Decision-making in the scheduling of endovascular treatment after brain arteriovenous malformation haemorrhage: a retrospective single centre study.

The appropriate timing for endovascular intervention after brain arteriovenous malformation (bAVM) rupture is not known. This paper aims to determine factors that lead to early endovascular intervention and to investigate whether early intervention has the same complication rate as late intervention in a single centre. All patients who underwent endovascular treatment for a ruptured bAVM at our institution in the period January 2007 and July 2010 were included in this retrospective observational study. Of 50 patients, 33 had early endovascular intervention, defined as within 30 days of haemorrhage and the remaining 17 patients had endovascular treatment at day 30 or beyond. A greater proportion of patients treated within the first 30 days were in neuro-intensive care preoperatively (51.5% vs. 23.5%, p=0.07). A 'high-risk' angioarchitectural feature was identified in more patients who had acute intervention (78.8% vs. 11.8%, p<0.0001) and targeted embolization was also more frequent in this group (48.5% vs. 5.9%, p=0.004). Nidal aneurysms, venous varices and impaired venous outflow (venous stenosis) were the principal 'high risk' features. Clinically apparent complications occurred in 10.8% of procedures with permanent neurological deficit in 3.6%. There was no directly procedure-related mortality. There was no statistically significant difference in the complication rate of early procedures compared with delayed interventions (12.5% vs. 7.4%, p=0.71). Greater initial injury severity and the presence of high-risk lesion characteristics are the factors that lead to early endovascular intervention. Early intervention is associated with a higher complication rate, but this difference is not statistically significant.