CryoPlasty therapy of the superficial femoral and popliteal arteries: A reappraisal after 44 months' experience

Abstract

Long-term patency remains a significant hurdle in the minimally invasive treatment of arteriosclerosis in the superficial femoral (SFA) and popliteal arteries. CryoPlasty therapy (PolarCath, Boston Scientific Corp, Natick, Mass) is a novel approach designed to significantly reduce injury, elastic recoil, neointimal hyperplasia, and constrictive remodeling. The technique combines the dilatation forces of percutaneous transluminal angioplasty (PTA) with cold thermal energy applied to the plaque and vessel wall. We previously reported a technical success rate of 96% and a 12-month freedom from restenosis rate of 82.2%. However, a review of the original cohort supplemented by experience with a further 47 lesions has demonstrated less desirable results. From December 2003 through July 2007, 92 lesions in 64 consecutive patients were treated and followed up for a median of 16 months with statistically significant follow-up at 24 months. The immediate technical success rate was 88%. Nine stents were immediately required after unsuccessful CryoPlasty (9.8%) five of which were as a result of a dissection. No unanticipated adverse events occurred, specifically, no thrombus, acute occlusions, distal embolizations, aneurysms, or groin complications. Vascular calcification was responsible for technical failure in six of the 11 immediately unsuccessful procedures. Freedom from restenosis for successfully treated lesions was 57% and 49% at 12 and 24 months, respectively. CryoPlasty of heavily calcified lesions, vein graft lesions, and in-stent stenosis faired poorly. Excluding these lesions from analysis would have resulted in an immediate success of 94% (81 of 86) and freedom from restenosis of 61% and 52% at 12 and 24 months, respectively. However, on an intention-to-treat basis, freedom from restenosis was 47% and 38% at 12 and 24 months, and CryoPlasty added approximately $1700 to the cost of each procedure. Analysis of this expanded, longer-term data suggests that our earlier, smaller study provided an overly optimistic appraisal of the benefits of CryoPlasty. It is possible that a larger analysis might have identified a subset of patients or lesions that would benefit from CryoPlasty, but considering the additional cost, we no longer use this technique in our practice.