Structured training pathway and proctoring; multicenter results of the implementation of transanal total mesorectal excision (TaTME) in the Netherlands

Short- and long-term impact of the TaTME learning process: a single institutional study

BACKGROUND

Transanal total mesorectal excision (TaTME) is a promising and innovative approach for lower rectal cancer but requires high technical skill and learning process that can affect patient outcomes. We aimed to determine the learning curve of TaTME and then to assess its impact on 5-year oncologic outcomes.

METHODS

Over a 54-month period, 94 patients underwent TaTME by experienced laparoscopic colorectal surgeons at our department. To provide a comprehensive overview of success, we used a composite criterion including the most relevant parameters related to the learning process: the conversion rate to an open procedure, TaTME procedure completion, severe postoperative morbidity, mesorectal integrity on macroscopic evaluation, and microscopic margins. Moving average method and cumulative sum analyses were performed.

RESULTS

The operative time continuously decreased over the entire study period. The success rate stabilised after 14 patients in a parallel and balanced analysis of the two surgeons' experiences. Mesorectal completeness was the most sensitive marker for the TaTME learning process (42.9% vs 71.25%; p = 0.06). The learning process did not significantly affect the postoperative morbidity, conversion rate, or R0 resection. Five-year oncological outcomes were similar between the groups.

CONCLUSION

Even among laparoscopically experienced surgeons, the TaTME learning process influences the oncological quality of the resection but not the postoperative morbidity. Gaining an early command of the surgical anatomy and technical skills and understanding the challenges through specific educational sessions are necessary. The results of this study could help generate a comprehensive training program and define necessary prerequisites for prospective trials.

TRIAL REGISTRATION

This study is registered in our Clinical Research Unit (2016_LELONG_01). Our database is registered in the clinicalTrials.gov registry: Institut Paoli Calmettes Colorectal Cancer Database (NCT02869503).

A systematic review and meta-analysis of oncological outcomes with transanal total mesorectal excision for rectal cancer

AIM

Transanal total mesorectal (taTME) excision is a method used to assist in the radical removal of the rectum. By adopting the concept of natural orifice surgery, it offers potential benefits over conventional techniques. Early enthusiasm for this strategy led to its rapid and widespread adoption. The imposing of a local moratorium was precipitated by the discovery in Norway of an uncommon multifocal pattern of locoregional recurrence. The aim of this systematic review and meta-analysis was to determine the incidence of local recurrence after taTME for rectal cancer.

METHOD

Conforming to the Cochrane Handbook for Systematic Reviews of Interventions and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines checklist, a systematic review and meta-analysis was conducted. This included case series and comparative studies between taTME and preferentially laparoscopic procedures published between 2010 and 2021.

RESULTS

There were a total of 1175 studies retrieved. After removal and screening for quality and relevance, the final analysis contained 40 studies. The local recurrence rate following taTME was 3.4% (95% CI 2.9%-3.9%, I2 = 0%) in 4987 patients with follow-up durations ranging from 0.7 to 5.5 years. Compared with laparoscopic TME, local recurrence was not statistically different for the taTME group (p = 0.076); however, it was less probable (OR = 0.51, 95% CI 0.24-1.09, I2 = 0%). Systemic recurrence and circumferential resection margin status were secondary outcomes; however, the differences were not statistically significant.

CONCLUSION

Our data suggest that the local recurrence for regular laparoscopic and transanal TME surgeries may be comparable, suggesting that taTME can be performed without influencing locoregional oncological outcomes in patients treated at specialized institutions and who have been cautiously selected.

Exfoliate cancer cell analysis in rectal cancer surgery: comparison of laparoscopic and transanal total mesorectal excision, a pilot study

PURPOSE

Minimally invasive surgery (MIS) is currently the standard treatment for rectal cancer. However, its limitations include complications and incomplete total mesorectal resection (TME) due to anatomical features and technical difficulties. Transanal TME (TaTME) has been practiced since 2010 to improve this, but there is a risk of local recurrence and intra-abdominal contamination. We aimed to analyze samples obtained through lavage to compare laparoscopic TME (LapTME) and TaTME.

METHODS

From June 2020 to January 2021, 20 patients with rectal cancer undergoing MIS were consecutively and prospectively recruited. Samples were collected at the start of surgery, immediately after TME, and after irrigation. The samples were analyzed for carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20) through a quantitative real-time polymerase chain reaction. The primary outcome was to compare the detected amounts of CEA and CK20 immediately after TME between the surgical methods.

RESULTS

Among the 20 patients, 13 underwent LapTME and 7 underwent TaTME. Tumor location was lower in TaTME (7.3 cm vs. 4.6 cm, P=0.012), and negative mesorectal fascia (MRF) was more in LapTME (76.9% vs. 28.6%, P=0.044). CEA and CK20 levels were high in 3 patients (42.9%) only in TaTME. There was 1 case of T4 with incomplete purse-string suture and 1 case of positive MRF with dissection failure. All patients were followed up for an average of 32.5 months without local recurrence.

CONCLUSION

CEA and CK20 levels were high only in TaTME and were related to tumor factors or intraoperative events. However, whether the detection amount is clinically related to local recurrence remains unclear.

What Is the Comparative Efficacy of Surgical, Endoscopic, Transanal Resection, and Radiotherapy Modalities in the Treatment of Rectal Cancer?

BACKGROUND

Rectal cancer is a significant healthcare burden, and effective treatment is crucial. This research aims to compare the effectiveness of surgical and endoscopic resection, transanal resection, and radiotherapy.

METHODS

A literature analysis was conducted in order to identify relevant studies, by comparing the different surgical approaches and variables affecting treatment decisions. The findings were analyzed and synthesized to provide a comprehensive overview.

RESULTS

Surgical treatment, particularly TME (total mesorectal excision), proved consistent efficacy in achieving complete tumor resection and improving long-term survival. Endoscopic treatment and transanal resection techniques were promising for early-stage tumors but were associated with higher local recurrence rates. Radiotherapy, especially in combination with chemotherapy, played a crucial role in locally advanced cases, improving local control and reducing recurrence risk. Patient data, tumor characteristics, and healthcare system factors were identified as important factors in treatment modality selection.

CONCLUSION

Surgical treatment, specifically TME, remains the recommended standard approach for rectal cancer, providing excellent oncological outcomes. Endoscopic treatment and transanal resection techniques can be considered for selected early-stage cases, while radiotherapy is beneficial for locally advanced tumors. Treatment decisions should be personalized based on patient and tumor characteristics, considering the available resources and expertise within the healthcare system.

Recurrence following transanal total mesorectal excision for rectal cancer: a monocentric retrospective series of technically difficult cases

PURPOSE

Transanal total mesorectal excision (TaTME) has been proposed to overcome surgical difficulties encountered during rectal resection, especially for patients having high body mass index or low rectal cancer. The aim of this study was to evaluate oncologic outcomes following TaTME.

METHODS

This retrospective study included all consecutive patients with rectal cancer who had a TaTME from 2013 to 2019. The main outcome was the incidence of locoregional recurrence by the end of the follow-up period.

RESULTS

Among a total of 81 patients, 96.3% were male, and their mean age was 63±9 years. The mean body mass index was 30.3±5.7 kg/m2, and the median distance from tumor to anal verge was 5.0 cm (interquartile range [IQR], 4.0-6.0 cm). Most patients had a low anterior resection performed (n=80, 98.8%) with a diverting ileostomy (n=64, 79.0%). Distal and circumferential resection margins were positive in 2.5% and 6.2% of patients, respectively. Total mesorectal excision was complete or near complete in 95.1% of patients. A successful resection was achieved in 72 patients (88.9%). After a median follow-up of 27.5 months (IQR, 16.7-48.1 months), 4 patients (4.9%) experienced locoregional recurrence. Anastomotic leaks were observed in 21 patients (25.9%). At the end of the follow-up, 69 patients (85.2%) were stoma-free.

CONCLUSION

TaTME was associated with acceptable oncological outcomes, including low locoregional recurrence rates in selected patients with low rectal cancer. Although associated with a high incidence of postoperative morbidities, the use of TaTME enabled a high rate of successful sphincter-saving procedures in selected patients who posed a technical challenge.

