Canadian taTME expert collaboration (CaTaCO) position statement

Local Recurrence-Free Survival After TaTME: A Canadian Institutional Experience

BACKGROUND

Transanal total mesorectal excision is a novel surgical treatment for mid to low rectal cancers. Norwegian population data have raised concerns about local recurrence in patients treated with transanal total mesorectal excision.

OBJECTIVE

This study aimed to analyze local recurrence and disease-free survival in patients treated by transanal total mesorectal excision for rectal cancer at a high-volume tertiary center.

DESIGN

This retrospective study used a prospectively maintained institutional transanal total mesorectal excision database. Patient demographics, treatment, and outcomes data were analyzed. Local recurrence, disease-free survival, and overall survival were analyzed using Kaplan-Meier analysis.

SETTINGS

The study was conducted at a single academic institution in Vancouver, Canada.

PATIENTS

All patients treated by transanal total mesorectal excision for rectal adenocarcinoma between 2014 and 2022 were included.

MAIN OUTCOME MEASURES

The primary outcome was local recurrence-free survival.

RESULTS

Between 2014 and 2022, 306 patients were treated by transanal total mesorectal excision at St. Paul's Hospital. Of these, 279 patients met the inclusion criteria. The mean age was 62 years (SD ± 12.3), and 66.7% of patients were men. Restorative resection was achieved in 97.5% of patients, with a conversion rate from laparoscopic to open surgery of 6.8%. The composite optimal pathological outcome was 93.9%. The median follow-up was 26 months (interquartile range, 12-47), and 82.8% of patients achieved reestablishment of GI continuity to date. The overall local recurrence rate was 4.7% (n = 13). The estimated 2-year local recurrence-free survival rate was 95.0% (95% CI, 92-98) and the estimated 5-year local recurrence-free survival rate was 94.5% (95% CI, 91-98).

LIMITATIONS

Limitations include the retrospective nature of the study and the generalizability of a Canadian population.

CONCLUSIONS

Recent European data have challenged the presumed oncologic safety of transanal total mesorectal excision. Although the learning curve for this procedure is challenging and poor outcomes are associated with low volume, this high-volume single-center study confirms acceptable oncologic outcomes consistent with the current standard. See Video Abstract .

SOBREVIDA SIN RECIDIVA DESPUS DE TATME EXPERIENCIA INSTITUCIONAL CANADIENSE

ANTECEDENTES:La excisión total del mesorecto por vía transanal es un tratamiento quirúrgico novedoso para los cánceres de recto medio a bajo. Estudios sobre la población noruega han generado preocupación debido a la recidiva local en pacientes tratados con excisión total del mesorecto por vía transanal.OBJETIVO:Nuestra finalidad fué de analizar la recidiva local y la sobrevida libre de enfermedad en pacientes tratados mediante la excisión total del mesorecto por vía transanal, debido a un cáncer de recto en un centro terciario de alto volúmen.DISEÑO:El presente estudio retrospectivo, utiliza una base de datos institucional sobre la excisión total del mesorecto por vía transanal mantenida prospectivamente. Se analizaron los datos demográficos, de tratamiento y los resultados de los pacientes sometidos a la técnica mencionada. La recidiva local, la sobrevida libre de enfermedad y la sobrevida global se analizaron mediante el modelo de Kaplan-Meier.AJUSTES:El estudio se llevó a cabo en una sola institución académica en Vancouver, Canadá.PARTICIPANTES:Se incluyeron todos los pacientes tratados mediante excisión total del mesorecto por vía transanal causado por adenocarcinomas de recto entre 2014 y 2022.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue la sobrevida libre de recidiva local.RESULTADOS:Entre 2014 y 2022, 306 pacientes fueron tratados mediante la excisión total del mesorecto por vía transanal en el Hospital St. Paul. De estos, 279 pacientes cumplieron los criterios de inclusión. La edad media fue de 62 años (DE ± 12,3) y el 66,7% de los pacientes eran varones. La resección restauradora se logró en el 97,5% de los pacientes con una tasa de conversión de cirugía laparoscópica en laparotomía del 6,8%. El resultado patológico óptimo combinado fué del 93,9%. La mediana de seguimiento fue de 26 meses (rango intercuartil 12-47) y el 82,8% logró el restablecimiento de la continuidad gastrointestinal hasta la fecha. La tasa global de recidiva local fué del 4,7% (n = 13). La sobrevida libre de recidiva local estimada a los 2 años fué del 95,0% (IC del 95%: 92-98) y del 94,5% a los 5 años (IC del 95%: 91-98).LIMITACIONES:Las limitaciones incluyen la naturaleza retrospectiva del estudio y la generalización de una población canadiense.CONCLUSIONES:Datos europeos recientes han cuestionado la supuesta seguridad oncológica de la excisión total del mesorecto por vía transanal. Si bien la curva de aprendizaje de este procedimiento es muy desafiante y los malos resultados se asocian con un volumen bajo, el presente estudio, unicéntrico de gran volumen confirma los resultados oncológicos aceptables consistentes con el estándar actual. (Traducción-Dr. Xavier Delgadillo ).

