The net immunologic advantage of laparoscopic surgery.

The trauma of surgery evokes a variety of physiologic and immunologic alterations that should contribute to host defense. However, an exaggerated response to injury may result in immunosuppression and lead to significant postoperative morbidity and mortality. Laparoscopic surgery may result in less induced surgical trauma than conventional open surgery. Decreased postoperative pain and speedy functional recovery of laparoscopic patients may be attributable to the reduced inflammatory response and minimal immunosuppression. Inflammation, an early protective homeostatic immune response to injury, is characterized by the production of proinflammatory cytokines and by activation of cellular and humoral immune mechanisms. Postoperative levels of the inflammatory cytokines have been consistently lower after laparoscopic procedures, indicating a smaller degree of surgical insult and acute inflammatory reaction. Surgical stress derails the functions of both polymorphonuclear and mononuclear cells, which may lead to an increased risk of postoperative infection. Comparative studies of cellular immunity after laparoscopic and conventional surgery demonstrate immunologic advantage conferred by laparoscopy. Exaggerated activation of peritoneal immunity may lead to a relative local immunosuppression, resulting in ineffective intraperitoneal bacterial clearance and serious postoperative infections. Functions of the peritoneal macrophages are better preserved when laparotomy is avoided. Decreased perioperative stress may be particularly important for oncologic patients. Laparoscopic approaches may result in diminished perioperative tumor dissemination and better cancer outcomes. Although laparoscopy is "minimally invasive," systemic immune responses still are undeniably activated. However, laparoscopic surgery appears to induce a smaller injury, resulting in proportionally decreased immunologic changes. In addition to improved cosmesis and faster functional recovery, a patient undergoing laparoscopic surgery may benefit most from a net immunologic advantage.