Clinical Application of a Curved Nitinol Stent-Graft for Thoracic Aortic Aneurysms

Abstract

Purpose: To evaluate the clinical efficacy of a curved nitinol stent-graft for repair of thoracic aortic aneurysms. Methods: The Matsui-Kitamura stent-graft (MKSG), composed of a self-expanding nitinol stent and polyester fabric, was shaped to match the aortic curvature of 11 patients (6 men; mean age 72.6 years, range 33–90) with 6 true and 5 false aneurysms of the distal arch or proximal descending aorta. The delivery system was an 18 or 20-F J-shaped sheath combined with a preloader-type introducer. The original mean proximal neck length was 16.4 mm, but 4 patients received an axilloaxillary bypass to lengthen the neck. Although the mean corrected proximal neck length was 21.9 mm (overall), 5 cases still had proximal necks <15 mm long. Results: All curved MKSGs were successfully deployed in the correct position and fitted to the curvature of the aortic arch, achieving complete aneurysm exclusion in 8 (73%) cases. The other 3 repairs displayed early endoleaks; 1 received an additional MKSG, but the other 2 are being observed. Thirty-day mortality was 0%. One patient developed transient renal failure requiring hemodialysis; no neurological complications were observed. Conclusions: Endovascular repair of thoracic aortic aneurysms using curved MKSGs appears to be feasible and clinically effective. A tighter fit of the device to the curvature of the aortic arch may exclude distal arch aneurysms despite a short proximal neck.