Oncological monitoring after transanal total mesorectal excision (TaTME) for rectal neoplasia

BACKGROUND

The surgical treatment of choice for rectal neoplasia is total mesorectal excision (TME). The transanal approach enables a better approach in male and obese patients and/or those with a narrow pelvis and in patients with small tumors. Short-term results are comparable with those for laparoscopy or the open approach, but the medium- and long-term oncological data are sparse. The aim of the present study was to evaluate our early experience with transanal TME (TaTME).

METHODS

This was a retrospective study conducted on patients who underwent TaTME at our center between August 2013 and April 2017 with a follow-up ≥ 3 years. Histopathology, complications, mortality, neoplastic recurrence and disease-free survival were analyzed.

RESULTS

One hundred patients (68 men and 32 women,, median age 66.8 years [range 29.6-91.2 years]) were included. There were 67 T3 cases (67%) with 74 N0 cases (74%), the mesorectal quality was graded optimal for 87.6% and only 2 cases of radial margin involvement were detected (2%). The median follow-up period was 47.6 months (range 11.8-78.9 months). Eighteen cases of recurrence were diagnosed, of which 3 (3%) recurred locally with an average disease-free period of 43.1 months. Overall survival was 80% and mortality due to progression of disease was 13%.

CONCLUSIONS

TaTME is a safe surgical procedure with surgical, anatomopathological and oncological results at 3 years (medium-term) comparable with those for the laparoscopic and open approaches. Better monitoring is required with studies of the long-term functional and quality of life outcomes, i.e., at 5 or 10 years.

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.

Challenges and Learning Curves in Adopting TaTME and Robotic Surgery for Rectal Cancer: A Cusum Analysis

Simple Summary

Rectal cancer surgery remains a challenge and information about the learning curve in adopting new techniques is lacking. This paper analyzes our experience in taTME (since 2015) and robotic surgery (since 2018) at a fully accredited referral center for the treatment of rectal cancer in Spain. In this retrospective study, we aim to analyze the learning curves for taTME and robot-assisted rectal procedures in the incorporation of these platforms into our practice. We sought to describe our team’s experience in incorporating these techniques and to analyze the difficulties that we have had. Hoping that sharing our experience can help other groups improve their results during the difficult initial phase of incorporating new techniques.

Abstract

New techniques are being developed to improve the results of laparoscopic surgery for rectal cancer. This paper analyzes the learning curves for transanal total mesorectal excision (taTME) and robot-assisted surgery in our colorectal surgery department. We analyzed retrospectively data from patients undergoing curative and elective surgery for rectal cancer ≤12 cm from the anal verge. We excluded extended surgeries. We used cumulative sum (CUSUM) curve analysis to identify inflection points. Between 2015 and 2021, 588 patients underwent surgery for rectal cancer at our center: 67 taTME and 79 robot-assisted surgeries. To overcome the operative time learning curve, 14 cases were needed for taTME and 53 for robot-assisted surgery. The morbidity rate started to decrease after the 17th case in taTME and after the 49th case in robot-assisted surgery, but it is much less abrupt in robot-assisted group. During the initial learning phase, the rate of anastomotic leakage was higher in taTME (35.7% vs. 5.7%). Two Urological lesions occurred in taTME but not in robot-assisted surgery. The conversion rate was higher in robot-assisted surgery (1.5% vs. 10.1%). Incorporating new techniques is complex and entails a transition period. In our experience, taTME involved a higher rate of serious complications than robot-assisted surgery during initial learning period but required a shorter learning curve.

