Innovating Patent Ductus Arteriosus Closure: Preclinical Evaluation of the First Iranian-Developed Nitinol Occluder in a Sheep Model.

Abstract

BACKGROUND: Patent ductus arteriosus (PDA) is a congenital defect characterized by abnormal blood flow between the aorta and pulmonary artery. Existing closure devices, such as the Amplatzer Duct Occluder (ADO), face challenges with affordability, biocompatibility, and anatomical adaptability. This study evaluates the safety and feasibility of a novel nitinol-based PDA occluder, the first developed sample in Iran, designed to enhance biocompatibility, reduce thrombogenicity, and improve durability. METHODS: This preclinical study was conducted in 2024 at the Large Animal Research Laboratory, Shiraz University of Medical Sciences, Shiraz, Iran. The occluder was fabricated from custom-made nitinol wires braided into a 72-wire conical mesh, ensuring flexibility and durability. Deployment was tested in a sheep model via femoral and pulmonary artery access. Post-procedure evaluations included angiography, clinical monitoring, and histopathological analyses to assess tissue integration, thrombogenicity, and biocompatibility. RESULTS: The device was successfully deployed in two target sites with stable positioning and no procedural complications. Angiographic imaging confirmed vessel patency, even in an artery with a size mismatch. The animal exhibited no adverse outcomes, maintaining normal pulses and activity over a three-month follow-up. Post-mortem analysis revealed secure device placement without migration, perforation, or aneurysm. Histopathological findings demonstrated mild inflammation, neointimal formation, and re-endothelialization, with no significant thrombus or granuloma, indicating excellent biocompatibility. CONCLUSION: This study provides preliminary evidence supporting the feasibility, safety, and biocompatibility of the Iranian-developed PDA occluder. These findings suggest the device may serve as a viable, cost-effective alternative for PDA closure, addressing device shortages and advancing regional medical technology.