The Use of Variable Pulse Width Frequency Doubled Nd:YAG 532 nm Laser in the Treatment of Port-Wine Stain in Chinese Patients

Abstract

background. Variable pulse width frequency doubled Nd:YAG 532 nm laser has previously been shown to be effective in the treatment of vascular lesions in Caucasians. For dark-skinned patients, such as Asians, its role has not been determined. objective. To assess the clinical efficacy and complication rate of the 532 nm Nd:YAG laser in the treatment of port-wine stain in Chinese patients. methods. Chinese patients with port-wine stain who had undergone Nd:YAG laser treatment were called for questionnaire assessment of their degree of clearing and clinical examination for complications by two independent observers. For 22 patients with pre-and posttreatment photographs, the two independent observers further assessed the degree of clearing. results. Assessment of the questionnaire indicated that 62.9% of the patients subjectively considered that they had more than 25% clearing, with 33.3% having more than 50% clearing. For those with pre-and posttreatment photographs, the objective degree of improvement was less impressive with 18.1% of patients having at least 25% improvement and only 13.6% having more than 50% improvement. Pigmentary and texture changes were seen in both groups (33% in group I and 11% in group II). The number of treatment sessions rather than previous use of pulsed dye laser therapy was an important risk factor for complications. conclusion. Nd:YAG laser is only partially effective for the treatment of port-wine stain in Chinese patients. Although most patients recorded some degree of subjective improvement, many did not improve by objective assessment. High fluence is necessary to achieve the desirable clinical response, and while contact cooling reduces the risk of epidermal damage, texture changes can still occur. Further study is necessary to compare its use with other similar devices, such as a pulsed dye laser with cryogen spray cooling.

Laser treatment of congenital facial port‐wine stains: Long‐term efficacy and complication in Chinese patients

“…We also con®rmed that Chinese patients were less responsive to laser treatment with a higher complication rate. Despite the fact that 532 nm lasers have had a higher complication rate reported in the literature than the PDL lasers, this did not occur in current study and our previous study [12]. The high percentage of patients in this study may have experienced complications due to the fact that the PDL used was a small spot size (3 mm), relatively high¯uence (8 J/cm 2 ) which is going to have more complications than the 7±10 mm spot size used today with 6±8 J/cm 2 with skin cooling.…”

An overview of clinical and experimental treatment modalities for port wine stains

“…71 Nevertheless, irradiating skin with 532-nm light is associated with greater risk of adverse effects as a result of predominant absorption by melanin, despite epidermal cooling. 72,73 The clinical applicability of the 532-nm laser may hence be limited.…”

Congenital giant nevocellular nevus of the back with deep extension to the fat and fascia

“…The carbon dioxide laser, the Er:YAG and the Q-switched ruby laser have all been recently used for resurfacing and to selectively treat deep pigmentation (32)(33)(34). The Q-switched ruby laser has been shown to have a potent effect on depigmentation, which could be used to lighten deep layers where resurfacing lasers are ineffective.…”

“…The worst concern, however, is that lightening those lesions may camouflage any malignant transformation (2). Other side effects of laser therapies include formation of scar and changes in skin texture and colour (34). There is no evidence at present that the laser used to treat giant congenital nevi could stimulate the melanocytes to malignant changes (7).…”

“…There is no evidence at present that the laser used to treat giant congenital nevi could stimulate the melanocytes to malignant changes (7). Nonetheless, longstanding effects on the residual nevomelanocytes are still under investigation (34).…”