title: Influence on spinal cord blood flow and function by interruption of bilateral segmental arteries at up to three levels: experimental study in dogs.
abstract: METHODS
  Segmental arteries were interrupted bilaterally at up to three levels to study the influence on spinal cord blood flow (SCBF) and function in dogs.
  
  
  OBJECTIVE
  Considering the need to limit blood loss during surgery for spinal tumors, such as total en bloc spondylectomy, we studied the SCBF and function after experimental interruption of segmental arteries at up to three levels.
  
  
  BACKGROUND
  Interruption of bilateral segmental arteries at three consecutive levels (T11, T12, and T13) has reduced blood flow to the vertebral body of T12 by one fourth of the control flow, but effects on the spinal cord have not been determined.
  
  
  METHODS
  SCBF was measured in spinal cord gray matter at T12 using a hydrogen clearance method after ligation of bilateral segmental arteries at 1 to three levels (T11, T12, and T13) in 6 dogs. Spinal cord function was evaluated by spinal cord evoked potentials, motor-evoked potentials, and neurologic assessment in 6 dogs.
  
  
  RESULTS
  SCBF at T12 decreased to 92.4%, 87.8%, and 84.6% of control flow after ligation of bilateral segmental arteries at T12, T11 plus T12, and T11-T13, respectively. Spinal cord evoked potentials and motor-evoked potentials showed no significant changes in any dog after ligation at three levels. No neurologic degradation was observed in any dog.
  
  
  CONCLUSIONS
  Interruption of bilateral segmental arteries at three levels did not damage spinal cord function in dogs, suggesting that in patients, preoperative embolization at three levels to reduce blood loss during surgery for spinal tumors would not compromise spinal cord function.
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Kanazawa University, Kanazawa, Japan. seikei@kenroku.kanazawa-u.ac.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ueda
authors.forename: Norio
authors.initials: N
authors.lastname: Kawahara
authors.forename: Katsuro
authors.initials: K
authors.lastname: Tomita
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Hideki
authors.initials: H
authors.lastname: Murakami
authors.forename: Koshi
authors.initials: K
authors.lastname: Nambu
mesh_terms: D000818:Animals; D001158:Arteries / Q000601:surgery; D004285:Dogs; D005071:Evoked Potentials; D019054:Evoked Potentials, Motor; D005260:Female; D008026:Ligation; D009424:Nervous System Physiological Phenomena; D009460:Neurologic Examination; D011184:Postoperative Period; D012039:Regional Blood Flow; D013116:Spinal Cord / Q000098:blood supply* / Q000503:physiopathology*; D013904:Thoracic Vertebrae; D050781:Transcranial Magnetic Stimulation