Thirty-day outcomes of open abdominal aortic aneurysm repair by proximal clamp level in patients with normal and impaired renal function.

ABSTRACT

OBJECTIVE: Open surgical repair (OSR) of abdominal aortic aneurysms (AAAs) has often been reserved in contemporary practice for complex aneurysms requiring a suprarenal or supraceliac proximal clamp level. The present study investigated the associated 30-day outcomes of different proximal clamp levels in OSR of complex infrarenal/juxtarenal AAA in patients with normal renal function and those with chronic renal insufficiency (CRI). METHODS: All patients undergoing elective OSR of infrarenal and juxtarenal AAA were identified in the American College of Surgeons National Surgical Quality Improvement Program-targeted AAA database from 2012 to 2018. The patients were stratified into two cohorts (normal renal function [estimated glomerular filtration rate, ≥60 mL/min] and CRI [estimated glomerular filtration rate, <60 mL/min and no dialysis]) before further substratification into groups by the proximal clamp level (infrarenal, inter-renal, suprarenal, and supraceliac). The 30-day outcomes, including mortality, renal and pulmonary complications, and major adverse cardiovascular event rates, were compared within each renal function cohort between proximal clamp level groups using the infrarenal clamp group as the reference. Supraceliac clamping was also compared with suprarenal clamping. RESULTS: A total of 1284 patients with normal renal function and 524 with CRI were included in the present study. The proximal clamp levels for the 1808 patients were infrarenal for 1080 (59.7%), inter-renal for 337 (18.6%), suprarenal for 279 (15.4%), and supraceliac for 112 (6.2%). In the normal renal function cohort, no difference was found in 30-day mortality with any clamp level. Increased 30-day acute renal failure was only observed in the supraceliac vs infrarenal clamp level comparison (5.9% vs 1.5%; adjusted odds ratio [aOR], 3.97; 95% confidence interval [CI], 1.04-5.18; P = .044). In the CRI cohort, supraceliac clamping was associated with an increased rate of renal composite complications (22.7% vs 5.6%; aOR, 8.81; 95% CI, 3.17-24.46; P < .001) and ischemic colitis (13.6% vs 3.0%; aOR, 4.78; 95% CI, 1.38-16.62; P = .014) compared with infrarenal clamping and greater 30-day mortality (13.6% vs 2.4%; aOR, 6.00; 95% CI, 1.14-31.55; P = .034) and renal composite complications (22.7% vs 10.8%; aOR, 2.87; 95% CI, 1.02-8.13; P = .047) compared with suprarenal clamping. Suprarenal clamping was associated with greater renal dysfunction (10.8% vs 5.6%; aOR, 2.77; 95% CI, 1.08-7.13; P = .035) compared with infrarenal clamping, with no differences in mortality. No differences were found in 30-day mortality or morbidity for inter-renal clamping compared with infrarenal clamping in either cohort. No differences were found in major adverse cardiovascular events with higher clamp levels in either cohort. CONCLUSIONS: In elective OSR of infrarenal and juxtarenal AAAs for patients with CRI, this study found a heightened mortality risk with supraceliac clamping and increased renal morbidity with suprarenal clamping, though these effects were not present for patients with normal renal function. Every effort should be made to keep the proximal clamp level as low as possible, especially in patients with CRI.