Endoscopic endonasal clipping of an unsecured superior hypophyseal artery aneurysm. Technical note.

Paraclinoidal aneurysms, especially superior hypophyseal artery (SHA) aneurysms (with medial projection), can be challenging to access via a pterional craniotomy and damage to the optic nerve can occur during surgery. The authors have previously reported on endonasal clipping and aneurysmorrhaphy of a vertebral artery aneurysm following proximal and distal protection of the aneurysm using partial coil embolization. To the best of the authors' knowledge no unprotected aneurysm has been clipped using an endonasal approach. The 56-year-old woman in this report was found to have two unruptured aneurysms: an anterior communicating artery (ACoA) aneurysm and an SHA aneurysm. An endoscopic endonasal, transplanar-transsellar approach was used to successfully clip the SHA aneurysm. Proximal and distal control was obtained endonasally prior to successful clip occlusion of the aneurysm. The ACoA aneurysm was clipped via a pterional craniotomy during the same anesthetic session. This report shows that it is possible to successfully clip a medially projecting, paraclinoidal aneurysm using an endonasal approach. Such cases must be chosen with extreme caution and only performed by surgeons with significant experience with both endoscopic endonasal approaches and neurovascular surgery.