The implication of Acom complex rotation and 3D CTA findings in surgical approach to anterior communicating artery aneurysms.

BACKGROUND: To investigate the usefulness of 3-dimensional computerized tomography angiography (3D-CTA) in the microsurgical management of anterior communicating artery (AcomA) aneurysms. METHODS: Twenty-six consecutive patients with AcomA aneurysms (22 ruptured) underwent microsurgical clipping. Detailed angioanatomic assessment of the AcomA complex and operative approach was based on the 3D-CTA. RESULTS: The 3D-CTA showed a dominant proximal anterior cerebral artery (A1) segment in 61% and symmetric A1s in 39% of aneurysms. Dominant A1 segments presented with rotation of the AcomA complex toward the contralateral side in 63%, toward the ipsilateral side in 25%, and without rotation in 12%. With symmetric A1s, the AcomA was parallel to the coronal plane in 90% and a right-sided approach was carried out in these patients. In rotated AcomA complexes, the virtual 3D views were compared to determine the side of the approach. For superior projecting aneurysms, we determined that the approach from the side in which the A1-distal anterior cerebral artery (posterior communicating) angle was posterior was more favorable. For posterior projecting aneurysms, the approach from the side where the A1-distal anterior cerebral artery (posterior communicating) angle was more anterior was more favorable. For anteroinferior projecting aneurysms, an approach from the dominant A1 side was chosen regardless of AcomA complex rotation. Postoperative 3D-CTA showed complete exclusion of 24 aneurysms (>92%) and 2 small remnants (<2 mm). Outcome was excellent or good (modified Rankin score 0-2) in 88% of patients. CONCLUSIONS: Rotation of the AcomA complex and dome projection are important angioanatomic elements in determining the surgical exposure and side of the approach. This study illustrates the role of 3D-CTA in the management of these difficult lesions by individualizing the surgical approach.