Prospective randomized study of stress and immune response after laparoscopic vs conventional colonic resection

Methods: In order to evaluate the stress and immunological response to laparoscopic and conventional colon resection we operated on male Wistar rats (350-380 g), performing either laparoscopic (n = 15) or open colon resection (n = 15). A third group (n = 10) underwent anesthesia only. Immediately before and after surgery as well as 1 and 7 days postoperatively a I mi sample of blood was taken from the retrobulbar veinous plexus. Stress (corticosterone) and immune parameters (neopterin and interleukin [IL] 1-beta) were measured. Furthermore, the body weight as a parameter of postoperative recovery was monitored. Results: The analysis of variance showed significant differences between the three groups over a period of 1 week (p < 0.0001 for corticosterone, p = 0.0854 for IL 1-beta, p = 0.0045 for neopterin). Additionally in a t-test significant differences were found between the laparoscopic and conventional group with regard to corticosterone(p = 0.08), to neopterin (p = 0.045), and to IL 1-beta (p = 0.0043) at the end of the operation. One week after the operation the stress and immune parameters were back to normal levels in each group except IL 1-beta, but the recovery indicated by body weight was different according to the kind of the applied operative procedure: 7 days postoperatively the rats lost 5.99% of their body weight after open surgery and only 2.4% after laparoscopic surgery. After anesthesia only the body weight increased by about 4.8%. Conclusion: Laparoscopic colon resection alters the stress and immune system of healthy rats less than open colon resection. This observation is confirmed by the quicker recovery in laparoscopically operated rats.