Incomplete Total Mesorectal Excision Research Articles

Fluorescence guidance using near-infrared fluorescent clips in robotic rectal surgery: a case series

PurposeTattoo markings are often used as preoperative markers for colorectal cancer. However, scattered ink markings adversely affect tumor site recognition intraoperatively; therefore, interventions for rectal cancer may lead to an inaccurate distal resection margin (DRM) and incomplete total mesorectal excision (TME). This is the first case series of fluorescence-guided robotic rectal surgery in which near-infrared fluorescence clips (NIRFCs) were used to localize rectal cancer lesions.MethodsWe enrolled 20 consecutive patients who underwent robotic surgery for rectal cancer between December 2022 and December 2023 in the current study. The primary endpoints were the rate of intraoperative clip detection and its usefulness for marking the tumor site. Secondary endpoints were oncological assessments, including DRM and the number of lymph nodes.ResultsClip locations were confirmed in 17 of 20 (85%) patients. NIRFCs were not detected in 3 out of 7 patients who underwent preoperative chemoradiation therapy. No adverse events, including bleeding or perforation, were observed at the time of clipping, and no clips were lost. The median DRM was 55 mm (range, 22–86 mm) for rectosigmoid (Rs), 33 mm (range, 16–60 mm) for upper rectum (Ra), and 20 mm (range, 17–30 mm) for low rectum (Rb). The median number of lymph nodes was 13 (range, 10–21).ConclusionThe rate of intraoperative clip detection, oncological assessment, including DRM, and the number of lymph nodes indicate that the utility of fluorescence-guided methods with NIRFCs is feasible for rectal cancer.

Using CT-Based Pelvimetry and Visceral Obesity Measurements to Predict Total Mesorectal Excision Quality for Patients Undergoing Rectal Cancer Surgery.

A complete total mesorectal excision is the criterion standard in curative rectal cancer surgery. Ensuring quality is challenging in a narrow pelvis, and obesity amplifies technical difficulties. Pelvimetry is the measurement of pelvic dimensions, but its role in gauging preoperatively the difficulty of proctectomy is largely unexplored. To determine pelvic structural factors associated with incomplete total mesorectal excision after curative proctectomy and build a predictive model for total mesorectal excision quality. Retrospective cohort study. A quaternary referral center database of patients diagnosed with rectal adenocarcinoma (2009-2017). Curative-intent proctectomy for rectal adenocarcinoma. All radiological measurements were obtained from preoperative CT images using validated imaging processing software tools. Completeness of total mesorectal excision was obtained from histology reports. Ability of radiological pelvimetry and obesity measurements to predict total mesorectal excision quality. Of the 410 cases meeting inclusion criteria, 362 underwent a complete total mesorectal excision (88%). Multivariable regression identified a deeper sacral curve (per 100 mm 2 [OR: 1.14; 95% CI, 1.06-1.23; p < 0.001]) and a greater transverse distance of the pelvic outlet (per 10 mm [OR:1.41, 95% CI, 1.08-1.84; p = 0.012]) to be independently associated with incomplete total mesorectal excision. An increased area of the pelvic inlet (per 10 cm 2 [OR: 0.85; 95% CI, 0.75-0.97; p = 0.02) was associated with a higher rate of complete mesorectal excision. No difference in visceral obesity ratio and visceral obesity (ratio >0.4 vs <0.4) between BMI (<30 vs ≥30) and sex was identified. A model was built to predict mesorectal quality using the following variables: depth of sacral curve, area of pelvic inlet, and transverse distance of the pelvic outlet. Retrospective analysis is not controlled for the choice of surgical approach. Pelvimetry predicts total mesorectal excision quality in rectal cancer surgery and can alert surgeons preoperatively to cases of unusual difficulty. This predictive model may contribute to treatment strategy and aid in the comparison of outcomes between traditional and novel techniques of total mesorectal excision. See Video Abstract . ANTECEDENTES:Una escisión mesorrectal total y completa es el estándar de oro en la cirugía curativa del cáncer de recto. Garantizar la calidad es un desafío en una pelvis estrecha y la obesidad amplifica las dificultades técnicas. La pelvimetría es la medición de las dimensiones pélvicas, pero su papel para medir la dificultad preoperatoria de la proctectomía está en gran medida inexplorado.OBJETIVO:Determinar los factores estructurales pélvicos asociados con la escisión mesorrectal total incompleta después de una proctectomía curativa y construir un modelo predictivo para la calidad de la escisión mesorrectal total.DISEÑO:Estudio de cohorte retrospectivo.ÁMBITO:Base de datos de un centro de referencia cuaternario de pacientes diagnosticados con adenocarcinoma de recto (2009-2017).PACIENTES:Proctectomía con intención curativa para adenocarcinoma de recto.INTERVENCIONES:Todas las mediciones radiológicas se obtuvieron a partir de imágenes de TC preoperatorias utilizando herramientas de software de procesamiento de imágenes validadas. La integridad de la escisión mesorrectal total se obtuvo a partir de informes histológicos.PRINCIPALES MEDIDAS DE VALORACIÓN:Capacidad de la pelvimetría radiológica y las mediciones de obesidad para predecir la calidad total de la escisión mesorrectal.RESULTADOS:De los 410 casos que cumplieron los criterios de inclusión, 362 tuvieron una escisión mesorrectal total completa (88%). Una regresión multivariable identificó una curva sacra más profunda (por 100 mm2); OR:1,14,[IC95%:1,06-1,23,p<0,001], y mayor distancia transversal de salida pélvica (por 10mm); OR:1,41, [IC 95%:1,08-1,84,p=0,012] como asociación independiente con escisión mesorrectal total incompleta. Un área aumentada de entrada pélvica (por 10 cm2); OR:0,85, [IC95%:0,75-0,97,p=0,02] se asoció con una mayor tasa de escisión mesorrectal completa. No se identificaron diferencias en la proporción de obesidad visceral y la obesidad visceral (proporción>0,4 vs.<0,4) entre el índice de masa corporal (<30 vs.>=30) o el sexo. Se construyó un modelo para predecir la calidad mesorrectal utilizando variables: profundidad de la curva sacra, área de la entrada pélvica y distancia transversal de la salida pélvica.LIMITACIONES:Análisis retrospectivo no controlado por la elección del abordaje quirúrgico.CONCLUSIONES:La pelvimetría predice la calidad de la escisión mesorrectal total en la cirugía del cáncer de recto y puede alertar a los cirujanos preoperatoriamente sobre casos de dificultad inusual. Este modelo predictivo puede contribuir a la estrategia de tratamiento y ayudar en la comparación de resultados entre técnicas tradicionales y novedosas de escisión mesorrectal total. (Traducción- Dr. Ingrid Melo).

