Landthaler M, Haina D, Brunner R, Waidelich W, Braun-Falco O
J Am Acad Dermatol. 1986 Jan;14(1):107-17. doi: 10.1016/s0190-9622(86)70014-5.
Three patients with port-wine stains with a nodular surface, one patient with macrocheilia resulting from a port-wine stain, and one patient with a capillary hemangioma were treated with a Nd-YAG laser (mediLas, MBB-AT, Munich). Irradiance was between 800 and 1,600 watts/cm2, with energy fluence between 400 and 1,600 joules/cm2. Treatments were performed with local anesthesia on an outpatient basis. In all patients, marked improvements could be obtained after only a few treatments. Histologically there was necrosis of epidermis and dermis immediately after laser application, and ectatic vessels contained coagulated erythrocytes. Depth of coagulation was up to 3.5 mm. Quick restoration of epidermis was observed. After some days, macrophages, fibroblasts, and capillary blood vessels grew into the agglutination thrombi and ectatic vessels were replaced by granulation tissue and, later, by fibrous tissue. In comparison with the argon laser, the Nd-YAG laser coagulates at a much deeper level, but processes of tissue repair take longer and fibrosis is more pronounced after Nd-YAG laser application. Clinically, therefore, scar formation is more likely. Chilling the skin surface during irradiation and shorter exposure times may be effective in reducing the risk of scar formation in the future.
