transanal (TATA)/5 abdominoperineal resection procedures in each group. Data regarding overall/taTME/MP TME are as follows: % positive-circumferential margin: 2.9/0/5.9% (p=0.32). Distal margin: 0/0/0%. Complete or near-complete TME: 97.1/100/94.1% (p=0.32). Incomplete TME 2.9/0/5.9% (p=0.32). Local recurrence: 2.9/5.9/0% (p=0.32). There were no perioperative mortalities. Morbidity in each group: 26.4/23.5/29.4% (p=0.79). There were no differences in perioperative or postoperative outcomes except days to clear liquids (1/2days, p=0.03) and largest incision length (1.3/2.6cm, p=0.05). We demonstrated no differences in perioperative/postoperative outcomes or pathologic TME outcomes of transanal or bottoms-up TME compared to standard laparoscopic TME. TaTME is a promising progressive approach to NOTES and deserves additional evaluation.

Surgery for low rectal cancer remains a challenge when a standard laparoscopic approach is used. Transanal endoscopic total mesorectal excision (TME) has been shown to be feasible and to be associated with a low conversion rate. Combining the transanal and transabdominal single-port approaches (with an abdominal single port implanted in the future stoma and extraction site) could allow TME with minimal wound trauma, low morbidity, and faster recovery. The aim of the current study was to assess the short- and mid-term results of this technique. We conducted a prospective single-centre study of consecutive patients presenting with low rectal cancer requiring a conservative proctectomy with a manual coloanal anastomosis between January 2012 and April 2015. During the study period, 41 patients were recruited. Conversion to open surgery was required in only one patient (2.4%). The median operating time was 358.5min (range 300-600min). Partial intersphincteric resection was necessary for 15 patients (36.6%). The specimens were mostly extracted via the abdominal access (n=34) without wound complications. The mean number of lymph nodes harvested was 12.7 (range 6-24lymph nodes). Specimens were graded as complete (n=31) or nearly complete (n=10) in all of the patients, and the circumferential resection margin positivity was 4.9%. Intraoperative morbidity rate was 4.9%, and the 30-day morbidity rate was 24.4% (n=10). Sixty per cent (n=6) of the patients with 30-day morbidity were Dindo I-II. At a median follow-up of 29months, overall and disease-free survival rates were 97.5 and 80.5%, respectively. The stoma-free survival rate was 95.1%. Combining an endoscopic transanal TME and a single laparoscopic ileostomy-site proctectomy is a promising minimally invasive approach for the treatment of low rectal cancer.

Transanal total mesorectal excision versus laparoscopic total mesorectal excision for mid and low rectal cancer (COLOR III): short-term outcomes of an international, multicentre, phase 3, randomised, controlled, non-inferiority trial.

BackgroundTransanal total mesorectal excision (TaTME) is associated with a relatively long learning curve. Force, motion, and time parameters are increasingly used for objective assessment of skills to enhance laparoscopic training efficacy. The aim of this study was to identify relevant metrics for accurate skill assessment in more complex transanal purse-string suturing.MethodsA box trainer was designed for TaTME and equipped with two custom made multi-DOF force/torque sensors. These sensors measured the applied forces in the axial direction of the instruments (Fz), instrument load orientation expressed in torque (Mx and My) on the entrance port, and the full tissue interaction force (Fft) at the intestine fixation point. In a construct validity study, novices for TaTME performed a purse-string suture to investigate which parameters can be used best to identify meaningful events during tissue manipulation and instrument handling.ResultsSignificant differences exist between pre- and post-training assessment for the mean axial force at the entrance port Fz (p = 0.01), mean torque in the entrance port Mx (p = 0.03) and mean force on the intestine during suturing Fft (p = 0.05). Furthermore, force levels during suturing exceed safety threshold values, potentially leading to dangerous complications such as rupture of the rectum.ConclusionsForces and torque measured at the entrance port, and the tissue interaction force signatures provide detailed insight into instrument handling, instrument loading, and tissue handling during purse-string suturing in a TaTME training setup. This newly developed training setup for single-port laparoscopy that enables objective feedback has the potential to enhance surgical training in TaTME.

