Combined Endoscopic Endonasal and Bilateral Subfrontal Approach for a Nonfunctioning Pituitary Adenoma Associated with an Internal Carotid Artery-Superior Hypophyseal Artery Aneurysm

BACKGROUND: An aneurysm embedded in a pituitary adenoma is rare, and treatment for both the aneurysm and pituitary adenoma is complex and controversial. CASE DESCRIPTION: A 53-year-old woman presented with a visual field defect. Magnetic resonance imaging showed a pituitary adenoma and coexistence of an aneurysm located at the orifice of the superior hypophyseal artery (SHA) from the internal carotid artery (ICA). The aneurysm was embedded in the pituitary adenoma; therefore, obliteration of the aneurysm was needed prior to tumor removal to prevent intraoperative rupture of the aneurysm. Although endovascular coil embolization was tried first, it was not successful. A combined endoscopic endonasal approach and transcranial approach was performed for simultaneous tumor removal and aneurysm clipping. A bilateral subfrontal approach was selected for aneurysm clipping because, using this approach, the parent artery was safely controlled from the ipsilateral trajectory, whereas exposure and clipping of the aneurysm were easily done from the contralateral trajectory. Additionally, the supine head position without rotation is comfortable for endoscopic endonasal surgery. The tumor was totally removed, and the aneurysm was safely and completely obliterated with a clip. The patient's postoperative course was uneventful, and her visual disturbance improved. CONCLUSIONS: A combined endoscopic endonasal and bilateral subfrontal approach is effective for a pituitary adenoma associated with an ICA-SHA aneurysm.