Intracranial aneurysms presenting with mass effect over the anterior optic pathways: neurosurgical management and outcomes

Object. Intracranial aneurysms may grow closer to anterior optic pathways, causing mass effect over these anatomical structures, including visual deficit. The authors retrospectively reviewed a series of aneurysms in patients presenting with visual field deficit caused by mass effect, to analyze the aneurysm's characteristics, the neurosurgical management of these aneurysms, as well as their clinical, visual, and radiological outcomes. Methods. The authors reviewed the medical charts, neuroimaging examination results, and surgical videos of 15 patients presenting with visual symptoms caused by an aneurysm's mass effect over the anterior optic pathways. These patients were treated at the Department of Neurosurgery, Center of Neurology and Neurosurgery Associates, Hospital Beneficencia Portuguesa de Sao Paulo, Brazil. Statistical analysis was performed to identify the variables related to partial or total recovery of the visual symptoms. Results. All patients underwent microsurgical clip placement and emptying of their aneurysms. After a mean follow-up of 38.5 months, the mean postoperative Glasgow Outcome Scale score was 4.33, and the visual outcomes were as follows: 1 patient (6.6%) unchanged, 7 (46.6%) improved, and 7 (46.6%) experienced complete recovery from visual deficits. The variables that influenced the visual outcomes were the size of the aneurysm (p = 0.039), duration of the visual symptoms (p = 0.002), aneurysm wall calcification (p = 0.010), and intraluminal thrombosis (p = 0.007). Postoperative examination using digital subtraction angiography showed complete aneurysm occlusion in 14 (93.3%) of the 15 patients. Conclusions. Intracranial aneurysms causing mass effect over the anterior optic pathways usually present with complex features. The best treatment option must include not only the aneurysm occlusion but also relief of the mass effect. Microsurgical clip placement with reduction of aneurysmal mass effect achieved improvement in visual ability or recovery from visual impairment, as well as total aneurysm occlusion, in 93.3% of the study group. Therefore, this option is well supported as the first choice of treatment for intracranial aneurysms presenting with mass effect over the anterior visual pathways. (DOI: 10.3171/2009.3.FOCUS0924)