Objective: To evaluate the AngioSculpt (R) (ASC), a novel scoring balloon catheter designed to treat complex diffuse fibro-calcific atherosclerotic lesions and avoid device slippage during deployment, in patients with infra-popliteal disease. Methods: The ASC incorporates a flexible nitinol scoring element containing three or more spiral struts which encircle a minimally compliant balloon to create focal concentration of the dilating force. Patients scheduled for percutaneous intervention of infra-popliteal arteries or planned amputation and with a reference vessel diameter of 1.5-3.5 mm were included in the study. Results: A total of 42 patients and 56 lesions were treated at five sites. Of these, 38 patients (90.5%) presented with critical limb ischemia (Rutherford Class >= 4). The ASC was successfully deployed in 98.2% (55/56) of lesions attempted and was used as primary therapy without stenting in 89.3% (50/56). Lesion morphology was complex, including moderate/severe calcification in 73%, lesion length 33.9 +/- 3 42.2 mm, bifurcation in 26.8%, and ostial in 12.5%. There was no significant device slippage and no perforations. Post-ASC dissections occurred in only six (10.7%) lesions and were minor or resolved with stenting. In 13 patients initially referred for amputation, ASC treatment resulted in limb salvage. Conclusions: The ASC is highly effective in a broad range of complex lesion morphologies, in most cases as stand-alone therapy, is associated with a very low complication rate and avoids device slippage during deployment. Additional studies are planned to assess the long term efficacy of this promising new technology. (c) 2007 Wiley-Liss, Inc.