Robotic transanal minimally invasive surgery (R-TAMIS): current evidence in the treatment of early rectal neoplasia.

INTRODUCTION: Robotic transanal minimally invasive surgery (R-TAMIS) was introduced in 2012 for the excision of benign rectal polyps and low grade rectal cancer. Ergonomic improvements over traditional laparoscopic TAMIS (L-TAMIS) include increased dexterity within a small operative field, with possibility of better surgical precision. We aim to collate the existing data surrounding the use of R-TAMIS to treat rectal neoplasms from cohort studies and larger case series, providing a foundation for future, large-scale, comparative studies. METHODS: Medline, EMBASE and Web of Science were searched as part of our review. Randomised controlled trials (RCTs), cohort studies or large case series (≥ 5 patients) investigating the use of R-TAMIS to resect rectal neoplasia (benign or malignant) were eligible for inclusion in our analysis. Quality assessment of included studies was performed via the Newcastle Ottawa Scale (NOS) risk of bias tool. Outcomes extracted included basic participant characteristics, operative details and histopathological/oncological outcomes. RESULTS: Eighteen studies on 317 participants were included in our analysis. The quality of studies was generally satisfactory. Overall complication rate from R-TAMIS was 9.7%. Clear margins (R0) were reported in 96.2% of patients. Local recurrence (benign or malignant) occurred in 2.2% of patients during the specified follow-up periods. CONCLUSION: Our review highlights the current evidence for R-TAMIS in the local excision of rectal lesions. While R-TAMIS appears to have complication, margin negativity and recurrence rates superior to those of published L-TAMIS series, comparative studies are needed.

Transanal ileal pouch-anal anastomosis: A systematic review and meta-analysis of technical approaches and clinical outcomes.

PURPOSE: Transanal minimally invasive surgery has theoretical advantages for ileal pouch-anal anastomosis surgery. We performed a systematic review assessing technical approaches to transanal IPAA (Ta-IPAA) and meta-analysis comparing outcomes to transabdominal (abd-IPAA) approaches. METHODS: Three databases were searched for articles investigating Ta-IPAA outcomes. Primary outcome was anastomotic leak rate. Secondary outcomes included conversion rate, post operative morbidity, and length of stay (LoS). Staging, plane of dissection, anastomosis, extraction site, operative time, and functional outcomes were also assessed. RESULTS: Searches identified 13 studies with 404 unique Ta-IPAA and 563 abd-IPAA patients. Anastomotic leak rates were 6.3% and 8.4% (RD 0, 95% CI -0.066 to 0.065, p = 0.989) and conversion rates 2.5% and 12.5% (RD -0.106, 95% CI -0.155 to -0.057, p = 0.104) for Ta-IPAA and abd-IPAA. Average LoS was one day shorter (MD -1, 95% CI -1.876 to 0.302, p = 0.007). A three-stage approach was most common (47.6%), operative time was 261(± 60) mins, and total mesorectal excision and close rectal dissection were equally used (49.5% vs 50.5%). Functional outcomes were similar. Lack of randomised control trials, case-matched series, and significant study heterogeneity limited analysis, resulting in low to very low certainty of evidence. CONCLUSIONS: Analysis demonstrated the feasibility and safety of Ta-IPAA with reduced LoS, trend towards less conversions, and comparable anastomotic leak rates and post operative morbidity. Though results are encouraging, they need to be interpreted with heterogeneity and selection bias in mind. Robust randomised clinical trials are warranted to adequately compare ta-IPAA to transabdominal approaches.

Duhamel and transanal endorectal pull-throughs for Hirschsprung disease: a Bayesian network meta-analysis.

