Clinical outcomes of bleomycin electrosclerotherapy (BEST) for the treatment of slow-flow vascular malformations (SFVMs): a UK single-centre experience.

BACKGROUND: Bleomycin Electrosclerotherapy (BEST) is an emerging treatment for slow-flow vascular malformations (SFVMs), utilising electroporation to enhance intralesional bleomycin uptake. This study evaluates the safety and clinical outcomes of BEST in reducing symptom severity (SS) and improving quality-of-life (QoL) in patients with SFVMs. METHODS: This retrospective, single-centre study analysed 20 consecutive patients with symptomatic SFVMs treated with BEST between September 2022 and November 2024. Patients underwent SS and QoL treatment specific questionnaires before treatment and at follow-up (mean: 286 days). Intralesional bleomycin injection was immediately followed by electroporation in every case. RESULTS: A total of 42 BEST procedures were performed, on the following anatomical areas: Face: 14 (70%), Neck: 2 (10%), Leg: 3 (15%), Arm: 1 (5%). Significant reduction in the mean SS (-8.2, p < 0.001) and QoL (-5.2, p < 0.001) scores was observed. The most improved domains were swelling (mean -2, p < 0.001), aesthetic concerns (mean -2, p < 0.001), and pain (mean -1.1, p < 0.003). No major complications were reported. Skin changes (needle marks) were reported in 13/20, and intra-oral ulcers occurred in 6/20 patients. Most skin changes were either fading away or resolved at follow up. All intra-oral ulcers resolved during follow up. CONCLUSIONS: BEST is a safe procedure and demonstrates significant symptom relief and QoL enhancement, particularly in patients with severe baseline symptoms and more conspicuous lesions. While multiple treatments yielded greater improvements, even a single treatment was effective. Post-procedural side effects were minor, the most severe being skin markings and self-limiting ulceration.