Objective: To investigate the mechanism of collagenase in degradation of hypertrophic scars and observe the clinical effects of this therapy.
Methods: Both animal experiment and clinical trial were conducted.
Results: The injection of collagenase into the hypertrophic scar tissues in nude mice resulted in 86% volume reduction after two injections within two weeks, while the control tissues reduced only by 35% during the same time. Clinically, 13 cases were treated with intralesional injection of bacterial collagenase. The volume reduction rate was 46.92% in average within two weeks. The volume reduction in 4 of 13 cases was above 50%. Three to sixteen months' follow-up of five patients revealed that only one case of keloid recurred after treatment in the second month. Examinations of histological sections and TEM showed the dissolved collagen fiber clearly.
Conclusion: Collagenase can degrade collagen fiber directly. The prompt significant effects and the mild complications make it a prospective therapy.