OBJECTIVE To describe the use of the 5 × 300-mm Proteus embolic capture angioplasty (ECA) balloon catheter to reduce embolic burden in complex TASC II (TransAtlantic Inter-Society Consensus) C and D femoropopliteal interventions. METHODS A non-randomized safety and feasibility study was conducted at 2 centers enrolling 15 subjects (9 women; mean age 72.5 ± 9.5 years, range 53-85) suffering from Rutherford-Becker category 2 to 4 occlusive disease. Of the 20 lesions in 15 limbs, 16 were TASC II D and 4 were TASC II C. Average baseline stenosis was 95%± 12%; 16 lesions were totally occluded. Half of the lesions were de novo, 5 were restenotic, and 5 were in-stent stenoses. Average lesion length was 284 ± 50 mm. In addition to using the ECA device, 18 of the target lesions were treated with stents and 4 with rotational thrombectomy devices. Distal angiography was performed before and after use of the ECA device to locate any periprocedural embolic events. RESULTS Procedural success was achieved in 100% lesions. The ECA balloon was used for predilation in 11 lesions and for postdilation in 9. No distal embolization or flow-limiting vessel dissections were observed despite the complex nature of the cases. Three non-device-related complications were reported (pseudoaneurysm, myocardial infarction, acute renal failure) and resolved without sequelae within 30 days. Analysis of the particles recovered from 5 ECA balloons demonstrated a mean 257 ± 185 particles, with a mean major axial dimension of 0.54 ± 0.04 mm (range 0.11-7.54). There were a mean 7.67 ± 6.03 particles >2 mm in diameter, and all samples contained 1 to 3 particles >4 mm in diameter. CONCLUSIONS In this small series, the 5 × 300-mm ECA embolic capture balloon catheter was an effective tool for avoiding embolic events in long peripheral lesions, with a good safety profile. The device might be considered as part of routine clinical practice for complex TASC II C/D femoropopliteal lesions.