Indications and Technical Considerations for Transanal Total Mesorectal Excision

A 53-year-old man presented after noting bright red blood from his rectum. On examination, he was found to have a mass 1 cm above the anal sphincter complex. He had a BMI of 40 kg/m2 and was otherwise healthy. MRI revealed a T2/early T3 lesion with extramural venous invasion and suspicious perirectal lymph nodes. Low rectal cancer was diagnosed. He underwent long-course neoadjuvant chemoradiation with good but not complete clinical response. Given his obesity and the low nature of his rectal cancer, a transanal total mesorectal excision (taTME) was planned.

Mesentery in Transanal TME

Oncological adequacy in rectal cancer surgery mandates not only a clear distal and circumferential resection margin but also resection of the entire ontogenetic mesorectal package. Incomplete removal of the mesentery is one of the commonest causes of local recurrences. The completeness of the resection is not only determined by tumor and patient related factors but also by the patient-tailored treatment selected by the multidisciplinary team. This is performed in the context of the technical ability and experience of the surgeon to ensure an optimal total mesorectal excision (TME). In TME, popularized by Professor Heald in the early 1980s as a sharp dissection through the avascular embryologic plane, the midline pedicle of tumor and mesorectum is separated from the surrounding, mostly paired structures of the retroperitoneum. Although TME significantly improved the oncological and functional results of rectal cancer surgery, the difficulty of the procedure is still mainly dependent on and determined by the dissection of the most distal part of the rectum and mesorectum. To overcome some of the limitations of working in the narrowest part of the pelvis, robotic and transanal surgery have been shown to improve the access and quality of resection in minimally invasive techniques. Whatever technique is chosen to perform a TME, embryologically derived planes and anatomical points of reference should be identified to guide the surgery. Standardization of the chosen technique, widespread education, and training of surgeons, as well as caseloads per surgeon, are important factors to optimize outcomes. In this article, we discuss the introduction of transanal TME, with emphasis on the mesentery, relevant anatomy, standard procedural steps, and importance of a training pathway.

Three-year outcomes of transanal total mesorectal excision versus standard laparoscopic total mesorectal excision for mid and low rectal cancer

INTRODUCTION

Since transanal total mesorectal excision (taTME) was introduced, it has become an important topic in rectal cancer treatment. Many previous studies reported positive relevant short-term results, histopathological results, and associated complications. Recently, concerns regarding the oncological safety of taTME have been raised due to reports showing high local recurrences (LR) rates. Therefore, this study aimed to compare the 3-year outcomes between taTME and laparoscopic total mesorectal excision (laTME) for mid-low rectal cancer.

METHODS

A total of 104 patients who underwent taTME were matched with 208 patients treated by laTME. The primary endpoint was 3-year LR rate; secondary endpoints in this matched-cohort study included the perioperative outcomes and histopathological outcomes.

RESULTS

taTME was associated with lower permanent ostomy rate (1% vs 13.5%) and lower conversion rate (0% vs 3.4%) compared to laTME. A similar quality of resected specimens was detected for each group. In both groups, the local recurrence rate was 3.8%. Within 3 years after surgery, the disease-free survival (DFS) rates were 78.8% in the taTME group and 76.9% in the laTME group (P = 0.640), while the overall survival (OS) rates were 93.3% in the taTME group and 89.9% in the laTME group (P = 0.327).

CONCLUSION

No significant differences regarding 3-year local recurrence rate (3.8%) were observed in the taTME group compared to laTME group.

UEG and EAES rapid guideline: Systematic review, meta-analysis, GRADE assessment and evidence-informed European recommendations on TaTME for rectal cancer

BACKGROUND

Evidence and practice recommendations on the use of transanal total mesorectal excision (TaTME) for rectal cancer are conflicting.

OBJECTIVE

We aimed to summarize best evidence and develop a rapid guideline using transparent, trustworthy, and standardized methodology.

METHODS

We developed a rapid guideline in accordance with GRADE, G-I-N, and AGREE II standards. The steering group consisted of general surgeons, members of the EAES Research Committee/Guidelines Subcommittee with expertise and experience in guideline development, advanced medical statistics and evidence synthesis, biostatisticians, and a guideline methodologist. The guideline panel consisted of four general surgeons practicing colorectal surgery, a radiologist with expertise in rectal cancer, a radiation oncologist, a pathologist, and a patient representative. We conducted a systematic review and the results of evidence synthesis by means of meta-analyses were summarized in evidence tables. Recommendations were authored and published through an online authoring and publication platform (MAGICapp), with the guideline panel making use of an evidence-to-decision framework and a Delphi process to arrive at consensus.

