Brain Arteriovenous Malformations: Experience in the Interventional Neuroradiology Unit, Ramathibodi Hospital

Abstract

Objective: To review patient demographics, clinical symptoms. presentation. imaging characteristics and embolization results as well as its complications of patients with brain AVMs seen in the Interventional Neuroradiology unit at Ramathibodi Hospital.

Materials and Methods: Retrospective review of all patients diagnosed with brain AVMs from cerebral angiography during January 2001 to December 2005 at the Interventional Neuroradiology Unit. Radiology Department, Ramathibodi hospital.

Results: There were a total of 189 patients. 44 patients were excluded due to incomplete medical records or loss of imaging data. Of the remaining 145 patients. 87 (60%) underwent partial-targeted embolization. 9 (6.2%) underwent curative embolization, 29 (20%) radiosurgery alone, 11 (7.6%) surgical resection alone, 1 (0.7%) spontaneously thrombosed, 2 (1.4%) received conservative treatment without any further treatment and 6 (4.1%) loss to follow up. 84 (57.9%) were male patients and 61 (42.1%) were female. The mean age at the time of angiographic diagnosis was 27.2 years +/- 15.1. The initial presentations included intracranial hemorrhage in 88 (60.7%), seizures in 29 (20%), headaches in 18 (12.4%), 2 (1.4%) with focal neurological deficit. incidental finding in 1 (0.7%) and 7 (4.8%) with other presentations. Ruptured AVM were mainly of small size (65.9%. P=0.03), single deep vein (27.3%, P<0.05) with locations in the deep gray nuclei, midline structures and corpus callosum (31.8%, P=0.001). Only 18 of 27 intranidal aneurysms were found in patient with ruptured AVMs. two times higher compared to patients with non-ruptured AVMs however without statistical significance (P=0.72). In 87 patients with goals of partial targeted embolization. the majority of the AVMs (55 of 80) had more than 50% reduced flow. which were related to small and medium sized AVMs (P<0.05). AVMs with single arterial feeder (P=0.001) and single draining vein (P<0.05). There was failure of partial targeted embolization in 3 of 87 patients. Success rate of curative embolization is 89% (8 of 9 patients). Clinically significant complications after embolization (ischemia or hemorrhage) were seen in 7 of 96 patients (7.3%).

Conclusion: In our experience, the presentation of brain AVMs and risk factors of hemorrhage were similar to the previous studies. The total success rate of curative embolization was 8.3%, while partial targeted embolization was able to reduce the AVM flow more than 50% in the majority of patients with less significant clinical complications.