Survival analysis of risk factors for major recurrence of intracranial aneurysms after coiling

Recurrence after intracranial aneurysm coiling is a highly prevalent outcome, yet to be understood. We investigated clinical, radiological and procedural factors associated with major recurrence of coiled intracranial aneurysms.

We retrospectively analyzed prospectively collected coiling data (2003-12). We recorded characteristics of aneurysms, patients and interventional techniques, pre-discharge and angiographic follow-up occlusion. The Raymond-Roy classification was used; major recurrence was a change from class I or II to class III, increase in class III remnant, and any recurrence requiring any type of retreatment. Identification of risk factors associated with major recurrence used univariate Cox Proportional Hazards Model followed by multivariate regression analysis of covariates with P<0.1.

A total of 467 aneurysms were treated in 435 patients: 283(65%) harboring acutely ruptured aneurysms, 44(10.1%) patients died before discharge and 33(7.6%) were lost to follow-up. A total of 1367 angiographic follow-up studies (range: 1-108 months, Median [interquartile ranges (IQR)]: 37[14-62]) was performed in 384(82.2%) aneurysms. The major recurrence rate was 98(21%) after 6(3.5-22.5) months. Multivariate analysis (358 patients with 384 aneurysms) revealed the risk factors for major recurrence: age>65 y (hazard ratio (HR): 1.61; P=0.04), male sex (HR: 2.13; P<0.01), hypercholesterolemia (HR: 1.65; P=0.03), neck size ≥4 mm (HR: 1.79; P=0.01), dome size ≥7 mm (HR: 2.44; P<0.01), non-stent-assisted coiling (HR: 2.87; P=0.01), and baseline class III (HR: 2.18; P<0.01).

Approximately one fifth of the intracranial aneurysms resulted in major recurrence. Modifiable factors for major recurrence were choice of stent-assisted technique and confirmation of adequate baseline occlusion (Class I/II) in the first coiling procedure.