Management and clinical outcome of posterior fossa arteriovenous malformations: report on a single-centre 15-year experience
- L da Costa1,2,
- L Thines3,4,
- A R Dehdashti3,4,
- M C Wallace3,4,
- R A Willinsky1,4,
- M Tymianski3,4,
- M L Schwartz2,4,
- K G ter Brugge1,4
- 1Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
- 2Division of Neurosurgery, Department of Surgery, Sunnybrook Hospital, University of Toronto, Toronto, Ontario, Canada
- 3Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada
- 4The Toronto Brain Vascular Malformation Study Group, Toronto, Canada
- Dr L da Costa, Sunnybrook Hospital, 2075 Bayview Avenue, Suite A1-37, Toronto, ON, Canada M4N 3M5; leo.dacosta{at}sunnybrook.ca
- Received 7 October 2008
- Accepted 1 May 2008
- Final version accepted 3 November 2008
- Published Online First 21 November 2008
Abstract
Objectives: Posterior fossa brain arteriovenous malformations (PFbAVMs) are rare lesions. Management is complicated by eloquence of adjacent neurological structures, multimodality treatment is often necessary, and obliteration is not always possible. We describe a 15-year experience in the management of posterior fossa brain AVMs with a focus on clinical outcome.
Methods: From 1989 to 2004, prospectively collected information on 106 patients with diagnosis of a PFbAVMs was obtained. Clinical and angioarchitectural characteristics, management options and complications are described and reviewed to evaluate their impact on final outcome as measured by the Modified Rankin Score (mRS).
Results: Ninety-eight patients were followed for an average of 3.3 years (1–14.6). The male-to-female ratio was 1:1. Ninety-five out of 98 patients (96.9%) were symptomatic at presentation, with 61 (62.2%) intracranial haemorrhages. Sixty-two patients were treated (46 cerebellar, 16 brainstem). Ten haemorrhages occurred in follow-up (4.1%/year). The mRS was obtained in 62 patients and was classified as low (good, mRS≤2) or high (poor, mRS≥3). Haemorrhage was the only predictor of poor mRS at presentation (p = 0.0229). A poor clinical outcome was correlated with the presence of AA (p = 0.0276), a poor initial mRS (p<0.0001) and the number of treatments needed (p = 0.0434). Patients were significantly more likely to improve than to deteriorate over time (p = 0.0201).
Conclusion: The final clinical outcome in PFbAVMs relates directly with the presence of associated aneurysms, number of treatments needed to obliterate the AVM and mRS at presentation. Despite the fact that patients tend to improve after brain AVM haemorrhage, the relationship of MRS at presentation and final outcome suggests that an expedited, more definitive treatment is probably a better choice, especially in patients with good grades after the initial bleeding.
Footnotes
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Competing interests: None.
