title: Combined use of an epidural cooling catheter and systemic moderate hypothermia enhances spinal cord protection against ischemic injury in rabbits.
abstract: BACKGROUND
  Epidural placement of a cooling catheter can protect against ischemic spinal cord injury. With the use of rabbits, we investigated whether this epidural cooling technique, when combined with systemic moderate hypothermia, can protect the spinal cord against ischemic metabolic stress.
  
  
  METHODS
  New Zealand white rabbits (n = 28) were assigned to 1 of 4 different groups. Animals underwent abdominal aortic occlusion for 30 minutes using a 3F balloon catheter. Group 1 (n = 7) underwent epidural cooling by the catheter and systemic moderate hypothermia (35 °C) induced with a cooling blanket. Group 2 (n = 7) underwent epidural cooling under systemic normothermia (38.5 °C). Group 3 (n = 7) underwent systemic moderate hypothermia (35 °C) without epidural cooling. Group 4 (n = 7) underwent neither epidural nor blanket cooling as a negative control. Neurologic status of their hind limbs was graded according to the modified Tarlov scale at 1, 2, and 7 days after surgery.
  
  
  RESULTS
  During infrarenal aortic ischemia, epidural temperature was significantly lower in group 1 (18.5 °C ± 0.8 °C) than in group 2 (28.6 °C ± 1.0 °C; P = .0001), group 3 (34.2 °C ± 0.06 °C; P = .0001), or group 4 (38.5 °C ± 0.2 °C; P = .0001). Hind limb function recovery was greater in group 1 (mean Tarlov score, 4.9 ± 0.057) than in group 2 (2.6 ± 0.3; P = .0028), group 3 (2.1 ± 0.34; P = .0088), or group 4 (0.0 ± 0.0; P = .0003).
  
  
  CONCLUSIONS
  Epidural cooling catheter combined with systemic moderate hypothermia produced additive cooling ability and protected the spinal cord against ischemia in rabbits more effectively than either intervention alone.
authors.affiliation: Department of Cardiovascular Surgery, Keio University School of Medicine, Shinjuku, Tokyo, Japan. inoueshinya1972@yahoo.co.jp
authors.forename: Shinya
authors.initials: S
authors.lastname: Inoue
authors.forename: Atsuo
authors.initials: A
authors.lastname: Mori
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Shimizu
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yoshitake
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Tashiro
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kabei
authors.forename: Ryohei
authors.initials: R
authors.lastname: Yozu
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000503:physiopathology / Q000601:surgery; D001833:Body Temperature Regulation; D057785:Catheters; D004195:Disease Models, Animal; D004824:Epidural Space; D004867:Equipment Design; D007036:Hypothermia, Induced / Q000295:instrumentation*; D008026:Ligation; D009043:Motor Activity; D010264:Paraplegia / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control; D011817:Rabbits; D020127:Recovery of Function; D015427:Reperfusion Injury / Q000209:etiology / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D013116:Spinal Cord / Q000098:blood supply* / Q000473:pathology; D020760:Spinal Cord Ischemia / Q000209:etiology / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors