Transanal Endoscopic Platforms: TAMIS versus Rigid Platforms: Pros and Cons.

Transanal endoscopic surgery encompasses the minimally invasive surgical techniques used to operate in the rectum under magnification while maintaining pneumorectum via a resectoscope or port. The view, magnification, and surgical precision afforded by these advanced transanal techniques have resulted in excellent specimen quality and low recurrence rates, especially compared with traditional transanal surgery. For rigid platforms, the surgeon operates through a rigid 4-cm diameter steel proctoscope of varying lengths that is clamped to the operating table with an articulating arm. Transanal minimally invasive surgery (TAMIS) is a newer flexible platform using a disposable port which "hooks" into the anorectal ring to remain in place. The cost-effectiveness and versatility of the TAMIS platform have resulted in its popularity and use in more advanced applications such as transanal total mesorectal excision. Ultimately, the choice of operating platform should be based on surgeon preference, patient characteristics, availability, and cost. The pros and cons of each platform will be discussed in this article.

Transanal Minimally Invasive Surgery: A Useful Technique That Continues to Evolve.

Colorectal cancer remains the 3rd most common cancer diagnosed among men and women in the United States. With improved screening, premalignant rectal lesions and rectal cancers are being detected at earlier stages. In addition, the use of neoadjuvant chemo- and radiotherapy has led to downstaging of larger lesions. There is growing interest among colorectal surgeons in local excision with organ preservation for patients with rectal cancer. There are multiple platforms for local excision of rectal cancers, including transanal excision (TAE), transanal endoscopic microsurgery (TEM) and transanal minimally invasive surgery (TAMIS). TAMIS was developed as an affordable platform that uses conventional laparoscopic equipment familiar to many colorectal surgeons. TAMIS allows for full-thickness benign or malignant lesion excision in any quadrant without the need for patient repositioning. The literature has shown that, for appropriately selected patients, TAMIS provides superior excision quality compared to TAE. Furthermore, TAMIS has oncologic outcomes equivalent to TEM at a fraction of the cost. Recently, robotic TAMIS has been introduced, which takes advantage of the articulating instruments of the robotic platform without the need for a skilled assistant. This article will cover multiple technical aspects for TAMIS including patient selection and preparation, technical tips for successful excision and defect closure, and recent advances, including robotic TAMIS.

Transanal minimally invasive surgery for rectal cancer.

Due to the increased uptake of rectal cancer screening and the increasing rates of complete clinical response to chemoradiotherapy, more early-stage and down-staged rectal cancers are being treated. This has triggered surgeons to question the necessity for proctectomy and its associated morbidity and consider local excision and organ preservation in selected cases. Transanal minimally invasive surgery (TAMIS) has evolved as an oncologically safe yet cost-effective platform for local excision of rectal tumors using traditional laparoscopic instruments. This review highlights the recent advances and current role of TAMIS in the treatment of rectal cancer.

Defining the learning curve for transanal total mesorectal excision for rectal adenocarcinoma.

BACKGROUND: Early observational data suggest that this approach is safe and feasible, but it is technically challenging and the learning curve has not yet been determined. The objective of this study was to determine the number of cases required achieve proficiency in transanal total mesorectal excision (TA-TME) for rectal adenocarcinoma. METHODS: All TA-TME cases performed from 03/2012-01/2017 at a single high-volume tertiary care institution for rectal adenocarcinoma were included. A cumulative summation (CUSUM) analysis was performed to determine the number of cases required to reach proficiency, defined as high-quality TME (complete or near-complete mesorectal envelope, negative distal (DRM), and circumferential resection (> 1 mm; CRM) margin). The acceptable and unacceptable rates of good quality TME were defined based on the incidence of high-quality TME in laparoscopic (unacceptable rate = 81.7%) and open (acceptable rate = 86.9%) arms of the ACOSOG Z6051 trial. RESULTS: A total of 87 consecutive cases were included with mean tumor height 4.8 cm (SD 2.7) and 80% (70/87) received neoadjuvant chemoradiation. Post-operative morbidity occurred in 44% (38/87) of cases, including 21% (18/87) readmissions. Median length of stay was 4 days [IQR 3-8]. A good quality TME was performed in 95% (83/87) of cases including 98% (85/87) negative CRM, 99% (86/87) negative DRM, and 99% (86/87) complete or near-complete mesorectal envelope. CUSUM analysis reported that the good quality TME rate reaches an acceptable rate after 51 cases overall, and 45 cases if abdominoperineal resections are excluded. CONCLUSION: TA-TME is a complex technique that requires a minimum of 45-51 cases to reach an acceptable incidence of high-quality TME and lower operative duration.

