First international training and assessment consensus workshop on transanal total mesorectal excision (taTME). Tech Coloproctol. 2016;20:343-352. [PMID: 27015679 DOI: 10.1007/s10151-016-1454-2]

Does surgeon or hospital volume influence outcome in dedicated colorectal units?-A Viennese perspective

OBJECTIVE

A clear relationship between higher surgeon volume and improved outcomes has not been convincingly established in rectal cancer surgery. The aim of this study was to evaluate the impact of individual surgeon's caseload and hospital volume on perioperative outcome.

METHODS

We retrospectively analyzed 336 consecutive patients undergoing oncological resection for rectal cancer at two Viennese hospitals between 1 January 2015 and 31 December 2020. The effect of baseline characteristics as well as surgeons' caseloads (low volume: 0-5 cases per year, high volume > 5 cases per year) on postoperative complication rates (Clavien-Dindo Classification groups of < 3 and ≥ 3) were evaluated.

RESULTS

No differences in baseline characteristics were found between centers in terms of sex, smoking status, or comorbidities of patients. Interestingly, only 14.7% of surgeons met the criteria to be classified as high-volume surgeons, while accounting for 66.3% of all operations. There was a significant difference in outcomes depending on the treating center in univariate and multivariate binary logistic regression analysis (odds ratio (OR) = 2.403, p = 0.008). Open surgery was associated with lower complication rates than minimally invasive approaches in univariate analysis (OR = 0.417, p = 0.003, 95%CI = 0.232-0.739) but not multivariate analysis. This indicated that the center's policy rather than surgeon volume or mode of surgery impact on postoperative outcomes.

CONCLUSION

Treating center standards impacted on outcome, while individual caseload of surgeons or mode of surgery did not independently affect complication rates in this analysis. The majority of rectal cancer resections are performed by a small number of surgeons in Viennese hospitals.

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.

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.

Serbian National Training Programme for minimally invasive colorectal surgery (LapSerb): short-term clinical outcomes of over 1400 colorectal resections

INTRODUCTION

The Serbian National Training Programme for minimally invasive colorectal surgery (LapSerb) was introduced to implement laparoscopic colorectal surgery across Serbia. The programme aimed to accelerate training of established colorectal surgeons through a competency-based programme. This involved knowledge assessment, workshops, live operating, and competency-based assessment of unedited videos. The aim of this study is to report the outcomes of laparoscopic colorectal resection performed by LapSerb certified surgeons.

METHODS

LapSerb prospectively maintained multicentred database was analysed for laparoscopic colorectal resections from January 2015 to February 2021. Data collected included patient demographics, indications for surgery, perioperative data, and 30-day outcomes.

RESULTS

A total of 1456 laparoscopic colectomies by 24 certified surgeons were included in the final analysis. Mean age was 67 (± 12) years old and male to female ratio was 1:1.5. 83.1% of the colectomies were malignant, mainly due to adenocarcinoma. Anterior resection was the most common procedure with 699 (48%) cases, followed by right and left colectomies with 357 (24.5%) and 303 (21%) procedure respectively. 4.8% of patients required conversion to open surgery. Thirty-day readmission and reoperation rates were 2.3% and 4.7%, respectively. Overall mortality in all cases was 1.1% and R0 resections were achieved in 97.8% of malignant colectomies.

CONCLUSION

The LapSerb programme successfully and safely established laparoscopic colorectal surgery across the country with comparable and acceptable short-term clinical outcomes.

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.

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.

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.

Development of a performance rubric for transanal endoscopic rectal purse-string sutures

BACKGROUND

Placing a transanal endoscopic rectal purse-string suture (taEPS) is the crucial first component of transanal total mesorectal excision (taTME). However, no structured training is available to improve the procedure-specific skills for taEPS. The aim of this study was to create a performance rubric to improve taEPS skills and provide preliminary evidence for its validity.

METHODS

A performance rubric was created based on technical considerations for taEPS, identified by consulting with taTME surgical and performance assessment experts. Ten independent, blinded raters assessed 10 videotaped taEPS procedures of consecutive taTME cases, at National Cancer Center Hospital East (NCCHE), Chiba, Japan, in January 2018-March 2019 using the rubric and the Global Operative Assessment of Laparoscopic Skills (GOALS). Internal consistency and inter-rater reliabilities were calculated. Videotaped taEPS procedures were timed and assessed by the rubric. Correlation between rubric scores and suturing times were analyzed.

RESULTS

The rubric consists of four items: loading the needle (LN), atraumatic needle passage (AP), planned suture path (PS), and overall performance (OA). Videotaped performances were graded on a 3-point Likert scale; scores were calculated as sums of the points. Cronbach's α for internal consistency was 0.713. Inter-rater reliabilities were LN: 0.73, AP: 0.76, PS: 0.71, and OA: 0.70. Rubric and GOALS scores were strongly correlated (r = 0.964, p < 0.001). In 112 consecutive taEPS performances, rubric scores were strongly correlated with suturing time (r =  - 0.69, p < 0.001). Surgeons' experience with taTME was associated with rubric scores and suturing time.

