PURPOSE: Thrombosis of cerebral arteriovenous malformation after embolization is rare, but can involve the normal venous network with extensive venous thrombosis. We report angioarchitecture findings, our management and prevention strategy for this complication in pediatric AVMs.
METHODS: In this 5.5-year retrospective series, we reviewed records of 13 patients under 15 years who were anticoagulated after embolization. In our initial experience 4 children who didn't receive any prophylactic anticoagulation presented with extensive venous thrombosis after embolization (group 1). Following this, nine children with similar angioarchitecture and embolization modalities were treated with prophylactic anticoagulation immediately after embolization (group 2). We analyzed the type of AVM, angioarchitecture, dose of prophylactic anticoagulant, efficacy/complications of treatment and late outcome.
RESULTS: All patients in group 1 had severe jugular bulb stenosis/occlusion associated with cerebral venous dilatation. In group 2 with similar angioarchitecture, only three patients (33%) developed extensive thrombosis. In both groups, thrombosis occurred within two days of treatment in six children and two weeks in one child. The diagnosis was suspected on intracranial hypertension in five patients and occulomotor disorder in one. One was asymptomatic. All children were treated with therapeutic doses of LMWH (anti-Xa: 0.5-1). No hemorrhagic complications occurred. Good venous remodeling was observed in all but one patient.
CONCLUSION: Anticoagulation in extensive venous thrombosis after AVM embolization in children appears to be safe and effective. In cases with angioarchitectural features of dilatation of the cerebral venous network and occlusion/severe stenosis of the jugular bulbs, full dose anticoagulation may be required to prevent thrombosis.