June 30, 2013
DURABILITY II Results Support Covidien's Protégé EverFlex for Single-Stent Treatment of Long SFA and PPA Lesions
July 1, 2013—Jon S. Matsumura, MD, et al have published results from the DURABILITY II trial in the Journal of Vascular Surgery (2013;58:73–83). DURABILITY II is evaluating endovascular treatment of lesions in the superficial femoral artery (SFA) and proximal popliteal artery (PPA) using the Protégé EverFlex self-expanding nitinol stent system (Covidien, Mansfield, MA).
The background of the study is that in the setting of symptomatic femoropopliteal disease, angioplasty alone is effective in short lesions, and longer lesions are often treated with stents for revascularization. However, multiple overlapping stents are expensive and may be associated with stent fracture. DURABILITY II evaluated the safety and efficacy of a single self-expanding stent (up to 20 cm in length) in patients with atherosclerotic disease of the SFA and PPA.
As summarized in the Journal of Vascular Surgery, DURABILITY II was a nonrandomized, prospective, multicenter trial that evaluated the Protégé EverFlex peripheral stent system in patients with lesions > 4 cm and < 18 cm. The study's primary endpoints were the 30-day major adverse event rate and duplex ultrasound-assessed patency at 1 year. These were compared with published performance goals. A preplanned analysis was conducted for the primary effectiveness endpoints at 1 year.
The investigators advised that follow-up, including history, ankle-brachial index, patient-reported outcomes, duplex ultrasound assessment, and radiographs, is planned through 3 years. A core laboratory reviewed angiograms, ultrasound scans, and plain radiographs. A subgroup of patients was studied with graded treadmill testing.
The study enrolled 287 patients (66% men; mean age, 68 years) with stenotic, restenotic, or occlusive lesions of the SFA at 44 investigational sites in the United States and Europe. Systemic comorbidities included hypertension (88%), hyperlipidemia (86%), diabetes (43%), and previous SFA intervention (41%). The mean lesion length measured by the core laboratory was 89 mm. The mean normal-to-normal lesion length measured by sites was 110 mm. A total of 303 stents were implanted, and 95% of patients received a single stent.
No major adverse events occurred at 30 days. At 1 year, the primary outcome of duplex ultrasound stent patency was 67.7% in evaluable patients, and among 1-year secondary outcomes, the mean ankle-brachial index increased by 0.25. Walking Improvement Questionnaire scores improved in pain by 33.7, distance by 37.1, speed by 18.6, and stair climbing by 24.7. The Kaplan-Meier estimate of primary patency was 77.2%, primary assisted patency was 86.9%, and secondary patency was 87.3%. Rutherford clinical category improved in 83.5% of patients, the stent fracture rate was 0.4%, and matched absolute claudication distance was 412 feet greater and was not statistically different in this subgroup of 29 individuals.
The results of DURABILITY II suggest that a new single-stent strategy is safe and effective for the treatment of long lesions of the SFA and PPA at 1 year, concluded the investigators in the Journal of Vascular Surgery.