Factors Predicting Difficulty of Laparoscopic Low Anterior Resection for Rectal Cancer with Total Mesorectal Excision and Double Stapling Technique

Development and validation of a nomogram for predicting operating time in laparoscopic anterior resection of rectal cancer

Aims

The goal of this study is to create and verify a nomogram estimate operating time in rectal cancer (RC) patients based on clinicopathological factors and MRI/CT measurements before surgery.

Materials and Methods

The nomogram was developed in a cohort of patients who underwent laparoscopic anterior resection (L-AR) for RC. The clinicopathological and pelvis parameters were collected. Risk factors for a long operating time were determined by univariate and multivariate logistic regression analyses, and a nomogram was established with independent risk factors. The performance of the nomogram was evaluated. An independent cohort of consecutive patients served as the validation dataset.

Results

The development group recruited 159 RC patients, while 54 patients were enrolled in the validation group. Independent risk factors identified in multivariate analysis were a distance from the anal verge <5 cm (P = 0.024), the transverse diameter of the pelvic inlet (P < 0.001), mesorectal fat area (P = 0.017), and visceral fat area (P < 0.001). Then, a nomogram was built based on these four independent risk factors. The C-indexes of the nomogram in the development and validation group were 0.886 and 0.855, respectively. And values of AUC were the same with C-indexes in both groups. Besides, the calibration plots showed satisfactory consistency between actual observation and nomogram-predicted probabilities of long operating time.

Conclusions

A nomogram for predicting the risk of long operating duration in L-AR of RC was developed. And the nomogram displayed a good prediction effect and can be utilized as a tool for evaluating operating time preoperatively.

Subjective Difficulty Scale in Liver Transplantation: A Prospective Observational Study

The predictive value of a subjective difficulty scale (DS) after surgical procedures is unknown. The objective of this study was to evaluate the prognostic value of a DS after liver transplantation (LT) and to identify predictors of difficulty. Surgeons prospectively evaluated the difficulty of 441 consecutive liver transplantations from donation after brain death at the end of the surgery by using a DS from 0 to 10 (“the easiest to the hardest you can imagine”). DS was associated with severe morbidity. The risk of graft loss at 1 year remained unchanged from 0 to 6 but increased beyond 6. Graft survival and patient survival of group with DS 7–10 was significantly impaired compared to groups with DS: 0–3 or DS: 4–6 but were significantly impaired for the group with DS: 7–10. Independent predictors of difficult LT (DS ≥ 7) were annular segment 1, transjugular intrahepatic portosystemic shunt, retransplantation beyond 30 days, portal vein thrombosis, and ascites. Of them, ascites was a borderline non-significant covariate (p = .04). Vascular complications occurred more often after difficult LT (20.5% vs. 5.9%), whereas there was no difference in the other types of complications. DS can be used to tailor monitoring and anticipate early complications. External validation is needed.

Posterior mesorectal thickness as a predictor of increased operative time in rectal cancer surgery: a retrospective cohort study

BACKGROUND

In rectal cancer surgery, larger mesorectal fat area has been shown to correlate with increased intraoperative difficulty. Prior studies were mostly in Asian populations with average body mass indices (BMIs) less than 25 kg/m². This study aimed to define the relationship between radiological variables on pelvic magnetic resonance imaging (MRI) and intraoperative difficulty in a North American population.

METHODS

This is a single-center retrospective cohort study analyzing all patients who underwent low anterior resection (LAR) or transanal total mesorectal excision (TaTME) for stage I-III rectal adenocarcinoma from January 2015 until December 2019. Eleven pelvic magnetic resonance imaging measures were defined a priori according to previous literature and measured in each of the included patients. Operative time in minutes and intraoperative blood loss in milliliters were utilized as the primary indicators of intraoperative difficulty.