Sphincter-preserving therapy for low rectal cancer has always been a difficult and hot topic in colorectal cancer. Advanced understanding of the biological behavior of rectal cancer and the pelvic fascial anatomy have laid the theoretical foundation for sphincter preservation, shifting the surgical paradigm from radical resection alone toward both oncological safety and function preservation. Guided by the principle of TME and supported by minimally invasive technologies, a variety of surgical methods including low anterior resection(LAR), Bacon, intersphincteric resection(ISR), conformal sphincter-preservation operation(CSPO) and transanal total mesorectal excision(taTME), have progressively pushed the sphincter-preserving surgery to the limit in the inheritance of history. In addition to surgery, non-surgical management based on the "Watch & Wait" strategy provides a new sphincter-preserving option for selected patients. Meanwhile, the rise of immunotherapy is reshaping the pattern of sphincter-preserving treatment in the future. The continuous trial and exploration of immunotherapy combined with neoadjuvant therapy in protein mismatch repair proficient(pMMR)/microsatellite stable(MSS) patients is expected to further improve the overall rate of sphincter preservation rate and organ preservation. In the future, sphincter-preserving treatment for low rectal cancer will be more patient-centered. By integrating the advantages of precision medicine and multidisciplinary collaboration, and giving full play to the potential of artificial intelligence, patients will achieve the best balance between oncology safety and function preservation.

To evaluate systematically the short- and long-term outcomes between laparoscope-assisted transanal total mesorectal excision (LA-taTME) and laparoscopic total mesorectal excision (L-TME) in the treatment of mid and low rectal cancer. Literatures comparing LA-taTME with L-TME published from January 2014 to January 2018 were systematically selected through searching PubMed, Ovid, EMbase, Cochrane Library, CNKI and Wanfang databases. Literature screening and methodology quality evaluation were carried out by two surgeons independently. Randomized controlled trial (RCT) was evaluated by the modified Jadad rating scale, in which 1 to 3 and 4 to 7 were considered as low and high quality,respectively(total scores: 7). Non-randomized controlled trial (NRCT) was assessed by the modified Newcastle Ottawa Scale (NOS), in which 1 to 3, 4 to 6, and 7 to 9 were defined as low, moderate, and high quality, respectively (total score: 9). Ratio of incomplete mesorectum, positive rate of circumferential resection margin (CRM), number of harvested lymph node, distance of distal resection margin, operation time, intraoperative blood loss, morbidity of postoperative complication, conversion rate, hospital stay, recurrence, 2-year disease-free survival (DFS) and 2-year overall survival (OS) were compared and analyzed by using Stata/SE12.0 software. Fourteen studies including 1 RCT and 13 NRCTs were enrolled finally. Among them, the RCT with a score of 6 was considered to be of high quality; all NRCTs (2 with 6 stars, 5 with 7 stars, and another 6 with 8 stars) were indicative of moderate to high quality; 450 patients underwent LA-taTME and 498 patients underwent L-TME. No significant differences were observed in terms of age, gender, tumor location and TNM stage between two approaches (all P>0.05). Compared to L-TME, LA-taTME had lower ratio of incomplete mesorectum (RR=0.53, 95%CI: 0.31 to 0.93, P=0.026), lower positive rate of CRM (RR=0.50, 95%CI: 0.29 to 0.86, P=0.012), lower conversion rate(RR=0.48, 95%CI: 0.26 to 0.86, P=0.014), lower morbidity of postoperative complication (RR=0.81, 95%CI: 0.67 to 0.99, P=0.036) and less intraoperative blood loss (SMD=-0.38, 95%CI:-0.68 to -0.08, P=0.013). While the differences between two groups had no statistical significance in terms of operative duration, number of harvested lymph node, distance of distal resection margin, hospital stay, overall recurrence, 2-year DFS and 2-year OS (all P>0.05). The short- and long-term outcomes of LA-taTME and L-TME for the treatment of mid and low rectal cancer are comparable, while LA-taTME can reduce the ratio of incomplete mesorectum, positive rate of CRM, conversion rate, and morbidity of postoperative complication, and intraoperative blood loss.

Objective To explore the effect and significance of structured training through the clinical work carried out by the trainees after undergoing structured training of transanal total mesorectal excision (taTME). Methods Statistical analysis of 20 surgical outcomes, postoperative complications, and subjective proficiency evaluation of taTME surgery performed after training through retrospective analysis. Results Twenty patients were divided into the first 10 cases (group A) and the latter 10 cases (group B) for grouping comparison. There was no statistical difference in the occurrence of surgical bleeding, preventive ostomy and anastomotic leakage, and there was no difference in the total operation time between the two groups, the time of perineal operation (t=2.557, P=0.05) and the time of the anus platform (t=4.575, P<0.01) were significantly lower than that of group A. There were more patients with manual anastomosis in group B than those in group A. There was no statistical difference in the evaluation indexes of prostate or vaginal posterior wall identification and suture of the two groups of patients. There were statistical differences in the evaluation of the quality of the anastomosis (t=8.667, P<0.05). Conclusion Before carrying out a taTME operation, through structured training, this reasonable teaching method can enable clinicians to deeply grasp the anatomical structure of pelvic perianal, shorten the learning curve, improve the safety of operation and protect the rights and interests of patients. Key words: Rectal neoplasms; Transanal total mesorectal excision; Structured training; Learning curve