Sigmoid ischemia and the inflammatory response following endovascular abdominal aortic aneurysm repair

Purpose: To assess the relationship between sigmoid colonic perfusion, endo toxemia, and cytokine generation in patients undergoing elective open repai r (OR) or endovascular repair (EVR) of infrarenal abdominal aortic aneurysm s (AAA). Methods: Ten patients (9 males; average age 67.6 +/- 2.5 years, mean aneury sm diameter 6.9 +/- 0.6 cm) undergoing OR were compared to 10 patients (all males; average age 70.3 +/- 2.6 years, mean aneurysm diameter 6.5 +/- 0.5 cm) whose repair was performed using the EVR technique. The partial pressur e of the carbon dioxide gap (PCO2gap = tissue PCO2 - arterial PCO2,) of the sigmoid colonic mucosa was measured using a silicone tonometer to evaluate bower perfusion. Blood samples were collected into pyrogen-free heparinize d tubes for quantification of plasma concentrations of endotoxin, tumor nec rosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) before, during, an d after aortic repair. Results: Patients in the OR group had a significantly greater increase in P CO2gap, suggesting a greater degree of bowel ischemia compared to the EVR g roup. This was associated with significantly greater postoperative concentr ations of endotoxin, TNF-alpha, and IL-6 in the OR group. A significant cor relation was found between PCO2gap, IL-6, and postoperative core temperatur e. Conclusions: The results suggest that the degree of bowel ischemia, endotox emia, and cytokine generation following elective infrarenal AAA reconstruct ion may be reduced if the endovascular technique is used instead of convent ional surgery.