Blood Perfusion May Determine the Therapeutic Effect of Pulsed Dye Laser on Port-Wine Stains Located on Extremities.

Background: Port-wine stains (PWS) on proximal limbs respond better to pulsed dye laser (PDL) than PWS on distal limbs. Objective: To investigate whether the superiority of PDL efficacy on the proximal limbs is related to variations in blood perfusion. Methods: Patients with untreated PWS on the extremities underwent three sessions of PDL. Blood perfusion of the selected sites on both the proximal and distal limbs, as well as control sites, was detected by laser speckle imaging before treatment. After treatment was completed, the therapeutic effect was evaluated both objectively and subjectively. Results: A total of 19 patients were included. Seventeen of them presented with PWS on the upper extremities and 2 patients on the lower extremities. The mean speckle flow imaging value of the PWS on the upper arms and thighs was significantly lower [80.51 ± 16.96 perfusion unit (PU), control: 66.36 ± 13.18 PU] than that on the hands and feet (155.68 ± 71.86 PU, control: 72.82 ± 18.97 PU). Meanwhile, the average blanching rate on the proximal and distal limbs was 48.33% and 22.12%, respectively. Significant correlations were identified between blood perfusion and PDL efficacy (r = -0.351, p = 0.031). Conclusions: PWS in the proximal limbs responded better to PDL than PWS on distal limbs. This variation in efficacy may be attributed to differences in blood perfusion. Clinical trial registration no. ChiCTR-OCB-15007326.