The expanded endonasal approach for an endoscopic transnasal clipping and aneurysmorrhaphy of a large vertebral artery aneurysm: technical case report.

OBJECTIVE Aneurysms of the vertebral artery are rare, comprising less than 5% of all aneurysms. They can present with subarachnoid hemorrhage, medullary compression, and cranial neuropathies. In consideration of their surrounding regional anatomy, they present a formidable surgical challenge to the neurosurgeon using traditional techniques. Recent advances in endoscopic transnasal surgery have provided an additional approach for the treatment of these difficult lesions. CLINICAL PRESENTATION We present a case of a large vertebral artery aneurysm causing mass effect on the medulla. Initial treatment consisted of endovascular trapping of the aneurysm; however, because of concerns that the remaining aneurysm and intraluminal thrombus was causing mass effect and continued brainstem compression, a decompressive procedure was required. INTERVENTION After the endovascular trapping, the patient underwent a completely endoscopic transnasal surgical clipping and aneurysmorrhaphy. After exposure of the aneurysm, distal and proximal clips were applied transnasal, and the aneurysmorrhaphy completed using suction and ultrasonic aspiration. CONCLUSION In consideration of their surrounding regional anatomy, aneurysms of the vertebral artery present a formidable surgical challenge to the neurosurgeon. Although endovascular techniques have proven to be extremely valuable for the treatment of these lesions, they are limited when patients have significant mass effect with brainstem compression or cranial neuropathy. Advances in endoscopic transnasal surgery have provided an additional approach for the treatment of these difficult lesions. This case report represents, to our knowledge, the first literature report of a transnasal endoscopic aneurysm clipping and thrombectomy.