CONCLUSIONS

This study provides preliminary validation for the taEPS skill performance rubric. The rubric's structured training may facilitate skill acquisition by providing trainees with critical clinical considerations.

Education and Training in Transanal Endoscopic Surgery and Transanal Total Mesorectal Excision

There is a paradigm shift in surgical training, and new tool and technology are being used to facilitate mastery of the content and technical skills. The transanal procedures for rectal cancer-transanal endoscopic surgery (TES) and transanal total mesorectal excision (TaTME)-have a distinct learning curve for competence in the procedures, and require special training for familiarity with the "bottom-up" anatomy, procedural risks, and managing complex cases. These procedures have been models for structured education and training, using multimodal tools, to ensure safe implementation of TES and TaTME into clinical practice. The goal of this work was to review the current state of surgical education, the introduction and learning curve of the TES and TaTME procedures, and the established and future models for education of the transanal procedures for rectal cancer.

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.

Neoadjuvant concurrent chemoradiotherapy followed by transanal total mesorectal excision assisted by single-port laparoscopic surgery for low-lying rectal adenocarcinoma: a single center study

Purpose

To assess the feasibility and short-term outcomes of neoadjuvant chemoradiotherapy (CCRT) followed by transanal total mesorectal excision assisted by single-port laparoscopic surgery (TaTME-SPLS) for low-lying rectal adenocarcinoma.

Methods and materials

A total of 23 patients with clinical stage II-III low-lying (from anal verge 0-8 cm) rectal adenocarcinoma who underwent neoadjuvant CCRT followed by TaTME-SPLS consecutively from December 2015 to December 2018, were enrolled into our study. Chi-squared testing and Student’s t testing were used to make parametric comparisons, and Fisher’s exact test or the Mann–Whitney U test were used to make nonparametric comparisons.

Results

Conversion rate in patients who underwent neoadjuvant CCRT followed by TaTME-SPLS was only 4%. The mean operation time was 366 min and the inter-sphincter resection (ISR) was done for 14 patients (60%). The mean number of lymph nodes harvested was 15. There was no surgical mortality, but the 30-day morbidity rate was 21% (5 patients were Clavien-Dindo I-II). Pathological complete response was 21.74% with 100% organ preservation and 100% clear distal margin after neoadjuvant CCRT followed by TaTME-SPLS.

Conclusion

TaTME-SPLS would be highly successful in lymph node negative and low T stage of low-lying rectal cancer patients who had pathological complete remission or high percentage of partial remission after neoadjuvant CCRT.

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.

The multidisciplinary management of rectal cancer

Rectal cancer treatment has evolved during the past 40 years with the use of a standardized surgical technique for tumour resection: total mesorectal excision. A dramatic reduction in local recurrence rates and improved survival outcomes have been achieved as consequences of a better understanding of the surgical oncology of rectal cancer, and the advent of adjuvant and neoadjuvant treatments to compliment surgery have paved the way for a multidisciplinary approach to disease management. Further improvements in imaging techniques and the ability to identify prognostic factors such as tumour regression, extramural venous invasion and threatened margins have introduced the concept of decision-making based on preoperative staging information. Modern treatment strategies are underpinned by accurate high-resolution imaging guiding both neoadjuvant therapy and precision surgery, followed by meticulous pathological scrutiny identifying the important prognostic factors for adjuvant chemotherapy. Included in these strategies are organ-sparing approaches and watch-and-wait strategies in selected patients. These pathways rely on the close working of interlinked disciplines within a multidisciplinary team. Such multidisciplinary forums are becoming standard in the treatment of rectal cancer across the UK, Europe and, more recently, the USA. This Review examines the essential components of modern-day management of rectal cancer through a multidisciplinary team approach, providing information that is essential for any practising colorectal surgeon to guide the best patient care.

Development and validation of a transanal endoscopic rectal purse string simulator

BACKGROUND

Rectal purse string placement for transanal mesorectal excision is challenging, and practice is difficult. The objective of this study is to build an endoscopic rectal purse string simulator and provide evidence for the validity of its use.

METHODS

A low-cost transanal endoscopic rectal purse string simulator was created and used to measure the performance of participants. Participants included general surgery residents, fellows, and staff surgeons from several Canadian university-affiliated institutions across Canada. The performance of the rectal purse string placement was measured by the time to completion of the task as well scoring with a modified objective structured assessment of technical skills (OSATS) score and a modified advanced laparoscopic suturing (ALS) score.

