Galenic pial arteriovenous fistulas: Angioarchitecture, clinical presentation, and therapeutic considerations.

Vein of Galen (VG) aneurysmal malformations (VGAMs) are complex vascular lesions. Their etiopathogenesis is extensively debated and remains poorly understood. Strictly speaking, true VGAMs are Galenic pial arteriovenous fistulas. They are believed to arise in utero and are contended to drain either into the true VG or the median prosencephalic vein of Markowski. Several classification systems have been proposed and are widely used. With the advent of endovascular therapy, precise understanding of the angioarchitecture is critical for management and therapeutic decision making. We review clinical presentation and diagnostic imaging findings, discussing angioarchitectural properties as they relate to treatment planning. Clin. Anat. 31:259-268, 2018. © 2017 Wiley Periodicals, Inc.

Spontaneous regression and complete disappearance of the vein of Galen aneurysmal malformation.

INTRODUCTION: Thrombosis is frequently observed in Galen malformation, but propagation of thrombosis resulting in the disappearance of the aneurysmal malformation is a very rare clinical condition. CASE REPORT: A rare case of spontaneous regression and disappearance of the vein of Galen aneurysmal malformation (VoGAM) in a pediatric patient with repeated generalized seizure, increased head circumference, and congestive heart failure is recorded. The course of regression from infancy to 8 years of age has been depicted. Radiological studies initially demonstrated VoGAM complicated by an intra-cerebral hemorrhage and hydrocephalus, which later underwent spontaneous regression. Long-term clinical and radiological follow-up is presented. DISCUSSION: Different conditions including hemodynamic alteration, compression of adjacent hematoma, and narrowing of related vascular structures have been described to cause thrombosis of VoGAM. The relevant literature to address possible mechanism is reviewed.

Endoscopic Third Ventriculostomy in an Untreated Vein of Galen Malformation Presenting Lately with Acute Obstructive Hydrocephalus.

BACKGROUND: Mural-type vein of Galen malformations (VoGMs) mostly manifest in later stages of infancy as macrocephaly, hydrocephalus, or failure to thrive unless previously diagnosed and treated. Literature is extremely limited on the success and safety of endoscopic third ventriculostomy (ETV) in acute obstructive hydrocephalus caused by an untreated VoGM. Thus, we aimed to present a case for demonstrating the possible efficacy and safety of ETV under such conditions. CASE DESCRIPTION: A 22-month-old boy presenting with acute-onset headache, vomiting, and lethargy was diagnosed with a mural-type VoGM and acute obstructive hydrocephalus. He was treated satisfactorily with ETV and endovascular embolization. We observed a shrinkage in malformation sac diameter of >20 mm in the magnetic resonance imaging angiography at postoperative year 1. The child showed normal motor and mental development at his outpatient clinic visit at postoperative month 15. CONCLUSIONS: To the best of our knowledge, this is the first case in the literature with an untreated VoGM presenting with acute obstructive hydrocephalus who was treated with the combination of ETV and endovascular embolization and had an adequate follow-up period.

[Vein of Galen malformations in children].

The literature review deals with historical stages of understanding of vein of Galen AVM pathogenesis in children up to state-of-art considerations. The authors analyzed existing classifications, clinical presentation, variants of natural course, problems of diagnostics and management of these patients. Causes of complications and possible ways for their prevention are also discussed.

Cerebral venous thrombosis after embolization of pediatric AVM with jugular bulb stenosis or occlusion: management and prevention.

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.