Atherectomy and Critical Limb Ischemia: A Treatment Approach for Severely Calcified Vessels

Incidence of critical limb ischemia (CLI) is estimated at 1% to 2% worldwide and is expected to rise. CLI with isolated infrapopliteal (IP) disease is seen mainly in elderly, diabetic, or dialysis-dependent patients. These patients exhibit calcified IP vessels, which put them at higher risk of amputation compared to those with combined femoropopliteal and IP disease. CLI patients with systolic ankle pressure <50 mmHg, nonpulsatile ple- thysmographic tracing, and/or transcutaneous oxygen pressure <30 mmHg would benefit from revascularization. The majority of IP chronic total occlusions reconstitute above the ankle via collaterals, which can sustain a limb but cannot heal a wound. CLI lesions are usually characterized by random deposition of calcium along the layers of the arterial wall. When subject to increasing barometric pressures during angioplasty, the distribution of pressure vectors is unpredictable with tendency to follow the paths of least resistance, increasing risk of spiral dissection, plaque rupture, perforation, embolization, and no-flow phenomenon, which are associated with poor clinical out - comes. These deposits also present a physical barrier to antiproliferative drug penetration and are a predisposing factor for stent fractures. Atherectomy devices excise, ablate, or modify calcified deposits and plaque, allowing compliance alteration of severely calcified vessels, rendering them more suitable for treatment with balloons and/ or stents. Results of studies such as CALCIUM360, COMPLIANCE360, and DEFINITIVE LE suggest the "gold standard" for the treatment of PAD may need to be revisited to include atherectomy as an integral part of the treatment of patients with CLI.