Extended Retrosigmoid Craniotomy and Approach Through the Glossopharyngeal Cochlear Triangle for Clipping of a High-Riding Vertebral-Posterior Inferior Cerebellar Artery Aneurysm: 2-Dimensional Operative Video

Abstract

The far lateral transcondylar (FL) craniotomy is the standard approach for posterior inferior cerebellar artery (PICA) aneurysm exposure through microsurgical dissection in the vagoaccessory triangle (VAT).1,2 However, the extended retrosigmoid (eRS) craniotomy and dissection through the glossopharyngeal-cochlear triangle (GCT) may be more appropriate when the patient has an aneurysm arising from a high-riding vertebral artery (VA)—PICA origin.3-5 We present a case of a 41-yr-old woman with hypertension presenting with left occipital pain and left-side hearing loss and past facial spasm and pain. Computed tomography angiography and digital subtraction angiography demonstrated an unruptured 8.4 × 9.0 × 10.2 mm saccular aneurysm at the left VA-PICA junction. Surgical clipping was chosen over endovascular therapy given the relationship of the PICA origin to the aneurysm neck as well as the history of cranial neuropathy. It was noted that the VA-PICA junction and aneurysm was high-riding at the level of the internal auditory canal. An eRS craniotomy was performed with dissection through the GCT, and the aneurysm was clipped as shown in the accompanying 2-dimensional operative video. Postoperative angiography demonstrated complete occlusion of the aneurysm and patency of the left VA and PICA without stenosis, and the patient had a favorable postoperative course although her left-sided hearing remained diminished. The eRS craniotomy allowed direct exposure via the GCT for clipping of the high-riding VA-PICA junction aneurysm and decompression of the cranial nerves. The traditional FL craniotomy and exposure through the VAT would likely have resulted in a less desirable inferior trajectory. The patient gave informed consent for the operation depicted in the video. Animation at 2:43 in video is used with permission from Barrow Neurological Institute, Phoenix, Arizona.

In Reply: The Glossopharyngo-Cochlear Triangle—Part II: Case Series Highlighting the Clinical Application to High-Riding Posterior Inferior Cerebellar Artery Aneurysms Exposed Through the Extended Retrosigmoid Approach

“…Indeed, at the time of this response, we have a narrated video submitted for review, which we hope the authors of this letter and others will find interesting and clinically beneficial. 4 Again, we would like to thank the authors 1 of this letter for their comments and their thoughtful response.…”

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

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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.

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