Impact of residual nodal involvement after complete tumor response in patients undergoing neoadjuvant (chemo)radiotherapy for rectal cancer.

BACKGROUND: The management of patients with a complete clinical response after neoadjuvant therapy for rectal adenocarcinoma is controversial. Those who advocate for resection point out the inaccuracy of N-staging with current imaging modalities. The objective of this study is to determine the impact of residual nodal involvement after complete tumor regression after neoadjuvant (chemo)radiotherapy. METHODS: The 2004 to 2014 National Cancer Database was queried for patients undergoing proctectomy for nonmetastatic rectal adenocarcinoma who had received neoadjuvant (chemo)radiotherapy and with ypT0 on final pathology. Patients were grouped based on pathologic nodal stage: ypT0N- and ypT0N+. The main outcome was 5-year overall survival. RESULTS: There were 5,156 patients with ypT0N- and 527 with ypT0N+. Mean lymph node harvest was similar (ypT0N- 12.2 nodes [standard deviation 9.1] vs ypT0N+ 11.6 nodes [standard deviation 10.3]; P = .086). Patients with ypT0N+ were more likely to have had clinically involved nodes (P < .001) and earlier clinical T-stage (P = .002). Overall survival at 5 years was less for patients with ypT0N+ (80% vs 86%, log-rank P = .014). ypT0N+ was independently associated with worse overall survival (hazard ratio 1.74, 95% confidence interval 1.33-2.28). CONCLUSION: Residual nodal involvement despite complete tumor regression was associated with worse 5-year overall survival compared to complete pathologic response. Additional therapy should be considered in the presence of complete clinical tumor regression after neoadjuvant (chemo)radiotherapy.

Carbon Dioxide Embolism Associated With Transanal Total Mesorectal Excision Surgery: A Report From the International Registries.

BACKGROUND: Carbon dioxide embolus has been reported as a rare but clinically important risk associated with transanal total mesorectal excision surgery. To date, there exists limited data describing the incidence, risk factors, and management of carbon dioxide embolus in transanal total mesorectal excision. OBJECTIVE: This study aimed to obtain data from the transanal total mesorectal excision registries to identify trends and potential risk factors for carbon dioxide embolus specific to this surgical technique. DESIGN: Contributors to both the LOREC and OSTRiCh transanal total mesorectal excision registries were invited to report their incidence of carbon dioxide embolus. Case report forms were collected detailing the patient-specific and technical factors of each event. SETTINGS: The study was conducted at the collaborating centers from the international transanal total mesorectal excision registries. MAIN OUTCOME MEASURES: Characteristics and outcomes of patients with carbon dioxide embolus associated with transanal mesorectal excision were measured. RESULTS: Twenty-five cases were reported. The incidence of carbon dioxide embolus during transanal total mesorectal excision is estimated to be ≈0.4% (25/6375 cases). A fall in end tidal carbon dioxide was noted as the initial feature in 22 cases, with 13 (52%) developing signs of hemodynamic compromise. All of the events occurred in the transanal component of dissection, with mean (range) insufflation pressures of 15 mm Hg (12-20 mm Hg). Patients were predominantly (68%) in a Trendelenburg position, between 30° and 45°. Venous bleeding was reported in 20 cases at the time of carbon dioxide embolus, with periprostatic veins documented as the most common site (40%). After carbon dioxide embolus, 84% of cases were completed after hemodynamic stabilization. Two patients required cardiopulmonary resuscitation because of cardiovascular collapse. There were no deaths. LIMITATIONS: This is a retrospective study surveying reported outcomes by surgeons and anesthetists. CONCLUSIONS: Surgeons undertaking transanal total mesorectal excision must be aware of the possibility of carbon dioxide embolus and its potential risk factors, including venous bleeding (wrong plane surgery), high insufflation pressures, and patient positioning. Prompt recognition and management can limit the clinical impact of such events. See Video Abstract at http://links.lww.com/DCR/A961.

