title: Extracranial-intracranial bypass surgery at high magnification using a new high-resolution operating microscope: technical note.
abstract: BACKGROUND
  We report a precise technique for EC-IC bypass surgery using a stereoscopic high-resolution microscope at magnifications of 40x and 50x.
  
  
  METHODS
  A stereoscopic operating microscope (Mitaka MM50 Surgical Microscope; Mitaka Kohoki Co, Tokyo, Japan) was used in STA-MCA anastomosis. This microscope has 2 optical systems, a standard zooming system, a newly developed high-magnification system, and 4 fixed working distances of 200, 250, 300 and 350 mm, with highest magnifications of 50.4x at 200 mm and 40.3x at 250 mm. High resolution is achieved by a new lens design in the optical system, which makes the image of the object very clear at high magnification. The magnification can be changed depending on the circumstances in a given procedure. The STA-MCA anastomoses were performed using this microscope.
  
  
  RESULTS
  Very small vessels were observable, and arterial anastomosis could be performed precisely at high magnification. All anastomoses were patent on postoperative angiograms.
  
  
  CONCLUSIONS
  Use of the new microscope allows visualization and manipulation of small vessels at high magnification and high resolution and may be very useful in EC-IC bypass surgery.
authors.affiliation: Department of Neurosurgery, Stroke Center, Saiseikai Toyama Hospital, Toyama 931-8533, Japan. sanataka@pk.ctt.ne.jp
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Matsumura
authors.forename: Takashi
authors.initials: T
authors.lastname: Shibata
authors.forename: Kimiko
authors.initials: K
authors.lastname: Umemura
authors.forename: Seiya
authors.initials: S
authors.lastname: Nagao
authors.forename: Yukio
authors.initials: Y
authors.lastname: Horie
mesh_terms: D002545:Brain Ischemia / Q000601:surgery*; D002548:Cerebral Revascularization / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000601:surgery*; D008866:Microsurgery / Q000295:instrumentation*; D009072:Moyamoya Disease / Q000601:surgery*; D013536:Suture Techniques