Is non-mentored initiation of laparoscopic colorectal surgery safe? Single surgeon initial experience with the first 40 cases.

Although laparoscopic colorectal surgery is now accepted as a standard procedure in treating colorectal cancer, the proportion of laparoscopically operated patients with colorectal cancer is still generally quite low. The aim of this study is to assess feasibility, safety, and outcomes of a non-mentored initiation of laparoscopic colorectal resections by a young surgeon without previous experience in laparoscopic colorectal surgery. We analyzed the characteristics of the first 40 elective cases of laparoscopic colorectal resections performed by a single surgeon during the period between June 2019 and March 2022. All of the operations were performed without the attendance or supervision of an experienced surgeon in laparoscopic colorectal surgery. The patients were divided into three groups (the early, intermediate, and late group). The conversion rate, complications rate, and postoperative recovery were similar among groups. The mean overall operative time was 219.5 min (range 130-420 min) and had reduced significantly during the learning curve (p = 0.047). The overall conversion rate was 12.5%. In two cases (5%), the oncological principles were violated (incomplete total mesorectal excision). In three patients (7.5%), intraoperative complications had occurred (small bowel injury, splenic injury, and significant bleeding from the minor peripancreatic artery). Three cases of major postoperative complications (Clavien-Dindo grade III) were recorded, two of which required reoperation (anastomotic bleeding and fascial dehiscence). There was no 90-day mortality reported. The overall mean number of lymph nodes retrieved was 12.45, which did not differ significantly among groups (p = 0.678). The average follow-up was 13.75 months (range 1-31 months). Cancer recurrence was recorded in four patients (10%). Port-site metastasis was not detected in any of the cases. A safe and non-mentored initiation of laparoscopic colorectal surgery with an acceptable rate of complications and acceptable oncological results can be achieved. Still, when compared with a structured initiation in a controlled environment with the supervision of an experienced surgeon in laparoscopic colorectal surgery, the results of a non-mentored initiation are worse in most of the fields, including operative time, conversion rate, complications rate, and duration of hospital stay. Therefore, I strongly recommend engaging young surgeons in fellowship programs on structured laparoscopic colorectal surgery whenever possible before starting performing these procedures on their own.

