Treatment of Chronic Lower Extremity Ulcers with Er:YAG Laser and RecoSMA Technology

Chronic lower extremity ulcers (CLEUs) are notoriously difficult to treat due to prolonged inflammation, impaired microcirculation, and disrupted tissue repair mechanisms. In a 2017 prospective study published in Laser Therapy, Alcolea et al. evaluated the clinical efficacy of an Er:YAG 2940 nm laser equipped with RecoSMA (spatially modulated ablation) technology for the treatment of refractory chronic ulcers .

The study investigated whether a mechanically driven microablative laser approach could reactivate stalled healing processes in long-standing ulcers unresponsive to conventional therapy.

Study Design

• Type: Prospective clinical study
• Patients enrolled: 18 (16 completed the study)
• Mean age: 66.3 ± 7.7 years
• Ulcer duration: ≥14 months (average 18.2 months)
• Ulcer types:
• 12 venous
• 4 mixed (arterial + venous)
• 2 lymphatic

All patients had previously failed multiple topical treatments. Active infections were excluded through serial cultures .

Treatment Protocol

Each patient received:

• 16 weekly treatment sessions (over 4 months)
• Laser irradiation covering the ulcer plus a 5 cm margin
• Energy dose: 3.2 J/cm²
• Frequency: 3 Hz
• Three passes per session with ~30% pulse overlap

When keratin accumulation was present, superficial ablation was first performed without RecoSMA to remove devitalised tissue.

After treatment, ulcers were covered with polyurethane film and non-compressive bandage only — no additional topical products were allowed.

Technology: Er:YAG + RecoSMA

The Er:YAG laser (2940 nm) is highly absorbed by water, enabling precise superficial microablation.

RecoSMA technology:

• Divides the beam into 10,000 microbeams/cm²
• Produces shallow epidermal ablation
• Generates mechanical-acoustic resonance waves
• Penetrates up to 6 mm into dermis
• Creates controlled microtrauma without thermal damage

The resulting mechanical-acoustic “pushing effect” stimulates:

• Neoangiogenesis
• Collagen remodelling
• Fibroblast activation
• Regeneration without fibrosis .

Clinical Outcomes

1️⃣ Ulcer Area Reduction

Initial average area: 15.7 ± 8.4 cm²

After treatment:

• 3 patients (18.75%) achieved complete closure
• 4 patients (25%) showed >75% reduction
• 2 patients (12.5%) had 50–75% reduction
• Over 65% of patients achieved ≥55% reduction

Final average ulcer area (non-closed ulcers): 7.8 ± 7.5 cm²

Reduction in ulcer area was statistically significant (p = 0.05) .

2️⃣ Pain Reduction

Pain scale (1–10):

• Initial: 4.4 ± 1.6
• Final: 2.3 ± 1.3

Pain reduction was statistically significant.

Interestingly, bleeding increased during treatment (interpreted as improved microvascular activation and tissue vitality).

3️⃣ Predictive Factors

Statistically significant predictors of better response:

• Younger age (p = 0.024)
• Shorter ulcer duration (p = 0.005)

Cardiovascular risk factors (diabetes, hypertension, dyslipidaemia, smoking) were not statistically significant in determining response under laser treatment .

Histological Findings

Biopsies were performed in 10 patients before treatment, at 6 weeks, and at 3 months.

Before treatment:

• Loss of epidermis
• Disorganised collagen
• Poor vascularisation
• Necrotic debris and pseudofibrosis

After 6 weeks:

• Disappearance of surface detritus
• Increased inflammatory infiltration
• Clear neoangiogenesis

After 3 months:

• Formation of granulation tissue
• Increased vascular density
• New collagen fibres with improved alignment
• Early re-epithelialisation

Importantly, no signs of thermal damage or fibrosis were observed .

Mechanism of Action

The authors propose that chronic ulcers remain “stuck” in a suppressed inflammatory state. RecoSMA-generated resonance waves:

• Reactivate the inflammatory phase
• Trigger microvascular recruitment
• Stimulate keratinocyte migration
• Promote collagen synthesis
• Facilitate granulation maturation

The mechanical-acoustic effect differentiates this approach from traditional low-level laser photobiomodulation.

Safety and Tolerability

• No anaesthesia required
• No complications reported
• Patients tolerated the procedure well
• No post-inflammatory hyperpigmentation

The absence of thermal damage significantly reduces morbidity risk.

Conclusion

The Er:YAG laser equipped with RecoSMA technology demonstrated a safe and effective alternative for the treatment of refractory chronic lower extremity ulcers.

In this cohort:

• Complete closure or >50% reduction was achieved in the majority of patients.
• Tissue regeneration was confirmed clinically and histologically.
• Healing was associated with microvascular activation and collagen remodelling rather than thermal destruction.

The study supports the role of mechanically modulated Er:YAG laser therapy as a promising regenerative approach in chronic ulcer management .
Source:

Alcolea JM, Hernández E, Martínez-Carpio PA, Vélez M, Khomchenko V, Sola A, Trelles MA. Treatment of Chronic Lower Extremity Ulcers with a New Er:YAG Laser Technology. Laser Therapy. 2017;26(3):211–222 .