Sirolimus in the Management of Complex Infantile Hemangiomas: A State-of-the-Art Review

Infantile hemangiomas (IHs) are common, benign vascular tumors frequently managed with beta-blockers as first-line therapy. While most IHs respond to propranolol, a subset of severe, refractory, or life-threatening lesions requires alternative interventions. Sirolimus (rapamycin), a mammalian target of rapamycin (mTOR) pathway inhibitor, has emerged as a promising second-line treatment option for complicated IHs, particularly those with visceral involvement, airway compromise, functional impairment, or significant cosmetic consequences. This article reviews reported clinical experiences and mechanistic insights supporting the use of sirolimus in managing complex IHs and proposes a protocol to guide patient selection, dosing, and monitoring.