IFT04 - Off-the-Shelf Branched Endografts for the Treatment of Thoracoabdominal Aortic Aneurysms: Two-Year Target Vessel-related Outcomes

Objectives: To assess clinical outcomes and target vessel patency through two years following thoracoabdominal aortic aneurysms (TAAA) repair with the off-the-shelf Zenith® t-Branch® Thoracoabdominal Endovascular Graft (William Cook Europe, Bjaeverskov, Denmark).

Methods: This post-market, observational study was conducted at three European sites between 2012-2020 with ambispective enrollment. Patients underwent endovascular TAAA repair with the t-Branch and bridging stents for the celiac (CA), superior mesenteric (SMA), left renal (LRA), and/or right renal arteries (RRA). Follow-up was through two years per sites’ standard of care. Procedural and one-year results were reported previously.

Results: Eighty patients (mean age 71.0±7.4 years, 70.0% men) were enrolled; six patients had symptomatic TAAAs and 15 patients had contained ruptures. Technical success was achieved in 98.75% (79/80) of patients. Median follow-up was 22.2 months (IQR: 9.2-25.1 months).
At 24 months, Kaplan-Meier (KM) freedom from all-cause and aneurysm-related mortality were 78.5% and 98.6%, respectively. Beyond 12 months, 38 adverse events occurred in 20 patients, including two aortic ruptures (one study aneurysm and one non-study aneurysm) and six deaths (none aneurysm-related). Maximum aneurysm diameter decreased (>5 mm) in 84.6% (44/52), remained unchanged in 3.8% (2/52), and increased (>5 mm) in 11.5% (6/52) of patients with imaging follow-up after 12 months. No conversions to open repair and no t-Branch or other endograft component migration, integrity issues, or loss of patency were reported. Throughout study duration, two patients had bridging stent compression, including covered and uncovered CA stents in one patient and a covered LRA stent in the other. KM freedom from secondary intervention was 76.3% at 24 months.
Seven patients had nine endoleaks (seven Type III and two Type Ic) involving bridging stents. Fourteen target vessel-related secondary interventions were performed, primarily consisting of stent placement for endoleak, stenosis, or occlusion. One reintervention involved bridging stent placement as part of a staged procedure. KM freedom from loss of primary patency were 94.8%, 100%, 91.3%, and 89.3% for the CA, SMA, LRA, and RRA, respectively, at 24 months. KM freedom from loss of secondary patency in the CA, SMA, LRA, and RRA were 96.3%, 100%, 98.2%, and 98.3% (Figure 1).

Conclusions: These results support the safety and effectiveness of the off-the-shelf t-Branch endograft for treatment of both stable and symptomatic TAAAs. Freedom from loss of secondary patency shows a high rate of target vessel maintenance.