Cavernous malformation – A rare complication of gamma knife surgery for Arteriovenous malformations (P6.002)

Objective: Cerebral arterio-venous malformation (AVM) is the most symptomatic of all vascular malformations and can present with various neurological manifestations similar to lobar hemorrhage or any space occupying lesion. Treatment modalities include endovascular embolization, microsurgical resection and radiosurgery. Although, surgical resection is the mainstay of treatment, gamma knife surgery is commonly employed for smaller and deep seated lesions in the brain. One of the rarest complications of Gamma knife surgery is development of a secondary vascular malformation i.e a cavernoma. The purpose of this article is to report such a case, discuss the diagnostic pitfalls of such rare presentations and literature review. Background: NA Design/Methods: Case report Results: We describe a 52 yr old male with arterio venous malformation who underwent multiple embolizations failing which was treated with gamma knife surgery. A year later he developed vasogenic edema around the surgical site which was thought to be radiation necrosis and treated with steroids. The edema worsened and underwent symptomatic hemorrhagic transformation involving the right fronto-parietal regions, subsequently developing malignant cerebral edema resistant to steroids and hyperbaric oxygen, with impending herniation. Patient underwent surgical resection of the hemorrhagic mass with histopathology reports of the resected mass demonstrating newly developed cavernoma as a complication of gamma knife surgery. It was concluded that bleeding from the cavernoma caused vasogenic edema which progressed to malignant cerebral edema. Following surgical resection, patient’s symptoms markedly improved with resolution of cerebral edema. Conclusions: Although development of vasogenic edema as a complication following gamma-knife surgery is commonly due to radiation necrosis; unresponsiveness to conventional anti-inflammatory therapy should raise suspicion for alternate diagnosis of newer and different vascular malformations such as cavernoma in our case. Prompt recognition and surgical resection can alleviate patient symptoms and reduce the morbidity and mortality. Study Supported by: NA Disclosure: Dr. Honganur has nothing to disclose. Dr. Haralur has nothing to disclose. Dr. Mechtler has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Philips, Allergan, Supernus. Dr. Holla has nothing to disclose.