[Stent wire fractures and mesh loosening in explanted endovascular prosthesis]

Vascular grafts are available since the middle of the 50's. Explant retrieval studies still reveal not published material degradation today, after over 40 years of product development. Endovascular grafts exist since the beginning of the 90's. New developments and modifications have lead to numerous devices. The importance of explant retrieval studies grows.

Among 33 stentgrafts, retrieved 5 to 43 months after implantation, the majority were 18 MinTec devices (17 Stentor, 1 Cragg). These 18 explants were examined by endoscopy, stereomicroscopy and scanning electron microscopy.

The following material degradation was observed. The textile coating showed holes along the longitudinal seam, the ligatures in-between the stentframes burst, allowing the frames to dislocate. Occasional fractures of the stent wire were seen accompanied by bowl-shaped alterations of the surface.

The Stentor device is, since its modification 1996, not available any longer. It was one of the most applied devices world-wide. The possible material deficiencies must be known by those performing patient follow-up. The occurrence of alterations within 43 months shows the importance of a continued follow-up besides clinical trials.