Transanal Total Mesorectal Excision: Why, When, and How

Oncologic outcomes following transanal total mesorectal excision: the United States experience

AIM

The benefits and short-term outcomes of transanal total mesorectal excision (taTME) for rectal cancer have been demonstrated previously, but questions remain regarding the oncologic outcomes following this challenging procedure. The purpose of this study was to analyze the oncologic outcomes following taTME at high-volume centers in the USA.

METHODS

This was a multicenter, retrospective observational study of 8 tertiary care centers. All consecutive taTME cases for primary rectal cancer performed between 2011 and 2020 were included. Clinical, histopathologic, and oncologic data were analyzed. Primary endpoints were rate of local recurrence, distal recurrence, 3-year disease recurrence, and 3-year overall survival. Secondary endpoints included perioperative complications and TME specimen quality.

RESULTS

A total of 391 patients were included in the study. The median age was 57 years (IQR: 49, 66), 68% of patients were male, and the median BMI was 27.4 (IQR: 24.1, 31.0). TME specimen was complete or near complete in 94.5% of cases and the rates of positive circumferential radial margin and distal resection margin were 2.0% and 0.3%, respectively. Median follow-up time was 30.7 months as calculated using reverse-KM estimator (CI 28.1-33.8) and there were 9 cases (2.5%) of local recurrence not accounting for competing risk. The 3-year estimated rate of disease recurrence was 19% (CI 15-25%) and the 3-year estimated overall survival was 90% (CI 87-94%).

CONCLUSION

This large multicenter study confirms the oncologic safety and perioperative benefits of taTME for rectal cancer when performed by experienced surgeons at experienced referral centers.

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

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

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.

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

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

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.

An MRI-based pelvimetry nomogram for predicting surgical difficulty of transabdominal resection in patients with middle and low rectal cancer

Objective

The current work aimed to develop a nomogram comprised of MRI-based pelvimetry and clinical factors for predicting the difficulty of rectal surgery for middle and low rectal cancer (RC).

Methods

Consecutive mid to low RC cases who underwent transabdominal resection between June 2020 and August 2021 were retrospectively enrolled. Univariable and multivariable logistic regression analyses were carried out for identifying factors (clinical factors and MRI-based pelvimetry parameters) independently associated with the difficulty level of rectal surgery. A nomogram model was established with the selected parameters for predicting the probability of high surgical difficulty. The predictive ability of the nomogram model was assessed by the receiver operating characteristic (ROC) curve and decision curve analysis (DCA).

Results

A total of 122 cases were included. BMI (OR = 1.269, p = 0.006), pelvic inlet (OR = 1.057, p = 0.024) and intertuberous distance (OR = 0.938, p = 0.001) independently predicted surgical difficulty level in multivariate logistic regression analysis. The nomogram model combining these predictors had an area under the ROC curve (AUC) of 0.801 (95% CI: 0.719–0.868) for the prediction of a high level of surgical difficulty. The DCA suggested that using the nomogram to predict surgical difficulty provided a clinical benefit.

Conclusions

The nomogram model is feasible for predicting the difficulty level of rectal surgery, utilizing MRI-based pelvimetry parameters and clinical factors in mid to low RC cases.

Robotic Transanal Total Mesorectal Excision Compared to Laparoscopic Transanal Total Mesorectal Excision: Oncologic Results of the Past 5 Years