Discordance in TME Specimen Grading in a Prospective Phase II Multicenter Rectal Cancer Trial: Are We Overestimating the Quality of our Resections ?

To report the results of a rigorous quality control (QC) process in the grading of total mesorectal excision (TME) specimens during a multicenter prospective phase II trial of transanal TME. Grading of TME specimens is based on macroscopic assessment of the mesorectum and standardized through synoptic pathology reporting. TME grade is a strong predictor of outcomes with incomplete (IC) TME associated with increased rates of local recurrence relative to complete or near complete (C/NC) TME. Although TME grade serves as an endpoint in most rectal cancer trials, in protocols incorporating centralized review of TME specimens for quality assurance, discordance in grading and the management thereof has not been previously described. A phase II prospective taTME trial was conducted from 2017-2022 across 11 North American centers with TME quality as primary study endpoint. QC measures included training of site pathologists in TME protocols, (2) blinded grading of de-identified TME specimen photographs by central pathologists, and (3) reconciliation of major discordance prior to trial reporting. Cohen's Kappa statistic was used to assess agreement in grading. Overall agreement in grading of 100 TME specimens between site and central reviewer was rated as fair, (κ=0.35 (95% CI, 0.10-0.61, P<0.0001). Concordance was noted in 54%, with minor and major discordance in 32% and 14% of cases respectively. Upon reconciliation, 13/14 (93%) major discordances were resolved. Pre- versus post-reconciliation rates of C/NC and IC TME are 77%/16% and 7% versus 69%/21% and 10%. Reconciliation resulted in a major upgrade (IC to NC, N=1) or major downgrade (NC/C to IC, N=4) in 5 cases overall (5%). A 14% rate of major discordance was observed in TME grading between site and central reviewers. Resolution resulted in a major change in final TME grade in 5% of cases, which suggests that reported rates or TME completeness are likely overestimated in trials. QC through central review of TME photographs and reconciliation of major discordances is strongly recommended.

Incidence and Risk Factors of Surgical Complications and Anastomotic Leakage After Transanal Total Mesorectal Excision for Middle and Low Rectal Cancer

PurposeTransanal total mesorectal excision (taTME) is a promising surgical procedure for middle and low rectal cancer; however, it is linked to significant morbidity. This study aimed to determine the incidence of postoperative surgical complications and anastomotic leakage following taTME and to identify their associated risk factors. MethodsThe prospective clinical data of 114 patients, who underwent taTME and primary anastomosis for mid-low rectal cancer between November 2016 and June 2022, were retrospectively analyzed. Univariate and multivariate analyses were performed to identify clinical characteristics and risk factors for predicting surgical complications and anastomotic leakage. ResultsSurgical complications occurred in 40 (35.1%) patients within the first 30 days following surgery. Based on the Clavien–Dindo classification, minor complications (Clavien–Dindo grades I + II) accounted for 30.7%, while major complications (Clavien–Dindo grades III + IV) accounted for only 4.4%. None of the patients died within 30 days. The incidence of anastomotic leakage was 15.8%: 4.4% as grade A (5 cases), 9.6% as grade B (11 cases), and 1.8% as grade C (2 cases). Preoperative T3-4 was identified as an independent risk factor for surgical complications (p = 0.031) by multivariate analysis. American Society of Anesthesiology score ≥ 3 (P = 0.021) and incomplete total mesorectal excision specimens (P = 0.030) were significantly associated with the risk of anastomotic leakage. ConclusionsIn this study, the incidence of surgical complications and anastomotic leakage in taTME aligned with previously reported rates. Preoperative T3-4 was significantly associated with surgical complications. American Society of Anesthesiology score ≥ 3 and incomplete TME specimens independently increased the risk of anastomotic leakage.

Involvement of tissue changes induced by neoadjuvant treatment in total mesorectal excision (TME): novel suggestions for determining TME quality.

