(IP059) Impact of Aneurysm Morphology on Outcomes of Fenestrated-Branched Endovascular Repair of Complex Aortic Aneurysms

Objectives: Saccular aortic aneurysms (SA) are considered to have increased rupture risk compared to fusiform aneurysms (FA), even at smaller sizes. However, perioperative and long-term repair outcomes are not clearly defined, as many clinical trials exclude saccular morphology. This study compares perioperative, early, and long-term outcomes of fenestrated-branched endovascular repair (FB-EVAR) for complex aortic aneurysms with saccular or fusiform morphology.

Methods: A retrospective review of patients who underwent elective FB-EVAR for complex abdominal (CAAA) and thoracoabdominal aortic aneurysms (TAAA) between 2007–2023 was conducted. Demographics, cardiovascular risk factors, aneurysm anatomy, and postoperative outcomes were analyzed. Patients were stratified by aneurysm morphology (SA vs FA) and analysis was performed based on aneurysm extent; CAAA and extent IV TAAA and extent I-III TAAA. Morphology was defined using preoperative computed tomography angiograms, independently analyzed by a vascular surgeon, radiologist, and a third investigator. Univariate analysis was performed to compare outcomes between groups. Freedom from endpoints over time was assessed using Kaplan-Meier survival curves.

Results: FB-EVAR was performed in 723 patients (72% male), including 637 (88%) with FA and 86 (12%) with SA. Patients with SA were older (75±8 vs. 74±7 years, p=0.02) and more likely to have undergone prior open aortic repair (34% vs. 22%, p=0.01). Other demographics, cardiovascular risk factors, and aortic-related history were similar. Fusiform aneurysms were larger at baseline (66±10 mm vs. 63±12 mm, p=0.005). Most FA and SA aneurysms were classified as CAAA or extent IV TAAA (79% SA vs. 65% FA, p=0.09).

At 30 days, technical success (95% vs 96%), target vessel patency (99% vs 98%), endoleak rates (42% vs 43%), reintervention rates (8% vs 5%), major adverse events (32% vs 24%), and mortality (2% vs 2%) were comparable between FA and SA, regardless of aneurysm extent (p>0.05). In patients with CAAA/extent IV TAAA, patients with SA had shorter hospital stays compared to those with FA (5±4 vs. 6±6 days, p=0.006). Mean follow-up was 52±35 months for FA and 57±37 months for SA (p=0.35). Long-term outcomes, including freedom from target vessel instability, types I-III endoleak, late reintervention, aortic rupture, and overall and aortic-related mortality, were similar between FA and SA (table and figure). Finally, in patients with Extent I-III TAAA, mean sac regression was significantly greater in SA (11±9 mm vs. 7±10 mm, p=0.02).

Conclusions: FB-EVAR achieves comparable perioperative and long-term outcomes across saccular and fusiform morphologies, with saccular aneurysms demonstrating greater sac regression in more extensive thoracoabdominal aneurysms.