Effects of sirolimus in the treatment of unresectable infantile hemangioma and vascular malformations in children: A single-center experience.

Objective: Recently, sirolimus has emerged as a safe and effective treatment modality for unresectable vascular lesions. In the present study, we investigated the effectiveness and safety of sirolimus from our early experience with patients with unresectable vascular anomalies.

Methods: The medical records and radiologic images of all patients with unresectable vascular anomalies treated with sirolimus at our center from January 2018 to November 2019 were retrospectively reviewed. All patients were administered oral doses of sirolimus 0.8 mg/m every 12 hours as the initial dose, followed by maintenance of a target serum concentration (5-10 ng/mL) with therapeutic drug monitoring.

Results: Six patients with unresectable vascular anomalies were treated with sirolimus for ≥10 months. Their median age at the initiation of sirolimus treatment was 17 months (range, 8-67 months). The median duration of treatment was 13 months (range, 10-16 months). One patient had a good response, four had an intermediate response, and one had no response to sirolimus therapy. None of the patients had discontinued sirolimus therapy because of adverse effects.

Conclusions: Sirolimus can be used effectively and safely for patients with unresectable vascular anomalies. However, further prospective studies are warranted to evaluate the long-term effects of sirolimus and clarify the indications for early intervention.