Few studies to date have investigated morphological changes after neoadjuvant treatment (NAT) and their implications in total mesorectal excision (TME). This study was primarily designed to evaluate whether tissue changes associated with NAT affected the quality of TME and additionally to suggest a more objective method evaluating TME quality. This study enrolled 1322 consecutive patients who underwent curative robot-assisted surgery for rectal cancer. Patients who did and did not receive NAT were subjected to propensity-score matching, yielding 402 patients in each group. NAT independently reduced complete achievement of TME [odds ratio (OR) = 2.056, p = 0.017]. Intraoperative evaluation identified seven tissue changes significantly associated with NAT, including tumor perforation, mucin pool, necrosis, fibrosis, fat degeneration, and rectal or perirectal edema NAT (p < 0.001-0.05). Tumor perforation (OR = 5.299, p = 0.001) and mucin pool (OR = 14.053, p = 0.002) were independently associated with inappropriate (near-complete + incomplete) TME. Complete TME resulted in significantly reduced local recurrence (4.3% vs 15.3%, p = 0.003) and increased 5-year DFS rate (80.6% vs 67.6%, p = 0.047) compared with inappropriate one. By contrast, two tiers of complete and near-complete TMEs vs incomplete TME did not. Notably, among patients with complete TME, those who received NAT had a lower 5-year DFS than those who did not (77.8% vs 83.3%, p = 0.048). NAT-associated tissue changes, somewhat interrupting complete TME, may provide unsolved clue to the relative inability of NAT to improve overall survival. The conventional three-tier grading of TME seems to be simplified into two tiers as complete and inappropriate.

Initial experience of Chinese surgical robot “Micro Hand S″-assisted versus open and laparoscopic total mesorectal excision for rectal cancer: Short-term outcomes in a single center

BackgroundA Chinese surgical robot, Micro Hand S, was introduced for clinical use as a novel robotic platform. This study aimed to comprehensively compare the early experience of the Micro Hand S robot-assisted total mesorectal excision (TME) with conventional approaches. MethodsBetween May 2017 and April 2018, 99 consecutive patients who underwent open, laparoscopic and Micro Hand S robot-assisted TME (O-/L-/RTME) for rectal cancer were included. Clinical and pathological outcomes were retrospectively analyzed. Surgical success as the primary endpoint was defined as the absence of (i) conversion, (ii) incomplete TME, (iii) involved circumferential and distal resection margins (CRM/DRM), (iv) severe complications. ResultsThe rate of surgical success was similar (89.7 vs. 86.4 vs. 84.6%, p = 0.851) in the three groups and the respective incidences were as follows: conversion (not applicable, 4.5 vs. 2.3%, p = 1.000), incomplete TME (6.9 vs. 6.8 vs. 3.8%, p = 0.980), involved CRM/DRM (0 vs. 2.3 vs. 3.8%, p = 0.592), severe complications (3.4 vs. 4.5 vs. 7.7%, p = 0.844). Compared with open and laparoscopic surgery, the robotic surgery was associated with longer operative time, less blood loss, earlier first flatus time and liquid intake time, and shorter length of hospital stay (p < 0.05). ConclusionsThe Micro Hand S assisted TME is safe and feasible, showing comparable outcomes than conventional approaches, with superiority in blood loss, recovery of bowel function, length of hospital stay, but with increased operative time.

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

BackgroundTransanal 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.MethodsTaTME 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.ResultsPropensity 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.ConclusionTaTME provided similar outcomes to cTME for rectal cancer with the application of IDEAL principles.

Re-evaluation of possible vulnerable sites in the lateral pelvic cavity to local recurrence during robot-assisted total mesorectal excision.

Despite mechanical and technical improvements in laparoscopic and robot-assisted (LAR) rectal cancer procedures, the absence of prognostic disparities among various approaches cannot improve the quality of TME. The present study re-evaluated robot-assisted total mesorectal excision (TME) procedures to determine whether these procedures may reveal technical faults that may increase the rate of local recurrence (LR). This study enrolled 886 consecutive patients with rectal cancer, who underwent curative robot-assisted LAR at Asan Medical Center (Seoul, Korea) between July 2010 and August 2017 (the first vs second period; n = 399 vs 487). The quality of TME and lateral pelvic mesorectal excision (LPME) were analyzed, as were LR rates and survival outcomes. Complete TME and LPME were achieved in 89.2% and 80.1% of these patients, respectively, with ≤ 1% having incomplete TME excluding intramesorectal excision. LR rates were 13.5 and 14.5 times higher in patients with incomplete TME and LPME, respectively, than in patients with complete TME and LPME (14.8% vs 1.1% and 8.7% vs 0.6%; p < 0.001 each by univariate analyses). Multivariate analyses showed that defective LPME was independently associated with incomplete TME and vice versa (p < 0.001). Cox regression analysis showed that defective LPME was independently correlated with reduced 5-year disease-free survival rate (hazard ratio, 1.563; 95% confidence interval, 1.052-2.323; p = 0.027). LR in rectal cancer patients was largely due to incomplete LPME, which was significantly associated with incomplete TME. Complete LPME may enhance the likelihood of complete TME, reducing LR rates.