Learning Curve for Transanal Total Mesorectal Excision for Low Rectal Malignancy

BACKGROUND

Although transanal total mesorectal excision (TaTME) is a promising treatment for low rectal cancer, it is considered technically demanding, and the number of cases required to become proficient in TaTME remains unknown. The purpose of this study was to assess the TaTME learning curve based on the total mesorectal excision completion time.

STUDY DESIGN

This retrospective analysis comprised 128 individuals who received TaTME between September 2016 and December 2021. The cumulative sum method was used to generate the learning curve. The duration of the procedure from the beginning to the end of the circumferential rendezvous was used to define the total mesorectal excision completion time.

RESULTS

The learning curve consists of 3 phases: phase I (learning phase: cases 1 to 38), phase II (consolidation phase: cases 39 to 70), and phase III (maturing phase: cases 71 to 128). As the phases varied, both the overall operative time and total mesorectal excision completion time decreased considerably. Through the 3 phases of TaTME, intraoperative adverse events decreased, and in phase III, none occurred. Only 1 instance of local recurrence occurred during phase III, and none occurred during phase I or II.

CONCLUSIONS

After 70 operations, the surgeon could join the mastery phase of TaTME based on the total mesorectal excision completion time. After the mastering phase began, there were no intraoperative negative occurrences. From the beginning, the oncological safety could be guaranteed.

Feasibility and safety of robotic surgery for low rectal cancer combined with transanal total mesorectal excision

PURPOSE

Laparoscopic surgery for low rectal cancer is often challenging. Transanal total mesorectal excision (TaTME) and robotic surgery have been introduced to overcome the technical difficulties in laparoscopic surgery and achieve more favorable outcomes. Hybrid robotic surgery, which combines TaTME with the abdominal robotic approach, incorporates the advantages of each of these surgical techniques and might achieve less invasive and safer surgery. This study evaluated the safety and feasibility of hybrid robotic surgery with TaTME (hybrid TaTME).

METHODS

We retrospectively reviewed 162 TaTME cases performed at our department from September 2016 to May 2022. Among them, 92 cases of conventional TaTME and 30 of hybrid TaTME were eligible. We used propensity score matching analysis (PSM) to adjust for patients' characteristics and compared the short-term outcomes of the two treatment groups.

RESULTS

Twenty-seven cases in each group were extracted using PSM. The operation time in hybrid TaTME was comparable to that in conventional TaTME. There was no significant difference in the postoperative hospital stay between the two groups. Other intra- and post-operative outcomes were also comparable between the two groups. Furthermore, no significant differences were observed between the two groups in the curative resection and recurrence rates.

CONCLUSION

Hybrid TaTME for low rectal cancer was as favorable as conventional TaTME in producing satisfactory short-term outcomes. However, furthermore, larger-scale studies conducted over longer study periods are needed to evaluate the validity of the findings.

Surgical Outcomes, Long-Term Recurrence Rate, and Resource Utilization in a Prospective Cohort of 165 Patients Treated by Transanal Total Mesorectal Excision for Distal Rectal Cancer

A transanal total mesorectal excision (taTME) is a smart alternative to a conventional TME. However, worrisome reports of a high recurrence and complications triggered a moratorium in a few countries. This study assessed the outcomes and resource utilization of a taTME. Consecutive patients with distal rectal cancer treated by a taTME were prospectively included. Outcomes were reported as the median and interquartile range (IQR). One hundred sixty-five patients (67% male and 33% female) with a tumor 7 cm (IQR 5-10) from the anal verge were followed for 50 months (IQR 32-79). The resection margins were threatened in 25% of the patients, while 75% of the patients received neoadjuvant radiochemotherapy. A good mesorectal dissection and clear margins were achieved in 96% of the specimens, and 27 lymph nodes (IQR 20-38) were harvested. Ninety-day major morbidity affected 36 patients (21.8%), including 12 with anastomotic leakages (7.2%). A recurrence occurred locally in 9 patients (5.4%), and 44 patients had a distant metastasis (26.7%). The five-year disease-free survival and overall survival were 67% and 90%, respectively. A multivariate analysis found a long operation and frailty predicted an anastomotic leak, while a positive distal margin and lymph nodes predicted a local recurrence and distant metastasis. A two-team taTME saved 102 min of operative time and EUR 1385 when compared to a one-team approach. Transanal total mesorectal excision produced sound surgical quality and excellent oncologic outcomes.

Reasonable Collocation of Two Different Functional 3D Laparoscopes May Improve the Efficiency of Transanal Total Mesorectal Excision Surgery Using a Synchronous Two-Team Approach?

Background: To investigate the effectiveness of two different functional three-dimensional (3D) laparoscopes in transanal total mesorectal excision (taTME). Methods: We retrospectively analyzed clinical data of 106 patients undergoing taTME of rectal cancer at the Affiliated Nanchong Central Hospital of North Sichuan Medical College between August 2017 and July 2020. Fifty-seven patients used the flexible 3D laparoscope (FTDL) and 49 patients used the rigid 3D laparoscope (RTDL). Results: Transabdominal operation duration in the FTDL group was shorter than in the RTDL group (125.5 ± 52.6 minutes versus 148.8 ± 59.3 minutes, P = .034). However, transanal operation duration in the FTDL group was longer than in the RTDL group (77.3 ± 26.8 minutes versus 104.6 ± 34.1 minutes, P = .000). There were no significant differences between the two groups in the number of harvested lymph nodes, total operation duration, postoperative complications, postoperative hospitalization, and quality of mesorectal specimen (P > .05). Conclusion: Synchronous two-team approach can be widely used in taTME. Making full use of the respective advantages of the two 3D laparoscopes is beneficial to improve the efficiency of taTME surgery. Clinical Trial Registration Number: NCT03416699.

Current status of transanal total mesorectal excision for rectal cancer and the expanding indications of the transanal approach for extended pelvic surgeries

Transanal total mesorectal excision (taTME) has been rapidly accepted as a promising surgical approach to the distal rectum. The benefits include ease of access to the bottom of the deep pelvis linearly over a short distance in order to easily visualize the important anatomy. Furthermore, the distal resection margins can be secured under direct vision. Additionally, a two-team approach combining taTME with a transabdominal approach could decrease the operative time and conversion rate. Although taTME was expected to become more rapidly popularized worldwide, enthusiasm for it has stalled due to unfamiliar intraoperative complications, a lack of oncologic evidence from randomized trials, and the widespread use of robotic surgery. While international registries have reported favorable short- and medium-term outcomes from taTME, a Norwegian national study reported a high local recurrence rate of 9.5%. The characteristics of the recurrences included rapid, multifocal growth in the pelvis, which was quite different from recurrences following traditional transabdominal TME; thus, the Norwegian Colorectal Cancer Group reached a consensus for a temporary moratorium on the performance of taTME. To ensure acceptable baseline quality and patient safety, taTME should be performed by well-trained colorectal surgeons. Although the appropriate indications for taTME remain controversial, the transanal approach is extremely important as a means of goal setting in difficult TME cases and as an aid to the transabdominal approach in various types of extended pelvic surgeries. The benefits in transanal lateral lymph node dissection and pelvic exenteration are presented herein.

Morbidity, Mortality, and Pathologic Outcomes of Transanal Versus Laparoscopic Total Mesorectal Excision for Rectal Cancer Short-term Outcomes From a Multicenter Randomized Controlled Trial

OBJECTIVE

To determine the morbidity, mortality, and pathologic outcomes of transanal total mesorectal resection (taTME) versus laparoscopic total mesorectal excision (laTME) among patients with rectal cancer with clinical stage I to III rectal cancer below the peritoneal reflection.

BACKGROUND

Studies with sufficient numbers of patients allowing clinical acceptance of taTME for rectal cancer are lacking. Thus, we launched a randomized clinical trial to compare the safety and efficacy of taTME versus laTME.

METHODS

A randomized, open-label, phase 3, noninferiority trial was performed at 16 different hospitals in 10 Chinese provinces. The primary endpoints were 3-year disease-free survival and 5-year overall survival. The morbidity and mortality within 30 days after surgery, and pathologic outcomes were compared based on a modified intention-to-treat principle; this analysis was preplanned.

