Technical factors are strongest predictors of postoperative renal dysfunction after open transperitoneal juxtarenal abdominal aortic aneurysm repair

Abstract

Objective: Juxtarenal abdominal aortic aneurysms (AAAs) have predominantly been repaired using an open technique. We present a series of patients with juxtarenal AAAs and analyze multiple factors predictive of postoperative renal dysfunction.

Methods: Between March 2000 and September 2011, all patients in our prospectively maintained database undergoing juxtarenal AAA repair were evaluated for demographics, operative details, and in-hospital outcomes. Postoperative renal dysfunction was classified using the RIFLE (risk, injury, failure, loss, end-stage renal disease) criteria (glomerular filtration rate decrease >25%). The relationship between perioperative factors and postoperative renal dysfunction was explored using both univariate and multivariate analysis (logistic regression).

Results: Of 169 patients, 76 (45%) required clamping above one renal artery, whereas 93 patients (55%) required clamping above both renal arteries. Mean (standard deviation) renal ischemia time was 29.2 (8.9) minutes (range, 12-65 minutes). Twenty-seven patients (16%) underwent adjunctive renal procedures, 19 (11.3%) required left renal vein division, and 130 (76.9%) received intraoperative mannitol. Postoperative renal dysfunction occurred in 63 patients (37.3%), with the majority (69%) resolving during hospital stay. Seven patients (4.1%) required postoperative dialysis, which was permanent in two cases. Patients who developed postoperative renal dysfunction had significantly longer mean renal ischemia times (34.7 [9.3] minutes vs 25.9 [6.6] minutes; P < .001), a higher rate of bilateral suprarenal aortic clamping (68.3% vs 47.2%; P = .008), higher rates of adjunctive renal artery procedures (26.7% vs 8.8%; P = .002), and higher rates of left renal vein division (20.6% vs 5.7%; P = .003). Logistic regression identified left renal vein division, renal ischemia time, and aortic clamp position as the strongest predictors of renal dysfunction. The use of mannitol was seen to be protective. Overall in-hospital mortality was 4.1% and was 9.5% among patients with postoperative renal dysfunction.

Conclusions: Postoperative transient renal dysfunction occurred in 37.3% of patients after open juxtarenal AAA repair, with a low incidence of dialysis and a low rate of permanent dysfunction. Technical factors including renal ischemia time, aortic clamp position, and left renal vein division are the strongest predictors of renal dysfunction. The use of intraoperative mannitol was associated with decreased postoperative renal dysfunction.