Physiologic responses to laparoscopic aortofemoral bypass grafting in an animal model.

Abstract

To measure and compare the physiologic, metabolic, and hemodynamic responses to aortofemoral bypass grafting by three techniques: open or conventional laparotomy, laparoscopic-assisted (minilaparotomy), and totally laparoscopic grafting. Twenty-four laboratory-bred hounds were randomized to one of three groups (open, laparoscopic-assisted, or totally laparoscopic). Four sets of parameters were measured: hemodynamic (intraoperative continuous cardiac output monitoring), inflammatory or hematologic (serial leukocyte and platelet levels), metabolic responses (serial blood glucose, serum cortisol and insulin, plasma epinephrine, plasma norepinephrine, and dopamine levels), and catabolic (24-hour urinary nitrogen excretion). Cardiac output increased transiently with aortic cross-clamping, more in the laparoscopic-assisted and total laparoscopic groups than in the open group, but the differences were not significant. White blood counts nearly doubled within 12 hours of surgery but were similar in all three groups. Platelet counts decreased significantly in all three groups, but no significant intergroup effects were observed. Metabolic parameters (e.g., blood glucose, cortisol, and catecholamine) rose significantly during surgery but fell to normal within 24 hours, with no important difference between groups. For the first 24 hours, urinary urea excretion fell by 50% but returned to normal by 7 days in all three groups. In the experimental animal model, the hemodynamic, hematologic, and metabolic responses to laparoscopic and laparoscopic-assisted aortofemoral bypass grafting are similar to those produced by conventional laparotomy graft placement. These data call into question whether laparoscopic techniques for aortic surgery have a significant physiologic advantage in humans.