The role of MRI pelvimetry in predicting technical difficulty and outcomes of open and minimally invasive total mesorectal excision: a systematic review.

The difficulty of performing total mesorectal excision (TME) for rectal cancer partly relies on the surgeon's subjective assessment of the individual patient's pelvic anatomy and tumour characteristics, which generally influences the choice of platform used (open, laparoscopic, robotic or trans-anal surgery). Recent studies have found associations between several anatomical pelvic measurements and surgical difficulty. The aim of this study was to systematically review existing data reporting the use of magnetic resonance imaging (MRI)-based pelvic measurements to predict technical difficulty and outcomes of TME, and determine whether pelvimetry could optimise patient-specific selection of a particular surgical approach. MEDLINE, Embase and Cochrane Library databases were systematically searched for studies reporting MRI-based pelvic measurements in patients undergoing surgery for rectal cancer, and the effect of these measurements on surgical difficulty. Eleven studies reporting the association between MRI-pelvimetry measurements and rectal cancer surgical outcomes were included. Indicators for surgical difficulty used in the included studies were involved circumferential resection margin, longer operative time, incomplete TME, higher blood loss, anastomotic leak, conversion to open surgery and overall complications. Bony pelvic measurements which were associated with increased surgical difficulty in more than one study were a smaller interspinous distance, a smaller intertubercle distance, a smaller pelvic inlet and larger pubic tubercle height. Two studies identified larger mesorectal fat area as a predictor of surgical difficulty. Bony pelvic measurements may predict surgical difficulty during TME, however, use of different indicators of difficulty limit comparison between studies. Early data suggest MRI soft tissue measurements may predict surgical difficulty and warrants further investigation.

Reconsideration of the Safety of Laparoscopic Rectal Surgery for Cancer.

The oncological outcomes of laparoscopic rectal cancer surgery were evaluated in recent multicenter randomized clinical trials (RCTs). The MRC-CLASSIC, COLOR II, and COREAN trials found no differences in local recurrence or diseasefree survival rate between laparoscopic and open surgery. However, the noninferiority of laparoscopic surgery with respect to open surgery for rectal cancer was not established on statistical analysis in the ACOSOG Z6051 and the ALaCaRT trials. Quality of total mesorectal excision (TME) is one of the most important prognostic factors. Incomplete TME had unfavorable oncologic outcomes compared to complete TME. Although TME quality can be clearly identified on pathologic evaluation, there is controversy regarding the acceptable range of oncologically safe TME for laparoscopic surgery. It is not certain whether near-complete TME has an unfavorable oncologic impact and whether laparoscopic surgery with near-complete TME is an oncological threat. Therefore, the surgical community will be interested in the long-term outcomes and meta-analyses of ongoing large-scale RCTs. Laparoscopic rectal cancer surgery has been steadily improving its safety for oncology surgery, which has been reported consistently in various multicenter RCTs. To improve surgical quality, colorectal surgeons should choose the most appropriate surgical technique, including laparoscopic surgery.

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

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. 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. There were 92 patients included in this study, of which 70% were male, the mean BMI was 26.0kg/m2, and the mean tumor height was 6.6cm. 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. 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.

