Effect of aneurysm size on procedure-related rupture in patients with subarachnoid hemorrhage treated with coil occlusion

Objective Procedure-related rupture is one of the most feared complications in treating patients with cerebral aneurysm. The primary aim of this study was to estimate the effect of aneurysm size on procedure-related rupture. We also estimated its effect on peri-procedural thromboembolic events. Methods This observational study was conducted using routinely-collected health data on patients admitted for subarachnoid hemorrhage and treated with aneurysm coil occlusion in the CHU de Québec — Enfant-Jésus hospital from January 1st, 2000 until sample size was reached. Patients were identified from the Discharge Abstract Database using the Canadian Classification of Health codes. Assessment of complications was blind to aneurysm size. Logistic regression models were performed to test associations between aneurysm size and procedure-related rupture or peri-procedural thromboembolic events, and between both procedure-related rupture and thromboembolic events and patients' outcomes. Results This study included 532 aneurysms treated with coil occlusion in 505 patients. Procedure-related rupture occurred in 34 patients (6.7%) and thromboembolic events in 53 (10.5%) patients. Aneurysms of 2 to 3 mm inclusively were not more significantly associated with procedure-related rupture or thromboembolic events than those larger than 3 mm (OR 1.02, 95% CI: 0.9–1.16, p = 0.78 and OR 1.06, 95% CI: 0.96–1.17, p = 0.3, respectively). However, procedure-related rupture had a significant effect on patient mortality (OR 3.86, 95% CI: 1.42–10.53, p < 0.01). Conclusions Very small aneurysm size should not preclude aneurysm coil occlusion. Every measure should be taken to prevent procedure-related rupture as it is strongly associated with higher mortality.