Cold Laser vs Excimer Laser in Lower Limb Atherosclerosis

Background Peripheral artery disease (PAD) caused by atherosclerotic stenosis or occlusion of the arteries of the lower extremities is a major global health concern. Despite advances in endovascular therapies, treating complex lesions such as heavily calcified segments and chronic total occlusions remains challenging, which limits procedural success and long-term patency. The novel 355-nm cold laser atherectomy (CLA) system offers a photochemical, low-thermal approach to plaque ablation, with potential advantages in safety and efficacy. Objectives The aim of this study was to evaluate the safety and efficacy of a 355-nm CLA system for treating lower limb atherosclerotic stenosis and occlusion in a prospective, multicenter, randomized controlled trial. Methods This trial enrolled 110 patients with symptomatic lower extremity PAD (Rutherford classes 2-5) and ≥70% stenosis or occlusion. Patients were randomly assigned to the CLA and excimer laser atherectomy (ELA) groups. The primary endpoint was improvement in vessel diameter stenosis (DS%) prior to any adjunctive therapy. Secondary endpoints included primary patency, target lesion revascularization (TLR), Rutherford classification improvement, and ankle-brachial index values at 30 days and 6 months postoperatively, as well as a device-oriented composite endpoint. Results A total of 109 patients (CLA, n = 58; ELA, n = 51) were included in the analysis. Baseline demographics and comorbidities were well balanced between the groups. Postprocedural DS% improved significantly in both groups, with no significant intergroup differences (CLA, 59.92% ± 15.02%; ELA, 57.52% ± 17.22%; P = 0.438). The mean improvement in DS% (CLA, 34.28%; ELA, 34.35%) met the noninferiority threshold. At 30 days, the primary patency rates were 85.1% (CLA) and 87.8% (ELA), with TLR rates of 0.0% and 1.9%, respectively. At 6 months, patency decreased to 71.7% (CLA) and 61.5% (ELA), and TLR occurred in 6.5% and 10.2% of patients, respectively ( P = 0.698). Ankle-brachial index values and Rutherford classification improved similarly in the 2 groups. Subgroup analyses revealed that for TASC (Trans-Atlantic Inter-Society Consensus) C/D and long lesions (≥10 cm), CLA had lower TLR rates at 6 months ( P < 0.05), suggesting potential advantages for complex lesions. Conclusions The 355-nm CLA system showed similar safety and efficacy to the excimer laser, with a trend toward reducing TLR in complex PAD lesions. These findings highlight its potential as a next-generation endovascular tool that could refine revascularization strategies and improve patient outcomes in clinical practice.