RESULTS

Thirty-nine participants were recruited into the study. Participants were split into three groups, based on prior experience with laparoscopic suturing, for the analysis of suturing a rectal purse string on the simulator based on three performance measures. There was a significant difference found in all three measures of performance in the three groups (time to completion p = 0.014, mean blinded OSATS score p = 0.007, mean blinded ALS score p = 0.020). Participants with previous laparoscopic suturing had significantly faster times to completion and higher skills scores when compared to residents (time: 5.1 ± 1.4 min vs 9.0 ± 4.8 min, p = 0.005; OSATS: 19.7 ± 2.8 vs 13.0 ± 5.8, p = 0.00398, ALS: 27.4 ± 4.0 vs 18.9 ± 8.5, p = 0.0151).

CONCLUSIONS

A transanal endoscopic purse string simulator was constructed and preliminary testing has shown variable performance based on prior laparoscopic suturing experience.

Tips and Tricks

The role of transanal total mesorectal excision (taTME) in minimally invasive proctectomy, especially rectal cancer surgery, is increasing. There has been exponential growth in uptake from the initial in vivo case in 2010 to the present day. Early adopters of taTME are well within the mature portions of their learning curve, but there are a significant number of novice taTME surgeons. We have overviewed the critical aspects of patient selection, operating room set-up, and necessary equipment. In particular, we recommend that a one-team approach is used for the early cases, and ideally with an experienced proctor. The important technical pearls that will aid the novice taTME surgeon were also described.

Implementing new surgical technology: a national perspective on case volume requirement for proficiency in transanal total mesorectal excision

Background

Early data suggest that transanal total mesorectal excision (TaTME) is a safe alternative to the abdominal approach for rectal cancer. This study aims to understand the approach to the management of rectal cancer in Canada and to ascertain perspectives on introducing TaTME.

Methods

Surgeons were invited to complete a survey that asked about their management practices relating to rectal cancer and their opinions regarding TaTME.

Results

Ninety-four surgeons completed the survey (38% response rate). The number of rectal cancer cases handled annually by surgeons varied widely (1–80 cases, median 15 cases). Twenty-seven percent of respondents performed TaTME at the time of the survey, and 43% of those who did not said they planned on learning the technique. Surgeons who performed TaTME felt that a higher annual volume of rectal cancer cases was required to maintain proficiency than did non-TaTME surgeons (median 20 cases [interquartile range (IQR) 15–25 cases] v. 15 cases [IQR 10–20 cases]). Surgeons who performed TaTME also felt that a higher annual volume of TaTME cases was required to maintain proficiency (median 12 cases [IQR 10–19 cases] v. 9 cases [IQR 5–10 cases]).

Conclusion

These findings help define the current practice environment for rectal cancer surgeons in Canada and highlight the complex issues associated with learning TaTME.

Incidence and Risk Factors for Anastomotic Failure in 1594 Patients Treated by Transanal Total Mesorectal Excision: Results From the International TaTME Registry

OBJECTIVE

To determine the incidence of anastomotic-related morbidity following Transanal Total Mesorectal Excision (TaTME) and identify independent risk factors for failure.

BACKGROUND

Anastomotic leak and its sequelae are dreaded complications following gastrointestinal surgery. TaTME is a recent technique for rectal resection, which includes novel anastomotic techniques.

METHODS

Prospective study of consecutive reconstructed TaTME cases recorded over 30 months in 107 surgical centers across 29 countries. Primary endpoint was "anastomotic failure," defined as a composite endpoint of early or delayed leak, pelvic abscess, anastomotic fistula, chronic sinus, or anastomotic stricture. Multivariate regression analysis performed identifying independent risk factors of anastomotic failure and an observed risk score developed.

RESULTS

One thousand five hundred ninety-four cases with anastomotic reconstruction were analyzed; 96.6% performed for cancer. Median anastomotic height from anal verge was 3.0 ± 2.0 cm with stapled techniques accounting for 66.0%. The overall anastomotic failure rate was 15.7%. This included early (7.8%) and delayed leak (2.0%), pelvic abscess (4.7%), anastomotic fistula (0.8%), chronic sinus (0.9%), and anastomotic stricture in 3.6% of cases. Independent risk factors of anastomotic failure were: male sex, obesity, smoking, diabetes mellitus, tumors >25 mm, excessive intraoperative blood loss, manual anastomosis, and prolonged perineal operative time. A scoring system for preoperative risk factors was associated with observed rates of anastomotic failure between 6.3% to 50% based on the cumulative score.

CONCLUSIONS

Large tumors in obese, diabetic male patients who smoke have the highest risk of anastomotic failure. Acknowledging such risk factors can guide appropriate consent and clinical decision-making that may reduce anastomotic-related morbidity.

