The effects of hospital volume on short-term outcomes of laparoscopic surgery for rectal cancer: A large-scale analysis of 37,821 cases on a nationwide administrative database.

Introduction Laparoscopic low anterior resection (L-LAR) has become widely accepted for the treatment of rectal cancer. However, little is known about the superiority of L-LAR in a real-world setting (including low-volume hospitals) and the association between the short-term outcomes and hospital volume focusing on L-LAR. Methods This is a retrospective cohort study. A total of 37,821 patients who underwent LAR for rectal cancer were analyzed using the Diagnosis Procedure Combination (DPC) database from January 2014 to December 2017. The short-term surgical outcomes were analyzed using a multilevel analysis. Hospital volumes were divided into quartiles, including low (1-31), middle (32-55), high (56-91) and very-high volume (92-444 resections per 4 years). The effects of hospital volume on the outcomes were investigated. Results The study population included 8,335 patients (22%) who underwent Open-LAR (O-LAR) and 29,486 patients (78%) who underwent L-LAR. The in-hospital mortality and morbidity were in consistent with previous reports. In patients who underwent L-LAR, the in-hospital mortality (0.12% vs 0.41%, OR0.33; p=0.005), the rate of reoperation (3.76% vs 6.48%, OR0.67; p<0.001) and perioperative transfusion rate (3.81% vs 5.90%, OR0.66; p<0.001) were significantly lower in very-high-volume hospitals than in low-volume hospitals. These effects of hospital volume were not observed in O-LAR. Conclusions Our present study demonstrate that high-volume improves outcomes in patients who underwent L-LAR in a real-world setting.