Double BioDisk: a new bioprosthetic device for transcatheter closure of atrial septal defects - a feasibility study in adult sheep

BACKGROUND: To evaluate the long-term effectiveness and safety of a new Double BioDisk (DBD) device for closure of atrial septal defect (ASD). MATERIALS AND METHODS. ASD was created with transeptal needle (TS) followed by balloon dilatation in 12 sheep weighing 40.1 to 64 kg (mean 55.2 ± 7.1). The ASD diameters were measured after creation and two weeks later before DBD implantation. The DBDs consists of two nitinol rings 18 to 28 mm in diameter connected with small cannulas and covered with a porcine small intestinal submucosa (SIS). They were implanted via a 10 Fr sheath. DBD effectiveness was evaluated by angiocardiography and by intra-cardiac echogram (ICE) with Doppler studies. Two animals were acute, two were followed for 6 weeks, three for 3 months, three for 6 months and two for 12 months. RESULTS: TS punctures were successful in 10 sheep. In two sheep ASD was created by existing PFO dilation. The ASD size ranged from 13–15 mm (mean 14.1± 0.73 mm) after initial balloon dilation and from 9–13 mm (mean 10.06 ± 1.37 mm) after two weeks. In all animals none of the successfully implanted DBDs spontaneously embolized on release or on follow up. ICE demonstrated no shunting around the DBDs during follows ups. Macroscopic and histologic evaluation of the 6, 12, 24 and 52 weeks animals showed that DBDs were well incorporated in the atrial septum with complete shunt closure. The SIS showed progressive remodeling with the host cells, including endothelization of the DBD devices. CONCLUSIONS: ASD closure with the Double BioDisk is safe and effective in adult sheep.