Background: The optimal treatment for large or giant paraclinoid aneurysms is still controversial. The present study evaluated the results of endovascular coiling and microsurgical clipping with special reference to visual outcomes.
Methods: The clinical data and treatment outcomes of 39 cases of large (>15 mm) paraclinoid aneurysms were retrospectively reviewed. Presenting symptoms were subarachnoid hemorrhage in 16 aneurysms and visual impairment in 18. Twenty-one aneurysms were treated by endovascular therapy and 18 were treated by direct surgery.
Results: Maximal aneurysm diameter ≥25 mm and preoperative visual acuity <20/100 were significantly related to poor visual outcome in univariate analysis. However, preoperative visual acuity was the only significant prognostic factor in multivariate analysis (odds ratio [OR] 0.12, 95 % confidence interval [CI] 0.01-0.95, p = 0.04). Although patients treated with endovascular coiling tended to have more favorable outcome than those with surgical clipping, adjustment for other confounding factors reduced the OR of favorable outcome following each treatment modality to nearly one (OR 1.14, 95 % CI 0.17-7.46, p = 0.89). Deteriorations in the visual field showed different patterns: upper visual field deficit after endovascular coiling, and inferior nasal quadrantanopia after microsurgical clipping.
Conclusions: Preoperative visual acuity was the only independent predictor of visual outcome in patients with large paraclinoid aneurysms. Although adjusted visual outcomes with microsurgical clipping and endovascular coiling were almost the same, selection of the optimal treatment for each aneurysm is essential with recognition of the potential risks and mechanisms of visual impairment.