Treatment of human papillomavirus-associated vulvar disease with the CO2-laser. Physical and histological aspects with use of a new scanning device, the SwiftLase.

The CO2-laser has a successful record in treatment of extensive, refractory vulvar condylomas and vulvar intraepithelial neoplasia. A prerequisite for optimal use of the laser is careful preoperative diagnosis and optimized surgical technique based upon the exact knowledge of the interaction process between laser radiation and tissue. Using a new CO2-laser scanning device, the Sharplan Swift-Lase, this in-vivo study analyses the effects of CO2-laser parameters [average power density (PD), beam size and exposure time] on vulvar skin to determine optimum laser settings. Our histomorphometric analyses reveal a minimal skin destruction (ablation depth 40 microns, extent of irreversible thermal damage 80 microns to 120 microns) after application of the CO2-laser energy with the SwiftLase using a PD of 1000 W/cm2 with a beam size of 1 mm diameter. Previous CO2-laser application techniques required low PD (200 W/cm2 to 750 W/cm2) and a larger beam size (1.5 mm to 2 mm) moving over the epithelial surface as fast as possible to obtain a precise skin destruction. The SwiftLase allows the laser beam to be moved slowly with a beam size of 1 mm and significantly higher PD (up to 5000 W/cm2). These advantageous application conditions guarantee precise, homogeneous vulvar skin treatments with minimal thermal damage to the surrounding normal skin. The SwiftLase enables a less experienced colposcopists to perform vulvar CO2-laser surgery.