ASO Visual Abstract: Volume-Outcome Relationships in Total Mesorectal Excision Quality and Grading: A National Cancer Database Study.

Total mesorectal excision (TME) is the surgical standard for mid-to-low rectal cancer, and the Commission on Cancer Standard 5.7 requires documentation of TME grade. The aim of our study was to describe national variation in TME grading and quality. This was a multicenter retrospective cohort of 5033 patients within the National Cancer Database who underwent TME for rectal adenocarcinoma in 2022, the first year TME quality is available. The exploratory outcomes were TME reporting and completeness by institution volume, assessed by quartiles and by the Leapfrog Group's standard of 16 proctectomies/year, and the associations of TME grades with surgical approach, lymph node yield, and surgical margins. There were significant differences in likelihood of TME reporting (p < 0.001) and in TME grades (p < 0.001) by facility volume quartile. Meeting the Leapfrog minimum of 16 annual proctectomies was associated with a higher likelihood of reporting TME grade (p = 0.02) but not with more complete TME grades (p = 0.68). Robotic-assisted approaches had the highest rate of complete TME among surgical approaches (p < 0.001) and lower rates of conversion to open than did laparoscopic approaches (4.6% vs 14.6%, p < 0.001). Complete TME was more likely to have at least 12 lymph nodes (p = 0.001), no residual tumor (p < 0.001), and negative circumferential resection margins (p < 0.001) than nearly complete and incomplete TME. High-volume institutions were more likely to report TME grades and achieve complete TME, which was associated with higher rates of adequate lymph node yield and negative margins. Robotic-assisted approaches were associated with the highest rates of complete TME grades.

High-level evidence on the long-term efficacy of postoperative TME quality in patients with low rectal cancer is lacking. The LASRE trial was used as background data to further explore the impact of TME quality on overall survival. We carried out a secondary analysis of the LASRE trial, which prospectively enrolled patients less than 5 cm from the dentate line from 22 hospitals in China who had undergone total mesorectal resection. TME quality was classified into 3 grades: grade A (complete), grade B (nearly complete), and grade C (incomplete), which were independently judged by the pathologist and surgeon, respectively, and if the results were inconsistent, then a third party finalized the grading based on photos of the specimen. 921 patients were included in the analysis, 787 (85.5%) in grade A, 108 (11.7%) in grade B, and 26 (2.8%) in grade C. The median follow-up was 36.0 months, and Kaplan-Meier curves showed that 3-year OS before PSM matching was 93.2% for grade A, 84.3% for grade B, 88.5% for grade C (P=0.0038), and 85.1% for grade B/C (P=0.0011). After PSM, it was 92.5% for grade A and 86.8% for grade B/C (P=0.044). TME quality was an independent influence on overall survival before PSM matching (HR=1.691, 95% CI: 1.133~2.522, p=0.010), and after PSM matching, TME quality remained an independent factor for OS (HR=1.881, 95% CI: 1.035~3.416, p=0.038). Excellent TME quality after surgery for low rectal cancer contributes to an improved prognosis and is an independent factor influencing long-term outcome.

Time to Surgery after Neoadjuvant Chemoradiation for Rectal Carcinoma is an Independent Predictor of Total Mesorectal Excision Quality

Total mesorectal excision quality (TMEq) is a prognostic factor associated with local recurrence in rectal adenocarcinoma. Neoadjuvant chemoradiotherapy (NCRT) reduces the risk of tumor recurrence, but may compromise TMEq. The time between NCRT and surgery (TTS) and how it influences TMEq and tumor control were evaluated. In prospective registry, 236 patients after NCRT and TME were analyzed. NCRT involved radiotherapy with 45Gy to the pelvis, plus tumor boost dose 5.4Gy with concurrent 5-fluorouracil infusion. NCRT was followed by TME after 9weeks on average (median 9.4 ± SD 2.5). TMEq was parametrically analyzed by standard three-grade system. With median follow-up of 47.5months, 3-year overall survival (OS) was 83.8%, disease-free survival (DFS) was 77.7%, and 6.4% was the rate of local recurrence (LR). TTS was not associated with OS, DFS, or LR. TMEq was found to be associated with LR in univariate analysis, but not in multivariate, where pathological tumor stage and resection margins remained dominant predictors. TMEq was negatively influenced by inferior location of the tumor, longer TTS, higher tumor and nodal stage, presence of tumor perforation, perineural invasion, and close/positive resection margins. Nonetheless, TTS remained a strong predictor of TMEq in multivariate analyses. TTS was proven to be an independent predictor of TMEq. With longer TTS, fewer complete TME with intact mesorectal plane were observed. However, TTS was not associated with survival deterioration or tumor recurrence. These were negatively influenced by other factors interfering with TMEq, especially by pathological tumor stage and resection margins.

