Spinal cord protection by papaverine and intrathecal cooling during aortic crossclamping

To extend the safe period of aortic crossclamping in the porcine model by intrathecally dilating the spinal arteries, with cooling of the spinal cord, or using selfoteL METHODS: Experimental design and setting: prospective domestic laboratory pig study.

fifteen animals were assigned to a control group (C, N=5), intrathecal papaverine plus spinal cord cooling group (IP+C, N=5), or selfotel group (S, N=5). In the IP+C group, a lumbar laminectomy was performed and an intrathecal catheter placed for intrathecal injection of papaverine and perfusion with cold Ringer's solution (4 degrees C) prior to aortic crossclamping. In the selfotel group, 20 mg/kg of selfotel was administered 30 minutes before aortic crossclamping. In all 15 animals, the aorta was crossclamped for 60 minutes at normothermia.

immediately after the operation and 24 hours later, lower limb function was evaluated.

All five control animals were paralyzed; all 5 IP+C animals could stand or walk (p=0.004 versus control); and in the selfotel group, one had paraparesis, three had paraplegia and one died before evaluation (p=n.s.)

The combination of intrathecal papaverine to dilate spinal arteries and prevent spasm from the cold solution plus intrathecally cooling the spinal cord appears to extend the period of safe aortic crossclamping. Selfotel, in this model of extended, severe, spinal cord ischemia, was ineffective.