Oral rapamycin: an alternative in children with complicated vascular abnormalities

Sirolimus mTOR inhibitor represents a major advance in the treatment of patients with complicated vascular abnormalities. The objective of this study was to present our series of pediatric patients with vascular abnormalities treated with oral sirolimus, and to conduct a review of the relevant literature.

A retrospective analysis of patients with complicated vascular abnormalities treated with oral sirolimus in our healthcare facility from 2016 was carried out. Initial dosage was 0.8 mg/m2 every 12 hours, and therapeutic range was 5-15 ng/ml. All patients received trimethoprim-sulfamethoxazole prophylaxis.

6 children -3 boys and 3 girls- with a mean age of 9.5 years at treatment initiation were included. 3 of them had head and neck lymphatic malformation, 2 had lower limb venous malformation, and 1 had combined lymphatic-venous malformation at the thoracoabdominal level. They all had received multiple previous treatments without improvement. Following sirolimus initiation, 5 patients had clinical improvement (mean time: 3.6 months) and 4 had radiological improvement (mean time: 6.6 months). Mild and transitory adverse effects were noted in the 3 cases. Today, 5 patients remain under treatment.

Oral sirolimus is an effective and safe treatment in patients with complicated vascular abnormalities. Our results support sirolimus use in lymphatic and venous malformations in which previous treatments have failed, with a good symptomatic and, to a lesser extent, radiological response.