RESULTS

Eighty-three patients (39.8% female, mean age: 62.4 ± 11.6 years) met inclusion criteria. The mean BMI of included patients was 29.4 ± 6.2 kg/m². Mean operative times were 227.2 ± 65.1 min and 340.6 ± 78.7 min for LARs and TaTMEs, respectively. On multivariable analysis including patient, tumor, and MRI factors, increasing posterior mesorectal thickness was significantly associated with increased operative time (p = 0.04). Every 1 cm increase in posterior mesorectal thickness correlated with a 26 min and 6 s increase in operative time. None of the MRI measurements correlated strongly with BMI.

CONCLUSION

As the number of obese rectal cancer patients continues to expand, strategies aimed at optimizing their surgical management are paramount. While increasing BMI is an important preoperative risk factor, the present study identifies posterior mesorectal thickness on MRI as a reliable and easily measurable parameter to help predict operative difficulty. Ultimately, this may in turn serve as an indicator of which patients would benefit most from pre-operative resources aimed at optimizing operative conditions and postoperative recovery.

Predictors of Surgical Difficulty in Laparoscopic Total Mesorectal Excision

Concerns have been raised regarding the oncological safety of laparoscopic total mesorectal excision (TME) as compared to an open approach. This study aimed to identify risk factors for surgically difficult laparoscopic TME. All consecutive laparoscopic rectal cancer cases were included from a prospectively maintained colorectal cancer database. The primary outcome was to identify risk factors for surgically difficult TME. A Surgical Difficulty Risk Score (SDRS) between 0 and 6 was calculated for each case with cases achieving an SDRS of 2 or greater being deemed as surgically difficult. A total of 2795 consecutive cases of laparoscopic TME were identified, with 464 (16.6%) surgically difficult cases. Univariate analysis found that operating in the male pelvis, performing abdomino-perineal resections, Hartmann’s procedures, and proctocolectomies were all significantly associated with higher operative difficulty (P < 0.001). A higher nodal stage of cancer (P = 0.046), and the resection of another organ (P = 0.003) were significantly associated with higher surgical difficulty. On multivariate analysis, a female pelvis was associated with a favorable laparoscopic resection (Odds ratio [OR] 0.54, 95% CI 0.43–0.67, P < 0.001), whereas patients who had another organ resection (OR 2.6, 95% CI 1.53–4.42, P < 0.001), nodal positivity (OR 1.37, 95% CI 1.11–1.69, P = 0.003), and high ASA scores had more difficult surgeries. Predictive factors for surgically difficult laparoscopic TME include male gender, high ASA scores, mid and low rectal cancer, positive nodal stage, and resection of another organ at time of surgery.

High-pressure CO2 insufflation is a risk factor for postoperative ileus in patients undergoing TaTME

The aim of this study is to evaluate the influence of high-pressure CO₂ insufflation during TaTME on the occurrence of postoperative ileus. All patients undergoing elective transanal total mesorectal excision (TaTME) between April 2015 and March 2019 were included in a prospective database. Eligible patients were adults with mid and low-level rectal cancer undergoing elective TaTME with colorectal anastomosis and diverting ileostomy, following a standardized ERAS pathway. Patients were divided into a low-pressure (LP) group, where surgery was performed with an intrabdominal CO₂ pressure of 12 mmHg, and a high-pressure (HP) group, where the intrabdominal pressure reached 15 mmHg of CO₂ once the two surgical fields were connected. Of 98 patients undergoing TaTME in the observed period, 74 met the inclusion criteria and were included in this study. There was no significant difference in postoperative complications between the LP and HP groups, except for postoperative ileus, which occurred in seven patients (13.2%) in the LP group and seven patients (33.3%) in the HP group (p value 0.046). The logistic multivariate analysis showed that a high intraabdominal CO₂ pressure (OR 7040, 95% CI 1591-31,164, p value 0.01) and male sex (OR 10,343, 95% CI 1078-99,256, p value 0.043) were significantly associated with postoperative ileus after TaTME. Intraabdominal CO₂ pressure should be carefully set, as it may represent a risk factor for postoperative ileus in patients undergoing TaTME.

MRI pelvimetry-based evaluation of surgical difficulty in laparoscopic total mesorectal excision after neoadjuvant chemoradiation for male rectal cancer

Purpose

Laparoscopic total mesorectal excision (LaTME) is technically demanding in rectal cancer after neoadjuvant chemoradiotherapy (NCRT). This study aimed to predict the surgical difficulty of LaTME after NCRT based on pelvimetric parameters.

