Latest vascular devices surveillance news: an overview

Since the late 1950s, grafts and endografts have been constructed from a variety of materials and have been designed to be implanted in several different ways. However, despite the level of safety, effectiveness and versatility these devices reached, failures still exist. METHODS: Material surveillance through a dedicated explant analysis program is the cornerstone towards improving knowledge about vascular grafts and endografts behavior in humans. Major lessons learned from explant analysis have already been published few years ago, but this review provides an update by summarizing the recent findings of a dedicated explant analysis program over the past five years. Recent findings include vascular grafts degradation, devices calcifications, mechanisms of endografts failure. Two mechanisms of vascular grafts degradation have been reported: a decrease in the density of the meshing and local ruptures of the polyethylene terephthalate fibers. The degradation occurred preferentially in some grafts zones where the textile was weakened during manufacturing process. Calcification of vascular grafts and endografts have also been reported, and may contribute to device failure, as calcification reduces compliance, increases stiffness and generated a compliance mismatch. Concerning mechanisms of endografts failure, it has been shown that the polymer used in the endobags of the Nellix EndoVascular Aneurysm Sealing (EVAS) System could lose weight and volume upon dehydration. Accordingly, the polymer deteriorated and failed to retain its weight, volume and shape, undergoing fragmentation, explaining the high rate of migration observed with this device. Endoleaks have also been investigated and endograft fabric damages responsible for endoleaks have been demonstrated. This review highlights that despite continuous improvement of vascular and endovascular devices, failure still exists. Accordingly, continuous material surveillance is mandatory in order to provide the latest information on the mechanisms responsible for degradation and implement knowledge concerning the biological and mechanical behavior of grafts and endografts.