Argon laser-port-wine stain interaction. Immediate effects

Abstract

Biopsy specimens from 11 patients with port-wine stains were examined by routine paraffin sections immediately after argon laser therapy, and the findings were correlated with those seen in 1-micron epoxy resin-embedded sections and with immunofluorescence microscopy studies localizing factor VIII-related antigen and type IV collagen. The histopathologic pattern was that of an arc-shaped injury to the papillary and upper reticular dermis, extending to a depth of 0.45 mm. Most of the abnormal vessels in the port-wine stain were encompassed in this zone and showed severe injury. Erythrocytes in these vessels displayed changes, ranging from near normal to complete fragmentation. Focally, vessels adjacent to the area of major injury contained clumped erythrocytes with tinctorial changes but intact walls. In two specimens, alterations in basement membrane and endothelial immunofluorescence staining patterns were present in the zones adjacent to the major cauterized areas, extending focally to a depth of 0.75 mm. This study suggests that, in addition to the major nonspecific destructive component of argon laser therapy, there is a smaller adjacent "specific" zone of damage in which collagenous stroma is maintained and chromophore content becomes important as a determinant of injury.

Laser Treatment of Port Wine Stains

“…A vessel specific action of the argon laser can only be observed in the dermal layers between 0.4 and 1.0 mm. In this layer light microscopic vessels seem to be coagulated and surrounding tissue undamaged [10,11]. This coagulated tissue is replaced by fibrous tissue within several weeks.…”