Clinical effect of rectus sheath block compared to intrathecal morphine injection for minimally invasive colorectal cancer surgery: a propensity score–matched study

Purpose: To evaluate the postoperative outcomes of a multimodal perioperative pain management protocol with rectus sheath blocks (RSBs) or intrathecal morphine (ITM) injection for minimally invasive colorectal cancer surgery. Methods: A total of 112 patients underwent minimally invasive colorectal surgery. Forty-one patients underwent RSB (group 1), whereas 71 patients underwent ITM (group 2) in addition to multimodal pain management using enhanced recovery after the surgery protocol. To adjust for the baseline differences and selection bias, baseline characteristics and postoperative outcomes were compared using propensity score matching. Results: Forty patients were evaluated in each group. There was no significant difference in the length of hospital stay between the two groups. According to the Comprehensive Complication Index (CCI) score, the postoperative complication rate was significantly lower in the RSB group (3.0 ± 7.8) than in the ITM group (8.1 ± 10.9; p = 0.016). During the first 24 h after surgery, the median postoperative visual analog scale score was significantly higher in the RSB group than in the ITM group (2.0 ± 1.1 vs. 1.5 ± 1.2; p = 0.048). Postoperative morphine use was also significantly higher in the RSB group than in the ITM group in the first 24 h (23.7 ± 19.8 vs 11.6 ± 15.6%; p = 0.003) and 48 h (16.9 ± 24.8 vs. 7.5 ± 11.9; p = 0.036) after surgery. Significant urinary retention occurred after the in the RSB and ITM groups (5% vs. 45%; p < 0.001). Conclusion: Although the RSB group had higher morphine use during the first 48 h after surgery, the length of hospital stay remained the same and the complications were less in terms of the CCI score. Thus, transperitoneal RSB is a safe and feasible approach for postoperative pain management following minimally invasive procedures.