Colorectal cancer is one of the deadliest diseases on the planet. Rectal cancer (RC) is the 8 th most common type of cancer disease worldwide, accounting for over 300,000 fatalities in 2018. Total mesorectal excision (TME) is considered as the gold standard approach for surgical RC management. To alleviate technical problems associated with dissection of distal rectal, transanal procedure to mesorectum was developed. The robotic operating platforms’ development has brought about the most significant change. The robotic method, which was described first in the year 2001, is gaining popularity in colorectal surgery. A stable camera platform with three-dimensional imaging and tremor filtering, motion scaling, instruments with numerous degrees of freedom, 3 rd arm for fixed retraction, ambidextrous capability, superior ergonomics, and less fatigue, all these advantages have all influenced robotics implementation. However, there are certain disadvantages to robotic surgery, such as high expenses, lengthy time of operation, a bulky cart, and absence of haptic sense. Robotic transanal TME (R-TA TME) is unique method that integrates potential advantages of perineal dissection with precise control of distal margins, along with all robotic technology advantages with respect to dexterity and greater precision. This review goal is to evaluate the available literature critically regarding R-TA TME in comparison to laparoscopic TA TME (L-TA TME) using the most prevalent histopathological metrics, which are the circumferential resection margin, the distal rectal margin, recurrence rate, specimen quality, advantages, and disadvantages. Oncological results for the past 5 years were used. The resources were obtained from electronic sources such as Google Scholar and PubMed. The conclusion of this review revealed that R-TA TME is as safe as well as feasible as L-TA TME, is technically possible, and has comparable oncological results and short-term post-operative outcomes. However, further investigation is required to evaluate long-term oncological or functional results.

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.

How to perform an anastomosis following a low anterior resection by transanal total mesorectal excision surgery: from top to bottom techniques

AIM

The aim was to describe the range of possibilities and our group's clinical outcomes when performing different types of anastomosis during transanal total mesorectal excision (taTME).

METHOD

A retrospective analysis was performed based on four taTME series from 2016 to 2021. Inclusion criteria were patients with rectal cancer in whom a sphincter-saving low anterior resection by taTME was performed. Four different techniques were employed for the anastomosis construction: (A) abdominal view, (B) transanal view, (C) hand-sewn coloanal anastomosis and (D) pull-through. Intra-operative and postoperative data were collected and compared.

RESULTS

A total of 161 patients were included. Tumour height was lower in groups C and D (4 [3-5] vs. 7 [6-8] group A vs. 6 [5-7] group B, P = 0.000), requiring a hand-sewn anastomosis. A transanal extraction of the specimen was more commonly performed in groups C and D (over 60% vs. 30% in groups A and B, P = 0.000). The rate of temporary stoma was similar between groups A, B and C (ranging from 84% to 98%) but was significantly lower in group D (P = 0.000). The overall rate of complications was similar between groups; however, group D had longer length of stay (15 days vs. 5-6 in groups A, B and C, P = 0.026).

CONCLUSION

Every type of anastomosis construction after a taTME procedure seems to be safe and feasible and should be chosen based on surgeon's experience, tumour height and the length of the rectal cuff after the rectal transection. Colorectal surgeons should be familiar with these techniques in order to choose the one that benefits each patient the most.

Transanal total mesorectal excision (TaTME) with delayed coloanal anastomosis versus TaTME with immediate coloanal anastomosis and temporary diversion in middle and low rectal cancer

BACKGROUND

Transanal total mesorectal excision (TaTME) avoids the difficulty of laparoscopic dissection of the lower part of the rectum. The need for stoma is associated with many stoma-related complications. The objective was to compare TaTME with immediate coloanal anastomosis and protective ileostomy (TaTME-IA) versus Turnbull-Cutait delayed coloanal anastomosis (TaTME-TC).

METHODS

A retrospective cohort study included patients with low rectal cancer at least 1 cm above the top of the anal sphincter. Patients had either TaTME-IA or TaTME-TC. Primary outcome measures were anastomotic and stoma-related complications. Secondary outcomes included rate of permanent stomas, local recurrence, continence, and quality of life (QOL).

RESULTS

TaTME-IA was done in 25 patients versus 20 who had TaTME-TC. TaTME-IA had significantly longer mean operative time (p = 0.04) and shorter length of stay (LOS) (4.5 vs. 11.4 days; p = 0.0001) compared to TaTME-TC. Anastomotic leak was reported in two patients of TaTME-IA versus one patient of TaTME-TC (p = 0.77). Anastomotic stenosis was reported in one patient in each group. No significant difference between groups as regard continence, local recurrence, and QOL.

CONCLUSION

TaTME-TC is a safe option that can be offered for patients with low rectal cancer who refuse or are not amenable to a temporary stoma. Anastomotic complications were similar in both groups. LOS was much longer in TaTME-TC, however, it avoids stoma complications. Both groups had similar functional oncologic outcomes and QOL.