Total mesorectal excision for rectal cancer patients: a comparative triple arm study of surgical results in open vs laparoscopic vs robotic-assisted surgery

Introduction: The curative intent surgery for rectal cancer is centered around the removal of the tumour-bearing segment with adequately clear margins and en bloc excision of the mesentery containing blood vessels and regional lymphatics. This was traditionally achieved by open surgery which later on was transformed by the introduction of minimally invasive surgery in the form of laparoscopic or the robotic approaches. In this study we aimed to analyse the surgical results in terms of completion of total mesorectal excision (TME), short-term surgical outcomes and hospital stay in open, laparoscopic and robotic-assisted rectal resections. Methods: A retrospective review of a prospectively maintained database of patients operated for carcinoma rectum between January 2013 to August 2018 was included in the study. Data of patients with local invasion (T2-3), with or without node involvement (N0-1), without metastases (M0), who underwent neo-adjuvant chemo/chemo-radiotherapy were included in the study. The neoadjuvant protocol included 50.4Gy-dose EBRT given in 28 fractions over 5.5 weeks, along with systemic 5-fluorouracil-based chemotherapy, followed by surgery 6–8 weeks later. The surgical parameters like completion of total TME, proximal, distal and circumferential resection margins, number of nodes retrieved, and total postoperative hospital stay were analysed in the open, laparoscopic-assisted and robotic-assisted groups. Results: A total of 100 patients were included in the study consisting of 25, 25 and 50 patients each in the open, laparoscopic, and robotic arms, respectively. The conversion rate was 8% (2 of 25) in the laparoscopic-assisted group and 2% (1/50) in the robotic-assisted group. The average postoperative hospital stay was 7.4, 7.36, and 6 days in the open, laparoscopic, and robotic-assisted groups (P = .01). The total number of lymph nodes harvested, circumferential resection margins obtained, and the postoperative hospital stay is summarized in Table 1. When the intactness of TME as reported on the final histopathology was compared, it was seen that there were two patients in the open arm and one patient each in the laparoscopic and robotic arms who had an incomplete TME, but this difference was not statistically significant (P = .45). The proximal and distal margins were negative in all 100 patients. On analysis of the subgroup of patients with low rectal tumours who underwent LAR(n = 28), the mean distal resection margins were 3.14 + 1.5, 4 + 2.8 and 4.7 + 0.8 in the open, laparoscopic, and robotic arms, respectively(P = .21). The CRM obtained in the robotic arm patients was higher than that of the other two groups (P= .005). The mesorectum was reported to be intact in 98% of patients in the robotic arm compared with 96% in laparoscopic and 92% in the open group (P = .38). Conclusion: Robotic rectal resections are associated with better surgical results in the form of improved circumferential resection margins, completeness of TME, and lower conversion rates.

Completeness of total mesorectum excision of laparoscopic versus robotic surgery: a review with a meta-analysis.

TME has revolutionized the surgical management of rectal cancer, and since the introduction of robotic TME (RTME), many reports have shown the feasibility and the safety of this approach. However, concerns persist regarding the advantages of robotic in surgery for the completeness of TME. The aim of this review is to compare robotic versus laparoscopic total mesorectal excision (TME) in rectal cancer, focusing on the completeness of TME. A systematic search was performed in the electronic databases for all available studies comparing RTME versus conventional laparoscopic LTME with declared grade of mesorectum excision. Data regarding sample size, clinical and demographic characteristics, number of complete, nearly complete, and incomplete TME were extracted. Primary outcome was the number of complete TME in robotic and laparoscopic procedures. Secondary outcomes were the numbers of nearly complete and incomplete TME in robotic and laparoscopic rectal resections. Twelve articles were included in the final analysis. Complete TME was reported by all authors, involving 1510 procedures, showing a significant difference in favor of robotic surgery (OR = 1.83, 95% CI 1.08-3.10, p = 0.03). Nearly complete and incomplete TME showed no significant difference between the procedures. Meta-regression analysis showed that none of patients' and tumors' characteristics significantly impacted on complete TME. Our results underline that the robotic approach to rectal resection is the better way to obtain a complete TME. However, it is mandatory that randomized clinical trials should be performed to assess definitively if robotic minimally invasive surgery is better than a laparoscopic resection.

