Evaluation of the vacuum-assisted handpiece compared with the sapphire-cooled handpiece of the 800-nm diode laser system for the use of hair removal and reduction

Background: A handpiece with a 35 × 22-mm treatment window that uses vacuum technology has been designed for the diode laser system. Vacuum suction stretches the skin and brings the hair follicle closer to the surface with the intent to damage the hair follicle at a lower surface fluence. The objective of this study was to compare the degree of follicular thermal damage between the sapphire-cooled smaller handpiece at a higher fluence versus the larger vacuum-assisted handpiece at a lower fluence. Methods: Five male patients with Fitzpatrick skin types IIV were enrolled in the study. Three test spots on the right back were treated with the vacuum-assisted laser handpiece at a setting of 1012 J/cm², and 61-ms pulse duration. Three test spots on the left back were treated with the sapphire-cooled handpiece with a setting of 3034 J/cm² and a pulse duration of 1416 ms. A punch biopsy was obtained from one treated area for each handpiece type. The biopsies were sectioned horizontally and examined for the degree of thermal damage to the hair follicle at the level of the isthmus and the bulb. Immediate treatment response, pain score, and total treatment time were recorded. Results: Biopsies from the skin treated with the sapphire-cooled handpiece and the vacuum-assisted handpiece showed the mean hair follicle diameter was 258.3 m (SE [standard error] 41.7) and 225.1 m (SE 17.1), respectively. The mean thermal damage diameter to hair diameter ratio was 0.91 (SE 0.10) and 0.72 (SE 0.12), respectively. The mean immediate treatment response, the mean pain severity, and the mean total treatment time were all lower for the vacuum-assisted handpiece. Conclusion: Treatment with the vacuum-assisted handpiece is faster and has a tendency to be more comfortable. Thermal damage to the hair follicle was greater with the sapphire-cooled handpiece.