RESULTS

This rapid guideline provides a weak recommendation for the use of TaTME over laparoscopic or robotic TME for low rectal cancer when expertise is available. Furthermore, it details evidence gaps to be addressed by future research and discusses policy considerations. The guideline, with recommendations, evidence summaries, and decision aids in user-friendly formats can also be accessed in MAGICapp: https://app.magicapp.org/#/guideline/4494 .

CONCLUSIONS

This rapid guideline provides evidence-informed trustworthy recommendations on the use of TaTME for rectal cancer.

Trajectory of change of low anterior resection syndrome over time after restorative proctectomy for rectal adenocarcinoma

BACKGROUND

Restorative proctectomy for rectal cancer is associated with a high incidence of low anterior resection syndrome (LARS), but few studies report longitudinal results for bowel function. The aim of our study was to examine the trajectory of change of LARS over the first 18 months after restorative proctectomy for rectal cancer.

METHODS

A prospective database measuring functional outcomes in rectal cancer patients from a single university-affiliated specialist colorectal referral center from 10/2018 to 03/2020 was queried. Patients were included in this study if they underwent restorative proctectomy for rectal cancer and had at least three assessments in the first 18 months after primary surgery or after closure of proximal diversion. Bowel function was assessed using the LARS score, administered at every surveillance follow-up after restoration of bowel continuity. Latent-class growth curve (trajectory) analysis was used to identify different trajectories of LARS changes over the first 18 months and group patients into these trajectory groups. These groups were then compared to identify predictors for each trajectory.

RESULTS

A total of 95 patients were included (63 males, mean age. 61.3 ± 12.5 years). Trajectory analysis identified three distinct trajectory groups. Group 1 had stable minimal LARS over time (26%). Group 2 had early LARS scores consistent with the minor LARS category and improved with time (28%). Group 3 had persistently high LARS scores (45%). Neoadjuvant therapy, intersphincteric resection, and proximal diversion were more common in group 3.

CONCLUSIONS

We identified three main trajectories of change of LARS in the 18 months after restorative proctectomy. These data may be used to better inform patients of their expected postoperative bowel function.

The impact of robotic surgery on a tertiary care colorectal surgery program, an assessment of costs and short term outcomes: A Canadian perspective

BACKGROUND

Robotic surgery for colorectal pathology has gained interest as it can overcome technical challenges and limitations of traditional laparoscopic surgery. A lack of training and costs have been cited as reasons for limiting its use in Canada. The objective of this paper was to assess the impact of robotic surgery on outcomes and costs in a Canadian setting.

METHODS

This is a retrospective study of consecutive patients undergoing left sided colorectal surgery ("Pre-Robotic Phase" n = 145 vs. "Post Robotic Phase" n = 150) and a single tertiary care centre in Ontario, Canada. Utilization and success of minimally invasive surgery (MIS), length of stay, complications and hospital costs were compared. Univariate and Multivariate analysis was used for these comparisons.

RESULTS

Characteristics, diagnosis and type of resection were similar between groups. Robotic Implementation resulted in higher rates of successful MIS (i.e. attempt at MIS without conversion) (85% vs. 47%, P < 0.001), shorter mean length of stay (4.7 days vs. 8.4 days, P < 0.001), and similar mean operative times (3.9 h vs. 3.9 h, P = 0.93). Emergency Department visits were fewer in the Robotic Phase (24% vs. 34%, P = 0.04), with no difference in readmission, anastomotic leak or unplanned reoperation. After robotic implementation, the mean total hospital costs decreased, but this was not statistically significant (-$1453, 95% CI -$3974 to +$1068, P = 0.25). Regression analysis, adjusting for age, gender, obesity, ASA and procedure showed similar findings (Robotic Phase -$657, 95% CI -$3038 to +$1724, vs Pre Robotic Phase [Reference], P = 0.59).

INTERPRETATION

Implementation of a robotic colorectal surgery program in a Canadian tertiary care centre showed improved clinical outcomes, without a significant increase in the cost of care. Although this study is from a single institution, we have demonstrated that robotic colorectal surgery is feasible and can be cost effective in the right setting.

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 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.

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.

