Kaposiform hemangioendothelioma (KHE) is a rare infiltrative vascular tumor that is potentially life-threatening when presenting with Kasabach-Merritt phenomenon (KMP). KMP is clinically characterized as severe thrombocytopenia and hypofibrinogenemia and therefore is associated with a high mortality rate. There is no standard of cure for KHE currently. Potential medications, including corticosteroids, propranolol, and chemotherapy drugs such as sirolimus, are often used for alleviating KHE symptoms. Although some case reports of sirolimus treatment have shown promising results with recovered coagulant parameters, the off-target effects may cause severe problems. Here we describe 2 cases of infant patients with KHE and KMP who were scheduled to receive sirolimus on a long-term basis. However, both patients developed paroxysmal cough and tachypnea shortly after the onset of sirolimus treatment and succumbed to infection thereafter. This report reveals a potential risk of infection in sirolimus-treated infant patients. The fatal complication highlights the importance of antibiotic prophylaxis and serum sirolimus level monitoring to ensure the safe use of sirolimus in the treatment of infant patients with KHE.

We introduce intralesional interstitial bleomycin injection as a treatment approach for early-stage arteriovenous malformations and show that it yields safe and effective outcomes. PurposeTo assess the efficacy and safety of intralesional interstitial bleomycin injection in the treatment of early-stage (Schobinger stage I or II) extracranial arteriovenous malformations (AVMs).Materials and MethodsThis prospective study involved 34 patients with early-stage AVMs, as defined by the Schobinger staging system. The patients received intralesional interstitial bleomycin injected at a maximum dose of 15 000 IU or 1000 IU per kilogram of body weight for children who weighed less than 15 kg per procedure for a total of 6 months (once every month). Therapeutic outcome was evaluated by the degree of devascularization at angiography and the clinical outcome 3 months after the last treatment. Further follow-up was evaluated based on further clinical outcome. Adverse events were recorded according to the Society of Interventional Radiology classification.ResultsOf the 34 patients with early-stage AVM, 32 (mean age, 20.5 years; 24 female [75%]) completed the study. The results showed that 27 (84.4...