RESULTS

Between April 13, 2016, and June 1, 2021, 1115 patients were randomized 1:1 to receive taTME or laTME. After exclusion of 26 cases, modified intention-to-treat set of taTME versus laTME groups included 544 versus 545 patients. There were no significant differences between taTME and laTME groups in intraoperative complications [26 (4.8%) vs 33 (6.1%); difference, -1.3%; 95% confidence interval (CI), -4.2% to 1.7%; P =0.42], postoperative morbidity [73 (13.4%) vs 66 (12.1%); difference, 1.2%; 95% CI, -2.8% to 5.2%; P =0.53), or mortality [1 (0.2%) vs 1 (0.2%)]. Successful resection occurred in 538 (98.9%) versus 538 (98.7%) patients in taTME versus laTME groups (difference, 0.2%; 95% CI, -1.9% to 2.2%; P >0.99).

CONCLUSIONS

Experienced surgeons can safely perform taTME in selected patients with rectal cancer.

Development and evaluation of a virtual knowledge assessment tool for transanal total mesorectal excision

BACKGROUND

Transanal total mesorectal excision (TATME) is difficult to learn and can result in serious complications. Current paradigms for assessing performance and competency may be insufficient. This study aims to develop and provide preliminary validity evidence for a TATME virtual assessment tool (TATME-VAT) to assess the cognitive skills necessary to safely complete TATME dissection.

METHODS

Participants from North America, Europe, Japan and China completed the test via an interactive online platform between 11/2019 and 05/2020. They were grouped into expert, experienced and novice surgeons depending on the number of independently performed TATMEs. TATME-VAT is a 24-item web-based assessment evaluating advanced cognitive skills, designed according to a blueprint from consensus guidelines. Eight items were multiple choice questions. Sixteen items required making annotations on still frames of TATME videos (VCT) and were scored using a validated algorithm derived from experts' responses. Annotation (range 0-100), multiple choice (range 0-100), and overall scores (sum of annotation and multiple-choice scores, normalized to μ = 50 and σ = 10) were reported.

RESULTS

There were significant differences between the expert, experienced, and novice groups for the annotation (p < 0.001), multiple-choice (p < 0.001), and overall scores (p < 0.001). The annotation (p = 0.439) and overall (p = 0.152) scores were similar between the experienced and novice groups. Annotation scores were higher in participants with 51 or more vs. 30-50 vs. less than 30 cases. Scores were also lower in users with a self-reported recent complication vs. those without.

CONCLUSIONS

This study describes the development of an interactive video-based virtual assessment tool for TATME dissection and provides initial validity evidence for its use.

A Way to Start Transanal Total Mesorectal Excision for Rectal Cancer

Introduction The optimal rectal cancer care is achieved by a multidisciplinary approach, with a high-quality surgical resection, with complete mesorectal excision and adequate margins. New approaches like the transanal total mesorectal excision (TaTME) aim to achieve these goals, maximizing the sphincter preservation ratio, with good oncologic and functional results. This report describes a way to implement TaTME without a proctor, presents the first case series of this approach in a center experienced in rectal cancer, and compares the results with those of the international literature.

Methods We performed a retrospective study of the first 10 consecutive patients submitted to TaTME for rectal cancer at our institution. The primary outcomes were postoperative complications, pathological specimen quality and local recurrence rate. The results and performance were compared with the outcomes of a known structured program with proctorship and with the largest meta-analysis on this topic.

Results All patients had locally advanced cancer; therefore, all underwent neoadjuvant therapy. A total of 30% had postoperative complications, without mortality or re-admissions. In comparison with the structured training program referred, no differences were found in postoperative complications and reintervention rates, resulting in a similar quality of resection. Comparing these results with those of the largest meta-analysis on the subject, no differences in the postoperative complication rates were found, and very similar outcomes regarding anastomotic leaks and oncological quality of resection were registered.

Conclusion The results of this study validate the safety and effectiveness of our pathway regarding the implementation of the TaTME approach, highlighting the fact that it should be done in a center with proficiency in minimally invasive rectal surgery.

Structured training curriculums for transanal total mesorectal excision in China: refinement is needed

BACKGROUND

Transanal total mesorectal excision (TaTME) is an alternative for mid-low rectal cancer. In China, this procedure has been performed in high-volume centers with structured training curriculums. The efficacy of the TaTME structured training curriculums in China is still unclear. This multicenter study aimed to explore the effectiveness of the structured training curriculums in China.

METHODS

Seven high-volume centers in China participated in this study. The first 25 patients who underwent TaTME in each center were enrolled. In the cohort, patients were divided into 3 groups. The first 5 procedures (group 1) were performed under proctoring according to the requirement of structured training curriculums. The latter 20 cases without proctoring were split into 2 groups (10 cases in each group, groups 2 and 3) according to the order of operation date. The baseline characteristics, perioperative complications, and pathological outcomes were compared between groups 1 and 2, as well as between groups 2 and 3.

RESULTS

Symptomatic anastomotic leakage (AL) occurred in 18.6% of the patients in group 2 compared with 5.7% in group 1 (P1=0.08) and 5.0% in group 3 (P2=0.04). Seven (11.3%) patients in group 2 developed defecation disorders whereas no patients had this complication in group 3 (P2=0.02). Compared with group 2, the operative time was shorter (235 vs. 223 min, P2=0.40), while the rates of intraoperative complications (15.7% vs. 5.7%, P2=0.10), postoperative complications (31.3% vs. 25.7%, P2=0.06), AL (20.0% vs. 8.6%, P2=0.04), and positive distal resection margin (DRM) (7.5% vs. 2.9%, P2=0.27) were lower in group 3.

CONCLUSIONS

The effect of the structured training curriculums was acceptable but needed further improvement. The prevalence of anastomosis-related complications and the quality control of specimens are still not optimal, and measures for refinement (for example, more cases under proctoring) are needed in the curriculums.

Surgical Training for Transanal Total Mesorectal Excision in a Live Animal Model: A Preliminary Experience

Background: In this preliminary experience, the feasibility and effectiveness of surgical training with an animal model for transanal total mesorectal excision (TaTME) were evaluated. Methods: The training was conducted in two experimental animal laboratories in Italy authorized by the Italian Ministry of Health, using female Danish Landrace pigs under the supervision of surgeons with extensive experience in TaTME, animal laboratory training and cadaver laboratory training. The procedure was divided into separate steps, and all the participants were guided step-by-step throughout the entirety of the procedure. Results: During all the editions of the animal laboratory, all the procedures were completed with no major damage to the anatomical structures or intraoperative death of the animals. Live animal tissue is very similar to human tissue, helping trainees improve their tactile feedback. The bleeding effect improved the value of the training and taught the participants how to address this complication. The lack of mesorectal tissue in pigs compared with humans was the main difference. Animal laboratories should not be considered alternatives to cadaver laboratories but as complementary training activities due to their effectiveness and lower costs. Conclusions: Surgical training in animal models for TaTME seems to be effective and could be an opportunity to improve training alongside the use of a cadaver laboratory and proctoring.

Transanal total mesorectal excision: short- and long-term results of the first hundred cases of a certified colorectal cancer center in Germany

BACKGROUND

Since 2010, laparoscopic transanal total mesorectal excision (TaTME) has been increasingly used for low and very low rectal cancer. It is supposed to improve visibility and access to the dissection planes in the pelvis. This study reports on short- and long-term outcomes of the first 100 consecutive patients treated with TaTME in a certified German colorectal cancer center.

PATIENTS AND METHODS

Data were derived from digital patient files and official cancer registry reports for patients with TaTME tumor surgery between July 2014 and January 2020. The primary outcome was the 3-year local recurrence rate and local recurrence-free survival (LRFS). Secondary endpoints included overall survival (OAS), disease-free survival (DFS), operation time, completeness of local tumor resection, lymph node resection, and postoperative complications. The Kaplan-Meier method was employed for the survival analyses; competing risks were considered in the time-to-event analysis.

