Efficacy and influencing factors of percutaneous sclerotherapy for venous malformations of the knee in children.

OBJECTIVE: To evaluate the clinical efficacy, safety, and the factors influencing percutaneous sclerotherapy combined with pingyangmycin and polidocanol foam for treating venous malformations of the knee in children. METHODS: A retrospective analysis was conducted on 13 pediatric patients with knee venous malformations who were treated with percutaneous sclerotherapy under ultrasound combined with digital subtraction angiography guidance between March 2020 and February 2026. Preoperative imaging was performed to classify the lesions as intra-articular, juxta-articular, localized, or diffuse, and to assess synovial involvement. All patients underwent sequential sclerotherapy at intervals of 4-6 weeks. Follow-up outcomes included pain relief assessed using the Visual Analog Scale, lesion volume regression on imaging, and postoperative complications. Subgroup analyses were performed to explore the impact of synovial involvement and lesion morphology on therapeutic response. RESULTS: The mean age of the 13 patients was 10.5 years, with a mean of 3.2 treatment sessions per patient. Among the 9 patients with preoperative pain, the pain relief rate was 88.9%. The overall imaging efficacy rate (significant + partial response) for lesion volume reduction was 61.5%. The subgroup analysis showed a higher lesion response rate in localized lesions than in diffuse lesions; moreover, patients without synovial involvement achieved better pain relief. All complications were minor transient local reactions of Society of Interventional Radiology grades A-B, with no major complications such as skin necrosis, nerve injury, deep vein thrombosis, or pulmonary embolism. CONCLUSION: Percutaneous sclerotherapy with pingyangmycin combined with polidocanol foam is a safe, effective, and minimally invasive method for treating pediatric knee venous malformations, with satisfactory pain relief and lesion regression. Synovial involvement and diffuse lesion morphology are the key adverse prognostic factors. Precise preoperative imaging evaluation and individualized multidisciplinary stratified treatment are essential for optimizing clinical outcomes.