Achieving complete total mesorectal excision (TME) is considered an important indicator of surgical quality in rectal cancer surgery. However, the impact of TME quality on overall survival (OS) remains controversial. This study aimed to evaluate the association between TME quality and OS in patients undergoing rectal cancer surgery. A retrospective analysis was conducted on 171 patients who underwent elective low anterior resection or abdominoperineal resection for rectal cancer between 2021 and 2022. OS was compared between patients with incomplete TME and those with near-complete or complete TME. In addition, clinical and pathological factors associated with TME quality were assessed. Incomplete TME was independently associated with worse OS [hazard ratio (HR)=2.53, 95% confidence interval (CI) 1.15-5.59, p=0.021], while undergoing a Hartmann procedure showed the strongest negative impact on OS (HR=4.60, 95% CI 2.04-10.38, p<0.001). At 36 months, OS was 86.3% in the near-complete/complete TME group versus 68.3% in the incomplete group (log-rank p=0.008). Factors associated with incomplete TME included lower preoperative albumin levels, larger tumor size, previous abdominal surgery, tumors located closer to the anal verge, lymphovascular invasion, and positive circumferential resection margins. Incomplete TME was associated with significantly worse OS in patients undergoing rectal cancer surgery. These findings highlight the importance of achieving optimal TME quality. Larger prospective studies are warranted to validate these results.

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).

PurposeRobotic surgery is expected to have advantages over laparoscopic surgery; however, there are limited data regarding the feasibility of robotic surgery for rectal cancer after preoperative chemoradiotherapy (CRT). Therefore, we evaluated the short-term outcomes of robotic surgery for rectal cancer. Materials and MethodsThirty-three patients with cT3N0-2 rectal cancer after preoperative CRT who underwent robotic low anterior resection (R-LAR) between March 2010 and January 2012 were matched with 66 patients undergoing laparoscopic low anterior resection (L-LAR). Perioperative clinical outcomes and pathological data were compared between the two groups. ResultsPatient characteristics did not differ significantly different between groups. The mean operation time was 441 minutes (R-LAR) versus 277 minutes (L-LAR, p < 0.001). The open conversion rate was 6.1% in the R-LAR group and 0% in the L-LAR group (p=0.11). There were no significant differences in the time to flatus passage, length of hospital stay, and postoperative morbidity. In pathological review, the mean number of harvested lymph nodes was 22.3 in R-LAR and 21.6 in L-LAR (p=0.82). Involvement of circumferential resection margin was positive in 16.1% and 6.7%, respectively (p=0.42). Total mesorectal excision (TME) quality was complete in 97.0% in R-LAR and 91.0% in L-LAR (p=0.41).ConclusionIn our study, short-term outcomes of robotic surgery for rectal cancer after CRT were similar to those of laparoscopic surgery in respect to bowel function recovery, morbidity, and TME quality. Well-designed clinical trials are needed to evaluate the functional results and long-term outcomes of robotic surgery for rectal cancer.

Background: Surgery for rectal cancer has evolved, with the adoption of minimally invasive and robotic techniques. This study evaluates whether robotic surgery for rectal cancer produces an improvement in perioperative and oncological outcomes compared with open and laparoscopic surgery in a retrospective analysis. Methods: A single-center retrospective study included 212 patients with histologically confirmed rectal cancer treated between 2012 and 2021. The patients were grouped by surgical approach: robotic (RR, n = 62), laparoscopic (LR, n = 68), and open resection (OR, n = 82). The primary endpoints were total mesorectal excision (TME) quality, operative time, and hospital stay. The secondary endpoints included the lymph node yield, the conversion rate, and the 5-year survival outcomes (OS and DFS), analyzed via Kaplan–Meier curves and proportional hazards models. Results: The TME quality was high across the groups (RR: 91.9%, LR: 86.8%, OR: 95.1%). The median operative time was the longest in the RR group (304 min vs. 221–222 min in LR/OR). Robotic surgery resulted in shorter median hospital stays (10 (RR) vs. 14 (LR) vs. 14 (OR) days) and a lower conversion rate (3.2% vs. 14.7% in LR). The lymph node yield was highest in the LR group (27.9), followed by the RR (25.5) and OR (23.0) groups. Postoperative pneumonia was most common in the OR group (12.2%), and bladder dysfunction occurred only in the OR group (4.9%). The five-year OS and DFS did not differ notably between the groups. Conclusions: Robotic surgery offers advantages in short-term outcomes, including fewer complications, shorter hospitalization, and lower conversion rates, despite longer operative times. Its oncological efficacy is equal compared to those of laparoscopic and open surgery.

