Use of an epidural cooling catheter with a closed countercurrent lumen to protect against ischemic spinal cord injury in pigs.
OBJECTIVE
We developed an epidural cooling catheter containing cold saline solution circulating in an isolated lumen. After placement by a minimally invasive approach, we evaluated protection effect against ischemic spinal cord injury in pigs.


METHODS
Fourteen pigs underwent thoracic aortic double clamping for 45 minutes under systemic mild hypothermia (36 degrees C). Group A (n = 7) underwent local hypothermia with the cooling catheter. Group B (n = 7) underwent catheter placement only, without cooling. Spinal cord somatosensory evoked potentials were recorded to assess electrophysiologic status. Neurologic function was evaluated with a modified Tarlov score.


RESULTS
At aortic crossclamping, spinal temperature in group A (26.5 degrees C +/- 2.4 degrees C) was significantly lower than that in group B (35.3 degrees C +/- 0.6 degrees C, P = .0001). Mean time from aortic crossclamping to onset of potential loss was significantly longer in group A (28.4 +/- 6.6 minutes) than in group B (18.3 +/- 5.0 minutes, P = .007). Mean duration of total loss of potentials was significantly shorter in group A (19.0 +/- 6.7 minutes) than that in group B (31.3 +/- 5.9 minutes, P = .003). Group A showed significantly better neurologic function (mean Tarlov score 4.4 +/- 0.8) than that of group B (0.1 +/- 0.4, P = .0001). Mean total number of intact motor neurons was significantly greater in group A (24.5 +/- 6.8) than that of group B (9.9 +/- 6.8, P = .0001).


CONCLUSIONS
By cooling the spinal cord selectively and continuously, the newly designed epidural cooling catheter prevented ischemic injury in a pig model of aortic crossclamping.
Yoshitake
Akihiro
A
Department of Cardiovascular Surgery, Keio University School of Medicine, Tokyo, Japan. akihiro197253@yahoo.co.jp
Mori
Atsuo
A
Shimizu
Hideyuki
H
Ueda
Toshihiko
T
Kabei
Nobuyuki
N
Hachiya
Takashi
T
Okano
Hideyuki
H
Yozu
Ryohei
R
D000818:Animals; D001013:Aorta, Thoracic / Q000601:surgery; D001831:Body Temperature; D002404:Catheterization; D003250:Constriction; D004195:Disease Models, Animal; D004824:Epidural Space; D005073:Evoked Potentials, Somatosensory; D007036:Hypothermia, Induced / Q000295:instrumentation*; D012965:Sodium Chloride / Q000627:therapeutic use; D013119:Spinal Cord Injuries / Q000209:etiology / Q000517:prevention & control*; D020760:Spinal Cord Ischemia / Q000209:etiology; D013552:Swine; D014656:Vascular Surgical Procedures / Q000009:adverse effects
D012965:Sodium Chloride