BACKGROUND: To comprehensively compare the effects of open Duhamel (OD), laparoscopic-assisted Duhamel (LD), transanal endorectal pull-through (TEPT), and laparoscopic-assisted endorectal pull-through (LEPT) in Hirschsprung disease. METHODS: PubMed, Embase, Cochrane Library, Web of Science, CNKI, WanFang, and VIP were comprehensively searched up to August 4, 2022. The outcomes were operation-related indicators and complication-related indicators. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to evaluate the quality of evidence. Network plots, forest plots, league tables and rank probabilities were drawn for all outcomes. For measurement data, weighted mean differences (WMDs) and 95% credibility intervals (CrIs) were reported; for enumeration data, relative risks (RRs) and 95%CrIs were calculated. RESULTS: Sixty-two studies of 4781 patients were included, with 2039 TEPT patients, 1669 LEPT patients, 951 OD patients and 122 LD patients. Intraoperative blood loss in the OD group was more than that in the LEPT group (pooled WMD = 44.00, 95%CrI: 27.33, 60.94). Patients lost more blood during TEPT versus LEPT (pooled WMD = 13.08, 95%CrI: 1.80, 24.30). In terms of intraoperative blood loss, LEPT was most likely to be the optimal procedure (79.76%). Patients undergoing OD had significantly longer gastrointestinal function recovery time, as compared with those undergoing LEPT (pooled WMD = 30.39, 95%CrI: 16.08, 44.94). The TEPT group had significantly longer gastrointestinal function recovery time than the LEPT group (pooled WMD = 11.49, 95%CrI: 0.96, 22.05). LEPT was most likely to be the best operation regarding gastrointestinal function recovery time (98.28%). Longer hospital stay was observed in patients with OD versus LEPT (pooled WMD = 5.24, 95%CrI: 2.98, 7.47). Hospital stay in the TEPT group was significantly longer than that in the LEPT group (pooled WMD = 1.99, 95%CrI: 0.37, 3.58). LEPT had the highest possibility to be the most effective operation with respect to hospital stay. The significantly reduced incidence of complications was found in the LEPT group versus the LD group (pooled RR = 0.24, 95%CrI: 0.12, 0.48). Compared with LEPT, OD was associated with a significantly increased incidence of complications (pooled RR = 5.10, 95%CrI: 3.48, 7.45). Patients undergoing TEPT had a significantly greater incidence of complications than those undergoing LEPT (pooled RR = 1.98, 95%CrI: 1.63, 2.42). For complications, LEPT is most likely to have the best effect (99.99%). Compared with the LEPT group, the OD group had a significantly increased incidence of anastomotic leakage (pooled RR = 5.35, 95%CrI: 1.45, 27.68). LEPT had the highest likelihood to be the best operation regarding anastomotic leakage (63.57%). The incidence of infection in the OD group was significantly higher than that in the LEPT group (pooled RR = 4.52, 95%CrI: 2.45, 8.84). The TEPT group had a significantly increased incidence of infection than the LEPT group (pooled RR = 1.87, 95%CrI: 1.13, 3.18). LEPT is most likely to be the best operation concerning infection (66.32%). Compared with LEPT, OD was associated with a significantly higher incidence of soiling (pooled RR = 1.91, 95%CrI: 1.16, 3.17). Patients with LEPT had the greatest likelihood not to develop soiling (86.16%). In contrast to LD, LEPT was significantly more effective in reducing the incidence of constipation (pooled RR = 0.39, 95%CrI: 0.15, 0.97). LEPT was most likely not to result in constipation (97.81%). LEPT was associated with a significantly lower incidence of Hirschprung-associated enterocolitis (HAEC) than LD (pooled RR = 0.34, 95%CrI: 0.13, 0.85). The OD group had a significantly higher incidence of HAEC than the LEPT group (pooled RR = 2.29, 95%CrI: 1.31, 4.0). The incidence of HAEC was significantly greater in the TEPT group versus the LEPT group (pooled RR = 1.74, 95%CrI: 1.24, 2.45). LEPT was most likely to be the optimal operation in terms of HAEC (98.76%). CONCLUSION: LEPT may be a superior operation to OD, LD and TEPT in improving operation condition and complications, which might serve as a reference for Hirschsprung disease treatment.

Laparoscopic total mesorectal excision versus transanal total mesorectal excision for mid and low rectal cancer: A systematic review and meta-analysis.

