Collagenase chemonucleolysis via epidural injection. A review of 252 cases.

Since 1975, collagenase has been injected into 252 herniated intervertebral discs for treatment of sciatica. Highly purified preparations of Chinese collagenase were extracted from Clostridium histolyticum CH 1093 in lyophylized form, which had a specific collagenolytic activity. It had a wide margin of safety as proven by repeated experiments in dogs by means of intradiscal, extradural, intradural, and intravenous injections. One hundred to two hundred units of collagenase dissolved in 5 ml of normal saline was injected epidurally in front of the line joining posterior vertebral body margins. The basic assumption is that the injected enzyme digested the nucleus pulposis. Symptoms disappeared or improved gradually within three to eight weeks. The total success rate was about 77%. For recurrent cases of those with less than satisfactory results, reinjections were performed without any visible antigenic reactions or neurologically adverse effects.