Angioarchitecture of Hereditary Arteriovenous Malformations

Abstract

This article describes three hereditary conditions known to be associated with arteriovenous malformation (AVM), along with their clinical and imaging features and angiographic angioarchitecture. Hereditary hemorrhagic telangiectasia, capillary malformation-AVM (CM-AVM), and PTEN tumor hamartoma syndrome are conditions with autosomal dominant inheritance, caused by mutations in different molecular pathways, which frequently present with symptomatic AVMs. Imaging biomarkers, including sites of predilection, angioarchitecture, and tissue overgrowth patterns, are helpful in identifying these patients and selecting appropriate treatment.

Pediatric Congenital Cerebrovascular Anomalies

“…The revised three‐tier Spetzler‐Martin scale for AVMs includes factors such as size (<3, 3–6, and >6 cm), location (+/– eloquent), and venous drainage (superficial or deep); and recommends surgical resection for class A (Spetzler‐Martin grade I and II); multimodal therapy, including open neurosurgery, endovascular embolization, or radiosurgery treatment for class B (Spetzler‐Martin grade III); and conservative management for class C (Spetzler‐Martin grade IV and V) . Pediatric brain AV shunts associated with hereditary conditions caused by mutations in different molecular pathways appear to have multifocal sites of AV shunting and present far more often with hemorrhage compared to adult patients . Following are the subdivisions of high flow arteriovenous shunts: intra‐axial: pial AV shunts, CM‐arteriovenous malformation (CM‐AVM), and vein of Galen aneurysmal malformation (VGAM) due to RASA1 gene mutation; and extra‐axial: dural AV shunts.…”

“…Characteristically, patients can have one or more cutaneous CM that may occur alone or together with high flow AV shunts typically involving the extremities, trunk, head and neck, and CNS . CNS lesions are usually type I AVFs, while the peripheral lesions such as seen in limb overgrowth (Parks Weber) syndrome tend to be predominantly type IIIa AVMs . An example of a pial AVF in CM‐AVM patient is shown in Figure .…”

“…51 Pediatric brain AV shunts associated with hereditary conditions caused by mutations in different molecular pathways 52 appear to have multifocal sites of AV shunting and present far more often with hemorrhage compared to adult patients. 50,52 Following are the subdivisions of high flow arteriovenous shunts: intra-axial: pial AV shunts, CM-arteriovenous malformation (CM-AVM), and vein of Galen aneurysmal malformation (VGAM) due to RASA1 gene mutation; and extra-axial: dural AV shunts.…”

“…61,62 CNS lesions are usually type I AVFs, while the peripheral lesions such as seen in limb overgrowth (Parks Weber) syndrome tend to be predominantly type IIIa AVMs. 52 An example of a pial AVF in CM-AVM patient is shown in Figure 13. Treatment of pial AV shunts can be microsurgical, endovascular techniques, or combined to close the fistulous connection, depending on clinical and angiographic factors.…”

Giant pediatric intracranial pial macrofistula

“…Macrofistulas are rare cerebral vascular malformations (1.6%) 1 frequently seen in children with hereditary hemorrhagic telangiectasia (HHT) or capillary malformation-arteriovenous malformation disorders. 2 In case of HHT, any associated pulmonary fistula has to be ruled out: left untreated, HHT would carry a risk of brain abscess or stroke. Treatment of the macrofistula is necessary to prevent complications due to hydrovenous disorders or hemorrhage.…”