P. H. L. Koster

Effect of the timing of treatment of port-wine stains with the flash-lamp-pumped pulsed-dye laser

BACKGROUND Port-wine stains can be treated with a flash-lamp-pumped pulsed-dye laser, but it is uncertain whether this treatment is more effective if administered early in life, when the skin is thinner and the lesion is smaller. METHODS We prospectively studied 100 patients with a previously untreated port-wine stain of the head or neck. They were treated with the flash-lamp-pumped pulsed-dye laser and divided into four age groups (0 to 5, 6 to 11, 12 to 17, and 18 to 31 years). The outcome measure was lightening of the port-wine stain (reduction in the difference in color between the skin with the stain and contralateral healthy skin) as measured with a colorimeter after an average of five treatments (range, three to seven) of the entire lesion. RESULTS Of the 100 patients, 11 could not be included in the analysis because they had received fewer than three or more than seven treatments, had an erroneous base-line color measurement, or were lost to follow-up. The sizes, locations, and colors of the port-wine stains were similar among the groups. When all 89 patients were analyzed together, the average reduction in the difference in color between the skin with the port-wine stain and contralateral healthy skin was 40 percent. The differences between age groups in the average reduction in color differences were not significant (P= 0.26). By the end of the study, only 7 of 89 patients had completed laser therapy, and in no case was clearance complete. Treatment was discontinued in all seven because the last three treatments did not lead to further lightening. CONCLUSIONS We found no evidence that treatment of port-wine stains with the flash-lamp-pumped pulsed-dye laser in early childhood is more effective than treatment at a later age.

HEREDITARY PORT-WINE STAINS. DO THEY EXIST?

Abstract. Patients with a port-wine stain applying for laser treatment often mentioned having a member in the family with a similar birthmark. Of 280 consecutive new patients with a port-wine stain 55 mentioned relatives with the same anomaly. Family tendency (19.6%) for vascular malformations in our group was significantly higher than mentioned by others. Pedigrees were made of 32 families with two or more affected members, including probands. We present nine representative pedigrees of families with three or more members affected by port-wine stains. In these families no clear mode of inheritance can be discerned. Genetic linkage studies identified causative gene defects in certain venous malformations and Rendu–Osler–Weber disease. Knowledge of new theories on angiogenesis and molecular genetics has to be linked to our patients with familial port-wine stains.

Assessment of clinical outcome after flashlamp pumped pulsed dye laser treatment of portwine stains : A comprehensive questionnaire

&NA; A generally accepted method to assess the clinical outcome of laser treatment of portwine stains is not available. This paper describes the development and evaluation of a comprehensive questionnaire for the assessment of the following portwine stain characteristics: color (hue and lightness), sharpness of boundary, pigmentation, size, shape, skin surface‐structure, and hypertrophy of underlying tissue. The questionnaire was applied to photographs of 70 patients with previously untreated portwine stains in the head/neck area. Photographs were taken before treatment and after five treatments of the entire portwine stain with a flashlamp pumped pulsed dye laser. Each photograph was evaluated separately by a panel of five professionals: the treating physician, two plastic surgeons, a dermatologist, and a clinical photographer. Treatment results were assessed by comparing ratings before and after treatment. Agreement among raters was acceptable for all portwine stain characteristics, as was shown by weighted kappa analysis. The reliability of the answers was further improved by taking the average rating of the five panel members. The scores thus obtained were very reliable, with Cronbach alpha coefficients of 0.8 on average. After five treatments of the entire portwine stain, the most considerable changes were measured in the ratings for color (lightening of the stain by 33 percent), boundary (sharpness reduced by 38 percent), and size (13‐percent decrease). Using the questionnaire can be helpful in the design of comparative clinical trials on portwine stain treatment and may facilitate comparison of treatment results between different treatment centers and/or different lasers. (Plast. Reconstr. Surg. 102: 42, 1998.)

Laser options for vascular lesions in childhood

To determine which laser can be used for a vascular lesion, the different working mechanisms of the individual lasers must first be understood. The localization and diameter of the vessels to be treated define whether a certain laser is appropriate for that lesion. For teleangiectasias and port-wine stains the pulsed-dye laser works without scarring. Hemangiomas respond only when flat and superficial. Deeper lesions can only be reached with the ND-Yag laser.

Histology of overlapping and nonoverlapping pulsed-dye-laser pulses on normal human skin

In treatment of port-wine stains with a pulsed dye laser, whether to deliver the pulses with or without overlap remains controversial. Therefore the effect of overlap on vascular damage was histologically objectivated by taking biopsies from normal human skin of 5 healthy volunteers, who had laser pulses delivered as follows: 1 single pulse, 2 completely overlapping pulses, 2 pulses with approximately 30% overlap, and 2 pulses with 1 - 2 mm normal skin in between. For these experiments a Candela SPTL-1 with a wavelength of 585 nm was used to deliver 5 mm diameter pulses at an energy level of 7.0 J/cm2. Light microscopy of the biopsies taken 24 hours after delivering the pulses shows that in overlapping pulses the inflicted damage still seems to be confined to the vessels, but that it extends deeper into the dermis. A striking observation, however, is that concerning the depth of vessel damage, even in non- overlapping pulses, the adjoining pulses have an invigorating effect on each other.