Developmental Venous Anomaly: Benign or Not Benign

Abstract

Developmental venous anomalies (DVAs), previously called venous angiomas, are the most frequently encountered cerebral vascular malformations. However, DVA is considered to be rather an extreme developmental anatomical variation of medullary veins than true malformation. DVAs are composed of dilated medullary veins converging centripetally into a large collecting venous system that drains into the superficial or deep venous system. Their etiology and mechanism are generally accepted that DVAs result from the focal arrest of the normal parenchymal vein development or occlusion of the medullary veins as a compensatory venous system. DVAs per se are benign and asymptomatic except for under certain unusual conditions. The pathomechanisms of symptomatic DVAs are divided into mechanical, flow-related causes, and idiopathic. However, in cases of DVAs associated with hemorrhage, cavernous malformations (CMs) are most often the cause rather than DVAs themselves. The coexistence of CM and DVA is common. There are some possibilities that DVA affects the formation and clinical course of CM because CM related to DVA is generally located within the drainage territory of DVA and is more aggressive than isolated CM in the literature. Brain parenchymal abnormalities surrounding DVA and cerebral varix have also been reported. These phenomena are considered to be the result of venous hypertension associated with DVAs. With the advance of diagnostic imagings, perfusion study supports this hypothesis demonstrating that some DVAs have venous congestion pattern. Although DVAs should be considered benign and clinically silent, they can have potential venous hypertension and can be vulnerable to hemodynamic changes.

Pediatric Congenital Cerebrovascular Anomalies

“…DVAs, also known as venous angiomas or venous malformations, consist of radially oriented collection of veins, also known as “caput medusa” which drains into a large collector vein (Fig ). These lesions are usually asymptomatic, but may become symptomatic if there is increase inflow, ie, upstream arteriovenous shunt or CM or if there is decreased outflow from compression, stenosis, or thrombosis of the outflow vein . Multiple DVAs are associated with sporadic or familial blue rubber bleb nevus syndrome (BRBN) …”

“…In rare circumstances, DVAs with AV shunts are associated with hemorrhage, venous hypertension, and may ultimately result in ischemic changes if there is thrombosis, stenosis, or compression of the draining vein. The etiology is related to narrowing of the vein near its drainage into a dural sinus . Chronic ischemic changes may lead to atrophy and calcification.…”

“…These lesions are usually asymptomatic, but may become symptomatic if there is increase inflow, ie, upstream arteriovenous shunt or CM or if there is decreased outflow from compression, stenosis, or thrombosis of the outflow vein. 23 Multiple DVAs are associated with sporadic or familial blue rubber bleb nevus syndrome (BRBN). 24 Hemorrhagic cases are most often attributed to DVAassociated CM.…”

“…The etiology is related to narrowing of the vein near its drainage into a dural sinus. 23,25 Chronic ischemic changes may lead to atrophy and calcification. Contrast-enhanced MR imaging clearly demonstrates the radial collection of veins and draining vein.…”

Medusa-like Atypical Intracerebral Vein: A Rare Case of Symptomatic Developmental Venous Anomaly

“…Neurosurgical intervention is not a choice for the treatment of isolated DVAs because this on its own can lead to unacceptable consequences (7,21,22). Therefore, excision or ablation of DVAs should be avoided because they may form part of the normal venous drainage for adjacent normal neural tissue.…”