Bleomycin Electrosclerotherapy (BEST) for treatment of slow-flow vascular malformations in children.

Background: This prospective study evaluates the effectiveness and safety of Bleomycin electrosclerotherapy (BEST) for treating slow-flow vascular malformations in a pediatric cohort. While retrospective studies have reported its efficacy, prospective data in pediatric populations are limited.

Methods: 30 pediatric patients (mean age: 9.5 years) with venous, veno-lymphatic, or capillary-veno-lymphatic malformations were enrolled in the study between 2020 and 2021 and received at least one BEST treatment. Follow-up continued through 2024 (mean: 25 months). MRI volumetry and clinical evaluation were performed at each follow-up.

Results: A total of 58 sessions (mean: 1.81 per patient) led to a median lesion volume reduction from 232 cm³ (range: 1.69 cm³-9814.12 cm³) pre-treatment to 41 cm³ (range: 0.57 cm³-1789.63 cm³) after the final session, corresponding to mean relative volume reduction of 59.4%. Symptoms resolved in 2 patients, improved in 18, and remained unchanged in 4. Minor side effects included skin hyperpigmentation (n = 6), inflammation (n = 3), temporary motion restriction (n = 1), and lymphorrhea (n = 1). No serious complications were observed.

Conclusion: BEST is a safe, effective treatment for pediatric slow-flow malformations, achieving lesion reduction and symptom relief. Future studies are warranted to optimize treatment protocols and establish long-term benefits.

Impact statement: Bleomycin Electrosclerotherapy (BEST) is a safe and effective treatment for slow-flow vascular malformations in pediatric patients, achieving lesion volume reduction and symptom improvement. The study assesses BEST exclusively in a pediatric cohort using standardized MRI-based volumetry alongside clinical outcomes. BEST can be effective not only in refractory cases but also as a first-line or early-line treatment option, broadening its potential indications. By indicating a cumulative therapeutic benefit of repeated BEST sessions, the study encourages further investigations into tailored, session-based treatment strategies for large or progressive malformations.