One-year outcomes from the pivotal trial of a four-branch off-the-shelf solution to treat pararenal and extent IV thoracoabdominal aortic aneurysms.

Objective: To report 1-year primary-arm outcomes of the GORE EXCLUDER Thoracoabdominal Branch Endoprosthesis pivotal trial.

Methods: The multicenter, nonrandomized, prospective study included patients with extent IV thoracoabdominal aortic aneurysms (TAAAs) and pararenal aortic aneurysms (PRAAs). All-cause and adjudicated lesion-related mortality were assessed at 12 months. Core-lab-reported, imaging-dependent outcomes included aneurysm size, endoleaks assessed through 1-year follow-up window, and target vessel instability (defined as occlusion, stenosis, type Ic/IIIc endoleak, or reintervention) at 1 year.

Results: One hundred two patients were treated; 59 patients had an extent IV TAAA and 43 had a PRAA. The mean maximum aneurysm diameter was 59.4 ± 7.8 mm. At 1 year, eight patients were lost to follow-up and six patients died (1 device-related, 1 procedure-related, and 4 unrelated causes). No lesion-related mortality occurred. Freedom from all-cause mortality was 94.1% ± 2.3%. The 1-year combined freedom from "clinically significant reintervention" and lesion-related mortality was achieved in 78.7% and 60.5% of patients with extent IV TAAAs and PRAAs, respectively (P = .09). At least one target vessel branch occlusion occurred in 14.7% of patients through 1 year of follow-up. At the vessel level, freedom from target vessel instability at 1 year was 94.2% ± 1.2% (celiac 99.0% ± 1.0%, superior mesenteric 97.1% ± 1.7%, right renal 90.8% ± 2.9%, and left renal 89.8% ± 3.1%). Acute kidney injury requiring dialysis occurred in three patients (n = 2 permanent, n = 1 temporary) through 1 year. Renal artery occlusion occurred more often in arteries with diameters <5 mm (odds ratio = 3.04; 95% confidence interval: 1.08, 8.54) and in patients with pararenal aneurysms (odds ratio = 2.85; 95% confidence interval: 0.88, 9.25, statistically insignificant). Of the 22 reinterventions in 15 patients, 16 (73%) reinterventions were classified as minor: 13 (81%) for target vessel complications and 3 (19%) for type II endoleaks. Device- or procedure-related major reinterventions in six patients included thrombectomy or thrombolysis for target vessel occlusion (n = 5) and one exploratory laparotomy after procedural aortic rupture. No type I/III endoleaks were identified (Core Lab) through 1 year. Aortic enlargement (>5 mm) occurred in 5 patients (6.0%). Aneurysm shrinkage (>5 mm) occurred in 20 patients (23.8%). Aortic component fractures identified in 3 patients (3.6%) were clinically insignificant.

Conclusions: Although mortality remains low 1 year after treatment with the GORE EXCLUDER Thoracoabdominal Branch Endoprosthesis device for extent IV and pararenal aneurysms, renal artery occlusion was the predominant adverse event and was primarily associated with PRAAs and smaller renal vessel diameters. During extended follow-up, attention should be focused on renal branch assessment to identify patients at risk for occlusion.