Abstract 330: Morphologic Analysis of Ruptured Aneurysms: A Retrospective Study

Background/Purpose: Aneurysm size and morphology have been previously correlated with risk of spontaneous rupture. However, there is a lack of consensus regarding which morphological parameters are useful for this prediction. The purpose of this study is to assess the size and morphology of ruptured aneurysms in our retrospective cohort and compare these findings to previously cited parameters within the literature. Materials and Methods: Between 2021‐2023, 150 patients with subarachnoid hemorrhage secondary to ruptured aneurysms were admitted to our hospital. Two investigators reviewed 3‐dimensional angiograms of all aneurysms to evaluate for morphological parameters which have been previously shown to correlate with rupture in previous studies. Results The average diameter of aneurysm rupture was 6.4 ± 4.4mm. 71% of these aneurysms were less than 7mm. The most common location of rupture was the anterior communicating artery (32.6%) followed by the posterior communicating artery (21.7%). The most common morphology of ruptured aneurysms were single sac aneurysms with irregular margins (39.1%) and multilobulated aneurysms (39.1%). The average aspect ratio was 1.23 ± 0.47. Only 28.2% of our patients demonstrated an aspect ratio >1.5. The average size ratio was 3.2 ± 2.0. 63% of these patients demonstrated a size ratio >2. The average area ratio was 6.5 ± 6.5 with 93% of these patients having an area ratio >1.5. The average bottleneck ratio, neck to parent artery ratio and height to width ratio are 1.9 ± 0.93, 1.4 ± 0.7 and 1.23 ± 0.47 respectively. Conclusions: Aneurysm size may not be a good predictor of rupture as aneurysms less than 7mm commonly rupture. However, morphology may be a better predictor as aneurysms with irregular margins and multilobulated aneurysms were commonly seen in our cohort. Additionally, previously cited parameters such as size ratio > 2 and an area ratio > 1.5 may be better predictors of rupture compared to the commonly cited aspect ratio > 1.5.