Arteriovenous malformations

Abstract

Arteriovenous malformations of the brain are congenital vascular lesions that affect 0.01-0.50% of the population, and are generally present in patients aged 20-40 years. The usual clinical presentations are haemorrhage, seizures, progressive neurological deficit, or headache. Results of natural history studies have shown a yearly haemorrhage rate of 1-4%. Frequency of rebleeding has increased over the years, and several factors that increase risk of haemorrhage have been identified. Although substantial, the morbidity associated with haemorrhages could be less than previously thought. Over the past decade, great advances have been made in application of endovascular embolisation techniques, stereotactic radiosurgery, and microsurgery, allowing effective multidisciplinary treatment of arteriovenous malformations, including those previously deemed to be untreatable. Increasing attention has been paid to management of flow-related aneurysms associated with these malformations. Finally, many reports of recurrent arteriovenous malformations have coincided with new theories regarding the embryogenesis of these disorders and laboratory work suggesting their proliferative potential.

Biology of Cerebral Arteriovenous Malformations with a Focus on Inflammation

“…9 History of hemorrhage, high blood pressure, intranidal aneurysm, venous stenosis, and deep venous drainage are the main factors that increase the likelihood of AVM rupture. 4,10,11 Although there are several therapeutic options to eradicate AVMs, the treatment-related morbidity is significant, especially for large, deep-seated, or eloquently located nidi. 6 The recently published ARUBA trial (A Randomized trial of Unruptured Brain Arteriovenous malformations) showed that medical management alone is superior to medical management with interventional therapy for the prevention of death or stroke in patients with unruptured brain AVMs.…”

Familial brain arteriovenous malformation maps to 5p13–q14, 15q11–q13 or 18p11: Linkage analysis with clipped fingernail DNA on high-density SNP array

“…This vascular malformation is thought to be congenital, and develops before or after birth [2] from a residual of the primitive artery-vein connection. Its most common symptom is intracranial hemorrhage with an estimated risk of 1.3-3.9% yearly after the diagnosis of AVM [3].…”

“…Other signs may include intractable seizures, headache and ischemic steal syndrome. The prevalence of AVM is estimated to be approximately 0.01% and the detection rate ranges between 1.12-1.34 per 100 000 person years [1,2]. Although most cases of AVM are sporadic, a total of 53 patients from 25 families have been reported [4].…”

Vascular Endothelial Growth Factor Induces Abnormal Microvasculature in the Endoglin Heterozygous Mouse Brain

“…However, the nature of VEGF-induced angiogenesis in the normal adult brain is unknown. A fundamental question that remains to be resolved in understanding the pathobiology of BAVM is whether the regional nature of vascular malformations is germline, such as HHT or venous malformations (Vikkula et al, 1996), or sporadic in nature, such as sporadic BAVM (Arteriovenous Malformation Study Group, 1999;Fleetwood and Steinberg, 2002). It is possible that some subclinical event might locally alter the balance of vascular signaling, such as minor trauma or ischemia in a subject with a genetic predispostion to have altered angiogenic responses.…”