BACKGROUND: Laparoscopic total mesorectal excision (LaTME) and transanal total mesorectal excision (TaTME) are popular mid and low rectal cancer trends. However, there is currently no systematic comparison between LaTME and TaTME of mid and low rectal cancer. Therefore, we systematically study the perioperative and pathological outcomes of LaTME and TaTME in mid and low rectal cancer. METHODS: Articles included searching through the Embase, Cochrane Library, PubMed, Medline, and Web of science for articles on LaTME and TaTME. We calculated pooled standard mean difference (SMD), relative risk (RR), and 95% confidence intervals (CIs). The protocol for this review has been registered on PROSPERO (CRD42022380067). RESULTS: There are 8761 participants included in 33 articles. Compared with TaTME, patients who underwent LaTME had no statistical difference in operation time (OP), estimated blood loss (EBL), postoperative hospital stay, over complications, intraoperative complications, postoperative complications, anastomotic stenosis, wound infection, circumferential resection margin, distal resection margin, major low anterior resection syndrom, lymph node yield, loop ileostomy, and diverting ileostomy. There are similarities between LaTME and TaTME for 2-year DFS rate, 2-year OS rate, distant metastasis rat, and local recurrence rate. However, patients who underwent LaTME had less anastomotic leak rates (RR 0.82; 95% CI: 0.70-0.97; I2 = 10.6%, P = .019) but TaTME had less end colostomy (RR 1.96; 95% CI: 1.19-3.23; I2 = 0%, P = .008). CONCLUSION: This study comprehensively and systematically evaluated the differences in safety and effectiveness between LaTME and TaTME in the treatment of mid and low rectal cancer through meta-analysis. Patients who underwent LaTME had less anastomotic leak rate but TaTME had less end colostomy. There is no difference in other aspects. Of course, in the future, more scientific and rigorous conclusions need to be drawn from multi-center RCT research.

Long-term oncological outcomes of transanal versus laparoscopic total mesorectal excision for mid-low rectal cancer: a retrospective analysis of 2502 patients.

BACKGROUND: Transanal total mesorectal resection (taTME) has recently emerged as a promising surgical approach for the treatment of mid-low rectal cancer. However, there is limited evidence on the long-term survival outcomes associated with taTME. This retrospective study aimed to compare the overall survival (OS), disease-free survival (DFS), and cancer-specific survival of taTME and laparoscopic TME (laTME) in patients with mid-low rectal cancer. MATERIALS AND METHODS: From July 2014 to June 2022, a total of 3627 patients were identified from two prospective cohorts: the laparoscopic rectal surgery cohort and the CNTAES cohort. To balance the baseline characteristics between the taTME and laTME groups, propensity score matching (PSM) was performed. RESULTS: A total of 2502 patients were included in the study. Prior to PSM, the laTME group comprised 1853 patients, while the taTME group comprised 649 patients. The 5-year OS (82.9% vs. 80.4%, P =0.202) and 5-year DFS (74.4% vs. 72.5%, P =0.167) were comparable between the taTME and laTME groups. After PSM, the taTME group showed no statistically significant difference in the 5-year OS (83.1% vs. 79.2%, P =0.101) and 5-year DFS (74.8% vs. 72.1%, P =0.135) compared to the laTME group. Subgroup analysis further suggested that taTME may potentially reduce the risk of death [hazard ratio 0.652; (95% CI, 0.452-0.939)] and disease recurrence [hazard ratio 0.736; (95% CI, 0.562-0.965)] specifically in patients with low rectal cancer. CONCLUSION: In this study, taTME demonstrated comparable oncologic safety to laTME in patients with mid-low rectal cancer. Moreover, the results indicate that taTME may confer potential survival benefits for patients with low rectal cancer.

Revolutionizing sphincter preservation in ultra-low rectal cancer: exploring the potential of transanal endoscopic intersphincteric resection (taE-ISR): a propensity score-matched cohort study.

BACKGROUND: With the optimization of neoadjuvant treatment regimens, the indications for intersphincteric resection (ISR) have expanded. However, limitations such as unclear surgical field, impaired anal function, and failure of anal preservation still exist. Transanal total mesorectal excision can complement the drawbacks of ISR. Therefore, this study combined these two techniques and proposed transanal endoscopic intersphincteric resection (taE-ISR), aiming to explore the value of this novel technique in anal preservation for ultra-low rectal cancer. MATERIAL AND METHODS: Four high-volume centres were involved. After 1:1 propensity score-matching, patients with ultra-low rectal cancer underwent taE-ISR ( n =90) or ISR ( n =90) were included. Baseline characteristics, perioperative outcomes, pathological results, and follow-up were compared between the two groups. A nomogram model was established to assess the potential risks of anal preservation. RESULTS: The incidence of adjacent organ injury (0.0% vs. 5.6%, P =0.059), positive distal resection margin (1.1% vs. 8.9%, P =0.034), and incomplete specimen (2.2% vs. 13.3%, P =0.012) were lower in taE-ISR group. Moreover, the anal preservation rate was significantly higher in taE-ISR group (97.8% vs. 82.2%, P =0.001). Patients in the taE-ISR group showed a better disease-free survival ( P =0.044) and lower cumulative recurrence ( P =0.022) compared to the ISR group. Surgery procedure, tumour distance, and adjacent organ injury were factors influencing anal preservation in patients with ultra-low rectal cancer. CONCLUSION: taE-ISR technique was safe, feasible, and improved surgical quality, anal preservation rate and survival outcomes in ultra-low rectal cancer patients. It held significant clinical value and showed promising application prospects for anal preservation.