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.

Clinical efficacy of laparoscopic modified Parks operation on the ultra-low rectal cancer

OBJECTIVES

To investigate the clinical efficacy of laparoscopic modified Parks operation on the patients with ultra-low rectal cancer.

METHODS

According to the preoperative stage and intraoperative anastomotic position, 98 patients with ultra-low rectal cancer above T2 stage underwent laparoscopic Dixon operation, modified Parks operation and Miles operation, respectively. All patients were divided into 3 groups: a Dixon operation group (n=39), a modified Parks operation group (n=43) and a Miles operation group (n=16). The clinical data and postoperative follow-up results were collected, compared, and analyzed to evaluate the clinical efficacy of laparoscopic modified Parks operation.

RESULTS

The patients were more obese, the distance between tumor and anal margin was closer, and the operation time was longer in the modified Parks operation group than those in the Dixon operation group (all P<0.05). However, the results of bleeding volume, the number of lymph nodes and the postoperative complications in the modified park operation group were similar than those in the Dixon operation group (all P>0.05). In addition, the exhaust and defecation time and the hospitalization time were shorter, and the total cost of hospitalization was lower in the modified Parks operation group than those in the Dixon operation group (all P<0.05). Although the anal function in the modified Parks operation group was poor in the early postoperative period, it reached the same level as that in the Dixon operation group from 6 months after the treatments with the regular anal function exercise (P>0.05). There were no significant differences in tumor size, body shape, distance between tumor and anal margin, operation time, bleeding volume, number of lymph nodes detected, postoperative exhaust and defecation time between the Miles operation group and the modified Parks operation group, but the hospitalization time was shorter, the incidence of complications and the total cost of hospitalization were lower in the modified Parks operation group (all P<0.05).

CONCLUSIONS

Laparoscopic modified Parks operation is a safe, economical and effective anus preservation operation, which can not only save the anus for some patients who had to perform Miles operation, but also recover better and faster after operation. Although the early anal function of patients performed with the modified operation is poor, it can gradually recover to the same level as the patients performed with the Dixon operation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pelvic dimensions on preoperative imaging can identify poor-quality resections after laparoscopic low anterior resection for mid- and low rectal cancer

BACKGROUND

High-quality surgery is essential for optimal oncologic outcomes in rectal cancer, but total mesorectal excision (TME) can be difficult for mid- and low rectal cancers. Preoperative identification of patients at risk for difficult TME may change the operative approach. The objective of this study was to determine if MRI pelvimetry can predict poor-quality surgery in patients undergoing laparoscopic low anterior resection (LAR) for mid- and low rectal cancer.

METHODS

All patients undergoing laparoscopic LAR for rectal cancer ≤ 9 cm from the anal verge at a single tertiary care referral center from 2011 to 2017 were retrospectively reviewed. Pelvic dimensions were measured from preoperative staging MRI on sagittal and axial views. Pelvimetry variables were all dichotomized based on median values. Exploratory factor analysis then identified the most relevant variables for regression analysis. The primary outcome was poor-quality resection, defined as an incomplete mesorectal grade, or involved circumferential (CRM) or distal (DRM) resection margins.

RESULTS

There were 92 patients included in this study, of which 70% were male, the mean BMI was 26.0 kg/m², and the mean tumor height was 6.6 cm. Preoperative (chemo)radiotherapy was administered in 70%, and the pathologic T-stage was T3/T4 in 41%. The overall incidence of poor-quality resection was 17%, including 13% incomplete TME, 7% involved CRM, and 1% involved DRM. Factor analysis identified S1-pubic symphysis and the angle between S1 and S5-bottom of symphysis (angle ABD) as relevant variables. After adjusting for pathologic T-stage, BMI, and tumor height, a S1-S5-bottom of symphysis angle > 74.3^° (OR 6.19, 95% CI 1.18-32.37) independently predicted poor-quality resection.

CONCLUSIONS

MRI pelvimetry can identify patients at risk for a poor-quality resection after laparoscopic proctectomy for mid- and low rectal cancer. These patients may benefit from the selective use of more advanced access methods to improve surgical resection quality.