Methods

This study enrolled 147 patients who underwent LaTME after NCRT. The surgical difficulty was graded as high or low according to the operative time, estimated blood loss, conversion to open surgery, postoperative hospital stay, and postoperative complications. Pelvimetry parameters were collected based on preoperative MRI. A logistic regression analysis was performed to identify predictors of high surgical difficulty, and a nomogram was developed.

Results

Totally, 18 (12.2%) patients were graded as high surgical difficulty. High surgical difficulty was correlated with a shorter interspinous distance (P = 0.014), a small angle α and γ (P = 0.008, P = 0.008, respectively), and a larger mesorectal area and mesorectal fat area (P = 0.041, P = 0.046, respectively). Tumor distance from the anal verge (OR = 0.619, P = 0.024), tumor diameter (OR = 3.747, P = 0.004), interspinous distance (OR = 0.127, P = 0.007), and angle α (OR = 0.821, P = 0.039) were independent predictors of high surgical difficulty. A predictive nomogram was developed with a C-index of 0.867.

Conclusion

A shorter tumor distance from the anal verge, larger tumor diameter, shorter interspinous distance, and smaller angle α could help to predict high surgical difficulty of LaTME in male LARC patients after NCRT.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00595-020-02211-3.

Can better surgical outcomes be obtained in the learning process of robotic rectal cancer surgery? A propensity score-matched comparison between learning phases

BACKGROUND

Although studies of robotic rectal cancer surgery have demonstrated the effects of learning on operation time, comparisons have failed to demonstrate differences in clinicopathological outcomes between unadjusted learning phases. This study aimed to investigate the learning curve of robotic rectal cancer surgery for clinicopathological outcomes and compare surgical outcomes between adjusted learning phases. Study design We enrolled 506 consecutive patients with rectal adenocarcinoma who underwent robotic resection by a single surgeon between 2007 and 2018. Risk-adjusted cumulative sum (RA-CUSUM) for surgical failure was used to analyze the learning curve. Surgical failure was defined as the occurrence of any of the following: conversion to open surgery, severe complications (Clavien-Dindo grade ≥ 3a), insufficient number of harvested lymph nodes (LNs), or R1 resection. Comparisons between learning phases analyzed by RA-CUSUM were performed before and after propensity score matching.

RESULTS

In RA-CUSUM analysis, the learning curve was divided into two learning phases: phase 1 (1st-177th cases, n = 177) and phase 2 (178th-506th cases, n = 329). Before matching, patients in phase 2 had deeper tumor invasion and higher rates of positive LNs on pretreatment images and preoperative chemoradiotherapy. After matching, phase 1 (n = 150) and phase 2 (n = 150) patients exhibited similar clinical characteristics. Phase 2 patients had lower rates of surgical failure overall and these components: conversion to open surgery, severe complications, and insufficient harvested LNs.

CONCLUSIONS

For robotic rectal cancer surgery, surgical outcomes improved after the 177th case. Further studies by other robotic surgeons are required to validate our results.

Factors Predicting Operative Difficulty of Laparoscopic Total Mesorectal Excision

BACKGROUND

Laparoscopic total mesorectal excision is a challenging procedure requiring high-quality surgery for optimal outcomes. Patient, tumor, and pelvic factors are believed to determine difficulty, but previous studies were limited to postoperative data.

OBJECTIVE

This study aimed to report factors predicting laparoscopic total mesorectal excision performance by using objective intraoperative assessment.

DESIGN

Data from a multicenter laparoscopic total mesorectal excision randomized trial (ISRCTN59485808) were reviewed.

SETTING

This study was conducted at 4 centers in the United Kingdom.

PATIENTS AND INTERVENTION

Seventy-one patients underwent elective laparoscopic total mesorectal excision for rectal adenocarcinoma with curative intent: 53% were men, mean age was 69 years, body mass index was 27.7, tumor height was 8.5 cm, 24% underwent neoadjuvant therapy, and 25% had previous surgery.

