Effect of biodegradable flow-diverting device on abdominal aorta and normal branches in rabbits

Abstract

Objective To evaluate the safety of biodegradable flow-diverting devices (FDs) for treatment of intracranial aneurysms in rabbits. Methods Biodegradable polyglycolic acid FDs (PGA-FDs) were implanted into the abdominal aorta in 12 New Zealand rabbits, covering the ostium of a lumbar artery. Animals underwent angiography at 3, 6, and 12 weeks after device implantation; and 3 animals were sacrificed at 3 and 6 weeks for pathology by HE staining, Veigert resorcinol (VG) staining, and CD34, CD68 and α smooth muscle actin (αSMA) immunohistochemistry. The diameter of abdomen arota and the patency of side branches covered by the devices were assessed. All animals were sacrificed after angiography for pathology at 12 weeks. Results No side branch occlusions were noted, either immediately after implantation or at follow-ups. Abdominal aorta neointimal hyperplasia was minimal, and there were no differences immediately after device implantation, or at 3, 6, and 12 weeks after device implantation (abdominal aorta diameter: [3.35±0.24] mm, [3.33±0.12] mm, [3.23±0.16] mm, [3.12±0.10] mm and [3.30±0.11] mm). Pathology results showed the neointima covered the strips of PGA-FD, and minial inflammation was abserved around the strips. The PGA strips were obsorbed completely at 12 weeks follow up with no apparent inflammation. The neointima predominantly comprised of smooth muscle cells and collagen fibers. Conclusion The PGA-FD is safe for abdominal aorta and normal side branches at short-term follow-up. Key words: Flow-diverting device; Biodegradation; Abdominal aorta; Side branch