Immune cell populations and cytokine production in spleen and mesenteric lymph nodes after laparoscopic surgery versus conventional laparotomy in mice
BACKGROUND This study compares the effects of carbon dioxide pneumoperitoneum versus laparotomy on cellular-mediated immune response in a murine model. METHODS Sixty-eight female C3H/He mice were sensitized to keyhole limpet hemocyanin (KLH) and to a mouse mammary carcinoma cell line (MC2) before surgery. Animals were randomized into 4 groups: group I, anesthesia (control); group II, pneumoperitoneum with carbon dioxide; group III, extraperitoneal wound; group IV, laparotomy. All animals were challenged subsequently with KLH and MC2 tumor cells. Delayed-type hypersensitivity skin reaction (DTH) to KLH was measured on postoperative days (PODs) 1, 2, 4, and 5. Tumor growth was assessed weekly as an indicator of postoperative cellular immune response. RESULTS Compared with preoperative values, postoperative DTH skin reactions were significantly less for all PODs in groups III and IV (P < .05), on POD 1 and 4 in group II (P < .05) and POD 4 for group I (P < .05). Group IV showed significantly fewer DTH skin reactions for all PODs compared with groups I and II (P < .05) and all PODs except on day 2 compared with group III (P < .05). Tumor growth was significantly increased at postoperative week 2 (n = 3/17 mice) and 3 (n = 4/17 mice) in group IV, when compared with groups I and II (P < .05). CONCLUSIONS Cellular immunity is preserved after carbon dioxide pneumoperitoneum compared with extraperitoneal incisions and laparotomy as measured by DTH and the ability to reject an immunogenictumor.