MAIN OUTCOME MEASURES

Surgical performance was assessed through the identification of intraoperative adverse events by using observational clinical human reliability analysis. Univariate analysis and multivariate binomial regression were performed to establish factors predicting the number of intraoperative errors, surgeon-reported case difficulty, and short-term clinical and histopathological outcomes.

RESULTS

A total of 1331 intraoperative errors were identified from 365 hours of surgery (median, 18 per case; interquartile range, 16-22; and range, 9-49). No patient, tumor, or bony pelvimetry measurement correlated with total or pelvic error count, surgeon-reported case difficulty, cognitive load, operative data, specimen quality, number or severity of 30-day morbidity events and length of stay (all r not exceeding ±0.26, p > 0.05). Mesorectal area was associated with major intraoperative adverse events (OR, 1.09; 95%CI, 1.01-1.16; p = 0.015) and postoperative morbidity (OR, 1.1; 95% CI, 1.01-1.2; p = 0.033). Obese men were subjectively reported as harder cases (24 vs 36 mm, p = 0.042), but no detrimental effects on performance or outcomes were seen.

LIMITATIONS

Our sample size is modest, risking type II errors and overfitting of the statistical models.

CONCLUSION

Patient, tumor, and bony pelvic anatomical characteristics are not seen to influence laparoscopic total mesorectal excision operative difficulty. Mesorectal area is identified as a risk factor for intraoperative and postoperative morbidity. See Video Abstract at http://links.lww.com/DCR/B35. FACTORES QUE PREDICEN LA DIFICULTAD OPERATIVA DE LA ESCISIÓN MESORRECTAL TOTAL LAPAROSCÓPICA: La escisión mesorrectal total laparoscópica es un procedimiento desafiante. Para obtener resultados óptimos, se requiere cirugía de alta calidad. Se cree que, factores como el paciente, el tumor y la pelvis, determinan la dificultad, pero estudios previos solamente se han limitado a datos postoperatorios.Informar de los factores que predicen el resultado de la escisión mesorrectal total laparoscópica, mediante una evaluación intraoperatoria objetiva.Datos de un ensayo multicéntrico y randomizado de escisión mesorrectal total laparoscópica (ISRCTN59485808).Cuatro centros del Reino Unido.Un total de 71 pacientes fueron sometidos a escisión mesorrectal total laparoscópica electiva, para adenocarcinoma rectal con intención curativa. 53% hombres, edad media, índice de masa corporal y altura del tumor 69, 27.7 y 8.5 cm respectivamente, 24% terapia neoadyuvante y 25% cirugía previa.Rendimiento quirúrgico evaluado mediante la identificación de eventos intraoperatorios adversos, mediante el análisis clínico observacional de confiabilidad humana. Se realizaron análisis univariado y la regresión binomial multivariada para establecer factores que predicen el número de errores intraoperatorios, reportes del cirujano sobre la dificultad del caso y los resultados clínicos e histopatológicos a corto plazo.Se identificaron un total de 1,331 errores intraoperatorios en 365 horas de cirugía (media de 18 por caso, IQR 16-22, rango 9-49). Ningún paciente, tumor o medición de pelvimetría pélvica, se correlacionó con la cuenta de errores pélvicos o totales, reporte del cirujano sobre dificultad del caso, carga cognitiva, datos operativos, calidad de la muestra, número o gravedad de eventos de morbilidad de 30 días y duración de la estadía (todos r <± 0.26, p > 0.05). El área mesorrectal se asoció con eventos adversos intraoperatorios importantes (OR, 1.09; IC 95%, 1.01-1.16; p = 0.015) y morbilidad postoperatoria (OR, 1.1; IC 95%, 1.01-1.2; p = 0.033). Como información subjetiva, hombres obesos fueron casos más difíciles (24 mm frente a 36 mm, p = 0.042) pero no se observaron efectos perjudiciales sobre el rendimiento o los resultados.Nuestro tamaño de muestra es un modesto riesgo de errores de tipo II y el sobreajuste de los modelos estadísticos.No se observa que las características anatómicas del paciente, tumor y pelvis ósea influyan en la dificultad operatoria de la escisión mesorrectal laparoscópica total. El área mesorrectal se identifica como un factor de riesgo para la morbilidad intraoperatoria y postoperatoria. Vea el resumen del video en http://links.lww.com/DCR/B35.