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.

Carbon dioxide embolism during transanal total mesorectal excision (TaTME): two case reports

Transanal total mesorectal excision (TaTME), a new approach for rectal cancers, requires transanal carbon dioxide (CO2) high-flow insufflation to create a workplace. Two patients scheduled for TaTME experienced CO2 embolism during the anterior mesorectal dissection in contact with the prostate. CO2 embolism resulted in a sudden drop of end-tidal CO2, preceded by a short increase in one patient, and in oxygen desaturation. Hemodynamic alterations were minor. We report these two cases and discuss the pathophysiology of CO2 embolism and risk factors that promote CO2 embolism during TaTME to warn anesthetists of this serious complication, often unexpected and misdiagnosed.

Transanal total mesorectal excision (TaTME) using flexible endoscope with laparoscopic assistance: a pilot study in porcine models

BACKGROUND

Transanal total mesorectal excision (TaTME) is routinely performed to excise low rectal tumors. TaTME often relies on transanal endoscopic microsurgery (TEM) or transanal minimally invasive surgery (TAMIS) platform, all using rigid endoscopes. Our study reported a novel approach to TaTME which was completed using flexible endoscope, and we named it F-TaTME.

METHODS

The feasibility of rectum resection using F-TaTME was evaluated in five pigs. Firstly, the superior rectal artery and vein were managed under the assistance of laparoscopy. Secondly, the flexible endoscope was used to complete the full-thickness rectotomy and rectal mobilization. Finally, the specimen was removed and the manual colon-rectal anastomosis was performed under direct vision.

RESULTS

F-TaTME was accomplished in all 5 pigs. The mean procedure time was 136.6 min (97-162 min). The mean length from the lower edge of the lesion to circumferential dissection line was 1.4 cm (1.0-1.8 cm) and mean length of exteriorized rectum was 12.6 cm (11-14 cm). No injury to colorectal wall, adjacent pelvic or abdominal organs was found.

CONCLUSIONS

Our preliminary data suggested that F-TaTME may be a feasible method for TaTME.

Transanal Total Mesorectal Excision: Description of the Technique

Surgery remains the gold standard for the treatment of locally advanced rectal cancer. The most effective approach to reduce locoregional recurrence is total mesorectal excision (TME). However, obtaining an optimal TME is demanding, especially in low rectal tumors and anatomically unfavorable pelvis. Transanal TME (taTME) was developed to facilitate low pelvis dissection and potentially provide optimal outcomes for oncologic resection. Current studies have reported satisfactory short-term outcomes. However, taTME is a technically challenging procedure and must be learned in an appropriate training process to allow for a safe implementation. Previous experience in laparoscopic and transanal surgery is strongly recommended. In this work, we provide a detailed discussion of the technique, based on the realization of more than 400 taTME interventions.

Learning Transanal Total Mesorectal Excision

A dynamic evolution is occurring in transanal surgery. Transanal techniques began with intraluminal surgical removal of rectal masses and have progressed to transanal total mesorectal excision (taTME) for rectal cancer. TaTME was first performed in 2009 by Sylla, Rattner, Delgado, and Lacy. This article documents the training pathway followed by pioneers in the taTME technique as well as consensus reports outlining the process of learning the taTME technique. A literature search was performed for taTME training, learning, and technique. Key elements in learning the taTME technique include appropriate indications, cadaver training, and outcomes reporting such as participating in a taTME registry. Consensus reports also agree on the following facets associated with improved outcomes: (1) appropriate case selection of mid and low rectal cancers, (2) prerequisite completion of an accredited training program in laparoscopic colorectal surgery and prior experience in transanal endoscopic surgery, (3) a two-team taTME approach from above and below is ideal, and (4) higher rectal cancer volume surgical practice. The unifying international recommendation for surgeons interested in learning the taTME technique conveys the following message: taTME is an advanced and complex technique that requires dedicated training and experience in TME surgery.

Anal function and quality of life analysis after laparoscopic modified Parks for ultra-low rectal cancer patients

Background

To assess postoperative anal function and quality of life of ultra-low rectal cancer patients treated by laparoscopic modified Parks surgery.

