The diameter of malformation capillaries does not influence the efficacy of photodynamic therapy for facial port-wine stains: a pilot study

BACKGROUND: Photodynamic therapy (PDT) is an effective treatment for port-wine stains (PWS). However, the relationship between the diameter of malformed capillaries and the efficacy of PDT in PWS has been rarely studied. OBJECTIVE: This study aimed to investigate the relationship between the diameter of malformed capillaries and the efficacy of PDT in PWS. METHODS: Dermoscopy and capillaroscopy images were obtained before the first treatment to assess the capillary patterns and diameters of malformation capillaries in PWS, respectively. VISIA images were captured before treatment and two months after the second PDT session to evaluate treatment efficacy. RESULTS: Forty-seven patients were included in this study. Univariate analysis indicated that lesion location, prior treatment history, and capillary pattern influenced the outcomes of facial PWS after two PDT sessions. However, no significant differences were observed among patients with varying capillary diameters. Logistic regression analysis confirmed that capillary pattern and lesion location were significant factors affecting the efficacy of PDT, whereas capillary diameter was not. CONCLUSION: In this study, no significant correlation was observed between the responses of facial PWS to PDT and the varying vascular diameters. However, a significant correlation was observed between PDT efficacy and the capillary pattern or lesion location.