Clinico-radiologic factors in paraclinoid aneurysms associated with aneurysm rupture: A CTA study

Paraclinoid aneurysms are commonly noted as incidental findings by computed tomography angiography (CTA), and there exists disagreement in the literature as to which patient and aneurysm characteristics predict subsequent rupture. This question is of particular significance given the complex anatomy of the paraclinoid region and the associated risks of aneurysm treatment. The purpose of this study was to determine significant associated risk factors for paraclinoid aneurysm rupture.

Medical records and CTA imaging from 179 patients with 205 paraclinoid aneurysms. Patient and aneurysm characteristics including aneurysm size, morphology, and multiplicity were gathered for analysis of rupture risk. Factors influencing the decision to treat or observe unruptured aneurysms were also evaluated. A Cox regression analysis was used, and results were corrected for multiple comparisons using the Bonferroni method.

Aneurysm size, diameter:neck ratio, and multilobularity were significantly associated with increased rupture risk; however, only multilobularity remained significant after Bonferroni correction for multiple comparisons. Intervention for unruptured aneurysms was significantly more likely to occur among younger patients and multilobulated aneurysms, or those having a larger diameter, height, height:neck ratio, or diameter:neck ratio.

Multilobularity constitutes a significant associated risk factor for rupture among paraclinoid aneurysms. Younger age, larger size and multilobulated aneurysms are characteristics that favored treatment over observation in this cohort.