Minimally invasive surgery for stage III colon adenocarcinoma is associated with less delay to initiation of adjuvant systemic therapy and improved survival.

BACKGROUND: Minimally invasive surgery (MIS) may improve surgical recovery and reduce time to adjuvant systemic therapy after colon cancer resection. The objective of this study was to determine the effect of MIS on the initiation of adjuvant systemic therapy and survival in patients with stage III colon cancer. METHODS: The 2010-2014 National Cancer Database was queried for patients with resected stage III colon adenocarcinoma, and divided into MIS, which included laparoscopic and robotic approaches, and open surgery. Propensity-score matching was used to balanced open and MIS groups. The main outcome measures were delayed initiation of adjuvant systemic therapy (defined as > 8 weeks after surgery) and 5-year overall survival (OS). Multiple Cox regression was performed to identify independent predictors for 5-year OS, including an interaction between delayed systemic therapy and MIS, and adjusted for clustering at the hospital level. RESULTS: There were 86,680 patients that were included in this study. Overall, 45% (38,713) underwent MIS colectomy, of which 93% underwent laparoscopic and 7% robotic surgery. After matching, 33,183 open patients were balanced to 33,183 MIS patients. Patient, tumor, and facility characteristics were similar in the matched cohort. More patients in the MIS group received adjuvant therapy within 8 weeks of surgery (49% vs. 42%, p < 0.001), and fewer MIS patients did not receive any systemic therapy (30% vs. 35%, p < 0.001). Delayed initiation of systemic therapy > 8 weeks was associated with worse 5-year OS (HR 1.27, 95%CI 1.19-1.36). MIS was independently associated with improved survival (HR 0.92, 95%CI 0.86-0.97). This relationship remained even if 90-day mortality was excluded. CONCLUSIONS: MIS approaches are associated with less delay to the initiation of adjuvant systemic therapy and improved survival in patients with stage III colon adenocarcinoma. Surgeons should favor MIS approaches for the treatment of stage III colon adenocarcinoma whenever possible.

A Multicenter Matched Comparison of Transanal and Robotic Total Mesorectal Excision for Mid and Low-rectal Adenocarcinoma.

OBJECTIVE: To compare the quality of surgical resection of transanal total mesorectal excision (TA-TME) and robotic total mesorectal excision (R-TME). BACKGROUND: Both TA-TME and R-TME have been advocated to improve the quality of surgery for rectal cancer below 10 cm from the anal verge, but there are little data comparing TA-TME and R-TME. METHODS: Data of patients undergoing TA-TME or R-TME for rectal cancer below 10 cm from the anal verge and a sphincter-saving procedure from 5 high-volume rectal cancer referral centers between 2011 and 2017 were obtained. Coarsened exact matching was used to create balanced cohorts of TA-TME and R-TME. The main outcome was the incidence of poor-quality surgical resection, defined as a composite measure including incomplete quality of TME, or positive circumferential resection margin (CRM) or distal resection margin (DRM). RESULTS: Out of a total of 730 patients (277 TA-TME, 453 R-TME), matched groups of 226 TA-TME and 370 R-TME patients were created. These groups were well-balanced. The mean tumor height from the anal verge was 5.6 cm (SD 2.5), and 70% received preoperative radiotherapy. The incidence of poor-quality resection was similar in both groups (TA-TME 6.9% vs R-TME 6.8%; P = 0.954). There were no differences in TME specimen quality (complete or near-complete TA-TME 99.1% vs R-TME 99.2%; P = 0.923) and CRM (5.6% vs 6.0%; P = 0.839). DRM involvement may be higher after TA-TME (1.8% vs 0.3%; P = 0.051). CONCLUSIONS: High-quality TME for patients with rectal adenocarcinoma of the mid and low rectum can be equally achieved by transanal or robotic approaches in skilled hands, but attention should be paid to the distal margin.

Lower survival after right-sided versus left-sided colon cancers: Is an extended lymphadenectomy the answer?

