Comparison of short-term outcomes between robot-assisted and laparoscopic rectal surgery for rectal cancer: A propensity score-matched analysis using the Japanese Nationwide diagnosis procedure combination database

Background: The use of robot-assisted surgery for rectal cancer is increasing, but its short-term results remain unclear. We compared the short-term outcomes of robot-assisted and laparoscopic surgery for rectal cancer using a nationwide inpatient database.Methods: We analyzed patients registered in the Japanese Diagnosis Procedure Combination database who underwent robot-assisted or laparoscopic surgery for rectal cancer from April 2018 to March 2020. Postoperative complication rates, anesthesia time, length of hospital stay, and cost were compared using propensity score matching for low anterior resection (LAR), high anterior resection (HAR), and abdominoperineal resection (APR).Results: Among 38 090 rectal cancer cases, 1992 LAR, 357 HAR, and 310 APR pairs were generated by propensity score matching and analyzed. Anesthesia time was longer for robot-assisted surgery compared with laparoscopic surgery (LAR: 388.6 vs. 452.8 min, p < 0.001; HAR: 300.9 vs. 393.5 min, p < 0.001; APR: 4478.5 vs. 533.5 min, p < 0.001). Robot-assisted surgery was associated with significantly shorter hospital stay for LAR (22.3 vs. 20.0 days, p < 0.001) and APR (29.2 vs. 25.9 days, p = 0.029). Total costs for LAR were significantly lower for robot-assisted surgery (2031511.6 vs. 1955216.6 JPY, p < 0.001). The complication rates for robot-assisted surgery tended to be fewer than laparoscopic surgery for all procedures, but the differences were not significant.Conclusions: Although the anesthesia time was longer for robot-assisted surgery, the procedure resulted in shorter hospital stay for LAR and APR, and lower costs for LAR compared with laparoscopic surgery. Robot-assisted surgery can thus help to reduce costs and can be performed safely.