Technical Advances in Endovascular Therapy of Brain Arteriovenous Malformations

Abstract

Endovascular therapy of intracranial vascular diseases—arteriovenous malformations (AVMs), aneurysms, fistulas, tumors—is a natural extension of techniques of cerebral angiography. The development of microcatheters with or without calibrated leak balloons in their tips allows safe navigation beyond the circle of Willis and catheterization of cortical or deep-seated arteries of the brain.¹ it is also possible to use the intracranial venous route and reach the venous sinuses or even the vein of Galen using a transfemoral technique. The latter technique is applied for embolization of AVMs involving the dural sinuses (especially transverse and cavernous sinuses²) or vein of Galen aneurysms in neonates.³ Various microcatheters are now available that allow safe navigation beyond the circle of Willis if used judiciously. We have catheterized 850 arterial feeders in 228 brain AVMs (Fig. 19.1). No technical or clinical complications were observed in the last 347 superselec-tive catheterizations of brain cortical or deep AVM feeders larger than 2 mm in diameter. Superselective angiography and Amytal testing of arterial feeders of AVMs located in eloquent areas of the brain may be performed on an outpatient basis. This superselective morphological and functional assessment of an AVM provides important information not available with standard cerebral angiography. For brain AVMs that appear to involve the motor cortex, this anatomical and functional localization is compared to localization techniques using somatosensory evoked potentials and intraoperative electrocorticography in an awake patient.⁴ The preliminary use of magnetoencephalography to localize the speech cortex has shown some potential, and it appears to be more useful for preoperative localization of the Wernicke area.⁵