Treatment of Brain Arteriovenous Malformations

A Systematic Review and Meta-analysis

Janneke van Beijnum, MD;
H. Bart van der Worp, MD;
Dennis R. Buis, MD;
Rustam Al-Shahi Salman, FRCP(Edin);
L. Jaap Kappelle, MD;
Gabriël J. E. Rinkel, MD;
Jan Willem Berkelbach van der Sprenkel, MD;
W. Peter Vandertop, MD;
Ale Algra, MD;
Catharina J. M. Klijn, MD

[+] Author Affiliations

Author Affiliations: Utrecht Stroke Center, Department of Neurology and Neurosurgery, Rudolf Magnus Institute of Neuroscience (Drs van Beijnum, van der Worp, Kappelle, Rinkel, Berhelbach, van der Sprenkel, Algra, and Klijn), and Julius Center for Health Science and Primary Care (Dr Algra), University Medical Center Utrecht; Department of Neurosurgery, Leiden University Medical Center, Leiden (Dr van Beijnum); and Department of Neurosurgery, Neurosurgical Center Amsterdam, VU University Medical Center and Amsterdam Medical Center, Amsterdam (Drs Buis and Vandertop), the Netherlands; and Division of Clinical Neurosciences, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Scotland (Dr Al-Shahi Salman).

Abstract

Context Outcomes following treatment of brain arteriovenous malformations (AVMs) with microsurgery, embolization, stereotactic radiosurgery (SRS), or combinations vary greatly between studies.

Objectives To assess rates of case fatality, long-term risk of hemorrhage, complications, and successful obliteration of brain AVMs after interventional treatment and to assess determinants of these outcomes.

Data Sources We searched PubMed and EMBASE to March 1, 2011, and hand-searched 6 journals from January 2000 until March 2011.

Study Selection and Data Extraction We identified studies fulfilling predefined inclusion criteria. We used Poisson regression analyses to explore associations of patient and study characteristics with case fatality, complications, long-term risk of hemorrhage, and successful brain AVM obliteration.

Data Synthesis We identified 137 observational studies including 142 cohorts, totaling 13 698 patients and 46 314 patient-years of follow-up. Case fatality was 0.68 (95% CI, 0.61-0.76) per 100 person-years overall, 1.1 (95% CI, 0.87-1.3; n = 2549) after microsurgery, 0.50 (95% CI, 0.43-0.58; n = 9436) after SRS, and 0.96 (95% CI, 0.67-1.4; n = 1019) after embolization. Intracranial hemorrhage rates were 1.4 (95% CI, 1.3-1.5) per 100 person-years overall, 0.18 (95% CI, 0.10-0.30) after microsurgery, 1.7 (95% CI, 1.5-1.8) after SRS, and 1.7 (95% CI, 1.3-2.3) after embolization. More recent studies were associated with lower case-fatality rates (rate ratio [RR], 0.972; 95% CI, 0.955-0.989) but increased rates of hemorrhage (RR, 1.02; 95% CI, 1.00-1.03). Male sex (RR, 0.964; 95% CI, 0.945-0.984), small brain AVMs (RR, 0.988; 95% CI, 0.981-0.995), and those with strictly deep venous drainage (RR, 0.975; 95% CI, 0.960-0.990) were associated with lower case fatality. Lower hemorrhage rates were associated with male sex (RR, 0.976, 95% CI, 0.964-0.988), small brain AVMs (RR, 0.988, 95% CI, 0.980-0.996), and brain AVMs with deep venous drainage (0.982, 95% CI, 0.969-0.996). Complications leading to permanent neurological deficits or death occurred in a median 7.4% (range, 0%-40%) of patients after microsurgery, 5.1% (range, 0%-21%) after SRS, and 6.6% (range, 0%-28%) after embolization. Successful brain AVM obliteration was achieved in 96% (range, 0%-100%) of patients after microsurgery, 38% (range, 0%-75%) after SRS, and 13% (range, 0%-94%) after embolization.

Conclusions Although case fatality after treatment has decreased over time, treatment of brain AVM remains associated with considerable risks and incomplete efficacy. Randomized controlled trials comparing different treatment modalities appear justified.

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