Short-term outcomes of intracorporeal anastomosis in laparoscopic colectomy for colon cancer: A nationwide, multi-institutional cohort study in Japan (ICAN study)

Background Several randomized controlled trials and meta-analyses have demonstrated the potential advantages of intracorporeal over extracorporeal anastomosis. However, the heterogeneity and small samples of these studies complicate drawing clear conclusions regarding such advantages. In this nationwide, multicenter, retrospective cohort study, we aimed to clarify the benefits of intracorporeal over extracorporeal anastomosis in patients undergoing laparoscopic colectomy for colon cancer. Methods This study included 46 institutions. Patients with clinical stage 0-III colon adenocarcinoma who underwent laparoscopic colectomy between January 2020 and December 2021 were evaluated. The effect of intracorporeal anastomosis on short-term outcomes compared to extracorporeal anastomosis was assessed using propensity score matching. Results A total of 1245 patients (intracorporeal, n = 615; extracorporeal, n = 630) were included in the final analysis. The operative time was longer (228 vs. 207 min, p < 0.001), but blood loss was also lower (5.0 vs. 10.0 mL, p < 0.001) and the incidence of intraoperative vascular injury appeared lower (0.5% vs. 1.6%, p = 0.091) in the intracorporeal group than those in the extracorporeal group. The time to first passage of stool (2.9 vs. 3.5 days, p < 0.001) and length of hospital stay (9.3 vs. 10.2 days, p = 0.008) were shorter in the intracorporeal group. Conclusions Intracorporeal anastomosis showed advantages over extracorporeal anastomosis in terms of blood loss, intraoperative vascular injury (potentially), bowel recovery, and length of hospital stay, despite the longer operative time.