Methods

From February 2017 to March 2019, 114 patients with ultra-low rectal cancer above T2 were treated respectively with ultra-low anterior resection (Dixon), modified coloanal anastomosis (modified Parks), and Miles according to the preoperative stage and anastomotic position. The postoperative anal function and Fecal Incontinence Quality of Life Scale (FIQL) of each patient were collected and synthetically analyzed.

Results

Compared with the Dixon group, the postoperative anal function and FIQL in the Parks group were poor at the early stage. However, from 6 to 12 months after surgery, the scores of anal function and FIQL in the Parks group were similar to those in the Dixon group (P > 0.05). Compared with the Miles group, the FIQL of the two groups were similar in the early postoperative stage. However, with the passage of time, from 3 to 9 months after surgery, the four domains of FIQL in the Parks group were higher than those in the Miles group successively (P < 0.05).

Conclusions

Laparoscopic modified Parks is a safe, effective, and economical anus-preserving surgery. Although its early anal function and FIQL were poor, it could gradually recover to the similar level as Dixon. Moreover, it can save the anus and obtain a better postoperative quality of life for some patients who previously could only undergo Miles.

Minimizing the impact of colorectal surgery in the older patient: The role of minimally invasive surgery in the geriatric population

With an aging population comes a greater incidence of colorectal cancer and a corresponding need for surgical resection in the geriatric population. This heterogeneous group of patients may benefit from multidisciplinary pre-operative evaluation and optimization, prehabilitation, enhanced recovery protocols, and a minimally invasive approach to resection. Concerns regarding the ability of the older patient to tolerate the physiologic demands of pneumoperitoneum have not been validated. Conversely, these vulnerable patients may experience a greater reduction in morbidity than their younger counterparts through the use of minimally invasive techniques.

Transanal total mesorectal excision for rectal cancer has been suspended in Norway

Background

Transanal total mesorectal excision (TaTME) for rectal cancer has emerged as an alternative to the traditional abdominal approach. However, concerns have been raised about local recurrence. The aim of this study was to evaluate local recurrence after TaTME. Secondary aims included postoperative mortality, anastomotic leak and stoma rates.

Methods

Data on all patients who underwent TaTME were recorded and compared with those from national cohorts in the Norwegian Colorectal Cancer Registry (NCCR) and the Norwegian Registry for Gastrointestinal Surgery (NoRGast). Kaplan–Meier estimates were used to compare local recurrence.

Results

In Norway, 157 patients underwent TaTME for rectal cancer between October 2014 and October 2018. Three of seven hospitals abandoned TaTME after a total of five procedures. The local recurrence rate was 12 of 157 (7·6 per cent); eight local recurrences were multifocal or extensive. The estimated local recurrence rate at 2·4 years was 11·6 (95 per cent c.i. 6·6 to 19·9) per cent after TaTME compared with 2·4 (1·4 to 4·3) per cent in the NCCR (P &lt; 0·001). The adjusted hazard ratio was 6·71 (95 per cent c.i. 2·94 to 15·32). Anastomotic leaks resulting in reoperation occurred in 8·4 per cent of patients in the TaTME cohort compared with 4·5 per cent in NoRGast (P = 0·047). Fifty-six patients (35·7 per cent) had a stoma at latest follow-up; 39 (24·8 per cent) were permanent.

Conclusion

Anastomotic leak rates after TaTME were higher than national rates; local recurrence rates and growth patterns were unfavourable.

Prediction of transabdominal total mesorectal excision difficulty according to the angle of pelvic floor muscle

BACKGROUND

Total mesorectal excision (TME) is challenging to perform in a deep, narrow pelvis. While previous studies used pelvimetry to assess bony pelvic structures, there is no consensus on exact definition of deep, narrow pelvis. We hypothesized that the shape of pelvic floor muscle may impact the performance of transabdominal pelvic dissection. We aimed to evaluate which parameters of the shape of pelvic floor muscle impact the difficulty of TME and present a predictive reference value for TME difficulty.

