LAS VEGAS — Drug-eluting stents have not worked as well in the peripheral vasculature as they have in the coronary arteries, but that doesn't mean that investigations should be abandoned, Gary Ansel, M.D., said at a meeting on vascular interventions sponsored by Medical Media Communications.
So far, clinical trials in which drug-eluting stents were compared with bare stents in the periphery have shown that restenosis in distant vessels is a different process, said Dr. Ansel, a peripheral vascular disease specialist who practices in Columbus, Ohio.
Trials in the renal arteries and the superficial femoral artery have not shown any demonstrable benefit from drug elution, but there has been some indication of benefit. In addition, most of the trials have been small and, therefore, not definitive.
The findings of the Sirolimus-Coated Cordis SMART Nitinol Self-Expanding Stent for the Treatment of Obstructing Superficial Femoral Artery Disease (SIROCCO) trial, for example, suggested that the drug sirolimus might have had some positive benefit for distant vessels, and that a significant benefit might be found with longer follow-up of the patients.
The trials have been complicated by the fact that the bare nitinol stents used for comparison have performed better than was expected at the outset of the trials, Dr. Ansel added.
On the negative side, one study of sirolimus in renal arteries suggested the drug may have an adverse effect on kidney function.
Drugs still considered worth investigating in stent trials include paclitaxel and bisphosphonates.
The way to get better results with stents in the periphery may not be in the use of a different agent, but, rather, in using stents with different drug delivery rates from those in coronary stents, Dr. Ansel said.