title: Bypass Surgeries in the Treatment of Cerebral Aneurysms.
abstract: During surgery for cerebral aneurysm, revascularization techniques are occasionally needed to (1) treat an aneurysm (trapping or flow alteration); (2) preserve blood flow during temporary parent artery occlusion (insurance); and (3) repair accidentally injured vessels (troubleshooting). Herein we present our surgical case experiences.
  
  
  
  Revascularization modalities were employed in 33 (7.6 %) of 452 cases of surgically treated aneurysms. The aneurysm locations and associated required bypass procedures were: (1) 7 middle cerebral artery (MCA) aneurysms with 7 superficial temporal artery (STA)-MCA bypass procedures; (2) 10 internal carotid artery (ICA) aneurysms with 9 high-flow and 1 STA-MCA procedures; (3) 10 vertebro-basilar artery aneurysms with 2 high-flow, 6 occipital artery (OA)-posterior ICA, and 1 STA-superior cerebellar artery (SCA) procedures; (4) 1 posterior cerebral artery (PCA) aneurysm with OA-PCA bypass; and (5) 5 anterior cerebral artery aneurysms with 4 A3-A3 and 1 A3-STA-A3 procedure. Curative bypasses for aneurysmal treatment, temporary bypasses, and troubleshooting procedures were performed in 25, 3, and 5 cases, respectively.
  
  
  
  Among the 26 aneurysms treated via curative bypass, 16 aneurysms that were trapped or clipped using revascularization techniques had better outcomes (no aneurysmal rupture and 1 perforator infarction), whereas among the 10 aneurysms that could not be trapped or clipped and were thereby treated via flow alteration (e.g., bypass plus proximal artery clipping), 2 developed symptomatic infarction and 2 exhibited aneurysmal rupture after partial thrombosis. Patients whose bypass procedures were used for temporary parent artery occlusion (insurance) or troubleshooting had no complications.
  
  
  
  Complex aneurysm clipping or trapping using bypass techniques yielded good results. In particular, perforator vessel ischemia still requires resolution. Flow alteration techniques leading to aneurismal thrombosis carried the risks of ischemic and hemorrhagic complications when applied to intracranial aneurysms. Bypasses for temporary use or troubleshooting were quite effective.
authors.affiliation: Department of Neurosurgery, Toranomon Hospital, 2-2-2 Toranomon, Minato-ku, Tokyo, 105-8470, Japan. takayuki_hara@syd.odn.ne.jp.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hara
authors.affiliation: Department of Neurosurgery, Toranomon Hospital, 2-2-2 Toranomon, Minato-ku, Tokyo, 105-8470, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Arai
authors.affiliation: Department of Neurosurgery, Toranomon Hospital, 2-2-2 Toranomon, Minato-ku, Tokyo, 105-8470, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Goto
authors.affiliation: Department of Neurosurgery, Toranomon Hospital, 2-2-2 Toranomon, Minato-ku, Tokyo, 105-8470, Japan.
authors.forename: Tsuguhito
authors.initials: T
authors.lastname: Takizawa
authors.affiliation: Department of Neurosurgery, Toranomon Hospital, 2-2-2 Toranomon, Minato-ku, Tokyo, 105-8470, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Uchida
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D001488:Basilar Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000601:surgery*; D002533:Cerebral Angiography; D002548:Cerebral Revascularization / Q000379:methods*; D000072226:Computed Tomography Angiography; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000379:methods; D020769:Posterior Cerebral Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D013525:Surgical Instruments; D013699:Temporal Arteries / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D014711:Vertebral Artery / Q000000981:diagnostic imaging / Q000601:surgery*
keywords: Bypass; Cerebral aneurysm; Clipping; Flow alteration; Trapping