Experimental study of chemolysis with collagenase outside the intervertebral disk / 中华麻醉学杂志

ABSTRACT

ve To assess the efficacy of chemolysis with collagenase injected into epidural space and the effects upon intervertebral disk and nerve roots. Methods Sixty-four healthy new Zealand rabbits of either sex, weighing 2.5-3.0kg were divided into four groups of sixteen each group A, B, C and D. In group A and B herniation of disk was produced by injecting normal salin 0.1ml into the intervertebral disk after surgical resection of spine and posterior arch of L4_6, while in group C and D no herniation of disk was produced. In group A and C collagenase 300u( in normal saline 0.5ml) was injected into the epidural space at the level of L4-6, and in group B and D normal saline 0.5ml was injected into epidural space as control. Three animals from each group were sacrificed on the 7th, 15th, and 30th day after operation and intervertebral disk and nerve roots at the operation site were removed and fixed for light and electron microscopic examination. Sciatic nerve conduction velocity (NCV) was measured before operation and on 1st, 7th, 15th and 30th postoperative day. Results In group A the intervertebral disk was dissolved to some extent. In group B nerve roots were injured to different degree. In group A and C NCV was higher than normal on the 7th and 15th day after operation. Conclusions Collagenase may dissolve the herniated intervertebral disk but does not injure the nerve roots. It may increase NCV.