[Transanal total mesorectal excision-a critical appraisal]

INTRODUCTION

Total mesorectal excision (TME) is the international standard for rectal cancer surgery. In addition to laparoscopic TME (lapTME), transanal TME (taTME) was developed in recent years to reduce the rate of incomplete TME, conversion to open surgery and postoperative functional impairment. Despite limited evidence, this technique is becoming increasingly more popular and is already routinely used by many hospitals for rectal cancer in varying tumor level locations. The aim of this review was to evaluate the taTME compared to anterior rectal resection with lapTME as the standard of care in rectal cancer surgery based on currently available evidence.

METHOD

The databases PubMed and Medline were systematically searched for publications on transanal total mesorectal excision (taTME) and transanal minimally invasive surgery (TAMIS). Relevant studies were selected and further research based on the reference lists was undertaken.

RESULTS

A total of 16 studies analyzing 3782 patients were identified. The taTME does not lead to a higher rate of complete TME-resected specimens compared to the standard procedure. So far, superiority could not be demonstrated for complication rates or for functional or oncological results. Serious complications secondary to dissection in incorrect planes were observed. The anastomotic level generally seems to be closer to the sphincter after taTME versus anterior lapTME.

CONCLUSION

Considering current evidence, taTME failed to show superiority compared to conventional anterior lapTME. Although taTME has some potential advantages, it carries substantial risks. If performed outside of clinical trials, it should therefore only be used in carefully selected patients with a high possibility of conversion, following adequate patient informed consent and after intense and systematic training of the surgeon.

The value of force and torque measurements in transanal total mesorectal excision (TaTME)

Background

Transanal total mesorectal excision (TaTME) is associated with a relatively long learning curve. Force, motion, and time parameters are increasingly used for objective assessment of skills to enhance laparoscopic training efficacy. The aim of this study was to identify relevant metrics for accurate skill assessment in more complex transanal purse-string suturing.

Methods

A box trainer was designed for TaTME and equipped with two custom made multi-DOF force/torque sensors. These sensors measured the applied forces in the axial direction of the instruments (Fz), instrument load orientation expressed in torque (Mx and My) on the entrance port, and the full tissue interaction force (Fft) at the intestine fixation point. In a construct validity study, novices for TaTME performed a purse-string suture to investigate which parameters can be used best to identify meaningful events during tissue manipulation and instrument handling.

Results

Significant differences exist between pre- and post-training assessment for the mean axial force at the entrance port Fz (p = 0.01), mean torque in the entrance port Mx (p = 0.03) and mean force on the intestine during suturing Fft (p = 0.05). Furthermore, force levels during suturing exceed safety threshold values, potentially leading to dangerous complications such as rupture of the rectum.

Conclusions

Forces and torque measured at the entrance port, and the tissue interaction force signatures provide detailed insight into instrument handling, instrument loading, and tissue handling during purse-string suturing in a TaTME training setup. This newly developed training setup for single-port laparoscopy that enables objective feedback has the potential to enhance surgical training in TaTME.

Evolution of transanal total mesorectal excision according to the IDEAL framework

Tremendous innovations have taken place in surgical procedures, but contrary to drug development, this process has been unregulated in the past. IDEAL promotes a structured framework for the safe implementation and assessment of a new surgical technique or intervention, by describing five stages for evaluating and reporting of innovations: Idea, Development, Exploration, Assessment and Long term. Transanal total mesorectal excision (TaTME) is a relatively new technique in rectal cancer surgery that has attracted huge interest and increasing adoption worldwide. This review article aims to provide an overview of the evolution of TaTME, according to the IDEAL framework, which guides us in the difficult yet exciting process of surgical innovation.

The current state of the transanal approach to the ileal pouch-anal anastomosis

BACKGROUND

The transanal approach to pelvic dissection has gained considerable traction and utilization continues to expand, fueled by the transanal total mesorectal excision (TaTME) for rectal cancer. The same principles and benefits of transanal pelvic dissection may apply to the transanal restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA)-the TaPouch procedure. Our goal was to review the literature to date on the development and current state of the TaPouch.

MATERIALS AND METHODS

We performed a PubMed database search for original articles on transanal pelvic dissections, IPAA, and the TaPouch procedure, with a manual search from relevant citations in the reference list. The main outcomes were the technical aspects of the TaPouch, clinical and functional outcomes, and potential advantages, drawbacks, and future direction for the procedure.

RESULTS

The conduct of the procedure has been defined, with the safety and feasibility demonstrated in small series. The reported rates of conversion and anastomotic leakage are low. There are no randomized trials or large-scale comparative studies available for comparative effectiveness compared to the traditional IPAA.

CONCLUSIONS

The transanal approach to ileal pouch-anal anastomosis is an exciting adaption of the transanal total mesorectal excision for refining the technical steps of a complex operation. Additional experience is needed for comparative outcomes and defining the ideal training and implementation pathways.

