Author + information
- Karl-Ludwig Schulte, MD, PhD⁎ ( and )
- Klaus Amendt, MD
- ↵⁎Vascular Center Berlin, Department of Internal Medicine, Ev. Hospital Königin Elisabeth, Academic Teaching Hospital of the Charité, 10365 Berlin, Germany
With great interest we read the prospective registry of stent fractures after femoropopliteal stenting in a recent issue of the Journal(1). The observed rate of fractures of nitinol stents, which represent an essential progress compared with the use of balloon-expandable stents or wall stents, is astonishingly high in contrast to other studies and our own experience. We therefore regard it as essential to make some critical comments to avoid a too high assessment of the single-center observation.
The described results touch on an observational series in a single center, laid out prospectively and described as a register. However, a registry demands an external monitoring and evaluation of the results. This did not happen. Three types of stents, in varying numbers and of different lengths, were inserted into the vessels.
In 93 patients, 121 extremities were treated interventionally; 261 stents were implanted. Moreover, the mean length of the stented segments was different in all, with the highest in the Luminexx stent with 168 mm (SD 94 mm). This is remarkably high, because, with a maximum stent length of 120 mm, more than two stents had to be used in various patients. But this is explicitly mentioned under precautions in the instructions for use.
Furthermore, in the publicized pictures of stent fractures of the original study and at different presentations at international congresses, only Luminexx stents are exposed. This is probably explained by the fact that a Luminexx stent, in comparison to a SMART or SelfX stent, is much more visible under X-ray. However, this can lead to a wrong assessment and overestimation of stent fractures. Furthermore, the color-coded duplex sonography was only used for stent patency. Therefore, the visual assessment of the stent has to be checked externally or carried out independently.
Finally, in different illustrations, stent implantations were shown without overlapping and also in the distal third of the superficial femoral artery (SFA) and in the first and second segment of the popliteal artery. In turn, this is obviously listed as a contraindication in the instructions for use. Therefore, the progress of the usage of nitinol stents in the SFA should not be questioned by an observational series done at a single center. Preferably, one should await the results of scientifically relevant prospective controlled and randomized studies.
- American College of Cardiology Foundation