Learning Curve of Robotic Rectal Surgery With Lateral Lymph Node Dissection: Cumulative Sum and Multiple Regression Analyses

OBJECTIVE

This study aimed to assess the learning curve of robotic rectal surgery, a procedure that has gained increasing focus in recent years because it is expected that the advanced devices used in this approach provide advantages resulting in a shorter learning curve than that of laparoscopic surgery. However, no studies have assessed the learning curve of robotic rectal surgery, especially when lateral lymph node dissection is required.

DESIGN

This was a nonrandomized, retrospective study from a single institution.

SETTING

All consecutive patients who underwent robotic rectal or sigmoid colon surgery by a single surgeon between February 2012 and July 2016 in the University of Tokyo Hospital were enrolled. The learning curve for console time was assessed using a cumulative sum analysis and multiple linear regression analysis.

PARTICIPANTS

A total of 131 consecutive patients underwent robotic rectal or sigmoid colon surgery performed by a single experienced surgeon. Of these, 41 patients received lateral lymph node dissection.

RESULTS

A cumulative sum plot for console time demonstrated that the learning period could be divided into 3 phases: Phase I, Cases 1 to 19; Phase II, Cases 20 to 78; and Phase III, Cases 79 to 131. Multiple linear regression analysis indicated that console time decreased significantly from one phase to another (Phase I-II, Δconsole time 83.0 minutes; Phase II-III, Δconsole time 40.1 minutes). Other factors affecting console time included body mass index, operative procedure, and lateral lymph node dissection, but not neoadjuvant therapy (such as chemoradiotherapy) or depth of invasion. Lateral lymph node dissection required an additional 138.4 minutes.

CONCLUSIONS

Our findings suggest that the first phase of the learning curve consists of the first 19 cases, which seems sufficient to master the manipulation of robotic arms and to understand spatial relationships unique to the robotic procedure.

Quantitative assessment of mesorectal fat: new prognostic biomarker in patients with mid-to-lower rectal cancer

OBJECTIVES

To investigate the impact of mesorectal fat area (MFA) on oncologic outcomes in patients with mid-to-lower rectal cancer who received curative-intent surgery.

METHODS

Patients with mid-to-lower rectal cancer who underwent preoperative abdominopelvic computed tomography (CT) and curative-intent surgery in 2011 were divided into two groups by tumour recurrence (group A) or no recurrence (group B) during a 5-year follow-up. Visceral fat area (VFA) and MFA were measured on preoperative CT and cutoff values were calculated using the Youden index. Univariate and multivariate regression analyses including BMI, VFA, and MFA were performed to investigate meaningful prognostic biomarkers. The Kaplan-Meier method with log-rank testing was used to validate prognostic biomarkers.

RESULTS

Group A contained 42 patients and group B had 155 patients. Cutoff values were 25 kg/m² for BMI, 130 cm² for VFA, and 10 cm² for MFA using the Youden index. On multivariate Cox regression analysis, MFA (odds ratio [OR] = 0.426, p = 0.010), TNM stage (p = 0.027), and perioperative complication grade (p = 0.028) were significantly different between groups. BMI and VFA did not show significant differences. By the Kaplan-Meier method with log-rank testing, disease-free survival (DFS) was significantly longer in patients with MFA ≥10 cm² compared to patients with MFA <10 cm² (p = 0.021), with no significant difference in overall survival (OS).

CONCLUSIONS

MFA was an independent biomarker for predicting DFS in patients who underwent curative-intent surgery for mid-to-lower rectal cancer.

KEY POINTS

• Mesorectal fat area is associated with the prognosis of rectal cancer patients. • Mesorectal fat area can be calculated easily in pre-operative CT scan. • Predicting prognosis of the cancer patient before operation is important.

