Photocoagulation using the argon laser has been proven to be an effective method for the treatment of port-wine stains (PWS). However, it is very difficult to reproduce the parameters of laser treatment. This leads to inaccurate energy dosages secondary to the difference in treatment patterns. The aim of this study was to compare the conventional point-by-point technique (PT) for PWS treatment against a new scanning technique (ST) using a device called "Hexascan" (PREIN & Partners, Ferney-Voltaire, France). A total of 249 patients (171 females and 78 males) using the argon laser have been studied in a retrospective study. Clinical results are presented. For each technique, blanching and hypertrophic scarring were examined. The results are classified into two groups: satisfactory and unsatisfactory. The clinical results show that the ST with the Hexascan is superior to the conventional PT. Scarring is drastically reduced because overdosage and overheating are avoided. Because of precisely controlled spot patterns, quality and homogeneity of blanching is improved. Treatment time can be reduced to 20% of that of the PT.

Laser therapy of port wine stains (PWS) is well established. However, the application of lasers to PWS treatment over the last decade has resulted in the use of many laser systems. The goal of this study is to describe the different laser parameters, treatment techniques, and delivery systems. Two methods, coagulation and microvaporization, are used to destroy the abnormal blood vessels. The coagulation method results in excellent treatment, but it requires careful control of laser parameters during the treatment process. Scanning devices can be utilized for this purpose. The microvaporization method, obtained with a pulsed dye laser, is restricted to PWS composed of small vessels since it is difficult to obtain a pulse longer than 450 microseconds. In addition, numerous retreatments are needed with the pulsed dye method. The initial assessment of the patient should contribute to an improvement in the choice of laser parameters and the outcome of treatment.

Venous ulcers are chronic wounds affecting up to 1% of adults in developed countries. Considering that noncontact normothermic therapy has been shown to modify the wound healing process, we conducted a prospective comparative clinical trial aimed at evaluating 980 nm diode laser in laser-assisted venous ulcer healing. Thirty-four Caucasian patients with venous leg ulcers were included in the study and separated into two homogenous groups based on age, sex ratio, size, and etiologies of the ulcers. In the laser group, 980 nm InGasAs diode laser (power 15 W, spot size 8 mm, time 3 seconds, fluence 90 J/cm(2) ) was applied weekly for 9 weeks to the ulcers in a homogenous standardized manner, resulting in a local temperature of 45-50 °C, which was controlled with a thermal infrared camera. Complete healing, reduction in size, and pain during and between each procedure were evaluated each time. Of the 18 patients in the laser group, three (16.7%) were completely healed during laser treatment. In the control group (16 patients), the healing was complete for four patients (25%). This difference was not significant (p=0.62). At the ninth follow-up visit, in the control group, the ulcers had decreased on an average to 94.3% of the original area of the ulcers. In the laser group, the decrease was to 74.2% of the original area of the ulcers. Again, this difference was not significant (p=0.60). The mean VAS score between each treatment was 2.7 (0.5-4.4) in the laser group compared with 3.8 (2.3-5.0) in the control group (0.13

Port wine stains are currently treated by the argon laser with the "point-by-point" technique, or the "painting technique." In both cases, the quality of the results depends greatly on the dermatologist's experience. Furthermore, the first technique is slow, and the second is painful and requires anesthesia. Therefore, we have decided to design a robotized system with the following specifications: easy, fast, non-painful treatment giving a homogeneous and reproducible blanching. The system is made of a handpiece with the scanning mechanism and a control box with the microprocessor. The system is independent of the laser (no electrical connection) and has its own power meter. The deposit of energy was optimized in function of heat diffusion in the skin. Over a 12-month period, 123 patients were treated with the robotized handpiece. The treatment modalities and the results conformed to the above-mentioned specifications. Hypertrophic scars were not reported. Therefore, we think that this system will be an interesting tool for the laser treatment of port wine stains and other cutaneous angiodysplasias.

Laser photocoagulation has proven to be valuable in the treatment of port-wine stains. In this application, the minimal blanching technique is used as an indicator of suitable dosage since it has been demonstrated that the immediate appearance a white mark is required to achieve permanent blanching a few months later. The objective of the investigations undertaken in this study was to correlate the temperature attained at the surface of port-wine stains with immediate blanching, upon irradiation with different laser fluences. A comparative study was performed using an argon laser (all lines), a 532 nm Nd:YAG and a 585 nm argon pumped dye laser. Surface temperature was studied using an infrared camera. Temperature was measured on 10 different port-wine stains using different fluences. Whitening threshold fluence was related to surface temperature. It appeared that whitening threshold fluence corresponded to a surface temperature of 53 degrees C (+/- 3 degrees C). The whitening threshold fluence was dependent on port-wine stains and wavelength. However, whitening threshold fluence remained lower for 532 nm and 585 nm and it correlated to the absorption curve of hemoglobin.