Transanal Total Mesorectal Excision Procedures Research Articles

LDCNet: Lightweight dynamic convolution network for laparoscopic procedures image segmentation

Medical image segmentation is fundamental for modern healthcare systems, especially for reducing the risk of surgery and treatment planning. Transanal total mesorectal excision (TaTME) has emerged as a recent focal point in laparoscopic research, representing a pivotal modality in the therapeutic arsenal for the treatment of colon & rectum cancers. Real-time instance segmentation of surgical imagery during TaTME procedures can serve as an invaluable tool in assisting surgeons, ultimately reducing surgical risks. The dynamic variations in size and shape of anatomical structures within intraoperative images pose a formidable challenge, rendering the precise instance segmentation of TaTME images a task of considerable complexity. Deep learning has exhibited its efficacy in Medical image segmentation. However, existing models have encountered challenges in concurrently achieving a satisfactory level of accuracy while maintaining manageable computational complexity in the context of TaTME data. To address this conundrum, we propose a lightweight dynamic convolution Network (LDCNet) that has the same superior segmentation performance as the state-of-the-art (SOTA) medical image segmentation network while running at the speed of the lightweight convolutional neural network. Experimental results demonstrate the promising performance of LDCNet, which consistently exceeds previous SOTA approaches. Codes are available at github.com/yinyiyang416/LDCNet.

Transanal total mesorectal excision (TaTME) in rectal cancer treatment within an expert center

The objective of this study was to evaluate treatment outcomes in patients who underwent the TaTME procedure for cancer of the middle and low rectum in an expert center. Prospective analysis of the outcomes of all consecutive patients treated using the TaTME technique for cancer of the middle and distal rectum at the our medical center between March 1, 2015, and March 31, 2022. A total of 128 patients (34 women, 94 men; mean age 66.01 [38–85] years) with cancer of the middle and distal rectum qualified for TaTME. TaTME procedures were performed in 127/128 (99.22%) patients. Complications of surgery were observed in 22/127 (17.32%) patients. Negative proximal and distal margins were confirmed in all 127 patients. Complete (R0) resection of the mesorectum was confirmed in 125/127 (98.43%) and nearly complete (R1) resection was confirmed in 2/127 (1.57%) patients. The average follow-up period was 795 days (296–1522) days. Local recurrence was detected during the follow-up period in 2/127 (1.57%) patients. This study showed that the TaTME procedure is an effective and safe method for the minimally invasive treatment of middle and low rectal cancers, particularly within an expert center setting.

Long-term outcomes after transanal total mesorectal excision for rectal cancer in Denmark: A prospective multicenter study from the late implementation phase

PurposeThe aim of this study was to evaluate the long-term surgical and oncological outcomes after transanal total mesorectal excision (TaTME) for rectal cancer during an implementation phase on a national level. MethodThis is a retrospective review of prospectively recorded data. Registration was initiated by the Danish Colorectal Cancer Group in order to assess the quality of care during the implementation of TaTME in Denmark. Data from four centers were pooled for simultaneous analysis. Short-term data was available from a prior study, and long-term data regarding recurrences, chemotherapy, and mortality was collected. ResultsFrom August 2016 to April 2019, 115 TaTME procedures were registered. Patients were predominantly male (n = 85, 74%) with mid-rectal (n = 88, 77%) tumors. The overall local recurrence rate was 7.8% (n = 9) of which six patients also had systemic recurrence. Mean long-term follow-up was 59.4 months, and median time to local recurrence was 24.9 months. Local recurrences occurred predominantly among initial implementation cases. The overall mortality rate was 13% (n = 15). Of the 17 patients with recurrence, 35% (n = 6) died and developed either solely distant recurrence (n = 2, 12%) or in combination with local recurrence (n = 4, 24%). ConclusionWe found acceptable long-term oncological results after TaTME during the implementation phase in Denmark. There was an accumulation of local recurrences in the early phase of the study which emphasizes the importance of thorough training and proctoring when starting the approach.

