The case histories of two patients with dural arteriovenous malformation (AVM) in the posterior fossa who were treated by transcatheter embolization with Ivalon followed by sinus isolation are reported in this paper.
Case 1: A 44-year-old male was admitted to our hospital complaining of visual disturbance. Neurological examination showed bilateral choked disc, bilateral visual field narrowing, left abducens palsy and right cerebellar signs. Marked elevation in cerebrospinal fluid pressure (500mmHg) was noted when lumber puncture was performed. The selective 6-vessel study revealed a dural AVM in the region of the straight sinus through the bilateral transverse sinuses, which was supplied by many dural and tentorial branches of the external carotid and the internal carotid and vertebral arteries. First, all main feeders from the bilateral external carotid arteries were embolized with Ivalon particles. After embolization was performed again on the recanalized arteries, isolation of the occipital, straight and bilateral transverse sinuses was done with minimum bleeding. Transient visual loss occurred just after the operation, but signs and symptoms based on increase intracranial pressure gradually disappeared.
Case 2: A 48-year-old male was admitted to our hospital because of pulsatory tinnitus and visual disturbance. He had a bilateral choked disc. The 6-vessel study revealed a dural AVM in the region of the left transverse through sigmoid sinus fed mainly by dural and tentorial branches of the left external and internal carotid arteries. Cerebellar cortical branches from the left superior cerebellar and anterior inferior cerebellar arteries also fed the dural AVM. After the first transcatheter embolization with Ivalon particles was performed, pulmonary embolism was unfortunately encountered in this patient, who was treated with heparin and urokinase. After the second embolization of the recanalized feeders, isolation of the straight, left transeverse, left sigmoid, left superior petrosal and occipital sinuses was done. As acute cerebellar swelling occurred during the operative procedure, uncapping of the left cerebellum was done. His visual disturbance disappeared gradually.
Although complete occlusion of the dural AVM was not achieved, transcatheter embolization followed by sinus isolation was effective in the treatment of neurological signs based on increased intracranial hypertension. However, several side effects including acute visual loss (Case 1), pulmonaly embolism and brain swelling (Case 2) were encountered in these cases. Further experience is needed to clarify the effectiveness of this procedure for dural AVM's in the posterior fossa.
