To compare the clinical outcomes of the conventional precision functional sphincter-preserving surgery (PPS) with modified PPS based on precision anastomosis and Liu's three-step anastomosis in the treatment of ultra-low rectal cancer.

Data of patients with ultra-low rectal cancer who underwent PPS from June 2019 to May 2021 were prospectively collected. Patients were divided into two groups, namely the conventional group and modified group. Baseline characteristics, pathological data, and postoperative outcomes were compared between the two groups.

A total of 135 patients were included, including 110 cases in the conventional group and 25 cases in the modified group. There was no significant difference in baseline characteristics and pathological data between two groups, including intraoperative bleeding (127 mL vs. 125 mL), operation time (207 min vs. 219 min) and distal resection margin (1.2 cm vs. 1.3 cm). There was no significant difference in postoperative hospital stay (13.5 days vs. 12.4 days) and operation cost (64 661.3 RMB vs. 62 096.8 RMB). The modified PPS significantly reduced the proportion of prophylactic stoma (37.3% vs. 12%, P=0.015), the overall incidence of complications (32.7% vs. 12.0%, P=0.039) and the incidence of anastomotic leakage (22.7% vs. 0%, P=0.008).

Modified PPS that based on precision anastomosis and Liu's anastomosis can significantly reduce the proportion of prophylactic stoma and the risk of anastomotic leakage, which has a broad prospect and good socioeconomic benefits.