The relationship between mesorectal grading and oncological outcome in rectal adenocarcinoma

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

BACKGROUND

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.

OBJECTIVE

To determine pelvic structural factors associated with incomplete total mesorectal excision after curative proctectomy and build a predictive model for total mesorectal excision quality.

DESIGN

Retrospective cohort study.

SETTING

A quaternary referral center database of patients diagnosed with rectal adenocarcinoma (2009-2017).

PATIENTS

Curative-intent proctectomy for rectal adenocarcinoma.

INTERVENTIONS

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.

MAIN OUTCOME MEASURES

Ability of radiological pelvimetry and obesity measurements to predict total mesorectal excision quality.

RESULTS

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.

LIMITATIONS

Retrospective analysis is not controlled for the choice of surgical approach.

CONCLUSIONS

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 .

USO DE MEDICIONES DE PELVIMETRA Y OBESIDAD VISCERAL BASADAS EN TC PARA PREDECIR LA CALIDAD DE TME EN PACIENTES SOMETIDOS A CIRUGA DE CNCER DE RECTO

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).

Long-term Outcomes of Minimally Invasive Versus Open Abdominoperineal Resection for Rectal Cancer: A Single Specialized Center Experience

BACKGROUND

Randomized studies have validated laparoscopic proctectomy for the treatment of rectal cancer as noninferior to an open proctectomy, but most of those studies have included sphincter-preserving resections along with abdominoperineal resection.

OBJECTIVE

This study aimed to compare perioperative and long-term oncological outcomes between minimally invasive and open abdominoperineal resection.

DESIGN

This study is a retrospective analysis of a prospectively maintained database.

SETTINGS

The study was conducted in a single specialized colorectal surgery department.

PATIENTS

All patients who underwent abdominoperineal resection for primary rectal cancer between 2000 and 2016 were included.

MAIN OUTCOME MEASURES

The primary outcomes measured were the perioperative and long-term oncological outcomes.

RESULTS

We included 452 patients, 372 in the open group and 80 in the minimally invasive group, with a median follow-up time of 74 months. There were significant differences between the groups in terms of neoadjuvant radiation treatment (67.5% of the open versus 81.3% of the minimally invasive group, p = 0.01), operative time (mean of 200 minutes versus 287 minutes, p < 0.0001), and mean length of stay (9.5 days versus 6.6 days, p < 0.0001). Overall complication rates were similar between the groups (34.5% versus 27.5%, p = 0.177). There were no significant differences in the mean number of lymph nodes harvested (21.7 versus 22.2 nodes, p = 0.7), circumferential radial margins (1.48 cm versus 1.37 cm, p = 0.4), or in the rate of involved radial margins (10.8% versus 6.3%, p = 0.37). Five-year overall survival was 70% in the open group versus 80% in the minimally invasive group (p = 0.344), whereas the 5-year disease-free survival rate in the open group was 63.2% versus 77.6% in the minimally invasive group (p = 0.09).

LIMITATIONS

This study was limited because it describes a single referral institution experience.

