A 355-nm cold laser atherectomy system proved noninferior to excimer laser for opening blocked leg arteries, with trends toward better outcomes in complex lesions.
Peripheral artery disease (PAD) affects roughly 8-12 million Americans and occurs when plaque buildup narrows arteries in the legs. For patients with severe blockages, calcified deposits, or completely occluded vessels, traditional treatments like balloon angioplasty and stenting often fail. This 110-patient randomized controlled trial tested whether a newer cold laser approach could match or exceed the performance of excimer laser atherectomy, an existing technology that uses ultraviolet light to vaporize plaque.
The cold laser atherectomy (CLA) system operates at 355 nanometers wavelength and works through photochemical ablation rather than heat generation. The distinction matters: lower thermal energy theoretically reduces vessel wall damage and inflammation, potentially improving healing and long-term patency. Excimer laser atherectomy (ELA), the comparison tool, uses 308-nm wavelength and has an established track record in PAD treatment. Both groups received the same baseline demographics and disease profiles, with about half the patients in each arm having complex TASC C/D lesions (the most difficult-to-treat category).
The primary finding centered on vessel diameter stenosis improvement prior to any additional therapy. Both systems performed nearly identically: cold laser reduced stenosis by 34.28 percentage points (from roughly 94% narrowed to 60% remaining) while excimer laser achieved 34.35 points improvement (from 92% to 57%). The difference was not statistically significant, meeting the noninferiority threshold for cold laser. At 30 days post-procedure, primary patency (vessels staying open) reached 85.1% with cold laser versus 87.8% with excimer laser. Neither group showed target lesion revascularization (TLR, meaning a repeat procedure to re-open the same spot) at 30 days in the cold laser group, compared to 1.9% in the excimer group.
The picture shifted slightly at 6-month follow-up. Patency rates declined in both groups but remained comparable: 71.7% for cold laser and 61.5% for excimer laser. TLR rates increased to 6.5% (cold laser) and 10.2% (excimer laser), though this difference was not statistically significant in the overall cohort. However, subgroup analyses revealed a clinically meaningful trend: in patients with TASC C/D lesions (severe calcification and chronic total occlusions) or lesions 10 cm or longer, cold laser showed lower TLR rates at 6 months (P less than 0.05). Rutherford classification (a symptom severity scale) and ankle-brachial index (a measure of leg blood flow) both improved similarly in both groups, indicating comparable clinical benefit regardless of laser type.
If you have symptomatic lower limb PAD with complex blockages, this trial provides moderate reassurance about treatment options. Cold laser atherectomy appears to be a viable alternative to excimer laser, not inferior and possibly superior for challenging lesion types. However, several practical limitations deserve mention.
First, both technologies show modest 6-month patency rates (roughly 60-70%), reflecting the inherent challenge of treating severely diseased vessels. This underscores why PAD management typically combines multiple approaches: laser atherectomy, balloon angioplasty, sometimes drug-coated balloons or stents, and crucially, aggressive risk factor management. Medication adherence (antiplatelet agents, statins), smoking cessation if applicable, and structured walking programs remain foundational.
Second, the TLR advantage in complex lesions for cold laser is noteworthy but not definitive. The study found a trend in subgroup analysis, which carries lower statistical power than the primary comparison. Larger or longer-term data would strengthen confidence in this finding. If you have heavily calcified or occluded vessels, asking your interventionalist whether cold laser availability and expertise exist at your center is worthwhile.
Third, improvement in stenosis immediately after the procedure does not guarantee durable patency. Both groups saw patency decline from 30 days to 6 months, a pattern common in PAD interventions. This highlights why post-procedure surveillance (duplex ultrasound or other imaging at intervals) and proactive retreatment when restenosis develops improves outcomes.
| Characteristic | Detail |
|---|---|
| Study type | Prospective, multicenter randomized controlled trial |
| Sample size | 109 analyzed (58 cold laser, 51 excimer laser) |
| Population | Symptomatic lower extremity PAD, Rutherford class 2-5, greater than or equal to 70% stenosis or occlusion |
| Intervention | 355-nm cold laser atherectomy vs. 308-nm excimer laser atherectomy |
| Primary outcome | Vessel diameter stenosis improvement prior to adjunctive therapy |
| Key secondary outcomes | Primary patency, target lesion revascularization, symptom improvement, ankle-brachial index at 30 days and 6 months |
| Primary result | Noninferior stenosis reduction (CLA 34.28%, ELA 34.35%, P=0.438) |
| 6-month patency | CLA 71.7%, ELA 61.5% (P not significant) |
| 6-month TLR | CLA 6.5%, ELA 10.2% (P=0.698 overall; CLA advantage in TASC C/D and long lesions) |
| Journal | JACC. Cardiovascular Interventions |
| Year | 2024 |
| PubMed ID | 42055649 |
Zeller T, et al. Cold Laser versus Excimer Laser in Lower Limb Atherosclerosis: A Prospective Multicenter Randomized Trial. JACC Cardiovasc Interv. 2024. PubMed: 42055649
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