Percutaneous dilatation of coarctation of the aorta, stenotic pulmonary arteries or homografts, and stenotic superior vena cava using Andrastents XL and XXL.

Background: Major vessel stenoses are currently successfully treated with stent implantation. Recently, new cobalt-chromium stents (Andrastents XL and XXL, Andramed, Germany) have been introduced into clinical practice. This alloy combines high biocompatibility with radial strength and flexibility.
Aim: To present our experience with the use of Andrastents XL and XXL for the dilatation of stenosed pulmonary arteries, coarctation of the aorta (CoA), and a stenosed superior vena cava (SVC).
Methods: The study group included 24 patients treated with 26 Andrastents. In 7 patients aged 23.3 (range 18-27) years, with the mean body weight of 64.7 (range 50-77) kg, prestenting of a calcified pulmonary homograft was performed using 9 Andrastents XL or XXL (length of 30, 39, or 48 mm) before the Melody valve implantation. In one patient with a long and stiff stenosis, 3 stents were necessary. In 12 patients with native CoA aged 30.1 (range 9-55) years, with the mean body weight of 60 (range 25-105) kg, twelve Andrastents XL or XXL (length of 30, 39, or 48 mm) were implanted. In 4 patients with the right or left pulmonary artery stenosis close to the bifurcation (age 8.5 [range 6-10] years, body weight 27.3 [range 17-33] kg), 4 Andrastents 30 XL were implanted. In one child (age 7.5 years, body weight 21.7 kg) with a iatrogenic SVC stenosis (after 2 venous cannulations necessary for 2 surgical corrections of his double-outlet right ventricle), the stenosed site was dilated using Andrastent 21 XL.
Results: All procedures were performed successfully. No stent fractures were observed during the follow-up. The mean pressure gradient was reduced from 42.4 to 18 mm Hg (RVOT) in patients who underwent Andrastent and Melody valve implantation, from 54.1 to 13.2 mm Hg in patients with CoA, and from 49 to 21.7 mm Hg in patients with pulmonary artery stenosis. No aneurysm formation, stent migration, or rupture of the treated vessel during stent implantation were observed in any patient. The mean fluoroscopy time during stent implanatation was 6.6 min in CoA, 8.8 min in pulmonary artery stenosis, 24.8 min during implantation of Melody valve (with prestenting of RVOT with Andrastents) and 17.6 min during SVC dilation. Procedural outcomes (evaluated using noninvasive methods) remained favourable during the follow-up (0.5-21 months), with no complications observed.
Conclusions: Implantation of Andrastents XL or XXL is a very good therapeutic option in the treatment of major vessel stenoses.