Transanal total mesorectal excision (TaTME): current status and future perspectives

Total mesorectal excision (TME) is the gold standard surgical treatment for mid- and low rectal cancer; however, it is associated with specific technical hurdles. Transanal TME (TaTME) is a new procedure developed to overcome these difficulties, through an enhanced visualization of the dissection plane. This potentially could result in a more accurate distal dissection with a lower rate of positive circumferential resection margins, increasing the rate of sphincter-saving procedures. The indications for TaTME are currently expanding, despite not being yet standardized, and structured training programs are ongoing to help overcome the steep learning curve related to the technique. The procedure is feasible and safe with similar intraoperative complications and readmission rates when compared with conventional open or laparoscopic TME. Favorable short-term oncologic results have been reported: in particular, TaTME is associated with mesorectal specimen of a better quality and a longer distal resection margin that is established at the beginning of the procedure under direct view. Robotics, when available, will probably overcome the steep learning curve related to the complexity of TaTME. Long-term follow-up and ongoing RCT trials data are awaited regarding functional results, local recurrence and survival, and to facilitate the comparison with standard laparoscopic or robotic rectal resections. The present review is focused on critically analyzing the theoretical benefits and risks of the procedure, its indications, short- and long-term results and future direction in the application of TaTME.

Spin in articles about minimally invasive transanal total mesorectal excision: an assessment of the current literature

AIM

Minimally invasive transanal total mesorectal excision (TaTME) is a new approach for treating rectal cancer. 'Spin' can be defined as 'reporting strategies to highlight that the experimental treatment is beneficial' despite limitations in study design. The aim of this study was to assess spin within publications about TaTME.

METHOD

EMBASE and MEDLINE (2009-2017) were searched for publications assessing TaTME in rectal cancer. All papers published between 2009 and 2017 were eligible for inclusion. Study titles and abstracts were assessed for evidence of spin, as previously defined.

RESULTS

A total of 1202 studies were identified through our search, and 73 were included. The majority were case series (n = 48, 66%). A total of 55 publications (75%) had evidence of spin within at least one domain. The most common type of spin was claiming safety without describing how this was defined or tested (56%). Other strategies included claiming superiority without support (33%) and reporting nonsignificance as equivalence (42%). We did not find that year of publication (P = 0.61), study design (P = 0.60), number of patients (P = 0.85) or declared conflict of interest (P = 0.43) were associated with spin.

CONCLUSION

We have shown that spin is common within studies assessing TaTME for rectal cancer. Despite a lack of support from study results, in the majority of studies authors concluded that TaTME is safe for use in rectal cancer. Readers of study abstracts describing new techniques need to be cautious about accepting the authors' conclusions, especially in case series and observational studies.

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.

Using cadaveric simulation to introduce the concept and skills required to start performing transanal total mesorectal excision

AIM

The aim was to document the outcomes of surgeons attending a cadaveric simulation course designed to provide an introduction to transanal total mesorectal excision (TaTME).

METHOD

This was a prospective observational study documenting the outcomes from classroom and wet lab activities. Follow-up questionnaires were used to monitor clinical activity after the course.

RESULTS

Outcomes of 65 delegates from 12 different countries attending seven cadaveric simulation courses are described. Median time to insert and close the rectal purse-string was 15 min (range 7-50 min) and median time to complete the transanal mesorectal dissection was 105 min (range 60-260 min). Objective assessment of specimen quality showed that 42% of specimens were complete, 47% nearly complete and 11% were incomplete. Failure of the intraluminal rectal purse-string was the most common difficulty encountered. Within 6 months of attending the course, nearly half (26/55; 47%) of the surgeons who responded had performed between 1 and 13 TaTMEs. Only 8/26 (31%) of the surgeons had arranged mentoring for their first case.

CONCLUSION

This training model provides high levels of trainee satisfaction and the knowledge and technical skills to enable them to start performing TaTME. There is still work to do to provide adequate supervision and mentorship for surgeons early on their learning curve that is essential for the safe introduction of this new technique.

Cognitive skills training in digital era: A paradigm shift in surgical education using the TaTME model

Surgical competence is a complex, multifactorial process, requiring ample time and training. Optimal training is based on acquiring knowledge and psychomotor and cognitive skills. Practicing surgical skills is one of the most crucial tasks for both the novice surgeon learning new procedures and surgeons already in practice learning new techniques. Focus is placed on teaching traditional technical skills, but the importance of cognitive skills cannot be underestimated. Cognitive skills allow recognizing environmental cues to improve technical performance including situational awareness, mental readiness, risk assessment, anticipating problems, decision-making, adaptation, and flexibility, and may also accelerate the trainee's understanding of a procedure, formalize the steps being practiced, and reduce the overall training time to become technically proficient. The introduction and implementation of the transanal total mesorectal excision (TaTME) into practice may be the best demonstration of this new model of teaching and training, including pre-training, course attendance, and post-course guidance on technical and cognitive skills. To date, the TaTME framework has been the ideal model for structured training to ensure safe implementation. Further development of metrics to grade successful learning and assessment of long term outcomes with the new pathway will confirm the success of this training model.

