The postoperative analgesic efficacy of preperitoneal continuous wound infusion compared to epidural continuous infusion with local anesthetics after colorectal cancer surgery: a randomized controlled multicenter study.

BACKGROUND: Open colorectal cancer (CRC) surgery induces severe and prolonged postoperative pain. The optimal method of postoperative analgesia in CRC surgery has not been established. We evaluated the efficacy of preperitoneal continuous wound infusion (CWI) of ropivacaine for postoperative analgesia after open CRC surgery in a multicenter randomized controlled trial. METHODS: Candidates for open CRC surgery randomly received preperitoneal CWI analgesia or continuous epidural infusion (CEI) analgesia with ropivacaine 0.2% 10 mL/h for 48 hours after surgery. Fifty-three patients were allocated to each group. All patients received patient-controlled IV morphine analgesia. RESULTS: Over the 72-hour period after the end of surgery, CWI analgesia was not inferior to CEI analgesia. The difference of the mean visual analog scale score between CEI and CWI patients was 1.89 (97.5% confidence interval = -0.42, 4.19) at rest and 2.76 (97.5% confidence interval = -2.28, 7.80) after coughing. Secondary end points, morphine consumption and rescue analgesia, did not differ between groups. Time to first flatus was 3.06 ± 0.77 days in the CWI group and 3.61 ± 1.41 days in the CEI group (P = 0.002). Time to first stool was shorter in the CWI than the CEI group (4.49 ± 0.99 vs 5.29 ± 1.62 days; P = 0.001). Mean time to hospital discharge was shorter in the CWI group than in the CEI group (7.4 ± 0.41 and 8.0 ± 0.38 days, respectively). More patients in the CWI group reported excellent quality of postoperative pain control (45.3% vs 7.6%). Quality of night sleep was better with CWI analgesia, particularly at the postoperative 72-hour evaluation (P = 0.009). Postoperative nausea and vomiting was significantly less frequent with CWI analgesia at 24 hours (P = 0.02), 48 hours (P = 0.01), and 72 hours (P = 0.007) after surgery evaluations. CONCLUSIONS: Preperitoneal CWI analgesia with ropivacaine 0.2% continuous infusion at 10 mL/h during 48 hours after open CRC surgery provided effective postoperative pain relief not inferior to CEI analgesia.