INTRODUCTION: Tumour location may affect oncologic outcomes for colon adenocarcinoma due to different levels of vascular ligation and nodal harvest, but the data are equivocal. The objective of this study is to determine the effect of tumor location and lymph node yield on overall survival(OS) in stage I-III colon adenocarcinoma. METHODS: The 2004-2014 National Cancer Database was queried for colectomies for non-metastatic colon adenocarcinoma, excluding transverse colon and rectal cancer. Patients were grouped based on left/right tumor location. Main outcome measure was 5-year OS. Propensity score matching created balanced cohorts. Multilevel survival analysis determined the independent effect of tumor location and nodal harvest on OS. RESULTS: There were 504,958 patients (273,198 right; 231,760 left) in the entire cohort: 26.4% stage-I, 37.3% stage-II, and 36.3% stage-III (equal distribution left/right). After 1:1 matching(n = 297,080), right cancers were associated with worse 5-year overall survival for stage-II (66% vs. 70%, p < 0.001) and -III (56% vs. 60%, p < 0.001) despite similar nodal harvest and proportion receiving systemic therapy. On multivariate analysis, right-sided cancers (HR 1.12, 95%CI 1.06-1.19) had worse OS, independent of stage and nodal harvest. Nodal harvest ≥22 nodes had the highest OS (HR 0.71, 95%CI 0.68-0.75). There was an interaction between right-sided cancer and >22 lymph node harvest towards increased survival (HR 0.86, 95%CI 0.80-0.92). CONCLUSIONS: Right-sided cancers are associated with worse oncologic outcomes compared to left-sided tumors but a higher lymph node yield improves survival. These data provide indirect evidence for a higher lymphatic harvest to improve survival.

Impact of Tumor Deposits on Oncologic Outcomes in Stage III Colon Cancer.

BACKGROUND: The prognosis of tumor deposits in stage III colon adenocarcinoma is poorly described. OBJECTIVE: The purpose of this study was to determine the impact of tumor deposits on oncologic outcomes in patients with stage III colon cancer. DESIGN: This was a multicenter retrospective cohort study. SETTINGS: The 2010 to 2014 National Cancer Database was queried for patients with resected stage III colon adenocarcinoma on final pathology. PATIENTS: Patients were divided into 3 groups: lymph nodes+tumor deposits-, lymph nodes+tumor deposits+, and lymph nodes-tumor deposits+. MAIN OUTCOME MEASURES: The main outcome was 5-year overall survival. RESULTS: Of 74,577 patients, there were 55,800 patients with lymph nodes+tumor deposits-, 13,740 patients with lymph nodes+tumor deposits+, and 5037 patients with lymph nodes-tumor deposits+. The groups had similar patient and facility characteristics, but patients with lymph nodes+tumor deposits+ had more advanced tumor characteristics. Patients with lymph nodes-tumor deposits+ were less likely to receive adjuvant systemic therapy (52% vs 74% lymph nodes+tumor deposits- and 75% lymph nodes+tumor deposits+, p < 0.001) and had a longer delay to initiation of adjuvant treatment (>8 weeks; 43% vs 33% lymph nodes+tumor deposits- and 33% lymph nodes+tumor deposits+, p < 0.001). Patients with lymph nodes+tumor deposits+ had the lowest 5-year overall survival (46.0% vs 63.4% lymph nodes+tumor deposits- vs 61.9% lymph nodes-tumor deposits+, p < 0.001). On multivariate analysis, patients with lymph nodes-tumor deposits+ had similar 5-year overall survival compared with patients with lymph nodes+tumor deposits- with ≤3 positive lymph nodes (HR, 0.93; 95% CI, 0.87-1.01). Patients with lymph nodes+tumor deposits+ had worse prognosis regardless of the number of involved lymph nodes (≤3 +lymph nodes: HR, 1.37; 95% CI, 1.28-1.47 and ≥4 +lymph nodes: HR, 1.30; 95% CI, 1.22-1.38). Of those not receiving adjuvant treatment, patients with lymph nodes-tumor deposits+ were younger and had more adverse tumor features than lymph node+ disease. Lymph nodes-tumor deposits+ was independently associated with less delivery of adjuvant systemic therapy (OR, 0.81; 95% CI, 0.80-0.82). LIMITATIONS: This study was limited by its retrospective analysis of a prospective database. CONCLUSIONS: The prognosis of patients with N1c disease is similar to nodal involvement without tumor deposits, yet these patients were less likely to receive adjuvant systemic therapy. Improvement in the delivery of appropriate care in these patients may increase survival and should be a target of future quality initiatives. See Video Abstract at http://links.lww.com/DCR/A666.