METHODS

From January 2015 to December 2015, 85 consecutive patients who had undergone curative resection for middle to lower rectal cancer were retrospectively studied. Pelvimetry was performed using preoperative T2-weighted magnetic resonance imaging. Predictive factor analysis for surgical duration was studied using linear regression. Mann-Whitney U test, comparing surgical duration between two groups classified by predictive factor, was used for the analysis of reference value.

RESULTS

Multivariate analysis revealed that body mass index, protective stoma, number of surgeon, and incline angle of pelvic floor muscle (β) were independent predictors of surgical duration. Test statistics of Mann-Whitney U for the difference in surgical duration between groups above and below a β of 54° were maximized.

CONCLUSIONS

The incline angle of pelvic floor muscle is an independent predictor of surgical duration. In patients with steeper incline of PFM, transabdominal TME is expected to be difficult. This index is novel, but needs to be further validated.

Detailed and applied anatomy for improved rectal cancer treatment

Rectal anatomy is one of the most challenging concepts of visceral anatomy, even though currently there are more than 23,000 papers indexed in PubMed regarding this topic. Nonetheless, even though there is a plethora of information meant to assist clinicians to achieve a better practice, there is no universal understanding of its complexity. This in turn increases the morbidity rates due to iatrogenic causes, as mistakes that could be avoided are repeated. For this reason, this review attempts to gather current knowledge regarding the detailed anatomy of the rectum and to organize and present it in a manner that focuses on its clinical implications, not only for the colorectal surgeon, but most importantly for all colorectal cancer-related specialties.

Anatomy of the smooth muscle structure in the female anorectal anterior wall: convergence and anterior extension of the internal anal sphincter and longitudinal muscle

AIM

The anatomy of the region between the vagina and anal canal plays an essential role when performing a proctectomy for low-lying tumours. However, the anatomical characteristics of this area remain unclear. The purpose of the present study was to clarify the configuration, and both lateral and inferior extensions, of the muscle bundles in the anorectal anterior wall in females.

METHODS

Using cadaveric specimens, macroscopic anatomical and histological evaluations were conducted at the anatomy department of our institute. Macroscopic anatomical specimens were obtained from six female cadavers. Histological specimens were obtained from eight female cadavers.

RESULTS

The smooth muscle fibres of the internal anal sphincter and longitudinal muscle extended anteriorly in the anorectal anterior wall of females and the muscle bundles showed a convergent structure. The anterior extending smooth muscle fibres merged into the vaginal smooth muscle layer, distributed subcutaneously in the vaginal vestibule and perineum and spread to cover the anterior surface of the external anal sphincter and the levator ani muscle. Relatively sparse space was observed in the region anterolateral to the rectum on histological analysis.

CONCLUSION

Smooth muscle fibres of the rectum and vagina are intermingled in the median plane, and there is relatively sparse space in the region anterolateral to the rectum. Therefore, when detaching the anorectal canal from the vagina during proctectomy, an approach from both the lateral sides should be used.

Short- and long-term outcomes of transanal versus laparoscopic total mesorectal excision for mid-to-low rectal cancer: a meta-analysis

BACKGROUND AND OBJECTIVES

Transanal total mesorectal excision (TaTME) is positioned at the cutting edge of minimally invasive approach to mid- and low rectal cancer. This meta-analysis was to compare the short- and long-term outcomes of TaTME versus laparoscopic total mesorectal excision (LTME) and to evaluate the safety, efficacy, and possible superiority of TaTME.

METHODS

A comprehensive search was conducted for randomized controlled trials (RCTs) and non-RCTs (NRCTs) comparing TaTME with LTME. Inter-group differences were evaluated via standardized mean differences and relative risks (RRs). All outcomes were analyzed using fixed effects or random effects models according to the heterogeneity. Statistical analysis was performed using Stata/SE 12.0 software.

RESULTS

Eleven studies (1 RCT and 10 NRCTs) with involving 757 patients were included. Among which, 361 patients underwent TaTME and 396 patients underwent LTME. Comparing the surgical and oncological quality of resection of TaTME with that of LTME, reports of TaTME indicated favorable outcomes considering mesorectal resection quality, circumferential resection margin involvement, intraoperative blood loss, conversions, and postoperative complications, while the differences between the two groups had no statistical significance in terms of distal resection margin, harvested lymph node, operation time, hospital stay, recurrence, 2-year overall survival (OS), and 2-year disease-free survival.

