title: Endovascular treatment of intracranial aneurysms.
abstract: OBJECTIVE
  To examine the techniques, reported experiences, and advantages and disadvantages associated with the endovascular treatment of intracranial aneurysms.
  
  
  METHODS
  We review the endovascular techniques used for the treatment of intracranial aneurysms and the sequelae of subarachnoid hemorrhage, which have evolved during the past 10 years.
  
  
  METHODS
  Two broad categories of endovascular therapy for intracranial aneurysms are described: occlusion of the parent artery and preservation of the parent artery by selective occlusion of the aneurysm with balloons or metallic coils. The Mayo protocol for testing tolerance of patients before permanent balloon occlusion of the parent artery is described, as are the types of aneurysms most amenable to this treatment. In addition, use of balloon angioplasty for cerebral vasospasm after subarachnoid hemorrhage is reviewed.
  
  
  RESULTS
  Recent improvements in microcatheter technology have facilitated the safe navigation of percutaneously introduced catheters in the intracranial circulation and selective catheterization of intracranial aneurysms. Surgically difficult aneurysms are now being treated with endovascular techniques more frequently than in the past. Early results from animal experiments and human trials have shown that selective occlusion of aneurysms with metallic coils may have a role in the treatment of intracranial aneurysms. Balloon angioplasty of symptomatic cerebral vasospasm has demonstrated improvement in neurologic function in approximately 70% of patients.
  
  
  CONCLUSIONS
  As technology continues to improve and as greater experience is obtained, interventional neuroradiologists will continue to have an increasingly important role in the treatment of intracranial aneurysms.
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN 55905.
authors.forename: D A
authors.initials: DA
authors.lastname: Nichols
authors.forename: F B
authors.initials: FB
authors.lastname: Meyer
authors.forename: D G
authors.initials: DG
authors.lastname: Piepgras
authors.forename: P L
authors.initials: PL
authors.lastname: Smith
mesh_terms: D015901:Angiography, Digital Subtraction; D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D002533:Cerebral Angiography; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D002546:Ischemic Attack, Transient / Q000209:etiology / Q000628:therapy*; D008279:Magnetic Resonance Imaging; D015641:Radiography, Interventional; D013345:Subarachnoid Hemorrhage / Q000150:complications* / Q000175:diagnosis / Q000209:etiology; D014057:Tomography, X-Ray Computed