Radiologic Evaluation of Clinically Benign Rectal Neoplasms May Not Be Necessary Before Local Excision.

BACKGROUND: Local excision may be curative for benign and malignant rectal neoplasms. Because many early rectal cancers are discovered incidentally after local excision of clinically benign lesions, it is unclear whether preoperative imaging with transrectal ultrasound or MRI affects management. OBJECTIVE: The purpose of this study was to determine the diagnostic characteristics and effect of preoperative imaging on the incidence of malignancy in benign rectal lesions undergoing local excision. DESIGN: Prospective data from 2 institutions were included. Coarsened exact matching created a balanced cohort comparing imaging and no-imaging groups. SETTING: The study was conducted at high-volume specialist referral hospitals. PATIENTS: Adult patients undergoing local excision via transanal endoscopic surgery between 1997 and 2016 for clinically benign rectal neoplasms were included. INTERVENTION: The study intervention included preoperative imaging with transrectal ultrasound and/or MRI. MAIN OUTCOME MEASURES: We measured the incidence of malignancy and diagnostic accuracy of preoperative imaging. RESULTS: A total of 620 patients were included (272 with preoperative imaging and 348 without). There were 250 patients undergoing transrectal ultrasound, and 24 patients undergoing MRI (2 patients underwent both). Transrectal ultrasound and MRI correctly identified malignant polyps in 50% (11/22) and 44% (8/18). Overall agreement for benign versus malignant polyps between preoperative imaging and final pathology was κ = 0.30 (95% CI, 0.18-0.41) for transrectal ultrasound and 0.29 (95% CI, 0.01-0.57) for MRI. In both the overall and unmatched cohorts, the incidence of malignancy, margin involvement, and proportion of patients requiring salvage surgery was similar. LIMITATIONS: Data were obtained from 2 institutions with different equipment over a long time period. CONCLUSIONS: Preoperative imaging did not accurately identify malignancy in clinically benign rectal lesions and did not affect the incidence of malignancy, margin involvement, or proportion of patients requiring salvage surgery. Therefore, preoperative imaging may not be necessary for clinically benign lesions undergoing local excision. See Video Abstract at http://links.lww.com/DCR/A695.

Outcomes of Closed Versus Open Defects After Local Excision of Rectal Neoplasms: A Multi-institutional Matched Analysis.

BACKGROUND: The management of the rectal wall defect after local excision of rectal neoplasms remains controversial, and the existing data are equivocal. OBJECTIVE: This study aimed to determine the effect of open versus closed defects on postoperative outcomes after local excision of rectal neoplasms. DESIGN: Data from 3 institutions were analyzed. Propensity score matching was performed in one-to-one fashion to create a balanced cohort comparing open and closed defects. SETTINGS: This study was conducted at high-volume specialist referral hospitals. PATIENTS: Adult patients undergoing local excision via transanal endoscopic surgery from 2004 to 2016 were included. Patients were assigned to open- and closed-defect groups, and further stratified by full- or partial-thickness excision. INTERVENTION: Closure of the rectal wall defect was performed at the surgeon's discretion. MAIN OUTCOME MEASURES: The primary outcome measured was the incidence of 30-day complications. RESULTS: A total of 991 patients were eligible (593 full-thickness excision with 114 open and 479 closed, and 398 partial-thickness excision with 263 open and 135 closed). After matching, balanced cohorts consisting of 220 patients with full-thickness excision and 210 patients with partial-thickness excision were created. Operative time was similar for open and closed defects for both full-and partial-thickness excision. The incidence of 30-day complications was similar for open and closed defects after full- (15% vs. 12%, p = 0.432) and partial-thickness excision (7% vs 5%, p = 0.552). The total number of complications was also similar after full- or partial-thickness excision. Patients undergoing full-thickness excision with open defects had a higher incidence of clinically significant bleeding complications (9% vs 3%, p = 0.045). LIMITATIONS: Data were obtained from 3 institutions with different equipment and perioperative management over a long time period. CONCLUSIONS: There was no difference in overall complications between open and closed defects for patients undergoing local excision of rectal neoplasms, but there may be more bleeding complications in open defects after full-thickness excision. A selective approach to defect closure may be appropriate. See Video Abstract at http://links.lww.com/DCR/A470.

