Intestinal manipulation during elective aortic aneurysm surgery leads to portal endotoxaemia and mucosal barrier dysfunction

Objectives: to investigate the effect of intestinal manipulation on intesti nal permeability and endotoxaemia during elective abdominal aortic aneurysm (AAA) surgery. Design: prospective randomised controlled study. Patients and methods: fourteen patients undergoing elective infrarenal AAA repair were randomised into either the transperitoneal (n = 7) or extraperi toneal approach (n = 7). Intestinal permeability was measured preoperativel y (PO), and at day 1 (D1) and day 3 (D3) after surgery using the lactulose/ mannitol absorption test. Portal and systemic blood samples were taken befo re clamping, at completion of proximal and distal anastomoses and immediate ly before abdominal wound closure, for endotoxin measurement using the chro mogenic limulus amoebocyte lysate assay. Results: intestinal permeability was significantly increased at D1 (0.107+/ -0.04 (mean+/-S.E.M.)) in the transperitoneal group compared to the PO leve l (0.020+/-0.004, p<0.05) and to the extraperitoneal group at D1 (0.020+/-0 .004, p<0.05) which showed no change in comparison with the PO level. No co rrelation was seen between increased intestinal permeability and aortic cla mp time, operation time, amount of blood lost or transfused. However, a sig nificantly higher concentration of portal endotoxin was detected intraopera tively in the transperitoneal group of patients in comparison to the extrap eritoneal group (p<0.05). There was a significant positive correlation betw een portal endotoxaemia and intestinal permeability (r(s)=0.955; p=0.001). Conclusion: an increase in intestinal permeability and a greater degree of portal endotoxaemia are observed during transperitoneal approach to the aor ta. This suggests that intestinal manipulation may impair gut mucosal barri er function and contribute to the systemic inflammatory response seen in AA A surgery.