Abstract WP91: Long-Term Risk of Stroke after Stent-Assisted Coiling of Unruptured Intracranial Aneurysms

Abstract

Background: Long-term comparative data are limited regarding stent-assisted coiling versus coiling alone for unruptured intracranial aneurysms. We compared the risks of ischemic stroke and intracranial hemorrhage after stent-assisted coiling versus coiling without stenting. Methods: Using administrative claims data on all admissions to nonfederal acute care hospitals in CA, FL, and NY from 2005-2013, we identified adult patients who underwent stent-assisted coiling or coiling without stenting for an unruptured intracranial aneurysm. Our primary outcome was a composite of ischemic stroke or intracranial hemorrhage (intracerebral, subarachnoid, or subdural hemorrhage). Our secondary outcomes were ischemic stroke and intracranial hemorrhage. Outcomes were ascertained by previously validated ICD-9-CM diagnosis codes. To focus on the long-term safety of these techniques, we excluded patients with an outcome during the index hospitalization. Kaplan-Meier survival statistics and Cox regression were used to compare stroke risk after stent-assisted coiling versus coiling alone. Results: We identified 5,398 patients (mean age, 58 [±13] years; 79% female) treated with endovascular coiling, of whom 254 (4.7%) underwent stent-assisted coiling. Over 4.2 (±2.0) years of follow-up, 357 outcomes were identified (205 ischemic strokes, 152 intracranial hemorrhages). By 8 years, the cumulative rate of stroke or hemorrhage was 8.5% (95% confidence interval [CI], 5.3-13.6%) with stent-assisted coiling versus 9.2% (95% CI, 7.8-10.9%) with coiling alone. Most outcomes occurred in the first year (3.6% after stent-assisted coiling versus 3.9% after coiling alone). After adjustment for demographics and vascular risk factors, the risk of ischemic stroke or intracranial hemorrhage was similar after stent-assisted coiling compared to coiling alone (hazard ratio [HR], 1.1; 95% CI, 0.7-1.7). Our results were unchanged when assessing the secondary outcomes of ischemic stroke (HR, 1.4; 95% CI, 0.8-2.4) or intracranial hemorrhage (HR, 0.7; 95% CI, 0.3-1.7). Conclusions: After uncomplicated coiling of an unruptured aneurysm, long-term rates of stroke and intracranial hemorrhage were similar for stent-assisted coiling and coiling without stenting.