Abstract
Anterior communicating artery aneurysm has a high rupture risk. Although several surgical approaches that take into account the complexity and importance of preserving perforators have been reported, few reports have evaluated the relationship among subarachnoid hemorrhage (SAH) severity, aneurysm projection, and clinical outcomes. We retrospectively evaluated 102 patients (41 men and 61 women; mean age, 61.0 ± 12.8 years) who underwent treatment for ruptured anterior communicating artery aneurysm at our institution between January 2006 and May 2015. The severity of SAH and clinical outcomes were evaluated by using the World Federation of Neurological Surgeons (WFNS) classification and modified Rankin scale (mRS), respectively. Aneurysm projections were classified as anterior, inferior, lateral, superior, and posterior by using three-dimensional computed tomographic angiography or digital subtraction angiography. A mRS score of <4 at the time of discharge was defined as a favorable outcome. We also identified possible prognostic factors by using multivariate logistic regression analysis.
The distribution of aneurysm projection was as follows: anterior, 45; inferior, 25; lateral, 20; superior, 9; and posterior, 3. The WFNS grades at admission were as follows: grade I, 5; grade II, 36; grade III, 16; grade IV, 17; and grade V, 28. The anterior group had significantly larger aneurysms than the lateral group, and the former had significantly better outcomes. Eighteen patients had a dissociation between SAH severity and clinical outcomes (i.e., good outcomes despite poor SAH grade). The anterior group consisted of 61% of these patients. In a multivariate logistic regression analysis, clipping as treatment modality and good SAH grade were found to be predictive of good outcomes. By contrast, neither aneurysm projection nor presence of hydrocephalus was predictive of good outcomes.
SAH severity in ruptured anterior communicating artery aneurysm may depend not only on primary brain damage by hemorrhage but also on disturbed blood flow to the hypothalamus and limbic system, which may partly explain the dissociation between SAH severity and clinical outcome in the anterior projection group.
