Inhibiting PI3K and MAPK Pathways

Abstract

Extracranial arteriovenous malformations (AVMs) are associated with significant morbidity and mortality and lack consistently effective non-surgical interventions. Genetic mutations have been associated with AVMs, leading to success in using targeted therapies to reduce comorbidities. We report a 19-year-old male with phosphatase and tensin homolog hamartoma tumor syndrome with a large AVM of the left leg, complicated by progressive dilated cardiomyopathy, requiring multiple trans-arterial and trans-venous embolizations. Despite management using systemic mammalian target of rapamycin inhibition by sirolimus and surgical interventions, this patient developed cardiac failure and chronic skin ulcers over the distal left leg, presumed to be due to stasis and tissue ischemia, leading to development of debilitating pain. Trametinib was added to target activation of mitogen-activated protein kinase pathway. His cardiac disease and AVM responded when trametinib and sirolimus were combined. After 2 months, his chronic skin ulcers healed completely. The patient can ambulate without the need for any pain medication, and his cardiac condition stabilized.