Erbium Laser in the Treatment of Trophic Purulent Wounds: Experimental Evidence from an Animal Study
2023-10-01 09:12
Chronic purulent and trophic wounds remain one of the most complex surgical challenges, largely due to persistent inflammation, biofilm formation, and impaired tissue regeneration. In a 2023 experimental study published in Medical News of North Caucasus, Zaitsev et al. investigated the effectiveness of high-intensity erbium laser therapy in a controlled animal model of trophic purulent wounds .
The study aimed to evaluate whether Er:YAG laser treatment — alone or combined with antiseptic therapy — improves wound cleansing, decontamination, and healing compared to standard care.
Study Design
The experiment was conducted on 80 white male rats, divided into four equal groups (n=20 per group):
1️⃣ Control group – saline dressings only
2️⃣ Antiseptic group – polyhexanide dressings
3️⃣ Laser group – Er:YAG laser treatment
4️⃣ Laser + antiseptic group – Er:YAG laser combined with polyhexanide
A standardized method was used to model trophic purulent wounds using a silicone disk technique. Outcomes were assessed on days 1, 3, 5, 7, and 12 using:
Visual wound assessment
Digital planimetry (ImageJ)
Bacteriological cultures
Cytological analysis
Light and electron microscopy
Statistical analysis included Mann–Whitney U-test and Pearson’s χ² test .
Laser Treatment Protocol
The high-intensity Er:YAG laser (wavelength 2.94 μm) was used in two modes:
🔹 Ablation Mode
Power density: 10 J/cm²
Ultra-short pulses (~300 ns)
Controlled vaporisation of necrotic tissue and biofilm
No thermal damage to underlying tissue
🔹 RecoSMA Mode
Power density: 1.8 J/cm²
Pulse frequency: 2–3 Hz
Converts laser radiation into mechanical waves
Penetration depth up to 6 mm
Induces microtrauma in dermis to stimulate regeneration
During the inflammatory phase, ablation was immediately followed by RecoSMA mode. In later healing phases, only RecoSMA mode was applied.
Laser therapy accelerated transition to productive healing phase.
3️⃣ Accelerated Wound Area Reduction
Reduction of wound area by >50% occurred:
Control: Day 16
Antiseptic: Day 12
Laser groups: Day 8
By Day 12:
Control mean wound area: 263.8 mm²
Antiseptic: 195.8 mm²
Laser: 112.4 mm²
Laser + antiseptic: 105.0 mm²
Laser groups demonstrated significantly greater area reduction (p < 0.001) .
4️⃣ Superior Bacterial Decontamination
On Day 5:
Control: 70% showed pronounced contamination
Antiseptic: 65% medium contamination
Laser groups: predominantly low contamination
On Day 12:
Laser groups: 65–70% wounds sterile or low contamination
Control group: persistent high contamination
Laser exposure disrupted biofilm integrity and destroyed microbial cells, confirmed via electron microscopy .
5️⃣ Cytological and Morphological Evidence of Regeneration
By Day 12:
Laser groups showed predominance of inflammatory-regenerative and regenerative cytograms
35% of laser smears demonstrated regenerative type (p < 0.001)
Control group retained inflammatory characteristics
Electron microscopy revealed:
Disruption of biofilm structure
Destruction of microbial cells
Increased fibroblast activity
Newly formed capillaries
Accelerated collagen deposition
In contrast, untreated wounds demonstrated persistent purulent-inflammatory changes and viable microbial communities .
Mechanistic Interpretation
The study confirms a dual mechanism:
1️⃣ Ablation Mode
Mechanical removal of necrotic tissue
Biofilm vaporisation
Rapid decontamination
2️⃣ RecoSMA Mode
Deep mechanical resonance effect
Microvascular stimulation
Activation of fibroblasts
Accelerated collagen synthesis
Enhanced epithelialisation
The laser groups demonstrated superior control of infection and faster transition from inflammatory to regenerative phase.
Clinical Implications
Although performed in an animal model, the findings suggest that Er:YAG laser therapy:
Effectively sanitises purulent wounds
Disrupts biofilms resistant to conventional treatment
Accelerates granulation and epithelialisation
May reduce risk of chronicisation
The results support the potential translation of this technology into clinical management of trophic and infected wounds.
Conclusion
In this controlled experimental study, high-intensity Er:YAG laser therapy — applied in ablation and SMA modes — significantly accelerated wound cleansing, reduced bacterial contamination, enhanced granulation maturity, and promoted faster epithelialisation compared to saline or antiseptic treatment alone.
The method appears promising for further clinical research and broader implementation in wound care practice . Source:
Zaitsev AE, Asanov ON, Chekmaryova IA. Analysis of the effectiveness of the erbium laser in the treatment of trophic purulent wounds in an experiment. Medical News of North Caucasus. 2023;18(4):394–397 .