# Prospective analysis of bleomycin electrosclerotherapy for clinical outcome and volume reduction in therapy refractory slow-flow malformations

## TL;DR

This study shows that bleomycin electrosclerotherapy effectively reduces the size and symptoms of hard-to-treat vascular malformations with minimal side effects.

## Contribution

The study introduces bleomycin electrosclerotherapy as a novel and effective treatment for therapy-resistant slow-flow vascular malformations.

## Key findings

- 94.3% of lesions showed symptomatic improvement after one treatment session.
- All lesions demonstrated volume reduction, with an average decrease of 33.24% after final treatment.
- Mild adverse events occurred but resolved within 4 weeks, indicating high safety.

## Abstract

Slow-flow vascular malformations are persistent congenital vascular lesions that progressively disrupt tissue structure and function, often causing pain, swelling, and esthetic concerns. Despite the availability of surgical and sclerotherapy-based interventions, treatment outcomes are often unsatisfactory, with high rates of recurrence and resistance. The aim of this study was to prospectively evaluate the safety and effectiveness of bleomycin electrosclerotherapy in reducing lesion volume, alleviating symptoms, and improving clinical outcomes in 33 patients with slow-flow vascular malformations resistant to previous treatments. The prospective design allowed real-time observation of patients’ responses to therapy, while the longitudinal follow-up, beginning with recruitment in 2020 and continuing through the end of 2024, allowed comprehensive monitoring of outcomes.

After one treatment session, 33 of 35 (94.3%) lesions demonstrated symptomatic improvement, and all lesions (n = 35/35, 100%) showed a reduction in volume. Average volume decreased from 1781.1 to 1335.0 mL (25.0%) after one session and 1189.13 mL (33.24%) after final treatment. Mild adverse events, including redness (n = 4) and swelling (n = 25), resolved within 4 weeks. Skin changes like hyperpigmentation (n = 3) and livid discoloration (n = 4) could be observed for longer periods of time.

Bleomycin electrosclerotherapy demonstrated high effectiveness and safety for treating slow-flow malformations, establishing it as a promising therapeutic option even for lesions that have responded insufficiently to previous treatment attempts.

The online version contains supplementary material available at 10.1186/s42155-025-00641-z.