Photothermally Induced Vessel-Wall Necrosis After Pulsed Dye Laser Treatment: Lack of Response in Port-Wine Stains With Small Sized or Deeply Located Vessels

Abstract

The optimal treatment of port-wine stains is laser-induced selective photothermolysis. Lesion color and location and the age of the patient are reported to influence the therapeutic outcome. This study was initiated to analyze the outcome not only by the clinical response of lightening, but also in terms of photothermally induced necrosis to the vessel wall. Punch biopsy specimens were taken from 51 patients before treatment. Post-treatment biopsies were taken after exposure to a pulsed dye laser (585-nm wavelength, 0.45-ms pulse length) with an irradiant fluence of 6.5 J/cm2. Vessel diameter, depth, and wall thickness were measured in all histologic slides. The viability of the vessel walls was evaluated using an enzyme histochemical method. Port-wine stains with good blanching had significantly more superficially located vessels than the moderate and poor responders (p < 0.000). The moderate and good responding lesions consisted of moderate-sized vessels with diameters of 38 +/- 17 micrometers and 38 +/- 19 micrometers (mean +/- SD), respectively. The lesions showing poor blanching had significantly smaller vessels, with a diameter of 19 +/- 6.5 micrometers < 0.000). Analyses of the post-treatment specimens showed that coagulated vessels were superficially located and of moderate size, whereas the viable vessels were small with a median diameter of 14 micrometers. The probability of coagulation correlated with the thickness of the vessel wall. These data indicate that the therapeutic outcome of port-wine stains can be improved by using the lesional vessel parameters to select the optimal laser wavelength, pulse duration, and dose.

Progress toward Understanding Vascular Malformations

“…During the migration process,, cell adhesion molecules such as integrins, vascular endothelial cadherin and fibronectin aree involved (24,31). For instance the function of integrin avp3 appears to be critical for formation and/orr maintenance of newly fomed vessels (57,58). Vascular endothelial cadherin is expressed earlyy during vasculogenesis at inter-endothelial junctions, probably playing a role during lumen formationn (35).…”

“…A nonsense mutation and a frameshift mutation havee been identified (58). The autosomal recessive cholestasis-lymphedema syndrome has been mappedd to 15q, but to date, the responsible gene has not been identified (59).…”

A Comparison of Acquired Port-wine Stain with Congenital Port-wine Stain Using an Image Analyzer

“…To demonstrate correlation between clinical features and therapeutic response, many investigations were done with no unanimity [10][11][12][13][14] . Histopathologic examinations of PWS have also been done to establish the relationship between pathologic parameters and therapeutic responses [7][8][9][15][16][17] . Hohenleutner et al 15 of a diameter up to 150μm were completely coagulated.…”

A new model of selective photothermolysis to aid laser treatment of port wine stains

“…Nowadays, pulsed dye lasers (PDL) of wavelengths from 585 to 600 nm together with CSC become the treatment of choice for PWSs. A complete clearance of PWSs is, however, rare (less than 25%) with many PWSs respond poorly to laser treatment [7][8][9].…”