Background/Objectives: The aim of the study was to compare the perioperative and oncologic outcomes of patients who underwent surgery for colorectal cancer (CRC) performed using laparoscopy or using the Medtronic Hugo™ Robotic-Assisted Surgery (RAS) system. Methods: This is a retrospective comparative single-center study of consecutive minimally invasive surgeries for CRC performed by two colorectal surgeons with extensive laparoscopic experience at the beginning of their robotic expertise. Patients were not selected for the surgical approach, but waiting lists and operating room availability determined whether the patients were in the robotic group or the laparoscopic group. The primary outcome was to compare 30-day postoperative complications according to the Clavien-Dindo classification and the Complication Comprehensive Index (CCI). The secondary outcomes included operating times, conversion rates, intraoperative complications, length of hospital stays (LOS), readmission rates, and short-term oncologic outcomes, such as the R0 resection, the number of lymph nodes harvested, the total mesorectal excision (TME) quality, and the circumferential resection margin (CRM). Results: Of the 109 patients, 52 underwent robotic and 57 laparoscopic CRC surgery. Patient demographic and clinical characteristics were similar in the two groups. There was no significant difference between the robotic and the laparoscopic groups regarding postoperative complications, the Clavien-Dindo classification, and the CCI. They also had similar operating times, conversion rates, intraoperative complications, LOSs, readmission rates, and short-term oncologic outcomes (the lymph nodes harvested, the R0 resection, TME quality, and CRM status). Conclusions: This study reports the largest cohort of CRC surgery performed using the Medtronic Hugo™ RAS system and is the first comparative study with laparoscopy. The perioperative and oncologic outcomes were similar, demonstrating that the Medtronic Hugo™ RAS system is safe and feasible for CRC as compared to laparoscopic surgery, even at the beginning of the robotic experience.

Total mesorectal excision has become the standard treatment for rectal cancer, and several investigators have shown that a transanal approach is a feasible option. This study aimed to evaluate the efficacy of transanal endoscopic total mesorectal excision in patients with rectal cancer. This study was a prospective, single-arm phase II trial. It was registered on clinicaltrials.gov under identifier NCT02406118. Inpatients at a hospital specializing in oncology were selected. This prospective study enrolled 49 patients with rectal cancer located 3 to 12 cm from the anal verge who were scheduled to undergo radical surgery. Laparoscopy-assisted transanal total mesorectal excision was performed. The primary end point was total mesorectal excision quality and circumferential resection margin. Secondary end points included the number of harvested lymph nodes, operation time, and 30-day postoperative complications. From March 2015 to April 2016, 32 men and 17 women with rectal cancer were enrolled. The mean age was 61.2 years, and mean BMI was 23.3 kg/m. The mean operating time was 158 minutes, and the mean estimated blood loss was 89.3 mL. There were no intraoperative complications and no conversions to open surgery. Successful treatment based on total mesorectal excision quality and circumferential resection margin was achieved in 45 patients (91.8%). Fifteen patients (30.6%) had 30-day postoperative complications, including 7 (14.3%) with anastomotic dehiscence, 5 (10.2%) with urinary retention, 2 (4.1%) with abdominal wound complications, and 1 (2.0%) with ileus. There was no postoperative mortality. This was a noncomparative single-arm trial conducted at a single institution. Transanal endoscopic total mesorectal excision showed acceptable results based on perioperative and short-term oncologic outcomes. Further investigations are necessary to show the benefits and long-term outcomes of this procedure. See Video Abstract at http://links.lww.com/DCR/A563.

Rectal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up.

The routine use of MRI in rectal cancer treatment allows the use of a strict definition for low rectal cancer. This study aimed to compare minimally invasive total mesorectal excision in MRI-defined low rectal cancer in expert laparoscopic, transanal and robotic high-volume centres. All MRI-defined low rectal cancer operated on between 2015 and 2017 in 11 Dutch centres were included. Primary outcomes were: R1 rate, total mesorectal excision quality and 3-year local recurrence and survivals (overall and disease free). Secondary outcomes included conversion rate, complications and whether there was a perioperative change in the preoperative treatment plan. Of 1071 eligible rectal cancers, 633 patients with low rectal cancer were identified. Quality of the total mesorectal excision specimen (P = 0.337), R1 rate (P = 0.107), conversion (P = 0.344), anastomotic leakage rate (P = 0.942), local recurrence (P = 0.809), overall survival (P = 0.436) and disease-free survival (P = 0.347) were comparable among the centres. The laparoscopic centre group had the highest rate of perioperative change in the preoperative treatment plan (10.4%), compared with robotic expert centres (5.2%) and transanal centres (2.1%), P = 0.004. The main reason for this change was stapling difficulty (43%), followed by low tumour location (29%). Multivariable analysis showed that laparoscopic surgery was the only independent risk factor for a change in the preoperative planned procedure, P = 0.024. Centres with expertise in all three minimally invasive total mesorectal excision techniques can achieve good oncological resection in the treatment of MRI-defined low rectal cancer. However, compared with robotic expert centres and transanal centres, patients treated in laparoscopic centres have an increased risk of a change in the preoperative intended procedure due to technical limitations.

