Endovascular Treatment of Ruptured Intracranial Aneurysms: Factors Affecting Midterm Quality Anatomic Results: Analysis in a Prospective, Multicenter Series of Patients (CLARITY)

Protocol

CLARITY was a prospective multicenter consecutive series that was conducted in 20 centers in France between March 2006 and September 2008. Institutional review board approval and written informed consent were obtained. Inclusion criteria were consecutive patients, 18–80 years of age, with an aneurysm <15 mm in maximum diameter, with a diagnosed rupture having occurred <7 days before treatment. Exclusion criteria were dissecting or fusiform aneurysms, aneurysms associated with a brain AVM, aneurysms already treated by clips or coils, and patients previously treated for another aneurysm.

Patient Population

The initial population in the CLARITY series was 782 patients. EVT failed in 5 patients, and they were subsequently excluded from the analysis. In 4 patients, immediate postoperative control DSA was not available or readable. During the follow-up period, 110 patients died. Eleven patients refused follow-up imaging, and 3 patients could not complete follow-up imaging for other reasons, including vegetative state. Ultimately, 649 patients were theoretically able to undergo midterm follow-up imaging. Ninety patients were lost to midterm follow-up. Thirty-five follow-up imaging cases had not been transmitted to the core laboratory at the time of publication. Seven follow-up examinations were judged insufficient for accurate evaluation by the core lab. Finally, midterm anatomic results were evaluated in a total of 517/649 patients for the target population (79.7%) and 517/773 for the whole population (66.9%).

Immediate Postoperative and Midterm Imaging

Immediate postoperative anatomic evaluation was obtained at the end of the EVT by using DSA. Midterm anatomic evaluation was performed by using DSA or MRA. On DSA, anatomic evaluation was performed with nonsubtracted and subtracted images in the frontal, lateral, and working views. 3D images were not required. On MRA, anatomic evaluation was performed by using 3D-time-of-flight images without contrast administration (native images and maximum-intensity-projection reconstructions). Anonymous images were collected through a Web-based data base that was also used for clinical data collection (Kika Medical, Nancy, France).

Image Analysis

Anatomic results were anonymously and independently reviewed by 2 experienced neuroradiologists (F.R. and R.A.), who were blinded to all clinical information. Discrepancies were resolved by consensus.

Midterm aneurysm occlusion was evaluated by using the Modified Montreal Scale, which classifies the degree of aneurysm occlusion into 3 groups: complete occlusion, neck remnant, and aneurysm remnant. We also used a 2-grade scale derived from the Modified Montreal Scale: adequate occlusion (complete occlusion or neck remnant) and aneurysm remnant. Evolution of aneurysm occlusion was evaluated by directly comparing postoperative and 1-year imaging. Evolution was classified into 3 groups: improvement, no change, or worsening. For statistical analysis, improvement and no change were compared with worsening.

Data Analysis

During the follow-up period, clinical events, including rebleeding of the treated aneurysms, were recorded. Midterm aneurysm occlusions and the evolution of aneurysm occlusion were evaluated according to the following:

• Clinical factors: sex, age, smoking, hypertension, and initial WFNS grade

• Anatomic factors: aneurysm location, aneurysm size, neck size, and dome-to-neck ratio

• Therapeutic factors: use of the remodeling technique, use of GDC or Matrix coils, and quality of postoperative aneurysm occlusion.

Age was divided into 2 groups: younger than 65 years of age and equal to or older than 65 years of age. No information was collected regarding hypertension treatments received by the patients and their efficacy. Initial WFNS grade was divided into 2 groups: ≤2 and >2. Anatomic locations were divided into 4 groups: ICA, MCA, ACA/AcomA, and VB. For statistical analysis, each group was compared with the 3 other groups as a whole. Aneurysm size was divided into 2 groups: ≤10 and >10 mm. Neck size was divided into 2 groups: ≤4 and >4 mm. Dome-to-neck ratio was divided into 2 groups: ≤1:5 and >1:5. For the analysis of the effect of the remodeling technique, the 10 patients treated with stent placement were added to the coiling and remodeling groups (5 patients each).

Statistical Analysis

Statistical analysis was independently conducted by Ariana Pharmaceuticals (Paris, France). The distributions of continuous variables were described by using means and SDs, and discrete variables were described as frequencies, percentages, and confidence intervals. The method used to construct the confidence intervals was the Clopper-Pearson exact method. For the analysis involving factors affecting anatomic results, the “event ” was defined as the adequate occlusion and the evolution of aneurysm occlusion and the statistical unit was the aneurysm. Potential association between procedural or aneurysm characteristics and angiographic outcome was assessed with univariate and multivariate logistic regression analyses. Subsequently, all factors found to be associated with the “event,” with a P value ≤.20 for the univariate analysis and potential prognostic factors according to clinical characteristics (age, sex) and factors linked to the study (techniques, type of coil), were included in the final multivariate model. Only those variables associated with a P value ≤.05 were retained in the final model. All statistical analyses were performed by using the Statistical Package for the Social Sciences, Version 18.0.0 (SPSS, Chicago, Illinois).