Endoscopic Endonasal Clipping of Intracranial Aneurysms: Technical Details and Anatomic Basis

Introduction: The role of the extended endoscopic endonasal approach (EEA) in the management of intracranial aneurysms is highly controversial. The aims of this study are to report the technical details of the endonasal clipping of an ophthalmic artery aneurysm and provide the anatomic basis of endoscopic endonasal aneurysm surgery.

Methods: Case report of a 42-year-old woman with an unruptured ophthalmic artery aneurysm medially projected below the optic nerve that was not considered amenable for endovascular treatment nor traditional transcranial clipping. Surgical exposure, aneurysm dissection and clipping, and a skull base reconstruction technique through an EEA are detailed. Intraoperative angiography and the ability to convert to an open procedure were available during the entire procedure. Moreover, five cadaver heads were prepared for endoscopic endonasal dissection of the cranial base cisterns emphasizing the degree of exposure of the intracranial arteries at the Surgical Neuroanatomy Laboratory of the University of Pittsburgh Medical Center.

Results: The aneurysm was successfully exposed and clipped through the EEA. The pedicled nasoseptal flap was used for skull base reconstruction. The postoperative period was uneventful. The patient remains asymptomatic. Anatomical dissections showed that the ophthalmic, anterior communicating, basilar, and posterior inferior cerebellar arteries are feasible for safe endoscopic endonasal manipulation.

Conclusions: The EEA is an option for clipping of aneurysms in well-selected cases. The basic principles of cerebrovascular surgery have to be strictly followed during the entire procedure. We emphasize that it must be done only by neurosurgeons who are well versed in both endoscopic endonasal and cerebrovascular surgery.