Abstract
Suboccipital arteriovenous malformations (AVMs) are the second most common cerebellar AVM.1 Superior cerebellar artery (SCA) aneurysms are rare and arise predominantly along the proximally S1 segment, adjacent to the basilar quadrification.2 This operative video shows complete resection of a suboccipital AVM and clipping of an associated feeding artery aneurysm, with demonstration of the pilot clipping technique. The patient, who consented to the procedure, was a man in his early 50s who presented with suddenonset headache and slurred speech. Head computed tomography showed acute cerebellar hemorrhage with intraventricular extension; digital subtraction angiography confirmed right suboccipital AVM and SCA aneurysm. Both lesions were approached by a torcular craniotomy with the patient in the sitting position using the supracerebellar infratentorial approach for the SCA aneurysm. AVM resection was performed first to avoid compromise of draining veins during aneurysm exposure. After superficial subarachnoid dissection and release of cerebrospinal fluid from the cisterna magna, the feeding arteries were identified and disconnected, and the circumferential dissection technique was used for complete AVM resection. The proximal SCA and aneurysm neck were then exposed using the supracerebellar infratentorial approach. After proximal SCA temporary clipping was performed, a partially occlusive pilot clip was placed across the aneurysm neck, parallel to the SCA, followed by a stacked permanent clip and removal of the pilot clip to re-establish SCA flow after aneurysm obliteration. This case highlights the versatility of the torcular craniotomy, the advantages of the sitting position for accessing lesions in these locations, and the importance of pilot clipping for cerebrovascular neurosurgery. The video is used with permission from Barrow Neurological Institute.