Evaluation and treatment of chemonucleolysis failures.

Fifty patients underwent chemonucleolysis for the treatment of lumbar disk herniations unresponsive to conservative therapy. In patients treated with chymopapain, unrelieved sciatica was the most common cause of clinical treatment failure. Eight patients (16%) experienced no relief or only a transient reduction in their radicular symptoms following chymopapain injection. All eight patients were clinically reevaluated and underwent repeat neuroradiographic studies. Computed axial tomography and lumbar myelography demonstrated persistent nerve root compromise at the level of the injected disk space. Open diskectomy was performed in all eight cases. Postoperatively, seven patients noted complete resolution of their radicular symptoms; one patient had intermittent low back and leg pain following surgery.