Analysis of Anterior Cerebral Artery Tortuosity: Association with Anterior Communicating Artery Aneurysm Rupture.

Background: Many researchers have found a correlation between tortuous arteries and development of aneurysms in cerebral arteries. However, there are no studies analyzing the impact of tortuosity on risk of subarachnoid hemorrhage (SAH) occurrence. Therefore, we decided to determine whether tortuosity of the anterior cerebral artery can be related to the rupture of anterior communicating artery aneurysm and to severity and treatment outcome of SAH.

Methods: We retrospectively analyzed anterior cerebral artery anatomy of 121 patients with anterior communicating artery aneurysms. From patients' medical records, we obtained their history including previous and current diseases and medications. For each patient we calculated relative length, sum of angle metrics, triangular index, product of angle distance, and inflection count metrics.

Results: Patients with SAH had significantly higher relative length (0.70 ± 0.19 vs. 0.63 ± 0.22; P = 0.03) and significantly lower inflection count metrics (0.10 ± 0.08 vs. 0.16 ± 0.19; P < 0.01), respectively. In multivariate logistic regression analysis, after adjustment of all possible confounders, diabetes mellitus (odds ratio [OR], 0.154; 95% confidence interval [CI], 0.032-0.553; P < 0.01) and higher inflection count metrics (OR, 0.604; 95% CI, 0.357-0.909; P = 0.042) remained independently associated with lower risk of SAH. We also found an independent correlation between aneurysm dome size (R = -0.289; P = 0.02) and triangular index (R = 0.273; P = 0.03) and Glasgow Coma Scale score on admission.

Conclusions: Higher anterior cerebral artery tortuosity might be a protective factor against anterior communicating artery aneurysm rupture.