Establishing the learning curve of transanal minimally invasive surgery for local excision of rectal neoplasms.

INTRODUCTION: Transanal minimally invasive surgery (TAMIS) is an endoscopic operating platform for local excision of rectal neoplasms. However, it may be technically demanding, and its learning curve has yet to be adequately defined. The objective of this study was to determine the number of TAMIS procedures for the local excision of rectal neoplasm required to reach proficiency. METHODS AND PROCEDURES: All TAMIS cases performed from 07/2009 to 12/2016 at a single high-volume tertiary care institution for local excision of benign and malignant rectal neoplasia were identified from a prospective database. A cumulative summation (CUSUM) analysis was performed to determine the number of cases required to reach proficiency. The main proficiency outcome was rate of margin positivity (R1 resection). The acceptable and unacceptable R1 rates were defined as the R1 rate of transanal endoscopic microsurgery (TEM-10%) and traditional transanal excision (TAE-26%), which was obtained from previously published meta-analyses. Comparisons of patient, tumor, and operative characteristics before and after TAMIS proficiency were performed. RESULTS: A total of 254 TAMIS procedures were included in this study. The overall R1 resection rate was 7%. The indication for TAMIS was malignancy in 57%. CUSUM analysis reported that TAMIS reached an acceptable R1 rate between 14 and 24 cases. Moving average plots also showed that the mean operative times stabilized by proficiency gain. The mean lesion size was larger after proficiency gain (3.0 cm (SD 1.5) vs. 2.3 cm (SD 1.3), p = 0.008). All other patient, tumor, and operative characteristics were similar before and after proficiency gain. CONCLUSIONS: TAMIS for local excision of rectal neoplasms is a complex procedure that requires a minimum of 14-24 cases to reach an acceptable R1 resection rate and lower operative duration.

Transanal Minimally Invasive Surgery for Local Excision of Benign and Malignant Rectal Neoplasia: Outcomes From 200 Consecutive Cases With Midterm Follow Up.

OBJECTIVE: This study describes the outcomes for 200 consecutive transanal minimally invasive surgery (TAMIS) local excision (LE) for rectal neoplasia. BACKGROUND: TAMIS is an advanced transanal platform that can result in high quality LE of rectal neoplasia. METHODS: Consecutive patients from July 1, 2009 to December 31, 2015 from a prospective institutional registry were analyzed. Indication for TAMIS LE was endoscopically unresectable benign lesions or histologically favorable early rectal cancers. The primary endpoints were resection quality, neoplasia recurrence, and oncologic outcomes. Kaplan-Meier survival analyses were used to describe disease-free survival (DFS) for patients with rectal adenocarcinoma that did not receive immediate salvage radical surgery. RESULTS: There were 200 elective TAMIS LE procedures performed in 196 patients for 90 benign and 110 malignant lesions. Overall, a 7% margin positivity and 5% fragmentation rate was observed. The mean operative time for TAMIS was 69.5 minutes (SD 37.9). Postoperative morbidity was recorded in 11% of patients, with hemorrhage (9%), urinary retention (4%), and scrotal or subcutaneous emphysema (3%) being the most common. The mean follow up was 14.4 months (SD 17.4). Local recurrence occurred in 6%, and distant organ metastasis was noted in 2%. Mean time to local recurrence for malignancy was 16.9 months (SD 13.2). Cumulative DFS for patients with rectal adenocarcinoma was 96%, 93%, and 84% at 1-, 2-, and 3-years. CONCLUSIONS: For carefully selected patients, TAMIS for local excision of rectal neoplasia is a valid option with low morbidity that maintains the advantages of organ preservation.

Uptake of Transanal Total Mesorectal Excision in North America: Initial Assessment of a Structured Training Program and the Experience of Delegate Surgeons.

