Superselective embolization of spinal arteriovenous malformations using the Tracker catheter.

Eighteen patients with spinal arteriovenous malformations had been treated with conventional embolization, surgical removal, feeder ligation, and/or feeder coagulation between February 1985 and March 1990. The lesions included six glomus, four juvenile, three extramedullary, and five dural arteriovenous malformations or fistulas. Embolic therapy was conducted in 14 patients by introducing the tip of a catheter into the segmental arteries and injecting polyvinyl alcohol strips (500-1000 microns) (conventional embolization). Follow-up spinal angiography disclosed recanalization in 10 patients (71.4%) and the appearance of new feeding arteries in five patients (35.7%). We introduced the Tracker vascular access system in April 1990. Eight patients (four glomus, one juvenile, and three dural arteriovenous malformations) were treated with the minicatheter and Ivalon particles (150-350 microns). Five patients showed neurological improvement immediately after treatment. The other three patients had severe paraparesis before treatment and did not show any improvement. One patient with a glomus-type arteriovenous malformation showed transient neurological deterioration just after embolization with the Tracker-10 to occlude a lesion fed by the posterior spinal artery, because the Ivalon particles migrated into the anterior spinal artery via the anterior spinal canal artery. In one patient with a juvenile arteriovenous malformation, the Tracker-18 catheter perforated the radiculomedullary artery originating from the right vertebral artery, and subarachnoid hemorrhage occurred. However, the Tracker-10 could later successfully occlude the arteriovenous malformation. The rates of recanalization and appearance of the new feeding vessels were 4/8 (50.0%) and 2/8 (25%), respectively.