Introduction: Attempts have been made to correlate risk of rupture of cerebral aneurysm to their size (Wiebers, 2003), morphology (Raghavan, 2005), and elasticity of tissue (Costalat, 2011). Advancement in MRI has allowed measurement of aneurysm wall thickness using a Double Inversion Recovery Black-Blood Sequence (Park, 2009). We undertook this study to assess whether aneurysm wall thickness is an independent risk factor for rupture.

Methods: Aneurysm domes from 15 patients were resected after surgical clipping. Wall thickness was measured on H&E sections for all aneurysms. Average wall thickness and clinical characteristics of patient were compared between patients with ruptured aneurysms (n=6) and unruptured aneurysms (n=9).

Results: There were six ruptured and nine unruptured aneurysms studied. There were no statistically significant differences in age, aneurysm size, smoking history, or family history between the two groups (Table 1). The average wall thickness in the ruptured aneurysms (0.30 mm) was greater than in the unruptured aneurysms (0.22 mm) and the average size was less (6.2 mm ruptured, 7.6 mm unruptured). These differences were not statistically significant.

Conclusions: In this study, ruptured aneurysms tended to be both smaller and have thicker walls than unruptured aneurysms although underpowered to show statistical significance. Our preliminary results show that each cerebral aneurysm case needs to be evaluated individually for therapeutic decision without any preset rules. Further study of cerebral aneurysms characteristics with higher number of subjects requires for statistically meaningful conclusion.

Patient Care: Understanding physical characteristics that are factor in rupture risk of cerebral aneuryms may help guide treatment decisions.

Learning Objectives: By conclusion of this session, participants should be able to understand the possible correlation between walk thickness, size, and rupture risk of cerebral aneurysms.

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