Abstract: 【Abstract】 Objective To evaluate the efficacy and safety of hemoporfin-mediated photodynamic therapy （HMME-PDT） for the treatment of port-wine stains （PWS） on the extremities. Methods A retrospective self-controlled study was conducted on patients diagnosed with extremity PWS and treated with HMME-PDT in the Department of Dermatology, Wuhan No.1 Hospital from April 2018 to December 2024. All patients received 1, 2, or 3 sessions of HMME-PDT. The efficacy and adverse reactions were analyzed. Based on the degree of lesion color fading, treatment outcomes were classified as near-complete remission, marked improvement, partial improvement, and no response. The Kruskal-Wallis H test, Mann-Whitney U test, and multivariate ordinal logistic regression analysis were used to analyze factors influencing the efficacy after 1 treatment session, and the Friedman M test was used to compare the efficacy after 1, 2, and 3 treatment sessions. Results A total of 135 patients with PWS on the extremities were enrolled, aged （M ［Q1,Q3］） 3 （2, 6） years （range: 1 - 36 years）, including 40 males （29.6%） and 95 females （70.4%）. Among the 135 patients, 57 completed only 1 session of PDT, 44 completed 2 sessions, and 34 completed 3 sessions. After a single treatment session, 69 patients （51.1%） showed no response; the efficacy in female patients was superior to that in male patients （Z = ?2.373, P = 0.018）; there was a significant difference in efficacy among different age groups, with patients aged > 12 years showing better efficacy （Z = 10.434, P = 0.015）. Multivariate ordinal logistic regression analysis of the efficacy after a single treatment session showed that the efficacy for pink-type PWS was superior to that for bright red-type PWS and purple-red-type PWS （both P < 0.05）, and the efficacy for lesions on the thigh, upper arm, and forearm was superior to that for lesions on the hand （all P < 0.05）; however, neither the location of PWS （on the extensor or flexor side of the extremity） nor prior treatment history affected the efficacy （both P > 0.05）. Among the 34 patients who completed 3 treatment sessions, the response rate after a single treatment session was 41.2% （14/34）, with no patients achieving marked improvement or near-complete remission; after 2 treatment sessions, the response rate was 50.0% （17/34）, the marked improvement rate was 17.6% （6/34）, with no patients achieving near-complete remission; after 3 treatment sessions, the response rate was 64.7% （22/34）, the marked improvement rate was 20.6% （7/34）, and the near-complete remission rate was 2.9% （1/34）; there was a significant difference in efficacy across different treatment sessions （M = 37.014, P < 0.001）. After a single treatment session, all the 135 patients presented with edema, pruritus, burning sensations, and stinging pain at the treatment sites; other adverse reactions included hyperpigmentation （57 cases, 42.2%）, crusting （28 cases, 20.7%）, hypopigmentation （9 cases, 6.7%）, blistering （7 cases, 5.2%）, mild atrophic scars （4 cases, 2.9%）, and infections （2 cases, 1.5%）, and no systemic adverse reactions were observed. Conclusion HMME-PDT demonstrates favorable efficacy and safety in the treatment of PWS on the extremities.

Key words: Port-wine stain, Photochemotherapy, Hemoporfin-mediated photodynamic therapy, Extremities, Treatment outcome