title: Macrovascular Decompression of the Brainstem and Cranial Nerves: Evolution of an Anteromedial Vertebrobasilar Artery Transposition Technique.
abstract: BACKGROUND
  Tortuous and dolichoectatic vertebrobasilar arteries can impinge on the brainstem and cranial nerves to cause compression syndromes. Transposition techniques are often required to decompress the brainstem with dolichoectatic pathology. We describe our evolution of an anteromedial transposition technique and its efficacy in decompressing the brainstem and relieving symptoms.
  
  
  OBJECTIVE
  To present the anteromedial vertebrobasilar artery transposition technique for macrovascular decompression of the brainstem and cranial nerves.
  
  
  METHODS
  All patients who underwent vertebrobasilar artery transposition were identified from the prospectively maintained database of the Vascular Neurosurgery service, and their medical records were reviewed retrospectively. The extent of arterial displacement was measured pre- and postoperatively on imaging.
  
  
  RESULTS
  Vertebrobasilar arterial transposition and macrovascular decompression was performed in 12 patients. Evolution in technique was characterized by gradual preference for the far-lateral approach, use of a sling technique with muslin wrap, and an anteromedial direction of pull on the vertebrobasilar artery with clip-assisted tethering to the clival dura. With this technique, mean lateral displacement decreased from 6.6 mm in the first half of the series to 3.8 mm in the last half of the series, and mean anterior displacement increased from 0.8 to 2.5 mm, with corresponding increases in satisfaction and relief of symptoms.
  
  
  CONCLUSIONS
  Compressive dolichoectatic pathology directed laterally into cranial nerves and posteriorly into the brainstem can be corrected with anteromedial transposition towards the clivus. Our technique accomplishes this anteromedial transposition from an inferolateral surgical approach through the vagoaccessory triangle, with sling fixation to clival dura using aneurysm clips.
authors.affiliation: Department of Neurological Surgery, University of California, San Francisco, California.
authors.forename: Omar
authors.initials: O
authors.lastname: Choudhri
authors.affiliation: Stanford Medical School, Stanford University, Stanford, California.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Connolly
authors.affiliation: Department of Neurological Surgery, University of California, San Francisco, California.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lawton
mesh_terms: D001933:Brain Stem / Q000098:blood supply / Q000601:surgery; D003391:Cranial Nerves / Q000098:blood supply / Q000601:surgery; D019299:Decompression, Surgical / Q000379:methods*; D006801:Humans; D019635:Neurosurgical Procedures / Q000379:methods*; D012189:Retrospective Studies; D014711:Vertebral Artery / Q000601:surgery*
keywords: Arterial transposition; Basilar artery; Brain stem compression; Dolichoectasia; Macrovascular decompression; Muslin sling; Vertebral artery