Evolution of transanal total mesorectal excision for rectal cancer: From top to bottom

The gold standard for curative treatment of locally advanced rectal cancer involves radical resection with a total mesorectal excision (TME). TME is the most effective treatment strategy to reduce local recurrence and improve survival outcomes regardless of the surgical platform used. However, there are associated morbidities, functional consequences, and quality of life (QoL) issues associated with TME; these risks must be considered during the modern-day multidisciplinary treatment for rectal cancer. This has led to the development of new surgical techniques to improve patient, oncologic, and QoL outcomes. In this work, we review the evolution of TME to the transanal total mesorectal excision (TaTME) through more traditional minimally invasive platforms. The review the development, safety and feasibility, proposed benefits and risks of the procedure, implementation and education models, and future direction for research and implementation of the TaTME in colorectal surgery. While satisfactory short-term results have been reported, the procedure is in its infancy, and long term outcomes and definitive results from controlled trials are pending. As evidence for safety and feasibility accumulates, structured training programs to standardize teaching, training, and safe expansion will aid the safe spread of the TaTME.

Developing a national colorectal educational agenda: a survey of the Association of Coloproctology of Great Britain and Ireland

AIM

In order to develop its education agenda, the Association of Coloproctology of Great Britain and Ireland (ACPGBI) sought the opinion of its members on current coloproctology training needs. The aims of this study were to canvass multidisciplinary needs and explore the perceived gaps and barriers to meeting them.

METHOD

A learner-needs analysis was performed between July 2015 and October 2016. A bespoke electronic survey was sent to 1453 colorectal healthcare professionals [ACPGBI membership (1173), colorectal nurse specialists and allied health professionals (NAHPs) (261) and regional chapter-leads (19)] seeking their needs, experiences and barriers to training across the coloproctology disciplines.

RESULTS

In all, 390 responses were received [26.8% overall; 180 consultants/trainees (15%); 196 NAHPs (75%); 14 (74%) chapter-leads]. Lack of funding and difficulties in obtaining study leave were the most frequently reported barriers to course and conference attendance. Transanal total mesorectal excision and laparoscopic training were the top educational needs for consultants and trainees respectively. 79% of NAHP respondents reported education gaps on a broad range of clinical and non-clinical topics. NAHPs lacked information on relevant training opportunities and 27% felt available courses were insufficient to meet their educational needs. Wide heterogeneity in ACPGBI chapter composition and activity was reported. All groups felt the ACPGBI should increase the number of courses offered with coloproctology knowledge updates commonly requested.

CONCLUSION

A series of training needs across the coloproctology disciplines have been identified. These will underpin the development of the educational agenda for the ACPGBI.

An assessment of an Australasian pathway for the introduction of transanal total mesorectal excision (taTME)

AIM

To evaluate the use of a pathway for the introduction of transanal total mesorectal excision (taTME) into Australia and New Zealand.

METHOD

A pathway for surgeons with an appropriate level of specialist training and baseline skill set was initiated amongst colorectal surgeons; it includes an intensive course, a series of proctored cases and ongoing contribution to audit. Data were collected for patients who had taTME, for benign and malignant conditions, undertaken by the initial adopters of the technique.

RESULTS

A total of 133 taTME procedures were performed following the introduction of a training pathway in March 2015. The indication was rectal cancer in 84% of cases. There was one technique-specific visceral injury, which occurred prior to that surgeon completing the pathway. There were no cases of postoperative mortality; morbidity occurred in 27.1%. The distal resection margin was clear in all cases of rectal cancer, and the circumferential resection margin was positive in two cases. An intact or nearly intact total mesorectal excision was obtained in more than 98% of cases.

CONCLUSION

This study demonstrates the safe and controlled introduction of a new surgical technique in a defined surgeon population with the use of a pathway for training. The authors recommend a similar pathway to facilitate the introduction of taTME to colorectal surgical practice.

Transanal TME - really needed?

In the last decade, thanks to natural orifice translumenal endoscopic surgery, the application of laparoscopy through the anus has gained interest from both research and clinical point of views. Therefore, an increased number of transanal procedures have been reported, from the resection of a large rectal polyp to total mesorectal excision, and for controlling perioperative complications like leak, bleeding, and stenosis. Currently, the most popular surgical trend remains transanal total mesorectal excision. In this article, the technique, advantages, and disadvantages are discussed.

Transanal Total Mesorectal Excision: Why, When, and How

Transanal total mesorectal excision (taTME) has evolved over the past decade fueled by advances in minimally invasive surgery. The technique aims to overcome the constraints posed by a narrow rigid pelvis and poor TME visualization that are encountered during "top-down" rectal surgery. A more accurate pelvic dissection should subsequently result in safer oncological resections and better preservation of pelvic autonomic nerves. taTME is an advanced complex technique that requires dedicated training and experience in TME surgery. Initial results from small cohorts are promising and confirmation by randomized controlled trials is eagerly awaited.

