Pretemporal Transcavernous Approach to Basilar Tip Aneurysms: Operative Technique and Surgical Nuances: 3-Dimensional Operative Video

Abstract

Microsurgical clipping of basilar tip aneurysms is known to be more durable than endovascular therapy, especially in wide neck aneurysms. 1-3 We present a case example of a complex basilar tip aneurysm, which was deemed nonfavorable for endovascular therapy, treated using the pretemporal transcavernous approach 4 in a 60-year-old woman. The patient consented for the procedure and the publication of their images. INDICATIONS: CORRIDORS AND LIMITS OF EXPOSURE: This approach provides a 360° view of the anterior upper third of posterior fossa which can tackle any kind of complex basilar aneurysm. It combines the benefits of both pterional/orbitozygomatic and subtemporal approaches. ANATOMIC ESSENTIALS: NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT: Computed tomography angiography revealed a low-lying basilar apex, so a full transcavernous approach was used. Electroencephalogram, somatosensory evoked potentials, and brainstem auditory evoked response are essential modalities to monitor during temporary clipping. ESSENTIAL STEPS OF THE PROCEDURE: Anterior clinoidectomy, dissection of cavernous sinus, and posterior clinoidectomy to expose the perforator-free zone of basilar artery proximal to the superior cerebellar artery are essential steps described in detail in the video. Analyzing the perforator anatomy around the aneurysm before putting a clip is utmost essential. PITFALLS/AVOIDANCE OF COMPLICATIONS: Clipping a basilar aneurysm using this approach requires a neurosurgeon to have a sound knowledge of the neuroanatomy as well as a skilled handset for performing clinoidectomy and cavernous sinus dissection to avoid neurovascular injury. VARIANTS AND INDICATIONS FOR THEIR USE: Pterional/orbitozygomatic (for high riding bifurcation), subtemporal (low riding bifurcation), and endovascular therapy (small aneurysm with narrow neck) are other options used for these aneurysms.