How angioarchitecture of cerebral arteriovenous malformations should influence the therapeutic considerations

To evaluate the angioarchitectural criteria of complex cerebral arteriovenous malformations (AVMs), concerning the risk of hemorrhage and therapy planing.

The magnetic resonance (MR) imaging and neuroangiographic findings of 227 AVMs (223 patients) were retrospectively evaluated. Statistical analysis was used to define the relative frequency of these lesions for hemorrhage in correlation with various parameters (i.e. age of the patient, size, location, associated aneurysms).

Onset of symptoms was between 21 and 40 years of age in 50% of cases. The ratio of centrally to convexially located lesions was 1:2. Convexial AVMs are classified by MR imaging into sulcal and gyral, according to the arterial supply (by terminal or transit feeding arteries, respectively), as proven by super-selective neuroangiography. Central location of the AVM, size of the nidus smaller than 2 cm diameter, and presence of related aneurysms, are high risk factors for hemorrhage. AVMs with one or two draining enlarged veins, or those without reflux presented a higher incidence of hemorrhage as well.

A team approach is required for the choice of the therapeutic method in patients with AVMs. Our results allow an approximate prognosis concerning the risk of hemorrhage in these patients and should be taken in consideration for the precise therapeutic planing.