ATTEMPT TO OBTAIN GREATER DERMAL DEPTH OF VASCULAR INJURY USING DYE-ENHANCED LASER TECHNIQUE - A NEW APPROACH

Background and Objective: Although pulsed dye laser has been successfu lly used in the treatment of portwine stains, a number of patients had incomplete clearance because the depth of penetration by the pulsed d ye laser was inadequate. This study was performed to establish the gre ater penetration depth of vascular injury using a dye-enhanced laser t echnique. Study Design/Materials and Methods: The ruby laser at 694.3 nm was used, and the corresponding specific dye was Prussian blue solu tion (maximum absorbance 694 nm). me compared the penetration depth of vascular injury by the ruby laser irradiation after the Prussian blue injection with that by the dye laser irradiation. A flashlamp dye las er with a pulse duration of 300 mu sec and a 5 mm diameter spot size w as used to 6.2 J/cm(2) at 590 nm. The Prussian blue solution was injec ted into the superficial epigastric artery of white male Japanese rabb its, immediately followed by the ruby laser exposure to 6.2 J/cm(2) at a pulse duration of 283 mu sec in a 15 x 15mm spotsize. Depth of pene tration was measured from the dermoepidermal junction to the deepest s ite of vascular injury at 24 hours after laser exposure. Results: Mean penetration of 590 nn of the dye laser light was 1.45 mm; mean penetr ation of the 694.3 nm ruby laser irradiation after the Prussian blue i njection was 2.33 mm. Ruby laser penetration was greater than that of the dye laser. Conclusion: This study emphasizes that the ruby laser i rradiation after the Prussian blue injection can induce deeper vascula r injury than the dye laser inducing similar pathological changes. (C) 1996 Wiley-Liss, Inc.