Conclusion
Sirolimus still is a new treatment option for vascular anomalies that has shown to provide some benefit to patients, especially with LM and VM. The safety profile has generally been favorable, although different patient populations might be more prone to complications. The results of our retrospective survey of the “off-label” use of sirolimus in different vascular anomalies illustrates the risk of SAEs including fatal outcomes in these patients. This highlights the importance of a close follow-up in these patients as well as the need for further clinical studies to establish the safety profile of sirolimus, the incidence of SAEs in different patient populations and the optimal antibiotic prophylaxis.