Open Abdominal Aortic Aneurysm Surgery and Renal Dysfunction; Association of Demographic and Clinical Variables with Proximal Clamp Location.

BACKGROUND:While cross-clamp site is a known risk factor for postoperative acute and chronic renal dysfunction following open abdominal aortic aneurysm surgery (AAA), the additive impact of patient demographic and clinical factors is lacking. In this study, we investigated the impact of body mass index (BMI), surgical duration and aneurysm diameter on the association between proximal cross-clamp location and postoperative renal dysfunction. METHODS:In this study, we conducted a retrospective analysis of 4,197 patients undergoing open AAA surgery between 2011 and 2018 using data housed in the American College of Surgeons National Safety Quality Improvement Program (ACS-NSQIP) database. The primary outcome was renal dysfunction, which was defined as patients requiring dialysis within 30 days or patients with ≥2 mg/dL rise in creatinine from baseline. We assessed the incidence of renal dysfunction with regard to clamp location and subsequently used multivariable logistic regression to assess clinical and demographic factors associated with renal dysfunction. We used a regression model to plot the association of BMI, surgical duration, and aneurysm diameter with an adjusted probability of postoperative acute and chronic renal dysfunction for individual cross-clamp locations. RESULTS:Of the 4,197 patients analyzed, 405 patients (9.6%) developed renal dysfunction within 30 days with 287 patients requiring dialysis. Patients with supraceliac clamp location had the highest incidence of renal dysfunction (20.4%). Our data showed a significant association of renal dysfunction with higher BMI patients [OR 1.04 (1.02, 1.07), P = 0.001], longer operative times [OR1.01 (1.01, 1.02), P < 0.001], clamp location between the superior mesenteric artery (SMA) and renal artery [OR 1.80 (1.17, 2.78), P = 0.007] and supraceliac clamp location [OR 2.47 (1.62, 3.76), P < 0.001]. CONCLUSIONS:The incidence of renal dysfunction increases with suprarenal clamps. Patients with higher BMI, longer operative times, and increasing aneurysm diameter, and a suprarenal clamp have a significantly increased risk of renal dysfunction compared to those who also had a suprarenal clamp but lower BMI, shorter operative times and smaller aneurysm diameter.