Background and Purpose—Intraprocedural rupture (IPR) is a well known complication of intracranial aneurysm treatment. Risks and predictors of IPR and its impact on outcome have not been clearly established.

Methods—Potential predictors of IPR were evaluated in patients treated in the Cerebral Aneurysm Rerupture After Treatment (CARAT) study using multivariate logistic regression with stepwise elimination stratified by treatment modality. Periprocedural death or disability was defined as death or a change of 2 points on the Modified Rankin Scale at discharge compared to before treatment.

Results—IPR occurred in 14.6% of 1010 patients (299 coiled, 711 clipped): 19% with clipping and 5% with coiling (P<0.001). Among those clipped, 31% with IPR had periprocedural death or disability compared to 18% without IPR (P=0.001); among those coiled, 63% with IPR had periprocedural death or disability compared to 15% without IPR (P<0.001). Overall, coronary artery disease and initial lower Hunt and Hess Grade were independent predictors of IPR. For those undergoing coiling, independent predictors of IPR were Asian race, black race, COPD, and lower initial Hunt and Hess Grade. Among those undergoing clipping, hyperlipidemia and lower initial Hunt and Hess Grade were both independent predictors of IPR.

Conclusions—IPR was common in patients undergoing treatment of ruptured aneurysms, particularly with surgical clipping. The frequency of IPR with new disability was similar in the surgical and endovascular treatment groups. Coronary artery disease, hyperlipidemia, race, COPD, and lower Hunt and Hess Grade were associated with greater risk of IPR, which may reflect differences in vessel fragility but requires further confirmation.