CONCLUSIONS

Although both approaches have similar perioperative outcomes, the minimally invasive approach benefits the patients with a shorter length of stay and a lower risk for surgical wound infections. Both approaches yield similar oncological technical quality in terms of the lymph nodes harvested and margins status, and they have comparable long-term oncological outcomes. See Video Abstract at http://links.lww.com/DCR/B754.RESULTADOS A LARGO PLAZO DE LA RESECCIÓN ABDOMINOPERINEAL MÍNIMAMENTE INVASIVA VERSUS ABIERTA PARA EL CÁNCER DE RECTO: EXPERIENCIA DE UN SOLO CENTRO ESPECIALIZADOANTECEDENTES:Estudios aleatorizados han validado la proctectomía laparoscópica para el tratamiento del cáncer de recto igual a la proctectomía abierta, pero la mayoría de esos estudios han incluido resecciones con preservación del esfínter junto con resección abdominoperineal.OBJETIVO:Comparar los resultados oncológicos perioperatorios y a largo plazo entre la resección abdominoperineal abierta y mínimamente invasiva.DISEÑO:Análisis retrospectivo de una base de datos mantenida de forma prospectiva.ENTORNO CLINICO:Servicio único especializado en cirugía colorrectal.PACIENTES:Todos los pacientes que se sometieron a resección abdominoperineal por cáncer de recto primario entre 2000 y 2016.PRINCIPALES MEDIDAS DE VALORACION:Resultados oncológicos perioperatorios y a largo plazo.RESULTADOS:Se incluyeron 452 pacientes, 372 en el grupo abierto y 80 en el grupo mínimamente invasivo, con una mediana de seguimiento de 74 meses. Hubo diferencias significativas entre los grupos en términos de tratamiento con radiación neoadyuvante (67,5% del grupo abierto versus 81,3% del grupo mínimamente invasivo, p = 0,01), tiempo operatorio (media de 200 minutos versus 287 minutos, p < 0,0001) y la duración media de la estancia (9,5 días frente a 6,6 días, p < 0,0001). Las tasas generales de complicaciones fueron similares entre los grupos (34,5% versus 27,5%, p = 0,177). No hubo diferencias significativas en el número medio de ganglios linfáticos extraídos (21,7 versus 22,2 ganglios, p = 0,7), márgenes radiales circunferenciales (1,48 cm y 1,37 cm, p = 0,4), ni en la tasa de márgenes radiales afectados (10,8 cm). % versus 6,3%, p = 0,37). La supervivencia general a 5 años fue del 70% en el grupo abierto frente al 80% en el grupo mínimamente invasivo (p = 0,344), mientras que la tasa de supervivencia libre de enfermedad a 5 años en el grupo abierto fue del 63,2% frente al 77,6% en el grupo mínimamente invasivo (p = 0,09).LIMITACIONES:Experiencia en una institución de referencia única.CONCLUSIONES:Si bien ambos tienen resultados perioperatorios similares, el enfoque mínimamente invasivo, beneficia a los pacientes con estadía más corta y menor riesgo de infecciones de la herida quirúrgica. Ambos enfoques, producen una calidad técnica oncológica similar en términos de ganglios linfáticos extraídos y estado de los márgenes, y tienen resultados oncológicos comparables a largo plazo. Consulte Video Resumen en http://links.lww.com/DCR/B754. (Traducción - Dr. Fidel Ruiz Healy).

Lower conversion rate with robotic assisted rectal resections compared with conventional laparoscopy; a national cohort study

Background

Conversion from laparoscopic to open access colorectal surgery is associated with a poorer postoperative outcome. The aim of this study was to assess conversion rates and outcomes after standard laparoscopic rectal resection (LR) and robotic laparoscopic rectal resection (RR).

Methods

A national 5-year cohort study utilizing prospectively recorded data on patients who underwent elective major laparoscopic resection for rectal cancer. Data were retrieved from the Norwegian Registry for Gastrointestinal Surgery and from the Norwegian Colorectal Cancer Registry. Primary end point was conversion rate. Secondary end points were postoperative complications within 30 days and histopathological results. Chi-square test, two-sided T test, and Mann–Whitney U test were used for univariable analyses. Both univariable and multivariable logistic regression analyses were used to analyze the relations between different predictors and outcomes, and propensity score matching was performed to address potential treatment assignment bias.

Results

A total of 1284 patients were included, of whom 375 underwent RR and 909 LR. Conversion rate was 8 out of 375 (2.1%) for RR compared with 87 out of 909 (9.6%) for LR (p < 0.001). RR was associated with reduced risk for conversion compared with LR (aOR 0.22, 95% CI 0.10–0.46). There were no other outcome differences between RR and LR. Factors associated with increased risk for conversion were male gender, severe cardiac disease and BMI > 30. Conversion was associated with higher rates of major complications (20 out of 95 (21.2%) vs 135 out of 1189 (11.4%) p = 0.005), reoperations (13 out of 95 (13.7%) vs 93 out of 1189 (7.1%) p = 0.020), and longer hospital stay (median 8 days vs 6 days, p = 0.001).

Conclusion

Conversion rate was lower with robotic assisted rectal resections compared with conventional laparoscopy. Conversions were associated with higher rates of postoperative complications.

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

BACKGROUND

A 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.

METHODS

Between 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.

RESULTS

The 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).

CONCLUSIONS

The 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.