Transanal Total Mesorectal Excision With Delayed Coloanal Anastomosis (TaTME-DCAA) Versus Laparoscopic Total Mesorectal Excision (LTME) and Robotic Total Mesorectal Excision (RTME) for Low Rectal Cancer: A Propensity Score-Matched Analysis of Short-term Outcomes, Bowel Function, and Cost.

INTRODUCTION: Total mesorectal excision (TME) with delayed coloanal anastomosis (DCAA) is surgical option for low rectal cancer, replacing conventional immediate coloanal anastomosis (ICAA) with bowel diversion. This study aimed to assess the outcomes of transanal TME (TaTME) with DCAA versus laparoscopic TME (LTME) with ICAA versus robotic TME (RTME) with ICAA. METHODS: This was a retrospective propensity score-matched analysis of patients who underwent elective TaTME-DCAA between November 2021 and June 2022. Patients were propensity-score matched in a ratio of 1:3 to patients who underwent LTME-ICAA and RTME-ICAA from January 2019 to December 2020. Outcome measures were histopathologic results, postoperative morbidity, function, and inpatient costs. RESULTS: Twelve patients in the TaTME-DCAA group were compared with 36 patients in the LTME-ICAA and RTME-ICAA groups each after propensity score matching. Histopathologic results and postoperative morbidity rates were statistically similar. Overall stoma-related complication rates in the ICAA groups were 11%. Median total length of hospital stays for TME plus stoma reversal surgery was similar across all techniques (10 vs. 10 vs. 9 days; P =0.532). Despite a significantly shorter duration of follow-up, bowel function after TaTME-DCAA was comparable to that of LTME-ICAA and RTME-ICAA. Overall median inpatient costs of TaTME-DCAA were comparable to LTME-ICAA and significantly cheaper than RTME-ICAA ($31,087 vs. $29,927 vs. $36,750; P =0.002). CONCLUSIONS: TaTME with DCAA is a feasible and safe technique compared with other minimally invasive methods of TME, while avoiding bowel diversion and stoma-related complications, as well as comparing favorably in terms of overall hospitalization costs.

Transanal minimally invasive surgery for benign and malignant rectal lesions: midterm outcomes from a tertiary center.

BACKGROUND: Although transanal minimally invasive surgery (TAMIS) for rectal neoplasia has gained wide acceptance, the mid-term and long-term outcomes are not widely reported in the literature. OBJECTIVE: Describe the mid-term outcomes of patients who underwent TAMIS for benign and malignant rectal lesions in a single center. DESIGN: Retrospective cohort study. SETTINGS: Tertiary referral center. PATIENTS AND METHODS: Demographic, clinical, and oncological outcomes of patients who underwent TAMIS between January 2015 and December 2022 were prospectively collected. The indication for TAMIS was based on the National Comprehensive Cancer Network guidelines. The follow up for the cancer patients included clinical examination, tumor markers every 6 months and MRI rectum at the end of one year. In addition, colonoscopy and CT scan at years one and three and a final CT scan and colonoscopy at year five. MAIN OUTCOME MEASURES: Mid-term oncological and clinical outcome. RESULTS: Thirty elective TAMIS procedures included adenocarcinoma for 33.3% (n=10) of the patients, 20% (n=6) neuroendocrine tumor and the 40% (n=12) were adenomatous lesions. Negative resection margins were achieved in all malignant lesions. Perioperative complications occurred in 2 patients (6.6%), one patient had breaching into the peritoneal cavity, and postoperative hypotension occurred in another patient. The median follow-up time was 23 months (range: 5-72 months). Two patients with adenoma and positive margins developed recurrent adenoma (6.6%) and one patient with initial polypectomy biopsy of adenocarcinoma, had TAMIS with histopathology of adenoma and distant metastasis had developed. CONCLUSIONS: TAMIS for local excision of rectal neoplasia is a valid option with favorable mid-term outcomes provided there is adherence to careful selection criteria. LIMITATIONS: Retrospective nature and small number of the patients.

