Electrosclerotherapy as a Novel Treatment Option for Hypertrophic Capillary Malformations: A Randomized Controlled Pilot Trial Sophie E.R. Horbach, MD, PhD,* Albert Wolkerstorfer, MD, PhD, † Folkert Jolink, MD,* Paul R. Bloemen, BEng, ‡ and Chantal M.A.M. van der Horst, MD, PhD* BACKGROUND Bleomycin sclerotherapy is ineffective for treating capillary malformations (CMs) because bleomycin cannot adequately be injected into the small-diameter capillary lumina. Electrosclerotherapy (EST) might be a new treatment modality for CMs, as it combines bleomycin sclerotherapy and “electroporation”— an electric field applied to the tissue. Electroporation disrupts the transmembrane potential, facilitating bleomycin transportation across the vessel wall, hypothetically leading to targeted drug delivery and increased effectiveness of bleomycin in CMs. OBJECTIVE To explore the efficacy, safety, and feasibility of EST for CMs in a randomized within-patient controlled pilot study. MATERIALS AND METHODS Fifteen regions of interest (ROI) within the hypertrophic CMs of 5 patients were randomly allocated to EST, bleomycin injection, or no treatment. Outcome was assessed after 7 weeks by the patient and a blinded outcome assessor using the patient-observer scar assessment score (POSAS), global assessment of change (GAC), colorimetry, and laser speckle contrast imaging. RESULTS Color and hypertrophy of all ROIs treated with EST significantly improved, based on the POSAS (medians patient 211; observer 213), GAC, and colorimetry (DE 3.4–16.5) scores. CONCLUSION This pilot study demonstrates the first proof of concept for electrosclerotherapy as a new treatment modality for CMs. Further research is warranted. The authors have indicated no significant interest with commercial supporters. The equipment for this study was provided by IGEA medical. IGEA medical was not involved in the study design, execution, analyses, and writing of the manuscript. This study was approved by the local institutional review board of the Academic Medical Center of the University of Amsterdam, the Netherlands, and was conducted conforming to the Declaration of Helsinki. The study protocol was published and registered at clinicaltrials.gov (NCT02883023) on August 29, 2016 and the Netherlands National Trial Register (NTR6169) on November 15, 2016. E lectrosclerotherapy (EST) combines bleomycin sclerotherapy and “electroporation”—an electric field applied to the tissue. This therapy is also known as “electrochemotherapy,” 1 in which the combination of bleomycin as a cytostatic agent, and electroporation is used as a form of local chemotherapy, leading to successful treatment of superficial skin and soft tissue tumors such as basal cell carcinoma, angiosarcoma, melanoma metastasis, and Kaposi sarcoma. 2–5 Standard operating procedures have been developed, 6 and good cosmetic outcomes were reported. 7 Bleomycin sclerotherapy exploits the sclerosing action of bleomycin on the vasculature rather than the cytostatic effect and is often used to treat low- flow vascular malformations such as venous and lymphatic malformations. 8 However, its effective- ness is suboptimal in capillary malformations (CMs), as intravascular injections in the capillaries *Departments of Plastic, Reconstructive and Hand Surgery, † Dermatology, and ‡ Biomedical Engineering and Physics, Academic Medical Center (AMC), Amsterdam University Medical Center, University of Amsterdam, the Netherlands © 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. All rights reserved. ISSN: 1076-0512 · Dermatol Surg 2019;00:1–10 · DOI: 10.1097/DSS.0000000000002191 1 © 2019 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.