Mass lesion in cases of cerebral arteriovenous malformations post gamma knife radiosurgery or embolization: Pathophysiology and management algorithm

Abstract

Background: Cerebral Arteriovenous Malformations (AVM) have been conventionally treated with surgery, embolisation and/or Gamma Knife Radiosurgery (GKRS). This article is to present a rare complication after Embolisation/ Gamma Knife Radio Surgery for Cerebral AVMs.

Method: 05 patients with cerebral AVMs presenting with an unusual complication of a mass lesion at the site of the treated lesion were treated. Two modes of index treatment were used: endovascular embolisation and/or GKRS. These patients developed new-onset neurological deficits at varying intervals after index treatment. They were investigated radiologically, revealing a mass lesion at the site of the treated AVM. The pathophysiology of this complication, along with the management algorithm, has been studied and is presented.

Results: All the patients in the series responded well to surgery. The histopathological examination revealed vascular elements in all cases without any evidence of neoplasm.

Conclusion: Delayed presentation as a mass lesion of a treated AVM is unusual. The mass lesion in cerebral arteriovenous malformations with suspicion of malignant transformation or with unresponsive raised intracranial pressure may mandate craniotomy and excision.