Eight years experience of transanal endoscopic microsurgery

Introduction: Transanal Endoscopic Microsurgery (TEM) is a minimally invasive method for management of different proctologic conditions. Despite widespread use of this method, it is not used widely in Iran. This report is about to describe the application of TEM in managing different proctologic conditions in a tertiary colorectal referral center in Iran regarding methods and complications. Methods: All of the patients' documents such as procedure, method, early postop complications and further operations were actively reviewed and the data were entered in to the database. Results: Since 2012 till the end of 2020 chart review was done and 150 cases of TEM operation were found. The most frequent procedure that was done was resection procedure. Using different energy devices during surgery or suturing versus not suturing the defect were not associated with complication. There was a case of in hospital mortality and one case delayed perianal fistula following TEM. Measurement of lesion distance from anal verge was not significantly different using TEM or colonoscopy. Villous adenomas detected in colonoscopy were mostly associated with malignancy. In evaluated resected lesions most of cases had free base and distance from anal verge or using different energy devices were not associated with obtaining free base. Conclusion: TEM is a safe minimal invasive procedure with acceptable complications that could be helped in managing different proctologic conditions and the results of reviewing our patients revealed the same results that is reported from other colorectal centers. (AU)

A prospective phase II clinical trial/IDEAL Stage 2a series of single-port robotic colorectal surgery for abdominal and transanal cases.

AIM: Slow laparoscopy adoption accelerated the uptake of robotic surgery. However, the current robotic platforms have limitations in transanal applications and multiple port sites. The da Vinci single-port (SP) robot is currently used on trial for colorectal surgery, and broad assessment of outcomes is needed. We aimed to report findings of a phase II clinical trial of SP robotic colorectal surgery. METHODS: A sequentially reported prospective case series was performed on patients using SP robotics at a tertiary referral centre from 1 October 2018 to 31 August 2021. Cases were stratified into abdominal and transanal cohorts. Demographics, intra-operative variables and 30-day postoperative outcomes were evaluated. Univariate analysis was performed, with statistical process control for the docking process. Main outcomes were conversion rates, morbidity, mortality and point of standardization of docking. RESULTS: In all, 133 patients were included: 93 (69.92%) abdominal and 40 (30.08%) transanal. The main diagnosis was rectal cancer (n = 59) and the procedure performed a robotic transanal abdominal transanal radical proctosigmoidectomy (n = 30). There were no conversions to open surgery. Two abdominal (2.15%) and three transanal cases (7.50%) were converted to laparoscopy. All colorectal adenocarcinomas had negative margins, proper lymph node harvest and complete mesorectal excision, as appropriate. Docking became a standardized process at cases 34 (abdominal) and 23 (anorectal). After surgery, bowel function returned on mean day 2 (abdominal) and 1 (transanal). The morbidity rate was 15.05% (abdominal) and 27.50% (transanal). There were two major morbidities in each cohort. Overall, there were three (2.65%) readmissions, one reoperation and no mortality. CONCLUSIONS: Single-port robotics is feasible for all types of colorectal procedures, with good clinical and oncological outcomes. With this development in colorectal surgery, further studies can develop best practices with this novel technology.

Clinical Experience of a Smart Articulating Digital Device for Transanal Minimally Invasive Surgery.