RESULTS

During the observation period, the average annual operation time decreased from 272 to 178 min. Complete local tumor resection was achieved in 97% of the procedures. Major postoperative complications (Clavien-Dindo 3-4) occurred in 11% of the cases. At a median follow-up time of 2.7 years, three patients had suffered from a local recurrence. Considering competing risks, this corresponds to a 3-year cumulative incidence rate for local recurrence of 2.2% and a 3-year LRFS of 81.9%. 3-year OAS was 82.9%, and 3-year DFS was 75.7%.

CONCLUSION

TaTME is associated with favorable short and long-term outcomes. Since it is technically demanding, structured training programs and more research on the topic are indispensable.

Clinical Status and Future Prospects of Transanal Total Mesorectal Excision

Low rectal cancer has always posed surgical challenges to gastrointestinal surgeons. Transanal total mesorectal excision (taTME) is a novel approach to radical resection for low rectal cancer. Compared with conventional laparoscopic TME (laTME), taTME is relevant to the benefits of better vision of the mesorectal plane, feasibility of operating in a narrow pelvis, and exact definition of distal resection margin, which may lead to a higher possibility of free circumferential resection margin, better quality of TME specimen, and lower conversion rate. Although there are concerns about its long-term oncological outcomes and complex learning curve, taTME is a promising alternative for rectal cancer. In this review, we discuss the application status and prospects of taTME.

The role of transanal total mesorectal excision

At inception, transanal total mesorectal excision (TaTME) was hypothesized to be a solution for several problems encountered in pelvic surgery, particularly for distal rectal cancer. The transanal part of the procedure is less hampered by patient related factors such as visceral obesity and a narrow bony pelvis and can thus overcome access and visualization problems encountered with a pure abdominal approach. Clearly, as for any new technique, a learning curve needs to be negotiated, ideally without unacceptable harm to patients. Once in experienced hands, TaTME might overcome challenges found in anatomically challenging rectal cancer patients as well as for other indications. The role of TaTME is not to replace, but rather complement its abdominal counterpart.

Lateral lymph node dissection in rectal cancer: State of the art review

Half of the local regional recurrences from rectal cancer are nowadays located in the lateral compartments, most likely due to lateral lymph node (LLN) metastases. There is evidence that a lateral lymph node dissection (LLND) can lower the lateral local recurrence rate. An LLND without neoadjuvant (chemo)radiotherapy in patients with or without suspected LLN metastases has been the standard of care in the East, while Western surgeons believed LLN metastases to be cured by neoadjuvant treatment and total mesorectal excision (TME) only. An LLND in patients without enlarged LLNs might result in overtreatment with low rates of pathological LLNs, but in patients with enlarged LLNs who are treated with (C)RT and TME only, the risk of a lateral local recurrence significantly increases to 20%. Certain Eastern and Western centers are increasingly performing a selective LLND after neoadjuvant treatment in the presence of suspicious LLNs due to new scientific insights, but (inter)national consensus on the indication and surgical approach of LLND is lacking. An LLND is an anatomically challenging procedure with intraoperative risks such as bleeding and postoperative morbidity. It is therefore essential to carefully select the patients who will benefit from this procedure and where possible to perform the LLND in a minimally invasive manner to limit these risks. This review gives an overview of the current evidence of the assessment of LLNs, the indications for LLND, the surgical technique, pitfalls in performing this procedure and the future studies are discussed, aiming to contribute to more (inter)national consensus.

A systematic review and meta-analysis of robotic-assisted transabdominal total mesorectal excision and transanal total mesorectal excision: which approach offers optimal short-term outcomes for mid-to-low rectal adenocarcinoma?

BACKGROUND

Resection of low rectal adenocarcinoma can be challenging in the narrow pelvis of male patients. Transanal total mesorectal excision (TaTME) appears to offer technical advantages for distal rectal tumours, and robotic-assisted transabdominal TME (rTME) was introduced in effort to improve operative precision and ergonomics. However, no study has comprehensively compared these approaches. The aim of the present study was to perform a systematic review of the literature to compare postoperative short-term outcomes in rTME and TaTME.

METHODS

A systematic online search (1974-July 2020) of MEDLINE, Embase, web of science and google scholar was conducted for trials, prospective or retrospective studies involving rTME, or TaTME for rectal cancer. Outcome variables included: hospital stay; operation duration, blood loss; resection margins; proportion of histologically complete resected specimens; lymph nodes; overall complications; anastomotic leak, and 30-day mortality.

RESULTS

Sixty-two articles met the inclusion criteria, including 37 studies (3835 patients) assessing rTME resection, 23 studies (1326 patients) involving TaTME and 2 comparing both (165 patients). Operating time was longer in rTME (309.2 min, 95% CI 285.5-332.8) than in TaTME studies (256.2 min, 95% CI 231.5-280.9) (p = 0.002). rTME resected specimens had a larger distal resection margin (2.62 cm, 95% CI 2.35-2.88) than in TaTME studies (2.10 cm, 95% CI 1.83-2.36) (p = 0.007). Other outcome variables did not significantly differ between the two techniques.

CONCLUSIONS

rTME provides similar pathological and short-term outcomes to TaTME and both are reasonable surgical approaches for patients with mid-to-low rectal cancer. To definitively answer the question of the optimal TME technique, we suggest a prospective trial comparing both techniques assessing long-term survival as a primary outcome.

Defining the learning curve of transanal total mesorectal excision: a systematic review and meta-analysis

BACKGROUND

Transanal total mesorectal excision (taTME) represents a novel approach to rectal dissection. Although many structured training programs have been developed worldwide to assist surgeons in implementing this new technique, the learning curve (LC) of taTME has yet to be conclusively defined. This is particularly important given the concerns regarding the complication profile and oncological safety of taTME. The aim of this review was to provide an up-to-date systematic review and meta-analysis of the LC for taTME, comparing the difference of outcomes between the LC and after learning curve (ALC) groups.

METHODS

An up-to-date systematic review was performed on the available literature between 2010-2020 on PubMed, EMBASE, Medline and Cochrane Library databases. All studies comparing taTME procedures before and after LC were analysed.

RESULTS

Seven retrospective studies of prospectively collected databases were included, comparing 333 (51.0%) patients in the LC group and 320 (49.0%) patients in the ALC group. There was a significantly reduced number of adverse intra-operative events, anastomotic leaks and improved quality of mesorectal excision in the ALC group.

CONCLUSION

This review shows that there is a significant improvement in clinical outcomes between the LC and ALC groups which supports the need for careful mastery and ongoing technical refinement during the LC in taTME. This procedure should be performed on a subset of carefully selected patients in the hands of experienced and well-trained teams dedicated to ongoing audit.

Transanal total mesorectal excision and transabdominal robotic surgery for rectal cancer: A retrospective study

BACKGROUND

Transabdominal robotic surgery and transanal total mesorectal excision (TaTME) are newly introduced strategies for rectal cancer. These procedures might have many advantages in rectal cancer treatment in terms of improving oncological and functional outcomes, especially in cases involving advanced cancer or technical difficulty. In the present study, we aimed to clarify the advantages and disadvantages of transabdominal robotic surgery and laparoscopic TaTME as a hybrid surgery for rectal cancer.

MATERIALS AND METHODS

We retrospectively evaluated six patients who underwent hybrid surgery for rectal cancer from August 2018 to April 2020. Both clinical and pathological outcomes were assessed.

RESULTS

Two patients showed circumferential margin involvement both before and after neoadjuvant therapy. Three patients were planned to undergo hybrid surgery with intersphincteric resection because of a narrow pelvis. One patient was planned to undergo hybrid surgery for a giant tumor of >10 cm. The median length of hospitalization was 17 days. No patients required conversion to an open procedure. All patients underwent formation of defunctioning ileostomies. Two patients had a stapled anastomosis and four had a hand-sewn coloanal anastomosis. Complications included one case of anastomotic leakage, which was managed conservatively with ultrasound- and computed tomography-guided drainage and antibiotics. Histological analysis revealed that all specimens had a negative radial margin and distal margin. The median number of lymph nodes harvested was 17.5. Two patients showed extensive lymph node metastases, including lateral node metastasis.

CONCLUSION

Hybrid surgery was performed safely and may improve oncological outcomes for rectal cancer. This technique has many potential benefits and would be alternative option in multimodal strategies for rectal cancer.

