The adverse effect of back-bleeding from lumbar arteries on spinal cord pathophysiology in a rabbit model.
OBJECTIVE
The purpose of this study was to evaluate the adverse effect of back-bleeding from the lumbar arteries on spinal cord pathophysiology in a rabbit model.


METHODS
White rabbits were divided into 3 groups. Through laparotomy, the abdominal aorta was clamped below the renal artery and above the aortic bifurcation for 15 minutes. In group 1 (n = 13), back-bleeding from the lumbar arteries was drained from the aorta during aortic clamping. In group 2 (n = 10), back-bleeding was not drained. Group 3 (n = 6) was the sham-operated group. Postoperative hind limb function was evaluated using the modified Tarlov scale, and cell damage was analyzed by counting the number of intact motor neurons and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL)-positive neurons.


RESULTS
At 4 hours after operation, all animals were neurologically impaired in group 1 and normal in group 2. Motor neurons were significantly damaged in group 1 compared with groups 2 and 3 (P < .05). Forty-eight hours later, almost all animals were neurologically and pathologically damaged in groups 1 and 2. There was no difference in the number of normal motor neurons between the two groups, but the number of TUNEL-positive cells in group 2 was significantly larger than those in group 1.


CONCLUSIONS
Rabbits with 15-minute aortic clamping in the infrarenal portion showed delayed paraplegia, and those with back-bleeding from lumbar arteries showed early onset of paraplegia. The prevention of back-bleeding from intercostal arteries and lumbar arteries during thoracoabdominal aortic surgery was considered to reduce spinal ischemic injury.
Kawanishi
Yujiro
Y
Division of Cardiovascular, Thoracic, and Pediatric Surgery, Kobe University Graduate School of Medicine, Kobe City, Hyogo, Japan.
Okada
Kenji
K
Tanaka
Hiroshi
H
Yamashita
Teruo
T
Nakagiri
Keitaro
K
Okita
Yutaka
Y
D000704:Analysis of Variance; D000818:Animals; D006488:Hemostasis, Surgical / Q000379:methods*; D020287:In Situ Nick-End Labeling; D008159:Lumbar Vertebrae / Q000098:blood supply*; D011817:Rabbits; D013116:Spinal Cord / Q000098:blood supply* / Q000503:physiopathology*; D020760:Spinal Cord Ischemia / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control*; D018709:Statistics, Nonparametric