OBJECTIVE

The term anterior communicating (ACom) aneurysm is often broadly used to classify any aneurysm formed on the A1-A2 junction, A1, A2, or ACom arteries. Aneurysm location has been associated with rupture risk, so whether an aneurysm is truly formed on the ACom artery can critically affect treatment decisions. The aim of this study was to reclassify broadly termed ACom aneurysms into 4 subgroups (A1, A2, true ACom, and A1-A2 junction) based on their location.

METHODS

A retrospective, pilot study was conducted to identify all consecutive patients with ACom aneurysm managed over the past 4 years in a single center. Using computed tomography angiography, aneurysms were classified into 1 of the 4 subgroups. Additional information was collected on patient demographics, subarachnoid hemorrhages, projections of aneurysm dome, and aneurysm diameter.

RESULTS

A total of 48 aneurysms with available computed tomography angiography imaging were included in the final analysis. The reclassification of ACom aneurysms into subgroups resulted in 40 A1-A2 junction, 6 true ACom, 2 A2, and zero A1 aneurysms. A total of 100% versus 80% of true ACom and A1-A2 junction aneurysms ruptured, respectively. All elective coiling procedures were performed on unruptured A1-A2 junction aneurysms.

CONCLUSIONS

We found only 13% of the aneurysms initially referred to as ACom to be true ACom aneurysms. A more nuanced approach to ACom aneurysm classification may better guide management strategies.