Predictors of Positive Circumferential Resection Margin in Rectal Cancer: A Current Audit of the National Cancer Database

BACKGROUND

Positive circumferential resection margin is a predictor of local recurrence and worse survival in rectal cancer. National programs aimed to improve rectal cancer outcomes were first created in 2011 and continue to evolve. The impact on circumferential resection margin during this time frame has not been fully evaluated in the United States.

OBJECTIVE

The purpose of this study was to determine the incidence and predictors of positive circumferential resection margin after rectal cancer resection, across patient, provider, and tumor characteristics.

DESIGN

This was a retrospective cohort study.

SETTINGS

The study was conducted using the National Cancer Database, 2011-2016.

PATIENTS

Adults who underwent proctectomy for pathologic stage I to III rectal adenocarcinoma were included.

MAIN OUTCOME MEASURES

Rate and predictors of positive circumferential resection margin, defined as resection margin ≤1 mm, were measured.

RESULTS

Of 52,620 cases, circumferential resection margin status was reported in 90% (n = 47,331) and positive in 18.4% (n = 8719). Unadjusted analysis showed that patients with positive circumferential resection margin were more often men, had public insurance and shorter travel, underwent total proctectomy via open and robotic approaches, and were treated in Southern and Western regions at integrated cancer networks (all p < 0.001). Multivariate analysis noted that positive proximal and/or distal margin on resected specimen had the strongest association with positive circumferential resection margin (OR = 15.6 (95% CI, 13.6-18.1); p < 0.001). Perineural invasion, total proctectomy, robotic approach, neoadjuvant chemoradiation, integrated cancer network, advanced tumor size and grade, and Black race had increased risk of positive circumferential resection margin (all p < 0.050). Laparoscopic approach, surgery in North, South, and Midwest regions, greater hospital volume and travel distance, lower T-stage, and higher income were associated with decreased risk (all p < 0.028).

LIMITATIONS

This was a retrospective cohort study with limited variables available for analysis.

CONCLUSIONS

Despite creation of national initiatives, positive circumferential resection margin rate remains an alarming 18.4%. The persistently high rate with predictors of positive circumferential resection margin identified calls for additional education, targeted quality improvement assessments, and publicized auditing to improve rectal cancer care in the United States. See Video Abstract at http://links.lww.com/DCR/B584.

PREDICTORES PARA UN MARGEN POSITIVO DE RESECCIN CIRCUNFERENCIAL EN EL CNCER DE RECTO UNA AUDITORA VIGENTE DE LA BASE DE DATOS NACIONAL DE CANCER

ANTECEDENTES:El margen positivo de resección circunferencial es un predictor de recurrencia local y peor sobrevida en el cáncer de recto. Los programas nacionales destinados a mejorar los resultados del cáncer de recto se crearon por primera vez en 2011 y continúan evolucionando. La repercusión del margen de resección circunferencial durante este período de tiempo no se ha evaluado completamente en los Estados Unidos.OBJETIVO:Determinar la incidencia y los predictores para un margen positivo de resección circunferencial posterior a la resección del cáncer de recto, según las características del paciente, el proveedor y el tumor.DISEÑO:Estudio de cohorte retrospectivo.AMBITO:Base de datos nacional de cáncer, 2011-2016.PACIENTES:Adultos que se sometieron a proctectomía por adenocarcinoma de recto con un estadío por patología I-III.PRINCIPALES VARIABLES EVALUADAS:Tasa y predictores para un margen positivo de resección circunferencial, definido como margen de resección ≤ 1 mm.RESULTADOS:De 52,620 casos, la condición del margen de resección circunferencial se informó en el 90% (n = 47,331) y positivo en el 18.4% (n = 8,719). El análisis no ajustado mostró que los pacientes con margen positivo de resección circunferencial se presentó con mayor frecuencia en hombres, tenían un seguro social y viajes más cortos, se operaron de proctectomía total abierta y robótica, y fueron tratados en las regiones del sur y el oeste en redes integradas de cáncer (todos p <0,001). El análisis multivariado destacó que el margen proximal y / o distal positivo de la pieza resecada tenía la asociación más fuerte con el margen postivo de resección circunferencial (OR 15,6; IC del 95%: 13,6-18,1, p <0,001). La invasión perineural, la proctectomía total, el abordaje robótico, la quimioradioterapia neoadyuvante, la red de cáncer integrada, el tamaño y grado del tumor avanzado y la raza afroamericana tenían un mayor riesgo de un margen de una resección positiva circunferencial (todos p <0,050). El abordaje laparoscópico, la cirugía en las regiones Norte, Sur y Medio Oeste, un mayor volumen hospitalario y distancia de viaje, estadio T más bajo y mayores ingresos se asociaron con una disminución del riesgo (todos p <0,028).LIMITACIONES:Estudio de cohorte retrospectivo con variables limitadas disponibles para análisis.CONCLUSIONES:A pesar del establecimiento de iniciativas nacionales, la tasa de margen positivo de resección circunferencial continúa siendo alarmante, 18,4%. El índice continuamente elevado junto a los predictores de un margen positivo de resección circunferencial hace un llamado para una mayor educación, evaluaciones específicas de mejora de la calidad y difusión de las auditorías para mejorar la atención del cáncer de recto en los Estados Unidos. Vea el resumen de video en http://links.lww.com/DCR/B584. Consulte Video Resumen en http://links.lww.com/DCR/B584.

Locoregional recurrence after transanal total mesorectal excision: an emotional rollercoaster

Transanal total mesorectal excision is a complex technique that should be performed in expert centers.

The learning curve of transanal total mesorectal excision for rectal cancer is associated with local recurrence: results from a multicentre external audit

AIM

Transanal total mesorectal excision (TaTME) has been suggested as a potential solution for the resection of challenging mid and low rectal cancer. This relatively complex procedure has been implemented in many centres over the last years, despite the absence of long-term safety data. Recently, concern has arisen because of an increase in local recurrence in the implementation phase. The aim of this study was to assess the correlation between accumulated experience and local recurrences.

METHOD

An independent clinical researcher performed an external audit of consecutive series of all TaTME procedures in six centres in the Netherlands. Kaplan-Meier estimated local recurrence rates were calculated and multivariate Cox proportional hazards regression analysis performed to assess risk factors for local recurrence. Primary outcome was the local recurrence rate in the initial implementation (cases 1-10), continued adoption (cases 11-40) and prolonged experience (case 41 onward).

RESULTS

Six hundred and twenty-four consecutive patients underwent TaTME for rectal cancer with a median follow-up of 27 months (range 1-82 months). The estimated 2- and 3-year local recurrence rates were 4.6% and 6.6%, respectively. Cox proportional hazards regression revealed procedural experience to be an independent factor in multivariate analysis next to advanced stage (ycMRF+, pT3-4, pN+) and pelvic sepsis. Corrected analysis projected the 3-year local recurrence rates to be 9.7%, 3.3% and 3.5% for the implementation, continued adoption and prolonged experience cohorts, respectively.

CONCLUSION

This multicentre study shows a high local recurrence rate (12.5%) after implementation of TaTME which lowers to an acceptable rate (3.4%) when experience increases. Therefore, intensified proctoring and further precautions must be implemented to reduce the unacceptably high risk of local recurrence at units starting this technique.

Oncological and Functional Outcomes of Transanal Total Mesorectal Excision in a Teaching Hospital in the Netherlands

Purpose

Transanal total mesorectal excision (TaTME) was developed to overcome surgical difficulties experienced in distal pelvic dissection. Concerns have been raised about potential worse postoperative functional outcomes after TaTME. Also, the oncological safety was questioned. This study aimed to describe the functional, surgical, oncological outcomes and quality of life (QoL) after TaTME.

Methods

All consecutive TaTME cases for rectal cancer without disseminated disease between December 2016 and April 2019 were included. The Wexner incontinence score, low anterior resection syndrome (LARS) score, fecal incontinence-related QoL, and the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-core questionnaire and 29-item module (EORTC QLQ-C30/CR29) were collected. Kaplan-Meier analysis was used to calculate local recurrence-free survival.