Quality of life and functional outcomes after transanal total mesorectal excision for rectal cancer-results from the implementation period in Denmark.

The standard operation for mid- and low rectal cancer total mesorectal excision (TME) is routinely performed as minimally invasive surgery. TME is associated with temporary or permanent functional impairment of pelvic organs, causing reduced quality of life (QoL). Concerns have been raised that the newest minimally invasive approach, transanal TME (TaTME), may further reduce urogenital and anorectal functions. To determine if functional outcomes affecting QoL are altered after TaTME. Primary end-point is the impact of TaTME on QoL and functional outcomes. Secondary end-point is assessing differences in QoL and functional outcomes after TME surgery from below (TaTME) or above (transabdominal TME). Observational study consisting of prospectively registered self-reported questionnaire data collected at baseline and follow-ups after TaTME. All patients who underwent TaTME during the Danish national implementation phase were included. Central surveillance of the implementation included questionnaires concerning QoL and functional outcomes. Analyses of functional results from the Danish cohort of the ROLARR trial (Jayne et al. in JAMA 318:1569-1580,(2017) are reported separately for perspective, representing the transabdominal approach to TME, i.e., laparoscopic- or robotic-assisted TME (LaTME/RoTME). Applied questionnaires include EORTC QLQ-C30, SF-36, LARS, ICIQ-MLUTS, ICIQ-FLUTS, IPSS, IIEF, SVQ, and FSFI. A total of 115 TaTME procedures were registered August 2016 to April 2019. LaTME/RoTME patients (n = 92) were operated on January 2011 to September 2014. A temporary postoperative decrease of QoL (global health status and functional scales) was observed, yet long-term results were unaffected by surgery in both groups. In TaTME patients, the anorectal dysfunction increased significantly (p < 0.001) from preoperative baseline to 13.5months follow-up, where 67.5% (n = 52) reported major LARS symptoms. Urinary function was not significantly impaired after TME regardless of technique. The paucity of responses concerning sexual function precludes conclusions. Although an initial reduction in QoL after TME occurs, it normalizes within the first year postoperatively. In concurrence with international results, we found that significant anorectal dysfunction is common after TaTME. No data on anorectal function was available for LaTME/RoTME patients for comparison. We found no indications that transanal TME is inferior to transabdominal TME surgery concerning urogenital functions or health-related QoL.

Quality Indicators of Transanal Total Mesorectal Excision (TaTME) for Rectal Cancer

Abstract Introduction Transanal total mesorectal excision (TaTME) has revolutionized the surgical techniques for lower-third rectal cancer. The aim of the present study was to analyze the outcomes of quality indicators of TaTME for rectal cancer compared with laparoscopic TME (LaTME). Methods A cohort prospective study with 50 (14 female and 36 male) patients, with a mean age of 67 (range: 55.75 to 75.25) years, who underwent surgery for rectal cancer. In total, 20 patients underwent TaTME, and 30, LaTME. Every TaTME procedure was performed by experienced colorectal surgeons. The sample was divided into two groups (TaTME and LaTME), and the quality indicators of the surgery for rectal cancer were analyzed. Results There were no statistically significant differences regarding the patients and the main characteristics of the tumor (age, gender, American Society of Anesthesiologists [ASA] score, body mass index [BMI], tumoral stage, neoadjuvant therapy, and distance from the tumor to the external anal margin) between the two groups. The rates of: postoperative morbidity (TaTME: 35%; LaTME: 30%; p = 0.763); mortality (0%); anastomotic leak (TaTME: 10%; LaTME: 13%; p = 0.722); wound infection (TaTME: 0%; LaTME: 3.3%; p = 0.409); reoperation (TaTME: 5%; LaTME: 6.6%; p = 0.808); and readmission (TaTME: 5%; LaTME: 0%; p = 0.400), as well as the length of the hospital stay (TaTME: 13.5 days; LaTME: 11 days; p = 0.538), were similar in both groups. There were no statistically significant differences in the rates of positive circumferential resection margin (TaTME: 5%; LaTME: 3.3%; p = 0.989) and positive distal resection margin (TaTME: 0%; LaTME: 3.3%; p = 0.400), the completeness of the TME (TaTME: 100%; LaTME: 100%), and the number of lymph nodes harvested (TaTME: 15; LaTME: 15.5; p = 0.882) between two groups. Conclusion Transanal total mesorectal excision is a safe and feasible surgical procedure for middle/lower-third rectal cancer.

