Evaluation of CardiaZn Pediatric Biodegradable Stent in a Long-Term Animal Model

A survey of interventional pediatric cardiologists identified bioresorbable stents for aortic and pulmonary coarctations as the most needed device.

PediaStent developed the CardiaZn stent and conducted a 2.5-year GLP preclinical study to evaluate device safety, biocompatibility, and functional performance.

Twelve Yucatan (17-23 kg) mini swine received two CardiaZn stents in the aorta and one in the pulmonary artery with terminal assessments performed at 3, 28, 360, 540, 730, and 902 days. At 180 days, all remaining animals underwent catheterization, with an additional CardiaZn stent placed over a previous aortic stent in four subjects. All subjects received CT scans at 1 year.

There were no stent migrations, evidence of vessel injury, angiographic obstruction, or stent fragment embolization. From 180 to 360 days, the pulmonary artery, sub-renal, and supra-iliac aortic stents increased in diameter by 18%, 24%, and 28%, on average, respectively. Simultaneously, the pulmonary and sub-renal aortic stents elongated by an average of 40%. All CardiaZn stents explanted from 28 through 902 days were completely endothelialized. Histopathology displayed moderate remodeling of the tunica media without loss of structural integrity or extension into the adventitia. MicroCT analysis showed loss of mass and structural integrity secondary to degradation resulting in stent cell disconnection, allowing for vessel growth by 9-12 months.

The CardiaZn stent provided vascular support for up to 9 months before safely degrading to allow for vascular growth. A clinical trial is planned to confirm safety and efficacy in children.