Transanal versus conventional total mesorectal excision for rectal cancer using the IDEAL framework for implementation

Background

Transanal total mesorectal excision (TaTME) is an innovative technique for distal rectal cancer dissection. It has been shown to have similar short-term outcomes to conventional open and laparoscopic total mesorectal excision (cTME), but recent studies have raised concern about increased morbidity and local recurrence rates. The aim of this study was to assess outcomes after TaTME versus cTME for rectal cancer.

Methods

TaTME was implemented in 2014 using IDEAL principles in a single institution. The institution maintains databases for all patients undergoing rectal cancer surgery. This retrospective review compared data collected from all patients who had TaTME with those from a propensity-matched cohort of patients who underwent cTME. The primary outcome was a composite pathological measure combining margin status and quality of total mesorectal excision (TME). Short-term clinical and survival outcomes were also measured.

Results

Propensity matching created 109 matched pairs for analysis. Nine patients (8.3 per cent) undergoing TaTME had positive margins and/or incomplete TME, compared with 11 (10.5 per cent) undergoing cTME (P = 0.65). There were no significant differences in morbidity between the TaTME and cTME groups, including number of anastomotic leaks (13.8 versus 18.3 per cent; P = 0.37). The estimated 3-year local recurrence-free survival rate was 96.3 per cent in both groups (P = 0.39). Estimated 3-year overall (93.6 per cent for TaTME versus 94.5 per cent for cTME; P = 0.09) and disease-free (88.1 versus 76.1 per cent; P = 0.90) survival rates were similar.

Conclusion

TaTME provided similar outcomes to cTME for rectal cancer with the application of IDEAL principles.

Controversies and consensus in transanal total mesorectal excision (taTME): Is it a valid choice for rectal cancer?

Transanal total mesorectal excision (taTME) is a novel approach to radical surgery for low rectal cancer. taTME is associated with the benefits of a higher rate of free distal resection margins (DRM) under direct visualization, better visualization of the mesorectal plane, and the feasibility of overcoming the restriction of the distal pelvis. Thus, it is increasingly used globally. In this review, we investigated whether taTME yields better short- and long-term outcomes than laparoscopic TME.

Association of Transanal Total Mesorectal Excision With Local Recurrence of Rectal Cancer

IMPORTANCE

Proponents of novel transanal total mesorectal excision (TME) suggest the procedure overcomes the technical and oncologic challenges of conventional approaches for treating rectal cancer. Recently, however, there has been controversy regarding the oncologic safety of the procedure.

OBJECTIVE

To assess the association of transanal TME with the incidence of local recurrence (LR) of cancer and the probability of remaining free of LR during follow-up.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter cohort study used data from 8 high-volume rectal cancer academic institutions from across Canada on all consecutive patients with primary rectal cancer treated by transanal TME at the participating centers. The study was conducted between January 2014 and December 2018, and data were analyzed from April 1, 2020, to September 15, 2020.

EXPOSURE

Transanal TME.

MAIN OUTCOMES AND MEASURES

The incidence of LR was reported as a direct measure of quality of resection. The cumulative probability of LR- and systemic recurrence (SR)-free survival at 36 months was estimated. Local recurrence and SR were defined as radiologic or endoscopic evidence of 1 or more new lesions in or outside the pelvis, respectively, documented during surveillance after the removal of the primary tumor.

RESULTS

Of 608 total patients included in the analysis, 423 (69.6%) were male; the median age was 63 years (interquartile range [IQR], 54-70 years). Local recurrence was identified in 22 patients (3.6%) after a median follow-up of 27 months (IQR, 18-38 months). The median time to LR was 13 months (IQR, 9-19 months). Sixteen of the 22 patients with LR (72.7%) were male, 14 (63.6%) received neoadjuvant chemoradiation, and 12 (54.5%) had American Joint Committee on Cancer stage III disease. Of those with LR, 16 (72.7%) had a negative circumferential radial margin and 20 (90.9%) had a negative distal resection margin, 2 (9.1%) experienced conversion to open surgery, and 15 (68.2%) also developed SR. The probability of LR-free survival at 36 months was 96% (95% CI, 94%-98%). According to the Cox proportional hazards regression model, the hazard ratio of LR was estimated to be 4.2 (95% CI, 2.9-6.2) times higher among patients with a positive circumferential radial margin than among those with a negative circumferential radial margin.

CONCLUSIONS AND RELEVANCE

In this cohort study, transanal TME performed by experienced surgeons was associated with an incidence of LR and SR that is in line with the published literature on open and laparoscopic TME, suggesting that transanal TME may be an acceptable approach for management of 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.