A nationwide comparison of short-term outcomes after transanal, open, laparoscopic, and robot-assisted total mesorectal excision.

Laparoscopic rectal cancer surgery has several limitations. Transanal total mesorectal excision (TaTME) can potentially overcome these limitations. The aim of this study was to compare the rates of non-radical surgery and anastomotic leakage after TaTME, open TME (OpTME), laparoscopic TME (LaTME) and robotic TME (RoTME) procedures in a nationwide cohort. We extracted the demographic, perioperative and pathological data of patients who underwent a curative OpTME, LaTME, RoTME or TaTME procedure between January 2014 and December 2018 from the national database of the Danish Colorectal Cancer Group (DCCG). We conducted multiple group-comparisons, uni- and multivariate analyses to determine the factors associated with positive resection margin (+RM) and anastomotic leakage. We included 2393 patients (OpTME = 205, LaTME = 1163, RoTME = 713 and TaTME = 312). The rate of +RM was 5.7% after TaTME. The lowest rate of +RM was achieved after RoTME (8.2%, 4.7%, 2.52%, and 5.7%, after OpTME, LaTME, RoTME and TaTME respectively, p<0.001). In multivariate analysis, having a T4 tumour and intraoperative bowel perforation were associated with the risk of +RM (p<0.001, p<0.001, respectively). The factors associated with anastomotic leakage in multivariate analysis were male gender, high BMI and intraoperative bowel perforation (p<0.001, p=0.049, p=0.002, respectively). TaTME was associated with the highest rate of sphincter-saving procedures (79.8%, p<0.001), the lowest rate of bowel perforation (2.9%, p=0.028) and the lowest rate of conversion to open surgery (1.3%, p<0.001). In a nationwide audit of TME approaches, the rate of +RM was lowest after RoTME. No differences were found between the four approaches regarding the risk of anastomotic leakage. TaTME offered advantages related to sphincter-saving, perforation and conversion.

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

AimTransanal 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.MethodAn 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).ResultsSix 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.ConclusionThis 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.

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

BackgroundDividing a surgical procedure into a sequence of identifiable and meaningful steps facilitates intraoperative video data acquisition and storage. These efforts are especially valuable for technically challenging procedures that require intraoperative video analysis, such as transanal total mesorectal excision (TaTME); however, manual video indexing is time-consuming. Thus, in this study, we constructed an annotated video dataset for TaTME with surgical step information and evaluated the performance of a deep learning model in recognizing the surgical steps in TaTME.MethodsThis was a single-institutional retrospective feasibility study. All TaTME intraoperative videos were divided into frames. Each frame was manually annotated as one of the following major steps: (1) purse-string closure; (2) full thickness transection of the rectal wall; (3) down-to-up dissection; (4) dissection after rendezvous; and (5) purse-string suture for stapled anastomosis. Steps 3 and 4 were each further classified into four sub-steps, specifically, for dissection of the anterior, posterior, right, and left planes. A convolutional neural network-based deep learning model, Xception, was utilized for the surgical step classification task.ResultsOur dataset containing 50 TaTME videos was randomly divided into two subsets for training and testing with 40 and 10 videos, respectively. The overall accuracy obtained for all classification steps was 93.2%. By contrast, when sub-step classification was included in the performance analysis, a mean accuracy (± standard deviation) of 78% (± 5%), with a maximum accuracy of 85%, was obtained.ConclusionsTo the best of our knowledge, this is the first study based on automatic surgical step classification for TaTME. Our deep learning model self-learned and recognized the classification steps in TaTME videos with high accuracy after training. Thus, our model can be applied to a system for intraoperative guidance or for postoperative video indexing and analysis in TaTME procedures.