Results

Thirty patients were eligible for analysis of which 23 received questionnaires. Response rate was 74%. After a median follow-up of respectively 20.0 and 23.0 months for functional and oncological outcomes, the median (interquartile range) of Wexner incontinence and LARS scores were 9.0 (7.0-12.0) and 33.1 (25.0-39.0). Major LARS was present in 73.3%. Fecal incontinence, general and colorectal-specific QoL subdomains that are associated with poor bowel function scored in line with previously reported data. The 2-year actuarial cumulative local recurrence rate was 3.7% (95% confidence interval, 2.4%-5.0%).

Conclusion

TaTME may lead to significant functional impairments. Patients should receive preoperative counseling on this topic and be fully aware of the potential consequences of their treatment. Oncological data were in line with other short- to moderate-term data and did not show alarming results.

Transanal mesorectal excision: early outcomes in Australia and New Zealand

BACKGROUND

Transanal total mesorectal excision (taTME) aims to overcome some of the technical challenges faced when operating on mid and low rectal cancers. Specimen quality has been confirmed previously, but recent concerns have been raised about oncological safety. This multicentre prospective study aimed to evaluate the safety of taTME among early adopters in Australia and New Zealand.

METHODS

Data from all consecutive patients who had taTME for rectal cancer from July 2014 to February 2020 at six tertiary referral centres in Australasia were recorded and analysed.

RESULTS

A total of 308 patients of median age of 64 years underwent taTME. Some 75.6 per cent of patients were men, and the median BMI was 26.8 kg/m2. The median distance of tumour from anal verge was 7 cm. Neoadjuvant chemoradiotherapy was administered to 57.8 per cent of patients. The anastomotic leak rate was 8.1 per cent and there was no mortality within 30 days of surgery. Pathological examination found a complete mesorectum in 295 patients (95.8 per cent), a near-complete mesorectum in seven patients (2.3 per cent), and an incomplete mesorectum in six patients (1.9 per cent). The circumferential resection margin and distal resection margin was involved in nine patients (2.9 per cent), and two patients (0.6 per cent) respectively. Over a median follow-up of 22 months, the local recurrence rate was 1.9 per cent and median time to local recurrence was 30.5 months.

CONCLUSION

This study showed that, with appropriate training and supervision, skilled minimally invasive rectal cancer surgeons can perform taTME with similar pathological and oncological results to open and laparoscopic surgery.

Deep learning-based automatic surgical step recognition in intraoperative videos for transanal total mesorectal excision

BACKGROUND

Dividing a surgical procedure into a sequence of identifiable and meaningful steps facilitates intraoperative video data acquisition and storage. These efforts are especially valuable for technically challenging procedures that require intraoperative video analysis, such as transanal total mesorectal excision (TaTME); however, manual video indexing is time-consuming. Thus, in this study, we constructed an annotated video dataset for TaTME with surgical step information and evaluated the performance of a deep learning model in recognizing the surgical steps in TaTME.

METHODS

This was a single-institutional retrospective feasibility study. All TaTME intraoperative videos were divided into frames. Each frame was manually annotated as one of the following major steps: (1) purse-string closure; (2) full thickness transection of the rectal wall; (3) down-to-up dissection; (4) dissection after rendezvous; and (5) purse-string suture for stapled anastomosis. Steps 3 and 4 were each further classified into four sub-steps, specifically, for dissection of the anterior, posterior, right, and left planes. A convolutional neural network-based deep learning model, Xception, was utilized for the surgical step classification task.

RESULTS

Our dataset containing 50 TaTME videos was randomly divided into two subsets for training and testing with 40 and 10 videos, respectively. The overall accuracy obtained for all classification steps was 93.2%. By contrast, when sub-step classification was included in the performance analysis, a mean accuracy (± standard deviation) of 78% (± 5%), with a maximum accuracy of 85%, was obtained.

CONCLUSIONS

To the best of our knowledge, this is the first study based on automatic surgical step classification for TaTME. Our deep learning model self-learned and recognized the classification steps in TaTME videos with high accuracy after training. Thus, our model can be applied to a system for intraoperative guidance or for postoperative video indexing and analysis in TaTME procedures.

Short-term outcomes after transanal total mesorectal excision for rectal cancer in Denmark - a prospective multicentre study

AIM

The aim of this study was to evaluate the short-term surgical and oncological outcomes after transanal total mesorectal excision (TaTME) for rectal cancer during the implementation phase of this procedure in Denmark.

METHOD

This is a retrospective review of prospectively recorded data. Registration was initiated by the Scientific Council of the Danish Colorectal Cancer Group (DCCG.dk) in order to assess the quality of care during the implementation of TaTME. Pre-, intra- and postoperative data including early recurrences were recorded at the operating centres.

RESULTS

From August 2016 to April 2019, 115 TaTME procedures were registered. Patients were predominantly male (74%) with mid-rectal (88%) tumours. The level of surgical complications was comparable to previous nationwide results. Anastomotic leakage occurred in 6/109 (5.5%). One urethral injury occurred. The plane of dissection was mesorectal in 60% of cases, intramesorectal in 28% and muscularis in 12%. Nonmicroradicality was seen in 8% (R1, 6%; R2, 2%). Four local recurrences occurred after a median of 23 months of follow-up. One of these was multifocal.

CONCLUSION

In an implementation phase where patient selection is expected, surgical and oncological results after TaTME were comparable to those of other approaches reported in the literature.

Robotic or transanal total mesorectal excision (TaTME) approach for rectal cancer, how about both? Feasibility and outcomes from a single institution

Laparoscopic surgery for rectal cancer is technically challenging. Robotic and transanal TME (TaTME) are both novel approaches developed to provide better visualization and dissection. We aim to combine both approaches in a hybrid procedure and evaluate the feasibility as well as patient and oncological outcomes in this study. A review of a prospectively maintained database of patients who underwent a hybrid abdominal robotic approach with TaTME for rectal cancer between January 2016 and October 2018 was undertaken. Patient demographics, tumor characteristics and surgical outcomes were recorded and analyzed. A total of 69 patients (43 males, 26 females) received this hybrid approach. Their median age was 58 years (range 35-87) with a mean BMI of 24.3 kg/m² (range 16.4-44.2). Median distance from anal verge was 5 cm (range 2-9). The patients had a median hospital length of stay of 7 days (range 5-28). Complication rate was 17.4% (12 patients) with 3 patients (4.3%) requiring a reoperation. TME quality was optimal with all of them either complete (81.2%) or almost complete (18.8%). 65 patients (94.2%) had an R0 resection with 4 patients (5.8%) with involved circumferential resection margins (≤ 1 mm). The median number of lymph nodes harvested was 20 (range 6-37). After a median follow-up of 27.7 months (range 7-42), local recurrence was identified in 2 patients (4%). Three patients (5.2%) had distant recurrence at the 3-year mark. Hybrid robotic abdominal dissection with transanal TME for rectal cancer appears to be feasible with comparable surgical outcomes to other traditional approaches.

Transanal total mesorectal excision outcomes for advanced rectal cancer in a complex surgical population

BACKGROUND

Total mesorectal excision (TME) is the gold standard for oncologic resection in low and mid rectal cancers. However, abdominal approaches to TME can be hampered by poor visibility, inadequate retraction, and distal margin delineation. Transanal TME (taTME) is a promising hybrid technique that was developed to mitigate the difficulties of operating in the low pelvis and to optimize the circumferential resection and distal margins.

METHODS

The objective of this study was to characterize our experience implementing taTME at our institution in a technically challenging patient population. We performed a retrospective review of consecutive patients who underwent taTMEs between November 2013 and May 2019 for rectal cancer at a tertiary community cancer center. Outcome measures included pathologic grading of TME specimen, post-operative complications, and oncologic outcomes.

RESULTS

Forty-four patients with mid and low rectal cancer underwent low anterior resection via taTME. The most common staging modality was rectal MRI which demonstrated T3 or T4 tumors in 89% of our patients prior to neoadjuvant. Eighty-six percent of patients underwent neoadjuvant chemoradiation. The initial cases were performed sequentially as a single team, but we later transitioned to a synchronous, two-team approach. Ninety-one percent of TME grades were complete or near complete. Only one patient (2.3%) had a positive circumferential margin. Six patients developed anastomotic leaks with an overall anastomotic complication rate of 18.2%. Two patients (4.5%) with primary rectal cancer developed local recurrence, one of which developed multifocal local recurrence.