CONCLUSION

TaTME is a promising surgical technique and is fully a safe, efficacious, and diffusible alternative to LTME in managing mid- and distal rectal cancer. Larger scale, national, multicentric RCTs are warranted to further verify these results and the possible superiority of TaTME.

Critical and Challenging Issues in the Surgical Management of Low-Lying Rectal Cancer

Despite innovative advancements, the management of distally located rectal cancer (RC) remains a formidable endeavor. The critical location of the tumor predisposes it to a circumferential resection margin that tends to involve the sphincters and surrounding organs, pelvic lymph node metastasis, and anastomotic complications. In this regard, colorectal surgeons should be aware of issues beyond the performance of total mesorectal excision (TME). For decades, abdominoperineal resection had been the standard of care for low-lying RC; however, its association with high rates of tumor recurrence, tumor perforation, and poorer survival has stimulated the development of novel surgical techniques and modifications, such as extralevator abdominoperineal excision. Similarly, difficult dissections and poor visualization, especially in obese patients with low-lying tumors, have led to the development of transanal TME or the "bottom-to-up" approach. Additionally, while neoadjuvant chemoradiotherapy has allowed for the execution of more sphincter-saving procedures without oncologic compromise, functional outcomes remain an issue. Nevertheless, neoadjuvant treatment can lead to significant tumor regression and complete pathological response, permitting the utilization of organ-preserving strategies. At present, an East and West dualism pervades the management of lateral lymph node metastasis, thereby calling for a more global and united approach. Moreover, with the increasing importance of quality of life, a tailored, individualized treatment approach is of utmost importance when taking into account oncologic and anticipated functional outcomes.

Transanal total mesorectal excision (taTME) in a single-surgeon setting: refinements of the technique during the learning phase

BACKGROUND

Transanal total mesorectal excision (taTME) is a safe and effective technique. We have progressively developed a systematic approach in the single-surgeon setting. The aim of this study was to compare our early vs late single-surgeon taTME experience as well as present the technical and logistical modifications that were crucial to achieve successful implementation of a taTME program.

METHODS

Review of prospectively collected data on 27 patients who had taTME in June 2015-September 2016 (early cohort) was included and compared with 43 patients who underwent taTME in October 2016-September 2017 (late cohort). Procedures were performed by a single-surgeon team at Health Sciences North (Sudbury, Ontario, Canada). Inclusion criteria were T1-3 or downstaged T4 mid- and low-rectal lesions. Cases of non-neoplastic disease were excluded. Outcomes assessed included mesorectal integrity, margin status, operative time, complications, morbidity, length of stay and 30-day readmission.

RESULTS

A total of 70 cases were included. Patients were divided into early (27 patients, 14 males; mean age 60.74 ± 9.77 years) and late (43 patients, 29 males; mean age 63.48 ± 10.85 years) cohorts. During the early phase, procedural modifications including regular takedown of the splenic flexure, intra-corporeal division of the mesentery, liberal use of a Pfannenstiel incision for extraction, abundant washing of the surgical field and regular use of the ICG technology were progressively introduced. There was no mortality nor statistically significant difference between the early and late cohort in terms of morbidity (33.3 vs 39.4% p = 0.727), anastomotic leak (14.8 vs 4.6% p = 0.19), operating time (5.05 ± 1.26 vs 4.96 ± 1.14 h p = 0.755), length of stay (4.0 ± 2.54 vs 4.81 ± 3.63 days p = 0.394) and CRM negative margin (96.3 vs. 97.7% p = 0.999), and no incomplete specimens were obtained on either cohort.

CONCLUSIONS

This study confirms the safety and effectiveness of single-surgeon implementation of taTME technique. Technical challenges experienced in this setting were not obstacles for further refinement and to establish a tendency towards better outcomes. Overcoming technical challenges is possible, familiarity with taTME is slow yet progressive, and improvement tends to occur with experience.