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.

Initial Experience with the Safe Implementation of Transanal Total Mesorectal Excision (TaTME) as a Standardized Procedure for Low Rectal Cancer

Introduction: The laparoscopic approach for TME is proven to be non-inferior in oncological outcome compared to open surgery. Anatomical limitations in the male and obese pelvis with resulting pathological shortcomings and high conversion rates were stimuli for alternative approaches. The transanal approach for TME (TaTME) was introduced to overcome these limitations. The aim of this study was to evaluate the outcomes of TaTME for mid and low rectal cancer at our center. Methods: TaTME is a hybrid procedure of simultaneously laparoscopic and transanal mesorectal excision. A retrospective analysis of all consecutive TaTME procedures performed at our center for mid and low rectal cancer between December 2014 and January 2020 was conducted. Results: A total of 157 patients underwent TaTME, with 72.6% receiving neoadjuvant chemoradiation. Mean tumor height was 6.1 ± 2.3 cm from the anal verge, 72.6% of patients had undergone neoadjuvant chemoradiotherapy, and 34.2% of patients presented with a threatened CRM upon pretherapeutic MRI. Abdominal conversion rate was 5.7% with no conversion for the transanal dissection. Early anastomotic leakage occurred in 7.0% of the patients. Mesorectum specimen was complete in 87.3%, R1 resection rate was 4.5% (involved distal resection margin) and in 7.6%, the CRM was positive. The three-year local recurrence rate of 58 patients with a follow-up ≥ 36 months was 3.4%. Overall survival was 92.0% after 12 months, and 82.2% after 36 months. Conclusion: TaTME can be performed safely with acceptable long-term oncological outcome. Low rectal cancer can be well addressed by TaTME, which is an appropriate alternative with low conversion, local recurrence, adequate mesorectal quality and CRM positivity rates.

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

The aim of this study was to evaluate the short-term surgical and oncological outcomes after transanal total mesorectal excision (TaTME) for rectal cancer during the implementation phase of this procedure in Denmark. This is a retrospective review of prospectively recorded data. Registration was initiated by the Scientific Council of the Danish Colorectal Cancer Group (DCCG.dk) in order to assess the quality of care during the implementation of TaTME. Pre-, intra- and postoperative data including early recurrences were recorded at the operating centres. From August 2016 to April 2019, 115 TaTME procedures were registered. Patients were predominantly male (74%) with mid-rectal (88%) tumours. The level of surgical complications was comparable to previous nationwide results. Anastomotic leakage occurred in 6/109 (5.5%). One urethral injury occurred. The plane of dissection was mesorectal in 60% of cases, intramesorectal in 28% and muscularis in 12%. Nonmicroradicality was seen in 8% (R1, 6%; R2, 2%). Four local recurrences occurred after a median of 23months of follow-up. One of these was multifocal. In an implementation phase where patient selection is expected, surgical and oncological results after TaTME were comparable to those of other approaches reported in the literature.

Comparison of transanal total mesorectal excision (TaTME) versus laparoscopic TME for rectal cancer: A case matched study

BackgroundTransanal total mesorectal excision (TaTME) has been developed to improve the quality of laparoscopic TME for patients with rectal cancer. Recently, international concern on TaTME was raised by a national cohort study showing an increased rate of local recurrences. This study aimed to compare clinicopathological and mid-term oncological outcomes of TaTME versus laparoscopic TME (LaTME) for mid and low rectal cancer of a high volume center. MethodsFrom August 2014 to October 2019, patients with mid or low rectal cancer who received TaTME procedure were identified. The cases were matched with patients treated with LaTME. Data were retrospectively collected including operative details, postoperative morbidity, pathologic results, and oncologic outcomes. Primary endpoint was the local recurrence (LR) rate. ResultsPropensity score matching yielded 70 patients in each of the groups. There were no statistically significant differences between the 2 groups in terms of postoperative complications, conversion rate to open surgery and circumferential resection margin. Local recurrence occurred in 2 patients (2.9%) in the transanal group, whereas 1 patient developed a local recurrence in the laparoscopic group (1.4%)(p = 0.559). Kaplan–Meier survival analysis showed a 2 year Local recurrence rate 1.5% VS 1.6%(p = 0.934), DFS 88.0% VS 87.7%, OS 94.0% vs 100% for transanal and laparoscopic group, respectively. ConclusionsIn a high volume center the transanal total mesorectal procedure is feasible, and appears to be safe alternative to laparoscopic surgery. Oncological outcomes were acceptable and no increased multi or unifocal local recurrence rate was found.

