Patient Characteristics
These 30 studies reported on 1181 total patients, of which 290 patients had a total of 315 infections. Of note, one study only listed the number of infections without specifying whether any patient had more than one infection, so we counted each infection in this study as a unique patient to avoid underestimating the number of patients experiencing infections.24 Patients in all included studies received sirolimus. Many studies lacked sufficient detail to determine key demographics of patients with infections. For example, age was not specified in 237/290 patients (82%). The remainder were younger than 1 year (n=16, 5%), 2 to 17 years (n=28, 10%), or older than 18 years (n=9, 3%). Similarly, sex was not specified for 268/290 patients (n=92%). The remainder were male (n=14, 5%) and female (n=8, 3%). Similarly, these studies lacked granular detail about the sites of VA disease (not specified in 83%) and whether sirolimus was held during infections (not specified in 81%). Patients with infections for whom they type of VA was reported (n=121/290) had a wide variety of VAs, with slow flow vascular malformations (n=60, 50%) and kaposiform hemangioendothelioma (KHE)/tufted angioma (n=24, 20%) most commonly reported. Given the limited granular reporting, 58% of participants did not have a specific VA diagnoses listed and instead were aggregated into the category “multiple VAs” (Table 2).