Extended Retrosigmoid Craniotomy: An Approach Through the Glossopharyngeal Cochlear Triangle for Clipping of Large, Wide Neck, Dysplastic Vertebral Artery Aneurysm: 2-Dimensional Operative Video

Abstract

The extended retrosigmoid (eRS) craniotomy has been described as an approach for highriding posterior inferior cerebellar artery (PICA) aneurysm exposure through microsurgical dissection of the glossopharyngeal cochlear triangle (GCT) [1][2][3] ; however, this approach may be useful for clipping distal vertebral artery (VA) aneurysms, which has not been previously described. We present a case of a 55-yr-old man with hypertension, chronic obstructive pulmonary disorder, congestive heart failure found to have COVID-19 pneumonia admitted for respiratory failure and bacteremia. On presentation, he was disoriented and dysarthric. Computed tomography angiography and digital subtraction angiography demonstrated an unruptured large, left posterosuperiorly pointing intracranial VA aneurysm. Magnetic resonance imaging further demonstrated brainstem compression and evidence of amyloid angiopathy (AA). After recovery from COVID-19 pneumonia, clipping was chosen over endovascular treatment given the patient history of medical noncompliance and presence of AA, placing the patient at high risk for thromboembolic and hemorrhagic complications. Clipping allowed for decompression of the brainstem and cranial nerves. The aneurysm was at the level of the internal auditory canal, making an eRS/GCT approach ideal. An eRS craniotomy was performed with microsurgical dissection through the GCT, and the aneurysm was clipped using 2 stacked fenestrated clips, as shown in the accompanying 2-dimensional operative video. Postoperative angiography demonstrated occlusion of the VA aneurysm without stenosis and with preservation of perforating arteries. The patient tolerated the procedure without complication and was discharged home after an extended hospital stay because of social reasons. The video demonstrates the versatility of the eRS/GCT approach beyond high-riding PICA aneurysms. The patient provided informed consent for the operation depicted in this video.