Purpose: To report the findings from a multicenter study of patients treated with cryoplasty who were then followed for an average of > 2 years post-treatment.
Methods: Extended clinical follow-up was obtained for 70 patients (45 men; mean age 70.5 +/- 8.8 years) who originally received cryoplasty therapy to treat symptoms of intermittent claudication as part of a multicenter investigational device exemption (IDE) study. For all subjects, cryoplasty was used to treat stenoses or occlusions < or = 10 cm in the femoropopliteal arteries. The original IDE study protocol enrolled 102 patients with a primary endpoint of target lesion patency at 9 months post-treatment. This collection of additional longer term follow-up data was initiated 2.5 years after the onset of study enrollment.
Results: Extended clinical follow-up ranged from 11 to 41 months (mean 31). The clinical patency rate (freedom from target lesion revascularization) calculated by the Kaplan-Meier method was 83.2% after the original follow-up period of 300 days. After > 3 years (1253 days), the clinical patency rate was well maintained at 75.0%.
Conclusions: Long-term data indicate that cryoplasty is a durable therapy, with relatively low long-term restenosis rates compared to other endovascular treatment approaches.