The Impact of Proximal Clamp Location on Peri-Operative Outcomes Following Open Surgical Repair of Juxtarenal Abdominal Aortic Aneurysms.

Objective: Open surgical repair of juxtarenal abdominal aortic aneurysms (AAA) requires an aortic cross clamp location above at least one renal artery. This study investigated the impact of clamp location on peri-operative outcomes using a United States based nationwide clinical registry.

Methods: The National Surgical Quality Improvement Program targetted vascular module was used to identify all elective open juxtarenal AAA repairs (2011-2017). Outcomes were compared between clamping above one vs. above both renal arteries, and above one or both renal arteries vs. supracoeliac clamping. The primary outcome was 30 day mortality and secondary outcomes included post-operative renal dysfunction (creatinine increase ≥ 177 μmol/L or new dialysis) and unplanned re-operations. Multivariable logistic regression models were constructed to perform risk adjusted analyses.

Results: A total of 615 repairs were identified, with a clamp location above one renal artery in 42%, above both renal arteries in 40%, and supracoeliac in 18% of cases. Procedures with a clamp location above one vs. above both renal arteries showed no difference in mortality (3.5% vs. 2.1%, p = .34) or renal dysfunction (6.9% vs. 4.9%, p = .34). In contrast, supracoeliac clamping compared with clamping above one or both renal arteries was associated with a higher mortality rate (8.0% vs. 2.8%, p = .023), renal dysfunction (12% vs. 6.0%, p = .017), and unplanned re-operations (24% vs. 10%, p < .001). In the multivariable adjusted models, outcomes were similar between clamping above both vs. above one renal artery, while supracoeliac clamping vs. clamping above one or both renal arteries was associated with higher mortality (odds ratio [OR]: 3.4; 95% CI: 1.3-8.8; p = .013) and unplanned re-operation (OR: 2.4; 95% CI: 1.4-4.1; p = .002).

Conclusion: Although there is no difference between clamping above one vs. both renal arteries during open juxtarenal AAA repair, a supracoeliac clamp location is associated with worse peri-operative outcomes. Surgeons should avoid supracoeliac clamping when clamping above one or both renal arteries is technically possible.