This retrospective study investigated the influence of prior pulse dye laser (PDL) treatment on the effectiveness of Hemoporfin-PDT in young children aged 1-3 years with PWS.

The study population included patients without a history of PDL treatment and patients with a history of PDL treatment.

Background Hemoporfin-mediated photodynamic therapy (Hemoporfin-PDT) is considered a safe and effective treatment for port-wine stains (PWS). This study aims to investigate the influence of prior pulse dye laser (PDL) treatments history on the effectiveness of Hemoporfin-PDT in young children aged 1-3 years with PWS.

Methods Data was gathered for individuals with PWS aged 1-3 years who received two or more Hemoporfin-PDT treatments. The study population was stratified into two groups: Cohort 1 (No PDL) comprised patients without a history of PDL treatment, while Cohort 2 (Prior PDL) consisted of patients with a history of PDL treatment. An analysis was conducted to investigate the relationship between treatment efficacy and variables including gender, age, location, and type of PWS.

Inclusion Criteria:

• Patients clinically diagnosed with PWS (Port Wine Stain) who were between 1 and 3 years old at the time of their first HMME-PDT treatment.

  • Patients who, after evaluation by a clinician, are deemed eligible for HMME-PDT treatment and whose guardians have signed an informed consent form.

    • Patients who have undergone two or more HMME-PDT treatments.

      ④ Patients with complete basic information and treatment-related information.

Exclusion Criteria:

• Exclusion of patients with syndromes associated with PWS.

  • Exclusion of patients with a history of treatments for PWS other than PDL treatment.

    • Patients with other vascular malformations. ④ Exclusion of patients who have received any other PWS treatment within 2 months prior to HMME-PDT treatment.

This cohort study is a retrospective, single-center study based on a database established by the photodynamic therapy team at the Second Affiliated Hospital of Xi'an Jiaotong University.We defined "young children" as children aged 1 to 3 years. This research encompassed young children who had undergone two or more sessions of Hemoporfin-PDT. Data on gender, age, medical history, type of PWS, lesion location, and post-treatment efficacy were collected following two rounds of Hemoporfin-PDT.