Influence of surgical start time on the quality of surgery for middle and low rectal cancer: a post hoc analysis of the real trial
Authors: Guodong He, Zhang Zhuojian, Weitang Yuan, Taiyuan Li, Bo Tang, Baoqing Jia, Yanbing Zhou, Wei Zhang, Ren Zhao, Cheng Zhang, Longwei Cheng, Xiaoqiao Zhang, Fei Liang, Ye Wei, Qingyang Feng, Jianmin Xu
Journal: International Journal of Surgery (2025)

Surgical start time is considered to influence the quality of surgery due to surgeon fatigue. High-quality studies on middle and low rectal cancer are lacking. The analysis aims to find out the influence of surgical start time on the quality of surgery for middle and low rectal cancer, and whether robotic surgery could avoid the influence. This study was a post hoc analysis of the REAL (robotic vs. laparoscopic surgery for middle and low rectal cancer) study, a multicenter, randomized, controlled, unblinded, parallel group, superiority trial. This analysis included the modified intention-to-treat population of the REAL study, who were divided into Group I (the surgeon's first surgery of the day), Group II (the surgeon's second surgery of the day), and Group III (the surgeon's third and subsequent surgeries of the day) based on surgical information registered in the REAL study. The primary outcome was the percentage of patients with a positive circumferential resection margin. The second outcomes were the macroscopic completeness of resection the incidence of intraoperative complications and 30-day postoperative complications. A total of 1171 patients from the REAL study were included and divided into three groups: 547 (46.7%) in Group I (the surgeon's first surgery), 420 (35.9%) in Group II (the surgeon's second surgery), and 204 (17.4%) in Group III (the surgeon's third and subsequent surgeries). There was a lower percentage of circumferential resection margin (CRM)-positive patients in Group I (3.9%) than in Group II (6.6%, unadjusted P = 0.069) and Group III (8.1%, unadjusted P = 0.027, adjusted P = 0.081). Group I also had fewer intraoperative complications (5.3%) than Group II (8.3%, unadjusted P = 0.060) and Group III (9.3%, unadjusted P = 0.046, adjusted P = 0.138). Macroscopic completeness of resection was not significantly different among the three groups (complete rate: Group I vs. Group II, 94.9% vs. 92.4%, unadjusted P = 0.254; Group I vs. Group III, 94.9% vs. 92.6%, unadjusted P = 0.334; Group II vs. Group III, 92.4% vs. 92.6%, unadjusted P = 0.488). The incidence of 30-day postoperative complications showed no significant difference among the three groups (Group I vs. Group II, 18.5% vs. 20.0%, unadjusted P = 0.547; Group I vs. Group III, 18.5% vs. 22.1%, unadjusted P = 0.268; Group II vs. Group III, 20.0% vs. 22.1%, unadjusted P = 0.551). The quality of robotic surgery was not significantly influenced by surgical start time. For laparoscopic surgery, Group I had a lower CRM positivity rate (4.3%) than Group II (9.4%, unadjusted P = 0.029, adjusted P = 0.087) and Group III (10.4%, unadjusted P = 0.031, adjusted P = 0.047). According to this post hoc analysis of the REAL study, for middle and low rectal cancer surgery, surgical start time could influence surgical quality by affecting surgeon fatigue. Surgeries start later in a day bring worse quality compared to those early in a day. Robotic surgery could reduce this influence to some extent, while laparoscopic surgery is more susceptible.