[Comparative study of clinical outcomes of robot versus laparoscopic radical surgery for rectal cancer based on propensity score matching]

Objective: To compare the short-term and long-term outcomes of robotic rectectomy and laparoscopic rectectomy for rectal cancer based on propensity score matching. Methods: The clinical data of 106 patients who underwent robotic or laparoscopic radical resection of rectal cancer at Department of General Surgery, the First Affiliated Hospital of Nanchang University from January 2015 to December 2015 were retrospectively collected. Propensity score matching method was used to perform 1∶1 matching between robot and laparoscopic rectal cancer radical surgery. Thirty-two patients in robot group and 32 patients in laparoscopic group were successfully matched. There were 15 males and 17 females in the robotic group, aging (56.2±7.5) years, 19 males and 13 females in the laparoscopic group, aged (55.5±7.6) years. The clinical outcome of the two groups were compared using t-test or Mann-Whitney U test for continuous variables, repeated measures analysis of variance, χ(2) test, Fisher exact test or Wilcoxon rank sum test for dichotomous variables. The overall survival curve was drawn by Kaplan-Meier curve and the difference of survival curve was compared by Log-rank method. Results: The general data of the two groups of patients were comparable after matching. Sixty-four patients successfully completed robotic or laparoscopic operation without conversion to open surgery or perioperative death case. The total operative time, the lymph node namely No. 253 group dissection time, intraoperative blood loss, postoperative urethral catheter retention time, the serum C-reactive protein levels of 24 hours after surgery were (135.7±12.1) minutes, (11.6±2.7) minutes, (66.8±10.2) ml, 3.0(1.0) d,(50.9±7.7) μg/L, respectively, while in laparoscopic group were (124.9±23.2) minutes, (13.2±2.7) minutes, (74.8±13.9) ml, 4.0(2.0) d, (55.9±6.7) μg/L respectively. The differences were statistically significant (t=2.341, t=-2.354, t=-2.621, Z=-2.743, F=7.902, respectively, P<0.05). There were no statistical differences in separation time, numbers of retrieved lymph nodes, time to first flatus, postoperative hospital stay, postoperative complication and Clavien-Dindo classification of postoperative complications (t=0.336, t=0.714, t=-0.568, Z=-1.766, Fisher Z=-0.586, respectively, all P>0.05). Conclusions: Robotic surgery not only has similar safety and feasibility but also has advantages of short-term outcomes compared with laparoscopic rectectomy for rectal cancer. The long-term outcomes were similar between two groups.