OBJECTIVETo evaluate the effect of ultra-early hyperbaric oxygenation on spinal edema and hind limb motor function in rats with complete spinal cord transection.

METHODSFifty-five healthy 3-month-old female SD rats were randomly divided into sham-operated group (n=15), complete spinal cord transection group (CSCT group, n=20) and hyperbaric oxygen group (HBO group, n=20). The rats in the sham-operated group underwent only laminectomy, while those in the other 2 groups underwent CSCT at the T10 level. The rats in HBO group were placed in an oxygen chamber 3 h after the operation for 10 days as a treatment course, and 3 treatment courses were administered at the interval of 6 days. In the first treatment course, 2 hyperbaric oxygenation sessions were given daily, and in the following 2 course, only 1 session was given daily. The recovery of hindlimb motor function was evaluated using the open-field Basso-Beattie-Bresnahan (BBB) scoring system once a week for 6 weeks. All the rats were sacrificed 6 weeks after the operation to measure the water content in the injured tissues.

RESULTSThe BBB scores of CSCT group and HBO group gradually increased with the passage of time after the operation, and from week 2 to week 6, HBO group had significantly higher scores than CSCT group (P<0.05). The water content was markedly increased in CSCT group at 6 weeks after the operation as compared with that in the sham-operated group (P<0.01), and significantly reduced in HBO group in comparison with that in the CSCT group (P<0.05).

CONCLUSIONUltra-early HBO can suppress spinal cord edema and promote hindlimb locomotor recovery in rats with complete spinal cord transection.