CONCLUSIONS

Using the taTME approach on selected locally advanced low rectal cancers, especially in technically complex irradiated and obese male patients, has yielded comparably safe and effective outcomes to laparoscopic proctectomy.

Transanal total mesorectal excision for stage II or III rectal cancer: pattern of local recurrence in a tertiary referral center

BACKGROUND

For mid and low rectal cancer, transanal total mesorectal excision (TaTME) has been established as an alternative approach to laparoscopic surgery. However, there are concerns about an unexpected pattern of local recurrence. This study aimed to analyze the pattern of local recurrence for patients treated with TaTME in a tertiary referral center.

METHODS

A retrospective single-center analysis was performed. Since 2011, all patients with rectal cancer undergoing TaTME with curative intent were prospectively included in a standardized database. Patients with tumors within 12 cm, clinical stage II or III were included. The primary endpoint of the study was the overall local recurrence rate, together with a critical analysis of the patterns of local failures.

RESULTS

Two hundred and five patients were included in this analysis. At the time of surgery, patients had a mean age of 67.1 years (SD 12.3), and 66.8% were male. Neoadjuvant therapy was administered in 73.7%. Mesorectal specimen quality was complete or near-complete in 98.5%, while circumferential resection margin was ≤ 1 mm (including T4 tumors) in 11.8%. After a median follow-up of 34.3 months (95% CI 30.1-38.5), 3.4% (n = 7) presented with local recurrent disease. Six out of the seven patients were also diagnosed with hematogenous metastases. Of the seven patients, three presented with at least one of the following risk factors: T4 tumor, N2 disease, incomplete mesorectal specimen, or positive CRM. Local failure was noted posteriorly (n = 3), laterally (n = 2), anteriorly (n = 1), and in the axial compartment (n = 1). Median time to relapse was 31.5 months (10.3-40.9). The median follow-up after local recurrence was 7.9 (95% CI 6.7-9.1) months, with an overall survival of 85.7%.

CONCLUSIONS

TaTME provided satisfactory local recurrence outcomes, and the most common patterns of failure were in the central pelvis.

Exploring the perioperative outcomes of a sample of successful adopters of transanal total mesorectal excision (taTME) during the learning phase

BACKGROUND

Transanal total mesorectal excision can be a technically challenging operation to master. While many early adopters have reported adequate outcomes, others have failed to reproduce these results. There are contradicting data on oncologic outcomes during the learning phase of this technique. Thus, our objective was to perform a multicentered assessment of oncological outcomes in patients undergoing transanal total mesorectal excision during the learning phase in a sample of successful adopting centers.

METHODS

Surgeons from 8 centers with experience in the management of rectal cancer were invited to participate. The initial 51 consecutive benign and malignant cases of the participating units were retrospectively reviewed, but only 366 cancer cases were included in the analysis. Procedures were divided into implementation (ie, the first 10 cases) and postimplementation (ie, case 11 on onwards) groups, and the main outcome was the incidence of local recurrence.

RESULTS

The overall prevalence of local recurrence was 4.1% at a median follow-up of 35 months (interquartile range 20.3-44.2); among implementation and postimplementation groups local recurrence was 7.5% and 3.1%, respectively, and the rate of local recurrence was observed to be nearly 60% lower in the postimplementation group (hazard ratio [95% confidence interval] = 0.43 [0.26-0.72]) Total mesorectal excision specimens were complete or nearly complete in 87.7% of cases, and the circumferential and distal margins were clear in 93.2% and 92.6%, respectively CONCLUSION: Local recurrence rate was low during the learning phase of the transanal total mesorectal excision in a sample of rectal cancer surgeons with acceptable surgical and oncologic outcomes. Both the prevalence and rate of local recurrence were markedly lower in the postimplementation phase, indicating improvement as experience accumulated.

[Transanal total mesorectal excision-Indications, technique and results]

Total mesorectal excision (TME) has become the standard treatment for rectal cancer in the middle and lower third. Meanwhile, many international trials have confirmed the noninferiority of laparoscopic TME compared to the open technique. Nevertheless, in the presence of anatomical limitations, such as narrow, obese, male pelvises as well as large rectal tumors, the adequate resection of the lower third of the rectum according to oncological criteria, is still challenging even for specialized colorectal surgeons. Therefore, the implementation of innovative approaches, such as robotic-assisted and transanal TME (TaTME) should shed light on this anatomically complex region and guarantee an oncological radical resection and the best possible preservation of neural structures. The advantages of this technique have so far only been provided by retrospective cohort studies by large international centers. Therefore, international prospective randomized trials are currently recruiting patients to analyze the surgical and oncological outcome of TaTME compared to conventional techniques. This article describes the TaTME technique per se, the fields of application and the current data situation. Practical recommendations for the safe implementation of this operative procedure are also presented. The TaTME procedure is reserved for highly specialized colorectal centers with a high volume of rectal cancer cases and appropriate expertise in minimally invasive visceral surgery.Die totale mesorektale Exzision (TME) ist der Goldstandard im Kontext der multimodalen Behandlung des Rektumkarzinoms im mittleren und unteren Drittel. Der transanale Zugang ist eine Ergänzung des zunehmend laparoskopischen Vorgehens, welcher gerade bei anatomischen Limitationen bei der onkologisch adäquaten Resektion des distalen Rektums Abhilfe schaffen soll. Die Nichtunterlegenheit in chirurgischen und onkologischen Parametern wird gegenüber konventionellen (laparoskopisch/offen) Operationsmethoden derzeit intensiv beforscht. Eine sichere Implementation dieser herausfordernden Technik ist an ein modulares Trainingskurrikulum gebunden.

A comparative cost analysis of transanal and laparoscopic total mesorectal excision for rectal cancer

Despite proven clinical benefits in the short term, technical difficulties limit utilization of laparoscopy in rectal cancer surgery (RCS). Transanal Total Mesorectal Excision (taTME) overcomes many technical limitations of laparoscopic RCS. However, the costs of this procedure have not been addressed yet. Our goal was to perform a comparative cost analysis of taTME and laparoscopic TME (lapTME). Consecutive patients undergoing curative TME between 1 February 2014 and 31 October 2018 were selected from a prospectively maintained database and stratified, according to the type of procedure, into taTME and lapTME groups. Patient demographics, tumour characteristics, operative parameters, and short-term outcomes were analyzed. The main outcome measure was intraoperative costs of the two procedures. Secondary outcomes were short-term outcome and the utilization of hospital resources to manage the postoperative course. Hundred and fifty-two patients with rectal cancer (66 lapTME, 86 taTME) were included in the study. Surgical supplies required for taTME procedure exceeded the cost of lapTME of 754,54 €. The duration of surgery was not significantly different between the two approaches (266 ± 92.85 vs 271 ± 83.63, p = 0.50). Short-term outcomes were comparable including postoperative complication rate (17 vs 20%, p = 0.68), reintervention rate, and length of stay. There was no difference in hospital resources utilization to manage postoperative course including blood test, diagnostics, consultations, and medications. TaTME has higher intraoperative costs in terms of supplies with respect to lapTME. Short-term outcomes and hospital resources to manage postoperative course are comparable.

Development and early outcomes of the national training initiative for transanal total mesorectal excision in the UK

AIM

Transanal total mesorectal excision (TaTME) has attracted substantial interest amongst colorectal surgeons but its technical challenges may underlie the early reports of visceral injuries and oncological concerns. The aim of this study was to report on the feasibility, development and the outcome of the national pilot training initiative for TaTME-UK.

METHODS

TaTME-UK was successfully launched in September 2017 in partnership with the healthcare industry and endorsed by the Association of Coloproctology of Great Britain and Ireland. This multi-modal training curriculum consisted of three phases: (i) set-up; (ii) selection of pilot sites; and (iii) formal proctorship programme. Bespoke Global Assessment Scoring (GAS) forms were designed and completed by both trainees and mentors. Data were collected on patient demographics, tumour characteristics and perioperative clinical and histological outcomes.