A novel surgical training simulator for transanal total mesorectal excision.

The transanal total mesorectal excision (TaTME) approach for rectal cancer has been gaining popularity. Although TaTME requires specific training, the opportunity to obtain this training is limited. We developed the first dry simulator that includes some important structural landmarks to provide training that includes all the procedural steps of TaTME. The model was structured based on a computed tomography scan data. The simulator mimics the rectum and surrounding key anatomical structures. All material components were made of polyvinyl alcohol and stained with various colors to easily identify these anatomical structures while undergoing the training. Our simulator is compact in its size and can be easily packed, stacked, and stored. The materials mimic the real one and the model allows us to perform the entire step-by-step TaTME procedures with genuine clinical devices from the attachment of operative platform to the anastomosis. We have held the course 24 times to date, with more than 200 surgeons participating not only from domestic hospitals but also from other countries. The result of the satisfaction survey from 65 participants, which was rated from 0 to 10 points, was an average score of 8.6 (± 1.4) points. We present the world's first TaTME simulator and believe that it will play an important role for the safe spread of TaTME surgery.

The ACPGBI recommends pause for reflection on transanal total mesorectal excision.

The ACPGBI recommends pause for reflection on transanal total mesorectal excision.

Our experience with transanal total mesorectal excision (TaTME) procedures in middle and distal rectal tumors.

Transanal total mesorectal excision (TaTME) is arelatively new approach in surgical treatment of rectal cancer. There are no clear indications when to choose this strategy. It is atechnically demanding procedure for the surgeon with along learning curve, which should also be taken into account in evaluation of this method. The results of both oncological and postoperative complications must be properly evaluated to explore the benefit of TaTME. The aim of this study is to assess the potential benefit of TaTME compared to other alternatives in middle and distal rectal tumors. Retrospective evaluation of patients undergoing TaTME procedure performed by one team of surgeons between October 2014 and June 2019. The authors analyzed demographic indicators of the group of patients, tumor characteristics, specimen quality, early postoperative complications and the possibility of stoma reversal. Atotal of 93 patients underwent TaTME procedure for middle and distal rectal cancer. Mean BMI was 27.6 (4.8). T3 or T4 tumor was found in 73 (78.5%) patients, 68 (73.1%) patients had positive lymph nodes and 12 (12.9%) patients were treated for synchronous metastatic rectal cancer. Neoadjuvant therapy was used in 80 (86%) patients. Conversion to open laparotomy was necessary in one case (1%). Stapled anastomosis was performed in 37 (39.7%) cases, handsewn in 56 (60.2%). Apositive circumferential resection margin (CRM) was found in 10 (10.7%) cases. Distal resection margin (DRM) was positive in 3 (3.2%) patients. Pathological analysis showed acomplete mesorectum in 18 patients (19.4%), nearly complete in 39 (41.9%) and an incomplete mesorectum in 36 (38.7%). Complications in the first 30 days after primary surgery were observed in 38 (40.8%) patients, mainly for anastomotic leak (19 patients, 20.4%). Reoperation was required in 7 (7.5%) patients. Permanent colostomy had to be performed in 4 (4.3%) cases. No patient died after surgery. In aselected group of patients it is possible to perform resection using this approach with acceptable postoperative morbidity and quality of the specimen. We used TaTME procedure in patients expected to have difficult TME due to obesity, size and distal localization of tumor. The incidence of conversion to open surgery was very low. Further studies for long term oncological outcomes are needed.

