title: Cerebral bypasses for complex aneurysms and tumors: long-term results and graft management strategies.
abstract: BACKGROUND
  Various techniques of cerebral bypasses are used to treat aneurysms and tumors.
  
  
  OBJECTIVE
  To study long-term clinical and radiological outcome of various bypass types and to analyze techniques used in the management of long-term graft problems.
  
  
  METHODS
  A consecutive series of patients who underwent revascularization during a 5-year period were analyzed for indications, graft patency, and neurological outcomes. Potential risk factors for bypass problems and the management of bypass stenosis were studied.
  
  
  RESULTS
  A total of 80 patients (69 with aneurysms and 11 with tumors) underwent 88 bypasses (59 extracranial-to-intracranial [EC-IC] bypasses [10 low flow, 49 high flow], 9 intracranial-to-intracranial [IC-IC] bypasses [3 long, 6 short], and 20 local bypasses), with mean radiological follow-up of 32 months (range, 1-53 months). At late follow-up, 5 of 9 (56%) IC-IC (5 short, 0 long grafts), 8 of 9 (90%) EC-IC low-flow, 44 of 48 (92%) EC-IC high-flow, and all local bypasses were patent. Four patients with EC-IC high-flow bypass occlusions were asymptomatic, but transient ischemic attacks were noted in 3 of 6 patients with graft stenosis. None of the risk factors evaluated were significantly predictive of EC-IC graft occlusions or stenosis. EC-IC HF graft stenoses were permanently corrected by microsurgery (n = 4) or endovascular surgery (n = 1).
  
  
  CONCLUSIONS
  The EC-IC and local bypasses have higher long-term patency rates (91% and 100%) compared with IC-IC bypasses (66%, 0% long graft). Some EC-IC bypasses may occlude asymptomatically (9%) or develop graft stenosis (13%) over the long term. Microsurgical and endovascular surgical techniques have been developed to treat graft stenosis.
authors.affiliation: Department of Neurological Surgery, University of Washington, Seattle, Washington 98104, USA.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Ramanathan
authors.forename: Nancy
authors.initials: N
authors.lastname: Temkin
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Kim
authors.forename: Basavaraj
authors.initials: B
authors.lastname: Ghodke
authors.forename: Laligam N
authors.initials: LN
authors.lastname: Sekhar
mesh_terms: D001932:Brain Neoplasms / Q000601:surgery*; D002548:Cerebral Revascularization / Q000009:adverse effects* / Q000379:methods*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology; D016896:Treatment Outcome; D014654:Vascular Patency