RESULTS

Twenty-four proctored cases were performed by 10 colorectal surgeons from five selected pilot sites. Median operative time was 331 ± 90 (195-610) min which was reduced to 283 ± 62 (195-340) min in the final case. Independent performance (GAS score of 5) was achieved for most operative steps by case 5. There was one conversion (4.2%), but no visceral injuries. Pathological data confirmed no bowel perforation and intact quality of the mesorectal TME specimens with clear distal margin in all cases and circumferential margins in 23/24 cases (96%).

CONCLUSION

This exploratory study demonstrates acceptable early outcomes in a small cohort suggesting that a competency-based multi-modal training programme for TaTME can be feasible and safe to implement at a national level.

International expert consensus guidance on indications, implementation and quality measures for transanal total mesorectal excision

AIM

To provide dynamic guidance from a rigorous and up-to-date consensus on the safe implementation and application of transanal total mesorectal excision (TaTME) from an international panel of expert surgeons and educationalists supported by 14 international surgical societies.

METHOD

An adapted Delphi method and focus group discussion approach was implemented for this consensus process, with expert advice from a guidelines methodologist. Statements were generated focusing on three main topics relating to the safe implementation of TaTME: (1) indications, (2) quality and outcome measures, (3) training and implementation of TaTME.

RESULTS

Five rounds of the Delphi consensus process were completed over a 13-month period. A total of 56 surgeons experienced in TaTME and surgical education participated in this project. By Delphi round four, 80.0% or greater agreement was reached for all statements except for two, which were further reviewed during a fifth round. More complex cases that are likely to benefit from TaTME were identified, with the recommendation that they should be referred to TaTME expert centres. The most agreed upon definition of expert centres is outlined.

CONCLUSION

We have provided a current framework of best practice related to implementation of TaTME. The statements are not indefinite and will continue to be 'dynamic' and updated as new evidence emerges.

Computer-assisted real-time automatic prostate segmentation during TaTME: a single-center feasibility study

BACKGROUND

Urethral injuries (UIs) are significant complications pertaining to transanal total mesorectal excision (TaTME). It is important for surgeons to identify the prostate during TaTME to prevent UI occurrence; intraoperative image navigation could be considered useful in this regard. This study aims at developing a deep learning model for real-time automatic prostate segmentation based on intraoperative video during TaTME. The proposed model's performance has been evaluated.

METHODS

This was a single-institution retrospective feasibility study. Semantic segmentation of the prostate area was performed using a convolutional neural network (CNN)-based approach. DeepLab v3 plus was utilized as the CNN model for the semantic segmentation task. The Dice coefficient (DC), which is calculated based on the overlapping area between the ground truth and predicted area, was utilized as an evaluation metric for the proposed model.

RESULTS

Five hundred prostate images were randomly extracted from 17 TaTME videos, and the prostate area was manually annotated on each image. Fivefold cross-validation tests were performed, and as observed, the average DC value equaled 0.71 ± 0.04, the maximum value being 0.77. Additionally, the model operated at 11 fps, which provides acceptable real-time performance.

CONCLUSIONS

To the best of the authors' knowledge, this is the first effort toward realization of computer-assisted TaTME, and results obtained in this study suggest that the proposed deep learning model can be utilized for real-time automatic prostate segmentation. In future endeavors, the accuracy and performance of the proposed model will be improved to enable its use in practical applications, and its capability to reduce UI risks during TaTME will be verified.

Locoregional recurrences after transanal total mesorectal excision of rectal cancer during implementation

Background

Transanal total mesorectal excision (TaTME) has been proposed as an approach in patients with mid and low rectal cancer. The TaTME procedure has been introduced in the Netherlands in a structured training pathway, including proctoring. This study evaluated the local recurrence rate during the implementation phase of TaTME.

Methods

Oncological outcomes of the first ten TaTME procedures in each of 12 participating centres were collected as part of an external audit of procedure implementation. Data collected from a cohort of patients treated over a prolonged period in four centres were also collected to analyse learning curve effects. The primary outcome was the presence of locoregional recurrence.

Results

The implementation cohort of 120 patients had a median follow up of 21·9 months. Short‐term outcomes included a positive circumferential resection margin rate of 5·0 per cent and anastomotic leakage rate of 17 per cent. The overall local recurrence rate in the implementation cohort was 10·0 per cent (12 of 120), with a mean(s.d.) interval to recurrence of 15·2(7·0) months. Multifocal local recurrence was present in eight of 12 patients. In the prolonged cohort (266 patients), the overall recurrence rate was 5·6 per cent (4·0 per cent after excluding the first 10 procedures at each centre).

Conclusion

TaTME was associated with a multifocal local recurrence rate that may be related to suboptimal execution rather than the technique itself. Prolonged proctoring, optimization of the technique to avoid spillage, and quality control is recommended.

A nationwide study on the adoption and short-term outcomes of transanal total mesorectal excision in the UK

BACKGROUND

The interest and adoption of transanal total mesorectal excision (TaTME) is growing worldwide, but evidence on nationwide implementation and short-term outcomes is scarce. This study aims to evaluate national results for this relatively new technique in the UK.

METHODS

All TaTME procedures performed in the UK and recorded on the international TaTME registry between January 2013 and January 2018 were analyzed. Surgeons who received training on TaTME in the UK were sent a survey regarding their experience with implementation of TaTME in their unit. Primary endpoint was a composite for "optimal pathology" (free resection margin (R0) and TME specimen with no major defects and no rectal wall perforations). Secondary outcomes included 30-day clinical course and survey outcomes.

RESULTS

Forty-two hospitals entered 513 cases over a 5-year period; 28 of 42 hospitals (66.7%) performed ten cases or less. The indication for surgery was cancer in 364 (71.0%) cases. Optimal pathology was achieved in 295 (92.8%), with an involved resection margin (R1) rate of 13 of 513 (4.1%). A Clavien-Dindo ≥III within 30 days was 13.4% (N.=45) and 6.8% (N.=10) in the cancer and benign groups, respectively. Based on the survey (response rate 68 of 86; 79%), 76.1% of the surgeons implemented TaTME in their unit after receiving training, all of whom experienced difficulties with performing TaTME.

CONCLUSIONS

This study reports acceptable nationwide short-term outcomes of TaTME. However, adoption occurred in a rapid and non-standardized manner. A structured TaTME training program is therefore recommended.

Long-term oncological results after transanal total mesorectal excision for rectal carcinoma

Background

Transanal total mesorectal excision (TaTME) for mid and low rectal cancer has been shown to improve short-term outcomes, mostly due to lower conversion rates and with improved quality of the specimen. However, robust long-term oncological data supporting the encouraging clinical and pathological outcomes are lacking.

Methods

All consecutive patients undergoing TaTME with curative intent for mid or low rectal cancer in two referral centers in The Netherlands between January 2012 and April 2016 with a complete and minimum follow-up of 36 months were included. The primary outcome was local recurrence rate. Secondary outcomes were disease-free survival, overall survival and development of metastasis.

Results

There were 159 consecutive patients. Their mean age was 66.9 (10.2) years and 66.7% of all patients were men. Pathological analysis showed a complete mesorectum in 139 patients (87.4%), nearly complete in 16 (10.1%) and an incomplete mesorectum in 4 (2.5%). There was involvement of the CRM (< 1 mm) in one patient (0.6%) and no patients had involvement of the distal margin (< 5 mm). Final postoperative staging after neoadjuvant therapy was stage 0 in 11 patients (6.9%), stage I in 73 (45.9%), stage II in 31 (19.5%), stage III in 37 (23.3%) and stage IV in 7 (4.4%). The 3-year local recurrence rate was 2.0% and the 5-year local recurrence rate was 4.0%. Median time to local recurrence was 19.2 months. Distant metastases were found in 22 (13.8%) patients and were diagnosed after a median of 6.9 months (range 1.1–50.4) months. Disease-free survival was 92% at 3 years and 81% at 5 years. Overall survival was 83.6% at 3 years and 77.3% at 5 years.

Conclusions

The long-term follow-up of the current cohort confirms the oncological safety and feasibility of TaTME in two high volume referral centers for rectal carcinoma. However, further robust and audited data must confirm current findings before widespread implementation of TaTME.