The Nature and Evolution of Port Wine Stains: A Computer-assisted Study

Abstract

In an attempt to understand the histogenesis and evolution of port wine stains (PWS), 100 patients with PWS were biopsied; the gross features of each lesion and the patient's associated clinical characteristics were recorded. A detailed analysis of each biopsy including both vessel and nonvessel parameters was made with the assistance of a computer. The central abnormalities characterizing port wine stains are an increase in vessel number (vascular profiles) and ectasia. Vessel number is highest in the immediate subepidermal area and then rapidly diminishes; mean vessel depth is .46 +/- .17 mm. In contrast mean vessel area shows less variation throughout the dermis, ectatic vessels being present when vessel number is very low. The product of both factors determines the percent of dermis occupied by vessels, but the mean vessel area is the major determinant. While age correlates poorly with vessel number, it correlates well with both progressive vessel ectasia and color shifts (pink to purple). Each of multiple vessel parameters analyzed (vessel number, mean vessel area, wall thickness, angulation, and luminal erythrocyte content) exhibited strong layer to layer correlation within the first .8 mm of tissue beneath the epidermis, indicating homogeneity of vessel characteristics within the lesion. The size of the lesion and facial quadrant distribution do not change with age nor are they related to any histological parameters. However the PWS lesion is found most often on the right side and lower quadrants, with a distinctive pattern being present in patients with glaucoma and mental retardation.

A new Monte Carlo program for simulating light transport through Port Wine Stain skin

“…This is in agreement with previous biopsy [3,4] and simulation [26,40] studies. As a result, any combination of these three vessel parameters, for a fixed epidermis, creates a unique spectral reflectance curve.…”

“…However, the blood vessel parameters predicted by the procedure were shown to be consistent with those found elsewhere in the literature [3,4] and resulted in spectral reflectance curves, which reproduced measured spectra to a satisfactory degree of accuracy. It is likely that further iterations of the procedure would have resulted in a closer fit between measured and simulated spectra, as well as improved repeatability in the predicted vessel parameters.…”

“…The effect is less pronounced at the haemoglobin absorption peaks, where the effective path length within the vessel is shortest and the albedo is smallest, in particular near 420 nm. Varying vessel number had a broad effect, Due to overlap of the region qves 2 with qves 1 and qves 3 , adjustment of lesion depth is performed independently of vessel number and diameter. This required an iterative technique, whereby vessel number and diameter were adjusted initially followed by lesion depth, before vessel number and diameter were again considered.…”

“…Biopsy studies [3,4] have shown that skin colour is affected by the depths, diameters and number density of PWS vessels. Although, skin colour measurements are the most established and widely used technique for the objective assessment of PWS skin [5][6][7], to date this method has not been used to extract such information.…”

Description and Analysis of Treatments for Port-wine Stain Birthmarks

“…The depth of PWS varies from 100 to 1000 µm, and blood vessel diameter ranges from 10 to 300 µm. 5,6 …”