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.

Objective assessment of minimally invasive total mesorectal excision performance: a systematic review

INTRODUCTION

Laparoscopy is widely used in colorectal practice, but recent trial results have questioned its use in rectal cancer resections. Patient outcomes are directly linked to the quality of total mesorectal excision (TME) specimen. Objective assessment of intraoperative performance could help ensure competence and delivery of optimal outcomes. Objective tools may also contribute to TME intervention trials, but their nature, structure and utilisation is unknown.

AIM

To systemically review the available literature to report on the available tools for the objective assessment of minimally invasive TME operative performance and their use within multicentre laparoscopic TME randomised controlled trials.

METHODS

A systematic search of the PubMed and Cochrane databases was performed to identify tools used in the objective intraoperative assessment of minimally invasive TME performance in accordance with the PRISMA guidelines, independently by two authors. The identified tools were then evaluated within reported TME RCTs.

RESULTS

A total of 8642 abstracts were screened of which 12 papers met the inclusion criteria; ten prospective observational studies, one randomised trial and one educational consensus. Eight assessment methods were described, which include formative and summative tools. The tools were mostly adaptations of colonic surgery tools based on either operative video review or post-operative trainer rating. All studies reported objective assessment of intraoperative performance was feasible, but only 126 (7%) of the 1762 included laparoscopic cases were TME. No multicentre laparoscopic TME trial reported using any objective surgical performance assessment tool.

CONCLUSION

Objective intraoperative laparoscopic TME performance assessment is feasible, but most of the current tools are adaptation of colonic surgery. There is a need to develop dedicated assessment tools for minimal access rectal surgery. No multicentre minimally invasive TME RCT reported using any objective assessment tool.

Developing and assessing a cadaveric training model for transanal total mesorectal excision: initial experience in the UK and USA

AIM

Transanal total mesorectal excision (taTME) has become one of the most promising technical advancements in the surgical treatment of rectal cancer, with rising numbers of surgeons seeking training. We describe our experience with human cadaveric courses for taTME delivered in two countries.

METHOD

Four fresh human cadaveric workshops conducted in Oxford, UK, in 2015 and two in Chicago, USA, in 2013-2014, trained a total of 52 surgeons. Parameters of operative performance for each delegate were recorded. Previous surgical experience and uptake of taTME in the surgeons' clinical setting were surveyed.

RESULTS

Forty-seven taTME cases were performed on cadaveric models. Participating surgeons had previous experience in laparoscopic TME surgery and transanal approaches but limited taTME exposure. The purse-string remained occluded throughout in 93% of UK and 60% of US cases. Operative timings for key procedural steps were similar between the two countries with a mean time from start of circumferential dissection to peritoneal entry of 79.5 min (range 25-155). 96% of surgeons dissected transanally to a level S2 or above. The TME specimen quality was complete or near complete in 81%, with improvements noted between the first and second procedure performed. 81% of surgeons surveyed are currently performing taTME in their local hospitals.

CONCLUSION

Fresh-frozen cadavers provide excellent teaching models for complex pelvic surgery. A structured training curriculum including reading material, dry-lab purse-string practice and postcourse mentorship will provide surgeons with a more complete training package and ongoing support, to ultimately ensure the safe introduction of taTME in the clinical setting.

Consensus on structured training curriculum for transanal total mesorectal excision (TaTME)

BACKGROUND

The interest and adoption of transanal total mesorectal excision (TaTME) is growing amongst the colorectal surgical community, but there is no clear guidance on the optimal training framework to ensure safe practice for this novel operation. The aim of this study was to establish a consensus on a detailed structured training curriculum for TaTME.

METHODS

A consensus process to agree on the framework of the TaTME training curriculum was conducted, seeking views of 207 surgeons across 18 different countries, including 52 international experts in the field of TaTME. The process consisted of surveying potential learners of this technique, an international experts workshop and a final expert's consensus to draw an agreement on essential elements of the curriculum.

RESULTS

Appropriate case selection was strongly recommended, and TaTME should be offered to patients with mid and low rectal cancers, but not proximal rectal cancers. Pre-requisites to learn TaTME should include completion of training and accreditation in laparoscopic colorectal surgery, with prior experience in transanal surgery. Ideally, two surgeons should undergo training together in centres with high volume for rectal cancer surgery. Mentorship and multidisciplinary training were the two most important aspects of the curriculum, which should also include online modules and simulated training for purse-string suturing. Mentors should have performed at least 20 TaTME cases and be experienced in laparoscopic training. Reviewing the specimens' quality, clinical outcome data and entering data into a registry were recommended. Assessment should be an integral part of the curriculum using Global Assessment Scales, as formative assessment to promote learning and competency assessment tool as summative assessment.

