High-Flow Dural Arteriovenous Malformations in Infants
Neil M. Borden, MD
Bruce L. Dean, MD
Richard A. Flom, MD
Burton P. Drayer, MD
Robert F. Spetzler, MD†
Division of Neuroradiology, †Division of Neurological Surgery, Barrow Neurological Institute, Mercy Healthcare Arizona, Phoenix, Arizona
Dural arteriovenous malformations (AVMs) in infants are rare lesions that are difficult to eradicate and often require both endovascular and surgical management. These lesions are often characterized by high flow and high volume resulting in venous hypertension. Review of the literature and analysis of the following two case reports suggest that many of the clinical and imaging findings in infantile dural AVMs are a sequelae of venous hypertension. There can be many similarities with infants who harbor vein of Galen malformations, which may relate to the underlying intracranial venous hypertension.
Key Words: infantile dural AVM, vein of Galen malformation, venous hypertension
Dural arteriovenous malformations (AVMs) are thought to represent about 10 to 15% of all intracranial vascular malformations with arteriovenous shunting.[1,25] Although most dural AVMs occur in adults, there are scattered reports of these lesions in neonates, infants, and children.[1,4,9,15,26] Current opinion is that many dural AVMs in adults are related to underlying dural sinus thrombosis and recanalization[13,22] although other factors have been implicated. Their occurrence in neonates and infants suggests a congenital origin in this subgroup of patients.[1,9,15,17,25] In contrast to adults, pediatric patients with dural AVMs demonstrate more systemic and cranial signs and symptoms reflecting higher flow and higher volume shunts.[1,11,15,17,25] These high-flow, high-volume shunts lead to venous hypertension. This process is similar to intracranial venous hypertension in infants with vein of Galen vascular malformations.[18,21] We believe that venous hypertension in both groups of patients can cause similar clinical and imaging findings. We present two cases of high-flow infantile dural AVMs that demonstrate clinical signs and symptoms and findings on diagnostic imaging that we believe resulted from intracranial venous hypertension.
Figure 1. (A) Axial contrast-enhanced computed tomography scan at the level of the lateral ventricles showing the partially thrombosed vascular lesion posteriorly (arrows) and the ventriculomegaly. (B) Unenhanced axial T1-weighted magnetic resonance (MR) image also demonstrating the large vascular lesion posteriorly (arrows). (C) Unenhanced T1-weighted sagittal MR image demonstrating the massive vascular enlargement (arrows) in the torcular region. (D) Lateral composite digital subtraction angiography (DSA) images from the superselective left occipital artery injection. Note the dural arteriovenous malformation (AVM) supplied by the occipital artery. Venous drainage first enters the venous pouch (arrowheads). The contrast is then diluted as it drains into the torcula (arrows). (E) Lateral DSA image after transvenous embolization of the recipient venous pouch with nine platinum coils (small arrows). Note patency of the torcula (large arrows) superior to the embolized pouch (small arrows).
After an uneventful gestation and birth, a 4-month-old female presented to our institution with seizure and vomiting, left periorbital swelling since birth, borderline macrocephaly, and decreased motor development with poor head control. Conventional cerebral angiography at an outside institution demonstrated a large AVM in the region of the vein of Galen. Ventriculomegaly also was identified and led to placement of a right ventriculoperitoneal shunt. On examination, left periorbital soft-tissue swelling and proptosis, prominent scalp and forehead veins, and generalized muscle hypotonia were noted. Computed tomography (CT) demonstrated a large mass with vascular elements between the leaves of the dura of the posterior falx (Fig. 1A). There was prominent mass effect on the cerebellum and fourth ventricle, and calcifications were evident along the posterior aspect of the blood-filled mass. The left cavernous sinus and the left superior ophthalmic vein were enlarged asymmetrically.