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Nitinol stent yields favorable 1-year outcomes in femoropopliteal arteries
In patients with severe atherosclerotic disease of the superficial femoral and popliteal arteries, an interwoven nitinol stent yielded a primary patency rate of 78.9% and clinically driven target lesion revascularization rate of 87.6% at 1 year.
Researchers for a retrospective, single-center study evaluated 111 consecutive limbs of 97 patients (mean age, 75 years; 68 men) with symptomatic femoropopliteal disease. All patients underwent treatment with an interwoven nitinol stent (Supera, Abbott Vascular) between June 2012 and October 2014. Reasons for intervention included claudication (Rutherford category 1-3) in 56% of the patients, critical limb ischemia with rest pain (Rutherford category 4) in 19% and tissue loss (Rutherford category 5/6) in 25%. More than 50% of the lesions were left-sided, and 14 patients were treated bilaterally.
The primary endpoint was the absence of binary restenosis. This was conservatively defined as freedom from more than 50% restenosis based on a peak systolic velocity ratio greater than 2 by duplex ultrasound. TLR was defined as procedures performed for more than 50% diameter stenosis within 5 mm of the target lesion detected by duplex and arteriography after known recurrence of peripheral artery disease symptoms. Any amputation above the ankle was classified as major amputation.
In total, 146 stents (1.32 stents per limb; length, 40-600 mm) were placed successfully without technical failure. The mean stented artery length was 175.5 ± 130.5 mm. Ninety-one patients completed clinical follow-up, and duplex ultrasound assessment was conducted in 100 limbs. Follow-up occurred at a mean of 6.92 ± 6.43 months (range, 0.2-27.7). Reintervention was conducted in all patients with recurring symptoms and evident in-stent restenosis. At 6 months, the Kaplan-Meier method estimated a 95% rate of freedom from TLR; and at 12 months, this rate was 87.6%. The rate of primary patency was 87.1% at 6 months and 78.9% at 12 months. Compared with longer stented arterial segments (> 120 mm), shorter segments (20-120 mm) had better 12-month primary patency (93.3% vs. 66.3%; P = .016). Compared with stenoses, complete occlusions had worse patency at 6 months (84% vs. 93.1%; P < .0001).
Occlusion or loss of patency occurred in 13 stents. Of these, failure was attributable to stent intussusception in four limbs, compromised inflow or outflow in two limbs, gross oversizing in one, and thrombophilia in one. The mechanism of occlusion could not be identified in five stents.
“The results with this novel stent design may be further improved by careful patient selection and the avoidance of deployment pitfalls,” the researchers wrote. – by Jennifer Byrne
Disclosure: One researcher reports serving as a consultant and advisory board member of Abbott Vascular.