CONCLUSIONS

A detailed framework for a structured TaTME training curriculum has been proposed. It encompasses various training modalities and assessment, as well as having the potential to provide quality control and future research initiatives for this novel technique.

Clinical outcomes and case volume effect of transanal total mesorectal excision for rectal cancer: a systematic review

Transanal total mesorectal excision (TaTME) has been developed to improve quality of TME for patients with mid and low rectal cancer. However, despite enthusiastic uptake and teaching facilities, concern exists for safe introduction. TaTME is a complex procedure and potentially a learning curve will hamper clinical outcome. With this systematic review, we aim to provide data regarding morbidity and safety of TaTME. A systematic literature search was performed in MEDLINE (PubMed), EMBASE (Ovid) and Cochrane Library. Case reports, cohort series and comparative series on TaTME for rectal cancer were included. To evaluate a potential effect of case volume, low-volume centres (n ≤ 30 total volume) were compared with high-volume centres (n > 30 total volume). Thirty-three studies were identified (three case reports, 25 case series, five comparative studies), including 794 patients. Conversion was performed in 3.0% of the procedures. The complication rate was 40.3, and 11.5% were major complications. The quality of the mesorectum was “complete” in 87.6%, and the circumferential resection margin (CRM) was involved in 4.7%. In low- versus high-volume centres, the conversion rate was 4.3 versus 2.7%, and major complication rates were 12.2 versus 10.5%, respectively. TME quality was “complete” in 80.5 versus 89.7%, and CRM involvement was 4.8 and 4.5% in low- versus high-volume centres, respectively. TaTME for mid and low rectal cancer is a promising technique; however, it is associated with considerable morbidity. Safe implementation of the TaTME should include proctoring and quality assurance preferably within a trial setting.

Transanal total mesorectal excision: Myths and reality

Transanal total mesorectal excision (TaTME) is a new and promising approach for the treatment of rectal cancer. Whilst the experience is still limited, there are growing evidences that this approach might overcome the limits of standard low anterior resection. TaTME might help to decrease the conversion rate especially in difficult patients, and to improve the pathological results, while preserving the urogenital function. Evaluation of data from large registries and randomized studies should help to draw firmer conclusions. Beyond these technical considerations, the next challenge seems to be clearly the safe introduction of this approach, motivating the development of dedicated courses.

Transanal total mesorectal excision for rectal cancer: the journey towards a new technique and its current status

INTRODUCTION

The surgical approach to total mesorectal excision (TME) for rectal cancer has undergone a substantial evolution with the adoption of more minimally invasive procedures. Transanal TME (taTME) is the latest advanced technique pioneered to tackle difficult pelvic dissections. Areas covered: The evolution of TME surgery from open to laparoscopic, robotic and transanal techniques was explored in this review. The outcomes to date on the latest approach, taTME, are reviewed and the future direction of rectal cancer surgery proposed. A literature search was performed using Embase, Medline, Web of Science and Cochrane databases for articles published between January 2005 to May 2016 using the keywords 'transanal', 'TME', 'laparoscopy', 'robotics', 'minimally invasive', 'outcomes' and 'training'. Expert commentary: Surgical experience in taTME is growing and randomised controlled trials have been planned and initiated worldwide. However, the learning curve for this procedure remains to be established and a structured training programme is necessary to ensure safe introduction and dissemination of the technique in the clinical setting. Further innovation including stereotactic navigation and more specialised transanal equipment are currently being explored and are likely to enhance the technique further.

Surgeons' assessment of internal anal sphincter nerve supply during TaTME - inbetween expectations and reality

Background: Intraoperative identification of nerve fibers heading from the inferior rectal plexus (IRP) to the internal anal sphincter (IAS) is challenging. The transanal total mesorectal excision (TaTME) is said to better preserve pelvic autonomic nerves. The aim of this study was to investigate the nerve identification rates during TaTME by transanal visual and electrophysiological assessment.

Material and methods: A total of 52 patients underwent TaTME for malignant conditions. The IRP with its posterior branches to the IAS and the pelvic splanchnic nerves (PSN) were visually assessed in 20 patients (v-TaTME). Electrophysiological nerve identification was performed in 32 patients using electric stimulation under processed electromyography of IAS (e-TaTME).

Results: The indication profile for TaTME was comparable between the v-TaTME and the e-TaTME group. The identification of IRP was more meaningful under electrophysiological assessment than under visual assessment for the left pelvic side (81% vs. 45%, p = 0.008) as well as the right pelvic side (78% vs. 45%, p = 0.016). The identification rates for PSN did not significantly differ between both groups, respectively (81% vs. 75%, p = 0.420 and 84% vs. 70%, p = 0.187).

Conclusions: The transanal approach facilitated visual identification of IAS nerve supply. In combination with electrophysiological nerve assessment the identification rate almost doubled. For further insights functional data are needed.