OBJECT: The authors report the 3-year results of the Barrow Ruptured Aneurysm 
Trial (BRAT). The objective of this ongoing randomized trial is to compare the 
safety and efficacy of microsurgical clip occlusion and endovascular coil 
embolization for the treatment of acutely ruptured cerebral aneurysms and to 
compare functional outcomes based on clinical and angiographic data. The 1-year 
results have been previously reported.
METHODS: Two-hundred thirty-eight patients were assigned to clip occlusion and 
233 to coil embolization. There were no anatomical exclusions. Crossovers were 
allowed based on the treating physician's determination, but primary outcome 
analysis was based on the initial assignment to treatment modality. Patient 
outcomes were assessed independently using the modified Rankin Scale (mRS). A 
poor outcome was defined as an mRS score>2. At 3 years' follow-up 349 patients 
who had actually undergone treatment were available for evaluation. Of the 170 
patients who had been originally assigned to coiling, 64 (38%) crossed over to 
clipping, whereas 4 (2%) of 179 patients assigned to surgery crossed over to 
clipping.
RESULTS: The risk of a poor outcome in patients assigned to clipping compared 
with those assigned to coiling (35.8% vs 30%) had decreased from that observed 
at 1 year and was no longer significant (OR 1.30, 95% CI 0.83-2.04, p=0.25). In 
addition, the degree of aneurysm obliteration (p=0.0001), rate of aneurysm 
recurrence (p=0.01), and rate of retreatment (p=0.01) were significantly better 
in the group treated with clipping compared with the group treated with coiling. 
When outcomes were analyzed based on aneurysm location (anterior circulation, 
n=339; posterior circulation, n=69), there was no significant difference in the 
outcomes of anterior circulation aneurysms between the 2 assigned groups across 
time points (at discharge, 6 months, 1 year, or 3 years after treatment). The 
outcomes of posterior circulation aneurysms were significantly better in the 
coil group than in the clip group after the 1st year of follow-up, and this 
difference persisted after 3 years of follow-up. However, while aneurysms in the 
anterior circulation were well matched in their anatomical location between the 
2 treatment arms, this was not the case in the posterior circulation where, for 
example, 18 of 21 posterior inferior cerebellar artery aneurysms were in the 
clip group.
CONCLUSIONS: Based on mRS scores at 3 years, the outcomes of all patients 
assigned to coil embolization showed a favorable 5.8% absolute difference 
compared with outcomes of those assigned to clip occlusion, although this 
difference did not reach statistical significance (p=0.25). Patients in the clip 
group had a significantly higher degree of aneurysm obliteration and a 
significantly lower rate of recurrence and retreatment. In post hoc analysis 
examining only anterior circulation aneurysms, no outcome difference between the 
2 treatment cohorts was observed at any recorded time point. CLINICAL TRIAL 
REGISTRATION NO.: NCT01593267 ( ClinicalTrials.gov ).