BACKGROUND: The constrained access associated with transanal minimally invasive surgery has led surgeons to deploy robotic-assisted platforms to offset inherent maneuverability limitations and, perhaps, skills deficits. IMPACT OF INNOVATION: A handheld, powered 5-mm lightweighted laparoendoscopic electromechanical digital device (HandX, HumanXtensions, Israel) with hardware and software components that convert surgical hand movements precisely to the instrument's articulating tip and enable robotic transanal minimally invasive surgery with full tip roticulation for hook diathermy and suturing. TECHNOLOGY, MATERIALS, AND METHODS: After bench and biomedical model training, HandX was used in 3 transanal minimally invasive surgery procedures (2 male patients and 1 female patient, mean age 66.3 years). The rectal lesions averaged 30 mm in maximum dimension and were located posteriorly (n = 2) and laterally (n = 1) a mean of 3 cm from the anal verge. Standard transanal minimally invasive surgery setup and instrumentation (Gelport Path, Applied Medical with Airseal, and Conmed) were used, adding the HandX device for circumferential lesion marking and hemostatic full-thickness excision as well as defect suturing where appropriate. PRELIMINARY RESULTS: All procedures were completed without undue prolongation (operating times <1 hour) despite nuisance hemorrhoidal bleeding in 1 patient. All lesions were fully excised, with 2 being T1 cancers and 1 tubulovillous adenoma with high-grade dysplasia. All patients were discharged within 48 hours postoperatively (1 experienced secondary hemorrhage on postoperative day 5). CONCLUSIONS AND FUTURE DIRECTIONS: HandX capably facilitated endoscopic robot-like instrument movement for transanal minimally invasive surgery without disrupting workflows. With time dedicated to instrument understanding and training, HandX increased dexterity with a small operating room footprint and may offer greater cost-effectiveness than other platforms.

The role of transanal compared to laparoscopic total mesorectal excision (taTME vs. lapTME) for the treatment of mid-low rectal cancer in obese patients: outcomes of a multicenter propensity-matched analysis.

To compare the rate of sphincter-saving interventions between transanal and laparoscopic Total Mesorectal Excision in this particular group of patients. A multicentre observational study was conducted using a prospective database, including patients diagnosed with rectal cancer below the peritoneal reflection and BMI ≥ 30 kg/m2, who underwent minimally invasive elective surgery over a 5-year period. Exclusion criteria were (1) sphincter and/or puborectalis invasion; (2) multi-visceral resections; (3) palliative surgeries. The study population was divided into two groups according to the intervention: transanal or laparoscopic total mesorectal excision. The primary outcome was the rate of sphincter-saving surgery. Secondary outcomes included conversion, postoperative complications, quality of the specimen, and survival. A total of 93 patients were included; 40 (43%) transanal total mesorectal excision were compared to 53 (57%) laparoscopic. In addition, 35 cases of transanal approach were case-matched with an equal number of laparoscopic approaches, based on gender, tumor's height, and neoadjuvant therapy. In both groups, 43% of the patients had low rectal cancer; however, the rate of sphincter-saving surgery was significantly higher in the transanal group (97% vs. 71%, p = 0.003). There were no conversions to open surgery in the transanal group, compared to 2 cases in the laparoscopic group (6%) (p = 0.246). The percentage of major complications was similar, including the rate of anastomotic leakage (10% transanal vs. 19% laparoscopic, p = 0.835). In our experience, higher percentages of sphincter-saving procedures and lower conversion rates are potential benefits of using the transanal approach in a complex surgical setting population of obese patients with mid-low rectal tumors when compared to laparoscopic.

Comparing perioperative and oncological outcomes of transanal and laparoscopic total mesorectal excision for rectal cancer: a meta-analysis of randomized controlled trials and prospective studies.

INTRODUCTION: Meta-analysis of the results of transanal total mesorectal excision (taTME) and laparoscopic TME (laTME) regarding perioperative and oncological outcomes have been conducted. Due to the lack of high-quality randomized controlled trials (RCTs) and prospective studies in the included literature, the conclusions are unreliable. This study included RCTs and prospective studies for analysis to obtain more reliable conclusions. MATERIALS AND METHODS: Systematic searches of the PubMed, Embase, and Cochrane Library databases were conducted up to June 2023. To assess the quality, the Cochrane quality assessment tool and the Newcastle-Ottawa Scale were employed. The perioperative and oncological outcomes were then analyzed. The I2 statistic was used to evaluate statistical heterogeneity and sensitivity analyses was conducted. RESULTS: A total of 22 studies, comprising 5056 patients, were included in the analysis, of which 6 were RCTs and 16 were prospective studies. The conversion rate in the taTME group was significantly lower than that in the laTME group (OR 0.14, 95% CI 0.09 to 0.22, P < 0.01), and the circumferential resection margin (CRM) was longer (MD 0.99 mm, 95% CI 0.66 to 1.32 mm, P < 0.01), with a lower rate of positive CRM involvement (OR 0.68, 95% CI 0.47 to 0.97, P = 0.03). No statistically significant differences were found in terms of the operation time, intraoperative blood loss, complications, anastomotic leakage, uroschesis, obstruction, secondary operation, hospital stay, urethral injury, readmission, mortality rate within 30 days, mesorectal resection quality, number of harvested lymph nodes, distal resection margin (DRM), positive DRM, local recurrence, and distance recurrence (P > 0.05). CONCLUSION: According to the findings of this meta-analysis, which is based on RCTs and prospective studies, taTME appears to have an advantage over laTME in terms of conversion rate and CRM involvement.

