Effect of epidural analgesia on colorectal anastomotic healing and colonic motility

Background and Objectives. To examine the effect of epidural local anesthetic and narcotic agents on colonic anastomotic healing. Methods. A prospective randomized study was conducted in a porcine model. Twenty-one pigs undergoing colorectal resection and anastomosis were randomized to receive either bupivacaine (Group 1), morphine (Group 2), or normal saline (Group 3) by intraoperative and postoperative epidural infusion. Colonic blood flow was measured using laser doppler velocimetry and colonic motility assessed with radio- opaque markers and daily x-rays postoperatively. Seven days postoperatively, the anastomoses were resected and analysis of bursting pressure and hydroxyproline content performed. Results. In this porcine model, epidural anesthesia accelerated colonic transit time. Group 1 and 2 animals had significantly faster colonic transit time (3.9 and 4 days, respectively) when compared with Group 3 animals (6 days; p < 0.05, chi-square analysis). There was no statistically significant difference in blood flow, bursting pressure, and hydroxyproline content between the three groups, and no anastomotic complications occurred in any animal. Conclusions. These findings suggest in this model that postoperative epidural analgesia is a safe technique after colorectal resection and anastomosis.