Transanal total mesorectal excision-a critical appraisal

Total mesorectal excision (TME) is the international standard for rectal cancer surgery. In addition to laparoscopic TME (lapTME), transanal TME (taTME) was developed in recent years to reduce the rate of incomplete TME, conversion to open surgery and postoperative functional impairment. Despite limited evidence, this technique is becoming increasingly more popular and is already routinely used by many hospitals for rectal cancer in varying tumor level locations. The aim of this review was to evaluate the taTME compared to anterior rectal resection with lapTME as thestandardofcareinrectal cancer surgery based on currently available evidence. The databases PubMed and Medline were systematically searched for publications on transanal total mesorectal excision (taTME) and transanal minimally invasive surgery (TAMIS). Relevant studies were selected and further research based on the reference lists was undertaken. Atotal of 16studies analyzing 3782 patients were identified. The taTME does not lead to ahigher rate of complete TME-resected specimens compared to the standard procedure. So far, superiority could not be demonstrated for complication rates or for functional or oncological results. Serious complications secondary to dissection in incorrect planes were observed. The anastomotic level generally seems to be closer to the sphincter after taTME versus anterior lapTME. Considering current evidence, taTME failed to show superiority compared to conventional anterior lapTME. Although taTME has some potential advantages, it carries substantial risks. If performed outside of clinical trials, it should therefore only be used in carefully selected patients with ahigh possibility of conversion, following adequate patient informed consent and after intense and systematic training of the surgeon.

Oncological Outcomes After Robotic Proctectomy for Rectal Cancer: Analysis of a Prospective Database.

The aim of this study is to evaluate the oncological outcomes of robotic total mesorectal excision (TME) at an NCI designated cancer center. The effectiveness of laparoscopic TME could not be established, but the robotic-assisted approach may hold some promise, with improved visualization and ergonomics for pelvic dissection. Oncological outcome data is presently lacking. Patients who underwent total mesorectal excision or tumor-specific mesorectal excision for rectal cancer between April 2009 and April 2016 via a robotic approach were identified from a prospective single-institution database. The circumferential resection margin (CRM), distal resection margin, and TME completeness rates were determined. Kaplan-Meier analysis of disease-free survival and overall survival was performed for all patients treated with curative intent. A total of 276 patients underwent robotic proctectomy during the study period. Robotic surgery was performed initially by 1 surgeon with 3 additional surgeons progressively transitioning from open to robotic during the study period with annual increase in the total number of cases performed robotically. Seven patients had involved circumferential resection margins (2.5%), and there were no positive distal or proximal resection margins. One hundred eighty-six patients had TME quality assessed, and only 1 patient (0.5%) had an incomplete TME. Eighty-three patients were followed up for a minimum of 3 years, with a local recurrence rate of 2.4%, and a distant recurrence rate of 16.9%. Five-year disease-free survival on Kaplan-Meier analysis was 82%, and 5-year overall survival was 87%. Robotic proctectomy for rectal cancer can be performed with good short and medium term oncological outcomes in selected patients.

Laparoscopic versus Open Total Mesorectal Excision for Resectable Rectal Cancer: An Updated Meta-analysis of Randomized Controlled Trials

Aim: This meta-analysis was conducted to evaluate the safety and efficacy of laparoscopic (LPS) versus open surgery for resectable rectal cancer. Methods: We analyzed and compared oncological outcomes, safety outcomes, and recovery outcomes between LPS surgery and open surgery. Meta-analyses were conducted using RevMan 5.3 software. Dichotomous variables were analyzed by risk ratio with 95% confidence intervals, and continuous variables were analyzed as mean differences. Results: A total of 16 randomized controlled trials were identified involving 5386 patients. Based on the currently limited evidence, LPS surgery showed similar oncological outcomes to open surgery in terms of lymph nodes retrieved, positive circumferential resection, incomplete total mesorectal excision, local recurrence, distant metastasis, and unsuccessful resection. LPS surgery was associated with better recovery than open surgery in terms of earlier first bowel movement, earlier start of fluid intake, and shorter hospital stay. However, there was no significant difference in perioperative mortality, re-operation, chest infection, anastomotic leakage, urinary injury, or incision hernia between the LPS and open surgery groups. Importantly, LPS surgery was associated with less intraoperative bleeding, wound infection, and bowel obstruction. Conclusion: Though the overall quality of LPS seems higher than that of open surgery, there is still insufficient evidence to recommend its routine application. However, its similar oncological outcomes, better recovery, and fewer complications suggests that LPS TME may represent a good option for experienced centers or surgeons.

Oncologic Outcomes of Extended Robotic Resection for Rectal Cancer.