BACKGROUND: Transanal total mesorectal excision is a new approach to curative-intent rectal cancer surgery. Training and surgeon experience with this approach has not been assessed previously in America. OBJECTIVE: The purpose of this study was to characterize a structured training program and to determine the experience of delegate surgeons. DESIGN: Data were assimilated from an anonymous, online survey delivered to attendees on course completion. Data on surgeon performance during hands-on cadaveric dissection were collected prospectively. SETTINGS: This study was conducted at a single tertiary colorectal surgery referral center, and cadaveric hands-on training was conducted at a specialized surgeon education center. MAIN OUTCOME MEASURES: The main outcome measurement was the use of the course and surgeon experience posttraining. RESULTS: During a 12-month period, eight 2-day transanal total mesorectal excision courses were conducted. Eighty-one colorectal surgeons successfully completed the course. During cadaveric dissection, 71% achieved a complete (Quirke 3) specimen; 26% were near complete (Quirke 2), and 3% were incomplete (Quirke 1). A total of 9.1% demonstrated dissection in the incorrect plane, whereas 4.5% created major injury to the rectum or surrounding structures, excluding the prostate. Thirty eight (46.9%) of 81 surgeon delegates responded to an online survey. Of survey respondents, 94.6% believed training should be required before performing transanal total mesorectal excision. Posttraining, 94.3% of surgeon delegates planned to use transanal total mesorectal excision for distal-third rectal cancers, 74.3% for middle-third cancers, and 8.6% for proximal-third cancers. The most significant complication reported was urethral injury; 5 were reported by the subset of survey respondents who had performed this operation postcourse. LIMITATIONS: The study was limited by inherent reporting bias, including observer and recall biases. CONCLUSIONS: Although this structured training program for transanal total mesorectal excision was found to be useful by the majority of respondents, the risk of iatrogenic injury after training remains high, suggesting that this training pedagogy alone is insufficient. See Video Abstract at http://links.lww.com/DCR/A335.

Quality of Local Excision for Rectal Neoplasms Using Transanal Endoscopic Microsurgery Versus Transanal Minimally Invasive Surgery: A Multi-institutional Matched Analysis.

BACKGROUND: There are no data comparing the quality of local excision of rectal neoplasms using transanal endoscopic microsurgery and transanal minimally invasive surgery. OBJECTIVE: The purpose of this study was to compare the incidence of tumor fragmentation and positive margins for patients undergoing local excision of benign and malignant rectal neoplasms using transanal endoscopic microsurgery versus transanal minimally invasive surgery. DESIGN: This was a multi-institutional cohort study using coarsened exact matching. SETTINGS: The study was conducted at high-volume tertiary institutions with specialist colorectal surgeons. PATIENTS: Patients undergoing full-thickness local excision for benign and malignant rectal neoplasms were included. INTERVENTIONS: Transanal endoscopic microsurgery and transanal minimally invasive surgery were the included interventions. MAIN OUTCOME MEASURES: The incidence of poor quality excision (composite measure including tumor fragmentation and/or positive resection margin) was measured. RESULTS: The matched cohort consisted of 428 patients (247 with transanal endoscopic microsurgery and 181 with transanal minimally invasive surgery). Transanal minimally invasive surgery was associated with shorter operative time and length of stay. Poor quality excision was similar (8% vs 11%; p = 0.233). There were also no differences in peritoneal violation (3% vs 3%; p = 0.965) and postoperative complications (11% vs 9%; p = 0.477). Cumulative 5-year disease-free survival for patients undergoing transanal endoscopic microsurgery was 80% compared with 78% for patients undergoing transanal minimally invasive surgery (log rank p = 0.824). The incidence of local recurrence for patients with malignancy who did not undergo immediate salvage surgery was 7% (8/117) for transanal endoscopic microsurgery and 7% (7/94) for transanal minimally invasive surgery (p = 0.864). LIMITATIONS: All of the procedures were also performed at high-volume referral centers by specialist colorectal surgeons with slightly differing perioperative practices and different time periods. CONCLUSIONS: High-quality local excision for benign and rectal neoplasms can be equally achieved using transanal endoscopic microsurgery or transanal minimally invasive surgery. The choice of operating platform for local excisions of rectal neoplasms should be based on surgeon preference, availability, and cost. See Video Abstract at http://links.lww.com/DCR/A382.