DAVMs spinal

DAVMs may occur anywhere within the cranium or the spinal canal. In adults, DAVMs mostly present in middle-aged or older patients with a mean age of 50-60 years. Spinal DAVMs commonly present after the fourth decade. 

Venous thrombosis has been proposed as the most probable pathogenetic mechanism for spinal DAVMs, although minor venous anomalies have also been recognized in such patients that may serve as predisposing factors (McCutcheon et al. 1996). 

DAVMs may occur anywhere within the cranium or in the spinal column. Intracranial DAVMs are located either in the anterior cranial fossa on or around the ethmoid groove (Fig. 4.3,1), in the middle cranial fossa at the cavernous sinuses (Fig. 4.3,2), in the posterior fossa at the transverse (Fig. 4.3,3) or the sigmoid (Fig. 4.3,4) sinuses, at the confluens sin-uum (Fig. 4.3,5), or around the foramen magnum... 

Spinal DAVMs are considered the most common spinal vascular malformations, constituting 80% of all spinal AVMs (Anson and Spetzler 1992 Lee et al. 1998). The majority of these lesions are located in the thoracolumbar region. 

Finally, Borden et al. (1995) created a simplified system by combining the previous two and including spinal DAVMs in the same classification (Tables 4.3 and 4.4, Figs. 4.13-4.15). This sys-... 

Table 4.4. Classification of spinal dural arteriovenous malformations (DAVMs) in relation to venous...

Venous drainage pattern Spinal DAVM Classification... 

Because transvenous embolization is not feasible for spinal lesions, transarterial embolization with glue is the treatment of choice for a spinal DAVM with an arterial feeder that allows safe and distal catheterization and does not supply the anterior spinal artery. Glue should be pushed until it reaches the draining vein (Fig. 4.18) (Cognard et al. 1996 Song et al. 2001). Clinical outcome seems to dependent on the severity of the symptoms at the time of treatment (Nagata et al. 2006). 

The treatment of spinal DAVM by surgery is easy, safe, and effective and requires interruption of the draining vein at its dural entrance only (Anson and Spetzler 1992). Therefore, embolization of spinal DAVM should be offered only if the feeding pedicle provides a safe approach to a position close to the fistula site and it does not give rise to radiculomedullary branches supplying the anterior spinal artery. If there is a risk of reflux into the anterior spinal artery, surgery is significantly safer and should be performed. 

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