A study found that a nitinol stent performed better than balloon angioplasty alone in treating blockages of the popliteal artery, which runs through the leg behind the knee. Results of the ETAP trial were presented today at the 24th annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium. Sponsored by the Cardiovascular Research Foundation (CRF), TCT is the world's premier educational meeting specializing in interventional cardiovascular medicine.
Due to its location behind the mobile knee joint, it is controversial whether to implant a stent in the popliteal artery for all cases or only for cases in which balloon angioplasty alone results in a suboptimal result. In this study, investigators conducted a prospective, randomized, multi-center trial comparing primary nitinol stent placement to angioplasty alone in patients who had a single, de-novo obstructive lesion in the popliteal artery.
A total of 246 patients from nine centers in Europe were included in this trial. Patients were randomly assigned to either a self-expanding nitinol stent (N=119) or a standard balloon angioplasty procedure (N=127). The primary study endpoint was one-year duplex ultrasound-derived primary patency, defined as freedom from target lesion restenosis without further intervention. Secondary endpoints included target lesion revascularization, secondary patency, changes in Rutherford categories from baseline, and limb salvage rates. X-rays were taken at one year and examined for stent fractures.
The mean lesion length for the PTA group was 43.2 mm compared to 41.3 mm for the stent group. Six patients (2.4%) died during the follow up period. The one-year primary patency rate was significantly higher in the nitinol-stent group (67.4 percent) than in the balloon angioplasty group (44.9 percent, P<0.05). Post procedure target lesion revascularization rates were 15.4 percent for the stent group and 21.4 percent for the optimal angioplasty group (P=0.29). No significant differences between the treatment groups could be observed concerning secondary patency, limb salvage rates, and the clinical course by Rutherford categories. Two stent fractures were reported at one year.
Patients in the stent group also reported more improved walking distances at one year than the angioplasty group.
"Results from this trial indicate that treatment of popliteal artery obstructive lesions with a nitinol self-expanding stent is safe. Additionally, one-year primary patency and target lesion revascularization rates (including acute angioplasty failures) were substantially better with the nitinol stent than with balloon angioplasty," said lead investigator Thomas Zeller, MD. Dr. Zeller is Professor of Clinic Cardiology and Angiology and the Chief of the Department of Angiology at Universitäts-Herzzentrum Freiburg Bad Krozingen in Germany.
The results of the ETAP trial will be presented on Wednesday October 24 at 12:46 PM EST in the Main Arena (Hall D) of the Miami Beach Convention Center.
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