title: Risk Factors for Low-Flow Related Ischemic Complications and Neurologic Worsening in Patients with Complex Internal Carotid Artery Aneurysm Treated by Extracranial to Intracranial High-Flow Bypass.
abstract: BACKGROUND
  The revascularization technique has remained indispensable for complex aneurysms. However, risk factors for low-flow related ischemic complications (LRICs) and neurologic worsening (NW) have been less well documented. We evaluated the risk factors for LRICs and NW in 67 patients treated with extracranial to intracranial bypass graft using radial artery or saphenous vein graft for complex internal carotid artery (ICA) aneurysm with ICA occlusion.
  
  
  METHODS
  Intraoperative middle cerebral artery pressure (MCAP) by backup superficial temporal artery to middle cerebral artery bypass was measured. The MCAP ratio was the ratio of the MCAP after release of the graft bypass to the initial MCAP. LRICs were defined as new neurologic deficits and ipsilateral cerebral blood flow reduction in single-photon emission computed tomography. Early and late NW were defined as an increase in 1 or more modified Rankin Scale at discharge and at the 12-month follow-up examination.
  
  
  RESULTS
  During a median follow-up period of 13.3 months, LRICs were observed in 7 patients (10%). The Cox proportional hazards model showed that an MCAP ratio ≤0.80 was significantly related to LRICs. Multivariate logistic regression analysis revealed that perforating artery ischemia was significantly associated with early NW (n = 13, 19%) and late NW (n = 7, 13%). It also showed that LRICs were also significantly related to late NW.
  
  
  CONCLUSIONS
  The present study showed that regardless of the graft type, the MCAP ratio was associated with LRICs, which were related to late NW in patients with complex ICA aneurysms treated by extracranial to intracranial high-flow bypass graft.
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo, Japan. Electronic address: nowornever1982@gmail.com.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Matsukawa
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo, Japan.
authors.forename: Rokuya
authors.initials: R
authors.lastname: Tanikawa
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Kamiyama
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tsuboi
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo, Japan.
authors.forename: Kosumo
authors.initials: K
authors.lastname: Noda
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo, Japan.
authors.forename: Nakao
authors.initials: N
authors.lastname: Ota
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Miyata
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Suzuki
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo, Japan.
authors.forename: Rihee
authors.initials: R
authors.lastname: Takeda
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo, Japan.
authors.forename: Sadahisa
authors.initials: S
authors.lastname: Tokuda
mesh_terms: D000328:Adult; D000368:Aged; D000783:Aneurysm / Q000601:surgery*; D001794:Blood Pressure; D002545:Brain Ischemia / Q000209:etiology*; D002340:Carotid Artery Diseases / Q000601:surgery*; D002548:Cerebral Revascularization / Q000379:methods*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009460:Neurologic Examination; D011183:Postoperative Complications / Q000209:etiology; D012307:Risk Factors; D015899:Tomography, Emission-Computed, Single-Photon
keywords: Brain ischemia; Extracranial to intracranial arterial bypass; Intraoperative monitoring