Eugene J. Nordby

Chemonucleolysis: the state of the art.

Abstract This review presents the history of chemonucleolysis, the techniques, indications, contraindications, and complications. Presenting an historical overview and comparison of success rates with surgical discectomy may provide a fresh understanding of the controversy surrounding chemonucleolysis and establish its efficacy in relation to more invasive treatments. A review of the literature from 1973 through 1998 for chemonucleolysis, open discectomy, and microdiscectomy provided published success rates for these procedures, and a mean rate with standard deviation was determined. In the experience and opinion of the authors, chemonucleolysis remains a viable alternative for patients who have exhausted all conservative means of treatment. Proper patient selection leads to success rates comparable to open discectomy and microdiscectomy.

Spine Update Chemonucleolysis

&NA; Even with a history of controversy and troubling complications, chymopapain has endured the test of time to show 30 years of clinical success in the treatment of herniated nucleus pulposus. Strict attention to indications, contraindications, and technique ensures safety and efficacy of treatment. A trend to decreased dosage may result in less postinjection spasm. Between 1982–1991, 121 adverse events in 135,000 patients were reported to the Food and Drug Administration and investigated. Seven cases of fatal anaphylaxis, 24 infections, 32 bleeding problems, 32 neurologic events, and 15 miscellaneous occurrences were found. Overall mortality rate was 0.019%. All categories were of lesser incidence 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 with chemonucleolysis over laminectomy are largely a matter of shorter hospitalization. A protocol for cervical chemonucleolysis is being developed in the United States after good results have been shown in Spain and France. Other enzymes continue under investigation, but chymopapain remains the standard to which they are compared.

Efficacy of chymopapain in chemonucleolysis. A review.

Study Design This study was designed to determine the current experience in the use of chymopapain injection in the treatment of herniated intervertebral discs by analyzing reports appearing between 1985 and 1993. Forty-five clinical studies included 7,335 patients treated worldwide, some including comparisons to open laminectomy/discectomy and others to percutaneous discectomy. Objectives Because controversy persists after 30 years of clinical use of chymopapain, the results of current experience should establish the efficacy for those who want to consider chemonucleolysis as a treatment for a herniated nucleus pulposus. Summary of Background Data There is the suggestion that use of other than conservative treatment is made only to achieve a better result in the short term. The selection of type of treatment will depend on contraindications, with failures of chemonucleolysis found largely in those having spinal stenosis or sequestrated discs. Worker compensation patients respond less successfully than those with better motivation. Methods The 45 studies were analyzed for determination of successful outcome and divided into 16 with more than 100 patients, 13 with less than 100 patients and 16 with comparison to other treatments. Results Individual success rates exceeded 60% whereas cohort total averaged 76%. In studies comparing chemonucleolysis with open discectomy, success rate averaged 76.2% as compared with 88% for open surgery. In two other studies, percutaneous discectomy was less successful than chemonucleolysis. Where included, duration of hospitalization showed less time and thus less costs for chemonucleolysis. Return to work compilations showed time off slightly less for chemonucleolysis than for laminectomy. Conclusions Chemonucleolysis, though somewhat less effective than open discectomy, can be successfully and safely used in about four of five carefully selected patients without the trauma, risks, and subsequent fibrosis associated with lumbar disc surgery.

Current Status of Chymopapain for Herniated Nucleus Pulposus

Summary:The history of chymopapain chemonucleolysis (CNL) has been peppered with controversy since CNL was first used 30 years ago for the treatment of unremitting sciatica of a herniated nucleus pulposus. Numerous studies from the United States, Europe, Canada, and Australia have shown that the procedure is a safe, effective, and practical alternative to laminectomy at an average of approximately half the cost of surgical diskectomy. Neurological complications have been shown to be due to faulty surgical technique, and anaphylaxis can be avoided in >99% of patients by using sensitivity testing. Through careful management, no deaths have occurred from anaphylaxis since 1987. Patient selection criteria for CNL are more rigorous than for laminectomy and must be carefully followed for a successful outcome. Long-term outcomes of CNL patients indicate that good to excellent results are enduring and compare favorably with those of laminectomy. A protocol for investigating chemonucleolysis in cervical disk herniation is being developed; positive results from Europe should pave the way for the expanded use of CNL in the United States. Although studies of other lytic enzymes are being conducted, chymopapain remains the standard by which they are to be judged.

Present Status of Chymopapain and Chemonucleolysis

An analysis of recent events and newly published data on Chymopapain and the technique of Chemonucleolysis including an objective analysis of clinical and basic research as well as the circumstances leading to the FDA curtailment of the use of Chymopapain in the United States, indicate that the drug should be reapproved for investigational use.

Eight- to 13-year follow-up evaluation of chemonucleolysis patients.

739 patients treated eight to 13 years previously with chymopapain injection are evaluated by questionnaire. The results were 76% satisfactory and 24% unsatisfactory. When those with prior surgery, midline discs, and spondylolisthesis were eliminated, there is a satisfactory result in 82% with 60% excellent, reinforcing the importance of patient selection for the procedure. Thirty-one percent of patients had preoperative myelograms, and all had discograms and were done under general anesthesia with the single needle technique. Of the excellent and good results, 50% had a two-level injection, while one-level injections produced only 23% and 20%, respectively. Results in midline discs are comparable to lateral displacement and the 13 patients with spondylolisthesis had 85% satisfactory outcome. In ten patients younger than 19 years of age, only one was a failure. Sixteen percent of patients had prior surgery and they reported a successful outcome of injection in 55%. Of the 179 unsatisfactory results in the series, subsequent treatment reduced the rate of failed end results to 14%. The study verifies the persistence of early satisfactory results and shows no late complications such as symptomatic iatrogenic spinal stenosis.

Four brief reports on long-term results of intradiscal chymopapain

Five- to 12-year statistics for 842 patients treated with intradiscal chymopapain are presented by four observers. While the results are presented in different formats, long-term satisfactory results can be reported for 81% of the patients, with a range of 71%-83%.

Disability evaluation of the neck and back. The McBride system.

To properly evaluate residual permanent disability arising from impairment of the spine, it is essential to conduct a careful and complete examination in order to arrive at a diagnosis and a determination that present findings are unlikely to change. A formula for computation of permanent disability as developed by McBride includes functional deficiency and physical disorders, taking into account 12 variables. This formula can be simplified to seven components if the physical disorders are mentally computed into the factors of quickness of action, coordination, strength, security, endurance, safety, and adverse employability, which are given weighted values. This method can provide a valid determination of percentage of disability. Some situations only require a delineation of the impairment present and defer disability determination to an agency or board. Currently, there is a trend toward equating the amount of disability with the loss of earnings, which is quite contrary to the longstanding, traditional view.