Three-dimensional MRA follow-up after stent placement may be applicable for stent patency evaluation in all instances. However, grading of stenoses seems to be unrealistic in steel stents and in most nitinol stents.
Poly‐Lactic‐Acid (PLA) was evaluated for coating of vascular endoprostheses in the treatment of experimental arterio‐venous‐fistulae (AVF). Bilateral carotid – external jugular AVF were created in 5 adult dogs. 7 PLA coated nitinol stents were placed via a transfemoral approach covering 5 AVF. The contralateral AVF remained untreated. Angiography was performed immediately after stent placement, at weeks 1 and 3 and at months 3, 6 and 9. All grafts were removed and underwent histologic examination. In 2 cases the occlusion of the AVF was successful, while misplacement occurred in 3 cases. Occlusion of the parent vessel was disclosed in 3 cases. Histologic examination revealed a mild inflammatory reaction with the presence of macrophages. There was no foreign‐body reaction or fragmentation of the arterial vessel wall. PLA, which is a well‐known biodegradable material, showed a good mid‐term biocompatibility. Elastic mismatch of the non‐elastic coating and the self‐expandable nitinol stent caused misplacement. Frequent vessel‐occlusions were probably due to PLA‐filaments fraying into the vessel lumen. Using a different textile structure PLA might be a material suitable for coating endovascular stents.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.