Economic burden of cancer among patients with surgical resections of the lung, rectum, liver and uterus: results from a US hospital database claims analysis

OBJECTIVES

To determine hospital resource utilization, associated costs and the risk of complications during hospitalization for four types of surgical resections and to estimate the incremental burden among patients with cancer compared to those without cancer.

METHODS

Patients (≥18 years old) were identified from the Premier Research Database of US hospitals if they had any of the following types of elective surgical resections between 1/2008 and 12/2014: lung lobectomy, lower anterior resection of the rectum (LAR), liver wedge resection, or total hysterectomy. Cancer status was determined based on ICD-9-CM diagnosis codes. Operating room time (ORT), length of stay (LOS), and total hospital costs, as well as frequency of bleeding and infections during hospitalization were evaluated. The impact of cancer status on outcomes (from a hospital perspective) was evaluated using multivariable generalized estimating equation models; analyses were conducted separately for each resection type.

RESULTS

Among the identified patients who underwent surgical resection, 23 858 (87.9% with cancer) underwent lung lobectomy, 13 522 (63.8% with cancer) underwent LAR, 2916 (30.0% with cancer) underwent liver wedge resection and 225 075 (11.3% with cancer) underwent total hysterectomy. After adjusting for patient, procedural, and hospital characteristics, mean ORT, LOS, and hospital cost were statistically higher by 3.2%, 8.2%, and 9.2%, respectively for patients with cancer vs. no cancer who underwent lung lobectomy; statistically higher by 6.9%, 9.4%, and 9.6%, respectively for patients with cancer vs. no cancer who underwent LAR; statistically higher by 4.9%, 14.8%, and 15.7%, respectively for patients with cancer vs. no cancer who underwent liver wedge resection; and statistically higher by 16.0%, 27.4%, and 31.3%, respectively for patients with cancer vs. no cancer who underwent total hysterectomy. Among patients who underwent each type of resection, risks for bleeding and infection were generally higher among patients with cancer as compared to those without cancer.

CONCLUSIONS

In this analysis, we found that patients who underwent lung lobectomy, lower anterior resection of the rectum (LAR), liver wedge resection or total hysterectomy for a cancer indication have significantly increased hospital resource utilization compared to these same surgeries for benign indications.

Factors Influencing Difficulty of Laparoscopic Abdominoperineal Resection for Ultra-Low Rectal Cancer

PURPOSE

Our current study was conducted to identify patients' anatomic, pathologic, and clinical factors to predict difficulty of performing laparoscopic abdominoperineal resection for ultra-low rectal cancer.

MATERIALS AND METHODS

Records of 117 consecutive patients with rectal cancer 2 to 5 cm from the anal verge were retrospectively reviewed. Using univariate and multivariate linear or logistic regression models, standardized operative time and blood loss, as well as postoperative morbidity were utilized as endpoints to screen patients' multiple variables to predict operative difficulty.

RESULTS

Multivariate linear regression analysis showed body mass index (BMI) (estimate=0.07, P=0.0056), interspinous distance (estimate=-0.02, P=0.0011), tumor distance from anal verge (estimate=-0.17, P=0.0355), prior abdominal surgery (estimate=0.51, P=0.0180), preoperative chemoradiotherapy (estimate=0.67, P=0.0146), and concurrent diseases (hypertension and/or diabetes mellitus) (estimate=0.49, P=0.0122) are predictors for standardized operative time. Age (estimate=0.02, P=0.0208) and concurrent diseases (estimate=0.43, P=0.0476) were factors related to standardized blood loss. BMI (estimate=0.15, P=0.0472) was the only predictor for postoperative morbidity based on logistic regression analysis.

CONCLUSIONS

Age, BMI, interspinous distance, tumor distance from anal verge, prior abdominal surgery, preoperative chemoradiotherapy, and concurrent diseases influence the difficulty of performing laparoscopic abdominoperineal resection for ultra-low rectal cancer. Standardized operative time allows researchers to amass samples by pooling data from all published studies, thus building reliable models to predict operative difficulty for clinical use.