Impact of trans-anal versus laparoscopic total mesorectal excision on the surgical and pathologic outcomes of patients with rectal cancer: meta-analysis of randomized controlled trials.

BACKGROUND: Despite its profound impact on the oncologic outcomes of rectal cancer, the most optimal surgical approach to total mesorectal excision (TME) has not been identified yet. All previous meta-analyses on this subject have been based on observational studies. This meta-analysis was conducted to assess the surgical and oncologic outcomes of laparoscopic TME (LaTME) compared to trans-anal TME (TaTME), utilizing only randomized controlled trials. DESIGN: Systematic review and meta-analysis of randomized controlled trials. METHODS: We searched electronic databases (MEDLINE, Cochrane CENTRAL, Clinicaltials.gov) from 2010 onwards, for all published clinical trials comparing TaTME to LaTME. Results are presented as risk ratios, with 95% CI, and pooled using the random effects model. RESULTS: A total of 1691 patients, from 6 eligible randomized controlled trials, were included for analysis. Analyzed data showed no significant difference in morbidity (RR: 0.85, p = 0.15), mortality (RR: 0.50, p = 0.44), conversion to open (RR: 0.40, p = 0.07), or anastomotic leakage (RR: 0.73, p = 0.10) between TaTME and LaTME. There was also no difference in the rate of positive distal resection margin (DRM) (RR: 0.55, p = 0.10) or positive circumferential resection margin (CRM) (RR: 0.67, p = 0.30). Patients undergoing TaTME were more likely to have a complete TME (RR: 1.06, p = 0.002) and shorter hospital stays (RR: - 0.97, p < 0.00001). CONCLUSIONS: Patients undergoing TaTME for rectal cancer were more likely to have a complete TME when compared to LaTME, though this did not translate into improved distal or circumferential resection margin. Additionally, TaTME and LaTME had similar surgical outcomes except for shorter length of stay with TaTME.

Multicenter phase II trial of transanal total mesorectal excision for rectal cancer: preliminary results.

BACKGROUND: Transanal TME (taTME) combines abdominal and transanal dissection to facilitate sphincter preservation in patients with low rectal tumors. Few phase II/III trials report long-term oncologic and functional results. We report early results from a North American prospective multicenter phase II trial of taTME (NCT03144765). METHODS: 100 patients with stage I-III rectal adenocarcinoma located ≤ 10 cm from the anal verge (AV) were enrolled across 11 centers. Primary and secondary endpoints were TME quality, pathologic outcomes, 30-day and 90-day outcomes, and stoma closure rate. Univariable regression analysis was performed to assess risk factors for incomplete TME and anastomotic complications. RESULTS: Between September 2017 and April 2022, 70 males and 30 females with median age of 58 (IQR 49-62) years and BMI 27.8 (IQR 23.9-31.8) kg/m2 underwent 2-team taTME for tumors located a median 5.8 (IQR 4.5-7.0) cm from the AV. Neoadjuvant radiotherapy was completed in 69%. Intersphincteric resection was performed in 36% and all patients were diverted. Intraoperative complications occurred in 8% including 3 organ injuries, 2 abdominal and 1 transanal conversion. The 30-day and 90-day morbidity rates were 49% (Clavien-Dindo (CD) ≥ 3 in 28.6%) and 56% (CD ≥ 3 in 30.4% including 1 mortality), respectively. Anastomotic complications were reported in 18% including 10% diagnosed within 30 days. Higher anastomotic risk was noted among males (p = 0.05). At a median follow-up of 5 (IQR 3.1-7.4) months, 98% of stomas were closed. TME grade was complete or near complete in 90%, with positive margins in 2 cases (3%). Risk factors for incomplete TME were ASA ≥ 3 (p = 0.01), increased time between NRT and surgery (p = 0.03), and higher operative blood loss (p = 0.003). CONCLUSION: When performed at expert centers, 2-team taTME in patients with low rectal tumors is safe with low conversion rates and high stoma closure rate. Mid-term results will further evaluate oncologic and functional outcomes.