title: Microsurgical removal of Onyx HD-500 from an aneurysm for relief of brainstem compression. Case report.
abstract: The authors report the successful removal of Onyx HD-500 from an aneurysm sac by means of ultrasonic aspiration. This 46-year-old woman presented with progressive spasms of her left arm and leg due to mass effect and compression on the right cerebral peduncle 5 years after endovascular treatment of an unruptured giant posterior communicating artery aneurysm with Onyx HD-500. No filling of the aneurysm was detected on angiography. The patient underwent a right pterional craniotomy and the aneurysm was opened to remove the Onyx mass. However, contrary to expectations, the aneurysm was still patent, filling with blood between the Onyx mass and the aneurysm wall. Under temporary clipping of the carotid artery, the Onyx mass within the aneurysm was removed in a piecemeal fashion using an ultrasonic aspirator and the aneurysm was then successfully clipped. The patient experienced significant improvement of the spasm after surgery. Angiography showed complete occlusion of the posterior communicating artery aneurysm. It is rarely necessary to remove embolization material such as Onyx HD-500, and little is known about the most appropriate surgical technique. This case report demonstrates that removal can be safely accomplished by means of ultrasonic aspiration.
authors.affiliation: Department of Neurosurgery, University Hospital Antwerp, Edegem, Belgium.
authors.forename: Katrin
authors.initials: K
authors.lastname: Van Loock
authors.forename: Tomas
authors.initials: T
authors.lastname: Menovsky
authors.forename: Maurits H
authors.initials: MH
authors.lastname: Voormolen
authors.forename: Mark
authors.initials: M
authors.lastname: Plazier
authors.forename: Paul
authors.initials: P
authors.lastname: Parizel
authors.forename: Dirk
authors.initials: D
authors.lastname: De Ridder
authors.forename: Andrew I R
authors.initials: AI
authors.lastname: Maas
authors.forename: Juha A
authors.initials: JA
authors.lastname: Hernesniemi
mesh_terms: D001933:Brain Stem; D002533:Cerebral Angiography; D003399:Craniotomy; D004121:Dimethyl Sulfoxide / Q000009:adverse effects*; D004621:Embolization, Therapeutic / Q000009:adverse effects*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications* / Q000628:therapy*; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000150:complications* / Q000628:therapy*; D019635:Neurosurgical Procedures / Q000379:methods*; D011145:Polyvinyls / Q000009:adverse effects*; D012086:Reoperation; D013396:Suction; D013681:Tegmentum Mesencephali / Q000473:pathology; D014464:Ultrasonic Therapy
chemical_list: C505752:Onyx HD 500; D011145:Polyvinyls; D004121:Dimethyl Sulfoxide