Abstract TP75: Natural History of Incidental Small Paraclinoid Unruptured Aneurysm
Objective: The optimal consensus over treatment of incidental small paraclinoid unruptured intracranial aneurysm (UIA) remains controversial. The aim of this study was to reveal the natural history of small paraclinoid UIA with the goal of informing a treatment plan.
Methods: A total of 344 patients harboring 364 paraclinoid UIA (≤5 mm) were retrospectively evaluated during the mean follow-up of 32±17.3 months from September 2001 to May 2011. Barami’s classification was used for categorizing aneurysm location. Univariate and multivariate analyses were used to determine the risk factors of aneurysm growth. The Kaplan-Meier product-limit estimator and generalized Wilcoxon tests were performed to assess the cumulative survival without aneurysm growth.
Results: None of the aneurysm ruptures and 12 (3.3%) cases of aneurysm growth were observed during the follow up of 969.7 aneurysm-years. Aneurysm ≥ 4mm (hazard ratio [HR], 6.73; p=0.001) and hypertension (HR, 4.92; p=0.02) were associated with aneurysm growth. Other variables including female (p=0.18), age (p=0.24), arterial branch related location (p=0.47), multiplicity (p=0.11), and smoking (p=0.36) did not differ significantly. The multivariate analysis disclosed that aneurysm ≥4mm (HR, 4.78; p=0.01) and hypertension (HR, 4.20; p=0.03) were significant predictable factors for aneurysm growth. The cumulative survival without aneurysm growth reached a significant difference in aneurysms ≥4mm (p<0.001) and with hypertension (p=0.01). No statistical difference was observed between arterial branch related and unrelated groups (p=0.16).
Conclusions: Incidental small paraclinoid UIA can be primarily treated conservatively. Patients with high risk factors including aneurysm ≥4 mm and hypertension must be monitored closely.
- © 2012 by American Heart Association, Inc.