ObjectivesA New Ultra-Low Pulse width 355 nm Solid-State Laser Shows Superior Performance to 308 nm Lasers in Preclinical Trials. Real-world statistics, however, are currently scarce. The purpose of this study is to assess the CLA-355 nm laser system's clinical safety and feasibility in human trials.MethodsThis study is a prospective, non-randomized, first-in-human trial. The main inclusion criterion was patients with peripheral artery disease (PAD), and the main exclusion criterion was the presence of vascular grafts in the target vessel. Enrolled patients received treatment with the 355 nm Laser Plaque Ablation System (Shenzhen Vivolight, China) in combination with a drug-coated balloon (Endovastec, China) during hospitalization. Efficacy was assessed by the improvement in the percent diameter stenosis (DS) of the target vessel after laser ablation. The primary endpoint was the 6-month primary patency, while secondary endpoints included 6-month clinically driven target lesion revascularization (CD-TLR), amputation, and death. Safety endpoints included device-oriented clinical events (MoCEs) and major adverse cardiovascular events.ResultsNine patients (10 limbs affected) were enrolled in this study; their average age was 69.55 +/- 7.99 years, and 44.44% of the patients were male. The femoral artery contained 60% of the lesions, 70% of which were eccentric, and the average lesion length was 49.13 +/- 53.87 mm. Chronic occlusive lesions accounted for 40% of lesions. One patient had vascular lesions that were extensively calcified, and the other patient had an aneurysm. Thrombosis and ulcerative lesions were absent from every lesion. Prior to the treatment, the minimal vessel diameter was 0.53 +/- 0.68 mm, and the DS was 88.09 +/- 15.26%. The reference vessel had a diameter of 4.22 +/- 0.69 mm. The residual stenosis after laser atherectomy was 47.94 +/- 16.78%, with a minimum lumen diameter of 2.26 +/- 0.75 mm. Following the procedure, after subsequent DCB angioplasty, the DS was reduced to 26.07 +/- 6.411% with a minimal vessel diameter of 3.00 +/- 0.54 mm. During the perioperative phase, there were no MoCEs (distal embolization, perforation, acute occlusion, vasospasm, or intravascular thrombosis). 90% of patients remained patent after six months, and CD-TLR was 100% free. None of the patients experienced MACEs, amputations, or any other problems.ConclusionsThis is the first exploratory study on treating PAD in people using the CLA-355 nm laser plaque ablation device. According to preliminary findings, this device exhibits good safety and feasibility in plaque ablation.