Transanal total mesorectal excision and adverse conditions for laparoscopic total mesorectal excision

Transanal total mesorectal excision (TaTME) is an alternative technique for rectal surgery that could facilitate the mobilization and the distal transection of the rectum. Our objective was to analyze whether the presence of factors affecting the difficulty of laparoscopic total mesorectal excision (TME) could affect surgical and oncological outcomes of TaTME for mid and low rectal cancer. 20 patients (13 male, 7 female) with a mean age of 66.5 years (range 55.5–75.7) and mid–low rectal cancer were prospectively submitted to TaTME. Every TaTME procedure was performed by two teams of experienced surgeons working simultaneously. Adverse conditions for laparoscopic TME were considered to be male gender, obesity, benign prostatic hypertrophy, low rectal cancer, pT3-T4, tumor size >5 cm, and neoadjuvant therapy. These factors were matched to surgical (morbidity, operative time, conversion rate) and pathological (quality of mesorectum, circumferential resection margin) outcomes. Male gender was associated with longer operative time (285 vs. 240 min, p = 0.031). There were no significant associations among the rest of the analyzed factors complicating laparoscopic TME and pathological and surgical outcomes of TaTME. Multivariate analysis showed that male gender was independently associated with operative time (β = 0.18 OR 1.019 CI95%:1.001–1.037; p = 0.042). TaTME seems to be more difficult in males but not in obesity, benign prostatic hypertrophy, low rectal cancer, pT3-T4, tumor size >5 cm, or neoadjuvant therapy. TaTME could be considered an alternative surgery for low rectal cancer in the presence of these factors affecting laparoscopic TME.

Impact of pneumoperitoneum on intra-abdominal microcirculation blood flow: an experimental randomized controlled study of two insufflator models during transanal total mesorectal excision : An experimental randomized multi-arm trial with parallel treatment design.

To compare changes in microcirculation blood flow (MCBF) between pulsatile and continuous flow insufflation. Transanal total mesorectal excision (TaTME) was developed to improve the quality of the resection in rectal cancer surgery. The AirSeal IFS® insufflator facilitates the pelvic dissection, although evidence on the effects that continuous flow insufflation has on MCBF is scarce. Thirty-two pigs were randomly assigned to undergo a two-team TaTME procedure with continuous (n = 16) or pulsatile insufflation (n = 16). Each group was stratified according to two different pressure levels in both the abdominal and the transanal fields, 10mmHg or 14mmHg. A generalized estimating equations (GEE) model was used. At an intra-abdominal pressure (IAP) of 10mmHg, continuous insufflation was associated with a significantly lower MCBF reduction in colon mucosa [13% (IQR 11;14) vs. 21% (IQR 17;24) at 60min], colon serosa [14% (IQR 9.2;18) vs. 25% (IQR 22;30) at 60min], jejunal mucosa [13% (IQR 11;14) vs. 20% (IQR 20;22) at 60min], renal cortex [18% (IQR 15;20) vs. 26% (IQR 26;29) at 60min], and renal medulla [15% (IQR 11;20) vs. 20% (IQR 19;21) at 90min]. At an IAP of 14mmHg, MCBF in colon mucosa decreased 23% (IQR 14;27) in the continuous group and 28% (IQR 26;31) in the pulsatile group (p = 0.034). TaTME using continuous flow insufflation was associated with a lower MCBF reduction in colon mucosa and serosa, jejunal mucosa, renal cortex, and renal medulla compared to pulsatile insufflation.