Impact of robotic learning curve on histopathology in rectal cancer: A pooled analysis

BackgroundRadical resection for mid and low rectal cancer is probably the most challenging type of surgery in colorectal surgery, especially in a narrow male pelvis. In this study, we aimed to define a simple and effective evaluation method based on magnetic resonance imaging (MRI) and body mass index (BMI) to predict the operation difficulty of radical resection for mid and low rectal cancer in male patients.MethodsA total of 264 male patients who underwent total mesorectal excision (TME) due to primary rectal cancer located in the mid and low rectum (distal tumor margin distance from the anal verge ≤ 7 cm) were retrospectively included in the study. An angle SAU° [formed by two lines: line 1 (connecting the anteroinferior border of the fifth sacral vertebra and center point of anus) and line 2 (connecting internal urethral orifice and center point of anus)] was measured using the built-in software of MRI for every patient. The patients were categorized into four groups according to the angle SAU° and BMI. The operative time, estimated blood loss, TME quality, and anastomotic leakage (AL) were compared between group 1 and group 2 as well as between group 3 and group 4.ResultsGroup 1 included 111 patients with angle SAU° > 60 and BMI < 25 kg/m2; group 2 included 51 patients with angle SAU° ≤ 60 and BMI < 25 kg/m2; group 3 included 74 patients with angle SAU° > 60 and BMI ≥ 25 kg/m2; group 4 included 28 patients with angle SAU° ≤ 60 and BMI ≥ 25 kg/m2. The operative time, estimated blood loss, and the rate of AL in group 1 and group 3 were significantly less than those in group 2 and group 4, respectively (P < 0.05). Similarly, the TME quality in group 1 and group 3 was significantly better than that in group 2 and group 4, respectively (P < 0.05).ConclusionAngle SAU° based on MRI combined with BMI is a simple and effective evaluation method to predict the difficulty in TME for male patients with mid and low rectal cancer. It may also have value in predicting AL.

The quality of the total mesorectal excision specimen in rectal cancer surgery is assessed with a three-tier grade (mesorectal, intramesorectal and muscularis propria). This study aimed to analyse the prognostic impact of the total mesorectal excision grade on survival, and to identify risk factors for intramesorectal and muscularis propria resection in a population-based setting. All patients in the Swedish Colorectal Cancer Registry with rectal cancer stage I-III ≤ 10 cm from the anal verge, diagnosed 2015-2019, undergoing total mesorectal excision were analysed. Clinical, surgical and pathological data were retrieved and analysed for the following primary outcomes: local and distant recurrence and overall and relative survival; secondary outcomes were risk factors for total mesorectal excision grading (intramesorectal or muscularis propria resection). Of note, postoperative death < 30 days or recurrence within 90 days were exclusion criteria for survival and recurrence analysis. Recurrence-free patients with less than 3 years follow-up, and patients lacking data regarding recurrence, were also excluded from recurrence analyses. Overall, of 7979 patients treated during the study interval, 1499 patients were eligible for recurrence, 2441 patients for survival and 2476 patients for risk-factor analyses, of which 75% were graded mesorectal, 17% intramesorectal and 8% muscularis propria. Median follow-up for survival was 42 (1-77) months. The worst total mesorectal excision grading (muscularis propria resection) was an independent risk factor for local recurrence in multivariable analysis (HR 2.73, 95% c.i. 1.07 to 7.0, P = 0.036). Total mesorectal excision grade had no impact on distant recurrence or survival. Female sex, tumour level <5 cm, abdominoperineal resection, minimally invasive surgery (laparoscopic and robotic), high blood loss, long duration of surgery and intraoperative perforation were independent risk factors for worse total mesorectal excision grading (intramesorectal and/or muscularis propria resection) in multivariable analyses. Muscularis propria resection increases the risk of local recurrence but does not seem to affect distant recurrence or survival.