Surgery for locally advanced rectal cancers beyond the plane of total mesorectal excision (TME) or extramesorectal nodal involvement should include complete resection. This study evaluated the oncologic feasibility and safety of robot-assisted surgery for rectal cancer beyond the TME plane. The study analyzed the operative, perioperative, and oncologic outcomes for all patients who underwent robot-assisted extended rectal cancer surgery from April 2009 to February 2015. Of 36 patients, 22 underwent multivisceral en bloc resection, and 18 underwent extramesorectal lymph node (EMRLN) dissection. The median tumor location was 5cm [interquartile range (IQR), 2.2-9.0cm] from the anal verge. A total of 32 patients underwent neoadjuvant chemoradiation therapy. The median body mass index of the patients was 26.8kg/m(2) (IQR, 24.0-31.9kg/m(2)). Conversion was required for one patient because of inability to tolerate the Trendelenburg position. All the resections were R0, and there were no incomplete TMEs. The vagina and prostate or periprostatic structures were the most commonly resected (n=13/22), and the lateral pelvic nodes were the most common EMRLNs (n=16/18). The median numbers of examined mesorectal lymph nodes and EMRLNs were respectively 20 (IQR, 18.0-28.0) and 2.5 (IQR, 1.0-6.0). The median hospital stay was 4days (IQR, 3.0-5.5days). Six patients experienced Clavien-Dindo grade 3 complications, the most common of which was deep abscess (n=5, 13.8%). The 5-year actuarial local recurrence rate was 3.6%. Minimally invasive resection for rectal cancer can be performed with extended lymph node dissection or en bloc multivisceral resection using the surgical robot in selected patients. This technique is feasible and has acceptable morbidity.

Transanal total mesorectal excision in rectal cancer: why, how and when

Down-to-up total mesorectal excision (TME) or transanal TME (taTME) has gained worldwide popularity. taTME is one of the most promising innovations of the last years in the field of gastrointestinal surgery. Due to the better view of the dissection planes even in difficult patients (i.e., narrow pelvis or low rectal cancer), taTME seems to achieve both better TME quality reducing the rate of incomplete TME and lower rates of positive circumferential resection margins. taTME has overall morbidity and anastomotic leak rates comparable with the up-to-down TME. Mid-term results of taTME seems to be comparable with those of the up-to-down approach but definitive conclusions cannot be drawn since the short follow-up and small cohort of patients of the present studies.

62. The virtual surgical pelvis: A highly-detailed 3D pelvic model for anatomical education and surgical simulation

Background: The surgical anatomy of the pelvis is highly complex. In case of rectal cancer the surgeon is challenged to perform a total mesorectal excision (TME) warranting complete removal of the tumor and preservation of the autonomic nerves. However, incomplete TME specimens and surgical damage to the nerves are still part of clinical reality. A highly-detailed 3D pelvic model would be an excellent tool to increase anatomical knowledge of the surgical anatomy of the pelvis. Visible Human Datasets (VHDs) are often used to create a 3D model, but they lack anatomical detail such as autonomic nerves and fasciae. Immunohistochemistry is an ideal method to study those key surgical structures at microscopic level. Recently, the Unified Anatomical Human (UAH) has been developed. UAH integrates heterogeneous anatomical data and will allow registration of patient-specific diagnostic images. In this study, we describe the development of The Virtual Surgical Pelvis (VSP) and its potential clinical value in anatomical education and surgical simulation. Material and methods: We selected 910 slices from a VHD that comprised the entire pelvis. All surgically relevant anatomical structures were manually segmented using Amira� software and three-dimensionally reconstructed using the UAH. The Online Anatomical Human (OAH), an online web-viewer, was developed as well. Paraffin embedded mega blocks of 1 female cadaveric pelvic exenteration specimen were sliced in transverse sections of 5 �m. A series was stained with Hematoxylin & Eosin and Masson�s Trichome and selected sections were immunohistochemically stained with S100, a pan-neuron marker. The autonomic nerves and fasciae were manually segmented in Amira� software, three-dimensionally reconstructed and integrated using the UAH. Results: Currently, the VSP presents most of the essential surgical anatomy of the pelvis, including the levator ani muscle and pudendal nerve, and can be interactively visualized in the UAH and OAH. Microscopic analysis of the female cadaveric specimen reveals the organization of autonomic nerves and fasciae in relation to pelvic organs. Conclusion: The VSP showing the complex pelvic anatomy is a potentially excellent tool for anatomical education. Registration of the VSP to patient-specific diagnostic images allows visualization of key surgical structures such as autonomic nerves and fasciae in relation to pelvic viscera. This makes surgical simulation a nearby future goal for all pelvic surgeons.