Effect and safety of ethanolamine oleate in sclerotherapy in patients with difficult-to-resect venous malformations: A multicenter, single-arm study.

Abstract

ObjectiveTo evaluate the effect and safety of sclerotherapy in patients with difficult-to-resect venous malformations treated with ethanolamine oleate.Design and settingThis investigator-initiated clinical trial employed a multicenter, single-arm design and was conducted in Japan.PatientsOverall, 44 patients with difficult-to-resect venous malformations were categorized into two cohorts: 22 patients with cystic-type malformations and 22 patients with diffuse-type malformations, including children (InterventionsAdult patients received injections of 5% ethanolamine oleate solution, double diluted with contrast or normal saline, with a maximum dose of 0.4 mL/kg. The same method of administration was used for children (Evaluation methodsTreatment effect was assessed by evaluating the difference in lesion volume using magnetic resonance imaging as a primary endpoint and differences in pain using a visual analog scale as a key secondary endpoint.ResultsAmong the 45 patients who consented, one was excluded owing to potential intracranial involvement of venous malformations during screening. Regarding the primary outcome, 26 of 44 patients (59.1%, 95% confidence interval: 44.41-72.31%) achieved ≥ 20% reduction in malformation volume, with 16 patients having cystic lesions (72.7%, 51.85-86.85%) and 10 patients having diffuse lesions (45.5%, 26.92-65.34%). Both cohorts showed significant improvement in self-reported pain scores associated with lesions 3 months post-sclerotherapy. No death or serious adverse events occurred. Hemoglobinuria was observed in 23 patients (52%), a known drug-related adverse event. Prompt initiation of haptoglobin therapy led to full recovery within a month for these patients.ConclusionsEthanolamine oleate shows potential as a therapeutic sclerosing agent for patients with difficult-to-resect venous malformations.