PRESERVATION OF IMMUNE-RESPONSE AFTER LAPAROSCOPY

We evaluated the immunologic responses following laparoscopic and open surgery by comparing delayed type hypersensitivity induration size be fore and after each method of accessing the abdominal cavity. One hund red and thirty-two male Sprague-Dawley rats were sensitized with keyho le limpet hemocyanine (KLH). Animals were challenged with KLH and phyt ohemaglutanin (PHA) 10 days after sensitization. On day 14 after initi al sensitization animals were randomly divided into three groups. Grou p one served as controls and had no procedure performed, group two und erwent peritoneal insufflation with carbon dioxide gas to a pressure o f 6-8 mm Hg for one half hour, and rats in group three had a midline l aparotomy which was closed after one half hour. Each rat was challenge d with KLH immediately and at three days postoperatively. The area of induration in response to each of the challenges was measured with cal ipers 24 and 48 hours after the challenge. Results of this skin testin g showed that the group of animals that underwent laparotomy, despite having normal responses preoperatively, had significantly diminished r esponses to both KLH and PHA when challenged postoperatively. The insu fflated group showed no differences from control animals at any time p oint examined. We conclude that DTH response in this model is better p reserved after laparoscopy than laparotomy. We further conclude that t he defect in DTH response is in the effector arm. The question of the clinical significance of these findings is addressed.