Even with a history of controversy and troubling complications, chymop
apain has endured the test of time to show 30 years of clinical succes
s in the treatment of herniated nucleus pulposus. Strict attention to
indications, contraindications, and technique ensures safety and effic
acy of treatment. A trend to decreased dosage may result in less posti
njection spasm. Between 1982-1991, 121 adverse events in 135,000 patie
nts were reported to the Food and Drug Administration and investigated
, Seven cases of fatal anaphylaxis, 24 infections, 32 bleeding problem
s, 32 neurologic events, and 15 miscellaneous occurrences were found.
Overall mortality rate was 0.019%. All categories were of lesser incid
ence than complications with laminectomy. Long-term results show that
improvement after chemonucleolysis is maintained, whereas the outcome
after laminectomy is reported to deteriorate with time. Cost savings w
ith chemonucleolysis over laminectomy are largely a matter of shorter
hospitalization. A protocol for cervical chemonucleolysis is being dev
eloped in the United States after good results have been shown in Spai
n and France. Other enzymes continue under investigation, but chymopap
ain remains the standard to which they are compared.