Early Clinical Outcomes of Initial Launch of the Zenith Alpha Abdominal Endovascular Graft in Japan

This study retrospectively evaluated the 12-month outcomes of the Zenith Alpha Abdominal Endovascular graft (Zenith Alpha AAA, Cook, Inc, Bloomington, Indiana), which was launched partially in Japan in March 2019, starting with 9 selected sites.

A retrospective analysis was performed of all endovascular aneurysm repairs (EVAR) for abdominal aortic aneurysms using the Zenith Alpha AAA. Late complications were defined as any aneurysm-related events occurring >30 days after EVAR, including an aneurysm sac enlargement of >5 mm and any reinterventions performed. Endoleaks without sac enlargement or reinterventions were excluded from late complications.

During the study period, 79 EVARs using the Zenith Alpha AAA were performed. The mean age was 76.6±6.9 years old, 91.1% of patients were male, and the mean aneurysm diameter was 51.1±7.5 mm. Instructions for use violation was observed in 27 patients (34.2%), most frequently being a severely angulated proximal neck (>60°). There were 4 intraoperative complications, including 2 unintentional partial renal artery coverages caused by the premature anchoring of the exposed suprarenal stent barb to the aortic wall, which was a result of the design change of the top cap deletion. Since it was a partial coverage without flow impairment and since renal stenting was unsuccessful, it was left untreated and had no subsequent renal function impairment. During the mean follow-up of 444±123 days, 74 patients completed 12 months of follow-up. Freedom from late complications at 12 months was 90.8%, which included 2 limb occlusions (2.5%). Of 71 patients with a 12-month computed tomography scan, there was only 1 type 1a endoleak (1.3%), 1 sac enlargement of >5 mm (1.3%), and an aneurysm sac shrinkage of >5 mm was observed in 42.2% of patients. There was no type 3 endoleak during the follow-up.

This study demonstrated that the new generation of low-profile Zenith Alpha AAA has satisfactory early clinical outcomes, comparable to those obtained with the conventional Zenith endovascular graft. Long-term follow-up is needed to determine whether these favorable outcomes persist.