Neutrophil Activation Occurs in the Lower-limbs of Patients Undergoing Elective Repair of Abdominal Aortic Aneurysm

Abstract Objectives AAA repair is associated with a systemic inflammatory response, mediated in part by neutrophils. The aim of this study was to determine where neutrophil activation occurs. Methods Blood was sampled from the femoral vein, portal vein and radial artery of 10 patients undergoing elective AAA repair at four time-points [induction of anaesthesia (systemic sample only), pre-aortic clamp application, pre-clamp removal and after 30 min of reperfusion]. Whole blood was analysed for the white cell count, neutrophil count, and for neutrophil CD11b expression. Results The white cell count and neutrophil counts increased after aortic clamp release. Neutrophil expression of CD11b was significantly higher in the femoral vein than the portal vein and systemic circulation during ischaemia [ P =0.001 (FV vs. PV), P =0.017 (FV vs. systemic)] and reperfusion [ P =0.001 (FV vs. PV), P =0.013 (FV vs. systemic)]. There were no significant differences in neutrophil CD11b expression between the systemic and portal vein samples at any time. Conclusions Ischaemia and reperfusion during abdominal aortic aneurysm repair are associated with a global increase in the white cell count and neutrophil count, but with increased neutrophil CD11b expression only in the femoral vein. This suggests the lower-limbs are sensitive to aortic clamp-related reperfusion injury and may fuel the inflammatory response.