Early and late effects of suprarenal aortic cross-clamping on kidney function in patients undergoing open surgery for complex abdominal aortic aneurysms

Background: Aim of this study was to analyze perioperative factors affecting long-term decline of renal function in patients undergoing Open Surgical Repair (OSR) with suprarenal aortic cross-clamping for pararenal/juxtarenal/"short-neck" abdominal aortic aneurysms (AAAs). Methods: Between November 2012 and February 2022, a retrospectively maintained dataset of all consecutive AAAs who underwent OSR was investigated. Elective surgery, suprarenal aortic cross-clamping, and pararenal/ juxtarenal/"short-neck" AAA have been considered eligibility criteria. One-hundred-eighteen patients were included. Early (30-day) outcomes were evaluation of acute kidney injury (AKI), defined either as a decrease in eGFR >50% or as a doubling of serum creatinine at the nadir of patient's kidney function (RIFLE criteria). At follow-up, main primary outcome was freedom from major adverse kidney event (MAKE). Secondary outcomes were survival, and freedom from reintervention(s). Estimated 5-year outcomes were assessed. Multivariate Cox regression analysis was used to evaluate factors affecting MAKE during the follow-up. Results: Complex AAAs were: pararenal in FOUR cases (3.4%), juxtarenal in 58 cases (49.1%), and 'short neck' in 56 cases (47.5%). Bilateral suprarenal was the most common modality of aortic cross-clamping (100, 84.7%). Mean renal ischemia time was 31.5 +/- 12.7 min. At 30 days, mortality rate was 2.5%. During the postoperative period, 19 patients (16.1%) developed AKI. Pre-existing CKD (OR 3.7; 95% CI: 2.9 to 4.6), operation time exceeding 240 minutes (OR 2.8; 95% CI: 2.1 to 3.9), and reinterventions (OR 4.6; 95% CI: 3.5 to 6.1) significantly affected the onset of postoperative AKI. Median duration of follow-up was 48 months IQR 24-84. Estimated 5-year survival, and freedom from reintervention(s) rates were 86.9% (95% CI: 79.3% to 91.2%), and 91.1% (95% CI: 88.5% to 95.4%), respectively. Multivariate Cox regression analysis showed that postoperative AKI was the only predictive factor (OR 7.7; 95% CI: 5.9 to 8.8) to develop MAKEs in no pre-existing CKD patients during follow-up. Conclusions: Pre-existing CKD, operation time >240 minutes, and reinterventions seemed to be risk factors for postoperative AKI in patients undergoing OSR with suprarenal aortic cross-clamping for complex AAAs. Postoperative AKI significantly affected M AKE in no p re-existing CKD patients during follow-up. MAKE seemed to occur starting from the third year of follow-up.