Single-docking robotic assisted proctectomy for rectal cancer below peritoneal reflection: a propensity score matching analysis.

Background The aim of this study was to compare the short and long-term outcomes of robotic assisted proctectomy (RP) and laparoscopic assisted proctectomy (LP) for rectal cancer below the peritoneal reflection using propensity score matching (PSM) analysis. Methods We evaluated the medical records of 200 patients who underwent proctectomy for rectal cancer below the peritoneal reflection through a robotic (n=81) or laparoscopic (n=119) approach between Jan 2015 and Dec 2017. The data were prospectively collected, and the patients were matched at a ratio of 1:1 according to age, sex, body mass index (BMI), previous abdominal surgeries, comorbidities, American Society of Anesthesiologist score (≤2/>2), and pathologic stage. Results After matching, each group included 74 patients. Compared to the LP group, the RP group showed shorter postoperative hospital stays (PHS) [7 (±2) vs. 9 (±2.3) d, P=0.003], shorter time to liquid diet [3 (±2) vs. 5 (±3) d, P<0.001], and shorter time to removal of catheter [6 (±2) vs. 7 (±2.3) d, p=0.014]. The operative expense was higher in the RP group [8,365 (±1,600) vs. 6,922 (±1,220) RMB, P<0.001]. The operation time, estimated blood loss, postoperative complications, and pathologic outcomes were similar between the two groups. No conversion to laparotomy, readmission, or mortality was observed in either group within 30 days after surgery. The 3-year disease-free survival (DFS) were 75.2% and 88.3% (P=0.070), and overall survival (OS) were 92.9% and 93.7% (P=0.810) in the RP and the LP groups, respectively and the risk of low anterior resection syndrome (LARS) was lower in the RP group (OR =0.304, 95% CI: 0.124-0.745, P=0.009). Conclusions Compared to LP, RP is worth recommending as it has long-term survival, faster postoperative recovery, and a lower risk of LARS in patients with rectal cancer below the peritoneal reflection.