title: Anterior clinoidectomy and opening of the internal auditory canal using an ultrasonic bone curette.
abstract: OBJECTIVE
  During cranial base surgery, use of a high-speed drill for osteotomy has become common. We performed anterior clinoidectomy and opening of the internal auditory canal using an ultrasonic bone curette, and we report the advantages and clinical applications of this method.
  
  
  METHODS
  The ultrasonic surgical equipment comprises a power supply unit, footswitch, and handpiece (weight, 110 g; diameter, 20 mm; length, 140 mm from tip to angled section). The handpiece tip is 2 mm wide, and the amplitude of longitudinal vibration can be varied from 120 to 365 microm at an ultrasonic frequency of 25 kHz. Cool-controlled irrigation fluid emerges near the tip, through the sheath.
  
  
  RESULTS
  We performed anterior clinoidectomy in eight cases of paraclinoid aneurysm and opening of the internal auditory canal in six cases of acoustic neuroma without damage to the dura mater or nearby structures such as brain tissue, blood vessels, and cranial nerves. In addition, no damage to the facial nerve or labyrinthine organ resulted from heat or vibration caused by the ultrasonic bone curette.
  
  
  CONCLUSIONS
  Ultrasonic bone curettage represents safe instrumentation for performance of anterior clinoidectomy and opening of the internal auditory canal without damage to surrounding structures. This technique allows surgeons to perform procedures on deep areas without incurring psychomotor stress.
authors.affiliation: Department of Surgical Neurology, Research Institute for Brain and Blood Vessels-Akita, Akita, Japan. hade@akita-noken.go.jp
authors.forename: Hiromu
authors.initials: H
authors.lastname: Hadeishi
authors.forename: Akifumi
authors.initials: A
authors.lastname: Suzuki
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Yasui
authors.forename: Yuichirou
authors.initials: Y
authors.lastname: Satou
mesh_terms: D003399:Craniotomy / Q000295:instrumentation*; D003475:Curettage / Q000295:instrumentation*; D007758:Ear, Inner / Q000473:pathology / Q000601:surgery*; D005158:Facial Paralysis / Q000517:prevention & control; D006319:Hearing Loss, Sensorineural / Q000517:prevention & control; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D009460:Neurologic Examination; D009464:Neuroma, Acoustic / Q000473:pathology / Q000601:surgery*; D011183:Postoperative Complications / Q000517:prevention & control; D019291:Skull Base / Q000473:pathology / Q000601:surgery*; D013525:Surgical Instruments; D014464:Ultrasonic Therapy / Q000295:instrumentation*; D014732:Vibration