Treatment of Port-Wine Stains With a Short Pulse Width 532-nm Nd:YAG Laser
January 2013 | Volume 12 | Issue 1 | Original Article | 66 | Copyright © January 2013
Kavitha K. Reddy MDa, Jeremy A. Brauer MDa, Munir H. Idriss MDb, Robert Anolik MDa,Leonard Bernstein MDa, Lori Brightman MDa, Elizabeth Hale MDa, Julie Karen MDa,Elliot Weiss MDa, Dirk Elston MDb, and Roy G. Geronemus MDa
aLaser & Skin Surgery Center of New York, New York, NY bAckerman Academy of Dermatopathology, New York, NY
Abstract
Background and Objective: Pulsed dye laser treatment often results in port-wine stain (PWS) improvement; however, results vary. A frequency-doubled neodymium-doped yttrium aluminum garnet (Nd:YAG) laser that allows for shorter pulse widths along with large spot sizes and high fluences has been developed for the treatment of cutaneous vascular lesions.
Study Design: A prospective, controlled study was performed in 5 adults with PWS using a frequency-doubled Nd:YAG laser (Excel V; Cutera Inc, Brisbane, CA) in 4 quadrants, using spot sizes of 6 to 10 mm, fluences of 4.8 to 9 J/cm2, and pulse durations of 3 to 6 ms. An adjacent control area was not treated. Each was assessed immediately posttreatment for purpura and edema and at 1 month for PWS color, size, texture, and thickness. Skin biopsies obtained immediately after and at 1 month posttreatment were evaluated.
Results: All treatment quadrants displayed purpura. At 1-month follow-up, all treatment quadrants showed at least 1 grade of color improvement, from a minimum of 1% to 25% to a maximum of 51% to 75% improvement (12/20 quadrants with 1%-25% improvement, 3/20 with 26%-50%, 5/20 with 51%-75%, and 0/20 with 76%-100%). Histologic evaluation of treatment quadrants revealed vascular changes ranging 0.35 to 4 mm in depth. Immediately posttreatment, thrombi and extravasated red blood cells were observed in treatment quadrants. Histology at 1 month revealed decreased number and diameter of vessels in treatment quadrants (superficial vessels decreased by mean 1.1 vessels per section [13%], and diameter by 3.0 μm [47%], midlevel vessels decreased in number by 2.3 [20%], diameter by 2.42 μm [25%], and deep vessels decreased in number by 1.5 [83%], and diameter by 7.44 μm [88%]).
Conclusions: A single treatment with a short pulse width, frequency-doubled Nd:YAG laser resulted in safe and effective improvement of PWS, with up to 75% improvement in color observed at 1 month. Histologic evaluation demonstrated vascular injury at depths of 0.35 to 4 mm with a reduction in vessel number and size at multiple dermal levels.
J Drugs Dermatol. 2013;12(1):66-71.
INTRODUCTION
Port-wine stains (PWS), congenital cutaneous capillary vascular
malformations, occur in approximately 0.3% of the population.1 The pathogenesis remains poorly understood; however, the resultant abnormality is the presence of a field area of dilated cutaneous vessels. Early treatment using lasers selectively
targeting dilated vasculature has been recommended to provide optimal lightening and to prevent the darkening, thickening,
nodularity, and/or hypertrophy that may occur with inadequate
treatment.2,3
Vascular-specific lasers with wavelengths targeting hemoglobin in PWS vessels represent the standard of care for treatment. A fluence
sufficient to induce vessel damage and a pulse width equal to or less than the thermal relaxation time of the targeted vessel has been recommended to avoid nonselective damage to surrounding
structures.4 The thermal relaxation time of PWS vessels has been estimated at 1 to 10 milliseconds (ms).5 Given the large size of many PWS and the need for frequent treatments, larger spot sizes aid in promoting optimal treatment. High fluences in a short pulse width are also important to destroy small PWS capillaries
that are often resistant to pulsed dye laser (PDL) treatment. This has presented a challenge in the treatment of PWS.
Frequency-doubled, 532-nm neodymium-doped yttrium aluminum
garnet (Nd:YAG) lasers have been studied in a limited manner in the treatment of PWS.6-8 A dual potassium titanyl phosphate/Nd:YAG laser (Excel V; Cutera Inc, Brisbane, CA) that allows large spot sizes up to 10 mm in diameter, along with short pulse widths of 5 to 10 ms and fluences up to 11 J/cm2 was recently approved by the US Food and Drug Administration (FDA) for the treatment of cutaneous vascular lesions. This laser was investigated for safety and efficacy in the treatment of PWS.