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

The interest and adoption of transanal total mesorectal excision (TaTME) is growing worldwide, but evidence on nationwide implementation and short-term outcomes is scarce. This study aims to evaluate national results for this relatively new technique in the UK. All TaTME procedures performed in the UK and recorded on the international TaTME registry between January 2013 and January 2018 were analyzed. Surgeons who received training on TaTME in the UK were sent a survey regarding their experience with implementation of TaTME in their unit. Primary endpoint was a composite for "optimal pathology" (free resection margin (R0) and TME specimen with no major defects and no rectal wall perforations). Secondary outcomes included 30-day clinical course and survey outcomes. Forty-two hospitals entered 513 cases over a 5-year period; 28 of 42 hospitals (66.7%) performed ten cases or less. The indication for surgery was cancer in 364 (71.0%) cases. Optimal pathology was achieved in 295 (92.8%), with an involved resection margin (R1) rate of 13 of 513 (4.1%). A Clavien-Dindo ≥III within 30 days was 13.4% (N.=45) and 6.8% (N.=10) in the cancer and benign groups, respectively. Based on the survey (response rate 68 of 86; 79%), 76.1% of the surgeons implemented TaTME in their unit after receiving training, all of whom experienced difficulties with performing TaTME. This study reports acceptable nationwide short-term outcomes of TaTME. However, adoption occurred in a rapid and non-standardized manner. A structured TaTME training program is therefore recommended.

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

BackgroundTransanal total mesorectal excision (TaTME) is a new complex technique with potential to improve the quality of surgical mesorectal excision for patients with mid and low rectal cancer. The procedure is technically challenging and has shown to be associated with a relative long learning curve which might hamper widespread adoption. Therefore, a national structured training pathway for TaTME has been set up in the Netherlands to allow safe implementation. The aim of this study was to monitor safety and efficacy of the training program with 12 centers.MethodsShort-term outcomes of the first ten TaTME procedures were evaluated in 12 participating centers in the Netherlands within the national structured training pathway. Consecutive patients operated during and after the proctoring program for rectal carcinoma with curative intent were included. Primary outcome was the incidence of intraoperative complications, secondary outcomes included postoperative complications and pathological outcomes.ResultsIn October 2018, 12 hospitals completed the training program and from each center the first 10 patients were included for evaluation. Intraoperative complications occurred in 4.9% of the cases. The clinicopathological outcome reported 100% for complete or nearly complete specimen, 100% negative distal resection margin, and the circumferential resection margin was positive in 5.0% of patients. Overall postoperative complication rate was 45.0%, with 19.2% Clavien–Dindo ≥ III and an anastomotic leak rate of 17.3%.ConclusionsThis study shows that the nationwide structured training program for TaTME delivers safe implementation of TaTME in terms of intraoperative and pathology outcomes within the first ten consecutive cases in each center. However, postoperative morbidity is substantial even within a structured training pathway and surgeons should be aware of the learning curve of this new technique.

Urethral injury in body donor TaTME training

Urethral injury is one of the major risks in transanal total mesorectal excision (TaTME). To provide surgeons with experience in and management of potential critical surgical scenarios, urethral and prostate injuries were intentionally created during a body donor workshop under standardized training conditions. We conducted a 2-day structured TaTME body donor training workshop. The theoretical module included lectures on topographic anatomy, clinical evidence, and surgical technique and pitfalls. Practical modules started with an interactive demonstration of crucial landmarks for the transanal approach using predissected formalin-fixed specimens. Next, surgical teams underwent proctored surgical training that implemented the key steps of TaTME on simulators and four male body donors. Strategies to avoid urethral damage involved intentional dissection and injury of the urethra and prostate, with subsequent demonstration of these lesions. After emphasizing the critical anatomical landmarks, the proctored surgical teams performed TaTME successfully without any urethral lesions. To demonstrate worst-case scenarios, two major pitfalls associated with TaTME, i.e., urethral injury and mobilization of the prostate, were simulated. These deliberate injuries proved to be critical learning experiences for all participants. Appraisal of crucial anatomical landmarks and deliberate implementation of urethral/prostatic injury scenarios in preclinical TaTME training workshops is an effective way to teach surgeons how to avoid those injuries in patients. Structured and supervised training should be offered to all surgeons prior to implementing TaTME procedures in order to acquire skills necessary to address the delicate structures at risk during transanal approach.