Arteriovenous Malformations of the Corpus Callosum —Radioanatomic Study and Effectiveness of Intranidus Emboli.zation—

Abstract

Forty-three patients with arteriovenous malformations (AVMs) of the corpus callosum treated by em bolization were reviewed. The following clinical and radioanatomic characteristics were found: 84% (36 patients) presented with intracranial hemorrhage, 43% (20 nidi) of the lesions were located in the posterior half of the corpus callosum, multiple nidi were more frequent (21%) than expected, 27 nidi (59%) were fed by branches of both the anterior and posterior cerebral arteries, AVMs mainly drained into the internal cerebral vein and/or interhemispheric superficial veins, and 19 (41%) had both draining pathways, 10 patients (23%) had impaired drainage through the straight sinus due to dys plasia. Staged embolization was performed in 245 feeders. Curative occlusion (more than 95%) was ob tained in 17 patients (40%) and considerable occlusion (more than 75%) in 33 patients (77%). Large and giant, diffuse-type, and multifocal AVMs were difficult to completely embolize. Complications as sociated with embolization occurred in six patients, mostly during the first 5 years. Only two patients had a permanent deficit related to a complication. Overall morbidity and mortality were 7% and 2%, respectively. Nine patients were referred for stereotactic radiosurgery, three of whom were completely cured and five patients have not been assessed. Most AVMs in the corpus callosum are supplied by mul ti-axial feeders, so multi-target intranidus embolization is very important to prevent the development of other feeders secondary to the hemodynamic shift. Combined therapy using maximum emboliza tion and subsequent radiosurgery may be the most effective method to treat AVMs in the corpus callo sum.

Angiographic factors influencing the success of endovascular treatment of arteriovenous malformations involving the corpus callosum

“…First, their midline position and anteroposterior extension result not only in a bilateral arterial supply but they may also be fed by both the anterior and posterior circulation 14. In general, AVMs of the anterior and middle part of the CC are fed by perforators originating from the pericallosal arteries and AVMs of the splenium of the CC are supplied by posterior pericallosal or posterior choroidal arteries 2. In our series, AVMs fed by both the anterior and posterior circulation represented 36.8% of cases.…”

“…AVMs of the CC are rare lesions, accounting for approximately 9–11% of brain AVMs 1 2. Yasargil et al 4 5 described the surgical possibilities concerning such lesions and proposed a simple and anatomical classification.…”

“…Since this first description, surgical management of CC AVMs has remained difficult7–9 despite recent advances, and are often associated with important postoperative neuropsychological disorders 3. In the past decade, the development of endovascular therapy2 10 and radiosurgery11 12 have fundamentally changed the cure rate and clinical outcome of deep seated cerebral AVMs.…”

“…Arteriovenous malformations (AVMs) of the corpus callosum (CC) are rare lesions, accounting for approximately 9–11% of brain AVMs 1 2. Microsurgery of such lesions remains difficult because of their deep location, and also because of possible neuropsychological disasters3 resulting from extended CC resection 4 5.…”

L'embolizzazione come unica scelta terapeutica

“…Le percentuali di occlusione completa e definitiva del "nidus" riportate in letteratura non sono omogenee ed oscillano per lo più tra il 10 e il 20 dei casi 1,14 . Solo in alcune casistiche si riscontra più del 40 di guarigioni complete 5,8,10,13 . Nella nostra, è stata ottenuta nell'11.5 dei pazienti trattati.…”