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

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 1 ml 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.

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%.

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.