A simple difficulty scoring system for laparoscopic total mesorectal excision.

Abstract

The proposed difficulty scoring system (DSS) may aid in preoperative planning for laparoscopic total mesorectal excision (L-TME) for rectal cancer. Fifty-three patients [28 males; 59.0 (31.0-88.0) years of age] treated for rectal cancer at ourinstitution from 2/2011-5/2018 were identified. "Difficult operation" (DO) was defined as the presence of ≥3 factors: operative time ≥320min, estimated blood loss >250ml, intraoperative complications, conversion to laparotomy, >2 stapler applications, incomplete TME quality, and/or subjective perceived difficulty. Univariate analysis and multivariate logistic regression model with backward elimination method were used to obtain a DSS which consists of two factors: sex (male = 1 and female = 0) and body mass index (BMI) (≥30kg/m2 = 1, <30kg/m2 = 0). In univariate analysis, sex (p = 0.0217), BMI (p = 0.0026), American Society of Anesthesiologists (ASA) score (p = 0.0372), and magnetic resonance imaging transverse diameter (p = 0.0441) correlated to DO. Multivariate analysis revealed that sexand BMI were the most important risk factors for aDO [area under the receiver operating characteristic curve [AUC] = 0.7761, 95% CI = (0.6443-0.9080)]. Male patients with a BMI ≥ 30kg/m2 were more likely to experience a DO (77.8%). Thesimplified DSS did not weaken the discriminating power compared to multivariate logistic regression model(AUC 0.7696 vs. 0.7761, p = 0.7387). L-TME with aDSS of 0, 1, and 2 had a DO rate of 10%, 33.3%, and 77.8%, respectively. A simplified DSS may be used preoperatively in preparation for L-TME.