The Association Between Thoracoabdominal Aneurysm Extent and Mortality after Complex Endovascular Repair.

OBJECTIVE Traditional open surgical repair of thoracoabdominal aneurysms (TAAA) historically carries 30-day mortality rates from 6% to 20%, depending on Crawford anatomic extent. While short-term survival is important, long-term survival is essential for patients to benefit from these often elective and potentially morbid procedures. Aneurysm extent impacts the long-term survival after open repair, but the impact on endovascular repair is unknown and could influence the decision process for repair. Here we sought to evaluate the association of aneurysm extent on survival, and to identify patient and perioperative factors associated with mortality following endovascular repair. METHODS A retrospective cohort of patients treated for TAAAs recorded in the Society for Vascular Surgery Vascular Quality Initiative (SVS VQI) thoracic and complex endovascular aneurysm repair registry were evaluated. All patients treated for asymptomatic degenerative aneurysms from 2010-2019 were included. Crawford extent I-V was defined using proximal and distal landing zones documented in the registry; patients without extension into the visceral aorta were used for comparison and categorized as extent 0a or 0b, depending on distal landing zone in the thoracic aorta. Kaplan Meier (KM) plots were used to estimate survival and Cox proportional hazard regression models were created to identify predictors of mortality. RESULTS From 2010-2019, 15,333 patients have been entered into the registry, of which 2,062 met inclusion criteria: Extent 0a (N=379), Extent 0b (N=848), Extent I (N=81,) Extent II (N=98), Extent III (N=130), Extent IV (N=454) and Extent V (N=72). Groups were created based on similar outcomes noted on preliminary analysis: extents 0a and 0b, extents I, II and III and extents IV-V were grouped for analysis. The mean survival time for extent 0a and 0b was 70.7 ± 1.43 months, while extent I, II and III was 48.6 ± 1.65 months, and extents IV and V was 57.6 ± 1.24 months. The corresponding one-year mortality was 8.4%, 18.4%, and 7.8%, respectively. Cox regression identified the following pre-operative factors to be associated with mortality: COPD (OR 1.70; p<.001), Crawford extent I- III (OR 1.64; p=.015), pre-existing CKD (OR 1.37; p=.024) and age per year (OR 1.03; p <.001), along with a number of post-operative factors. CONCLUSIONS Similar to open TAAA repair, patients with more extensive aortic disease treated with endovascular repair have worse one-year and long-term survival. Extent of aortic disease and anticipated post-operative survival should factor prominently into the surgical decision-making process for elective endovascular TAAA repair.