New Help for Slipped Discs

Papaya injections alleviate lower-spine pain

Keith Elliott of Rumson, N.J., was desperate for help. Two of the spongy discs separating the vertebrae in his lower back had herniated, pressing on spinal nerves and causing excruciating pain. The 40-year-old business executive could either choose surgery to remove the "slipped" discs or go to Canada for a simpler, much ballyhooed but controversial therapy. The treatment: injection of chymopapain, a substance derived from the tropical papaya fruit.

Following the example of thousands of Americans, Elliott went north. Beginning in January, however, such pilgrimages will no longer be necessary. The Food and Drug Administration has approved chymopapain for use in the U.S. Says Orthopedist Eugene Nordby, chairman of a joint committee of the American Academy of Orthopaedic Surgeons and the American Association of Neurological Surgeons: "The injections could revolutionize treatment of herniated discs."

An estimated 200,000 Americans now annually undergo operations known as laminectomies to correct this ailment. The new technique, called chemonucleolysis, may eliminate the need for up to 75% of such surgery. In the hourlong procedure, the surgeon, guided by images on a fluoroscope, inserts a 6-in. needle into the gelatinous core of the disc and injects 1 to 1.5 milliliters (about one-third of a teaspoon) of chymopapain into the disc. Within seconds, the pulpy tissue dissolves, relieving pressure on the nerves.

The patients usually stay in the hospital for two to five days, and most return to a full work schedule within two months. By contrast, laminectomies require ten to 14 days in the hospital, and the patient needs three to six months for full recovery. Another advantage: a laminectomy can cost $9,000, compared with an expected $4,000 for chemonucleolysis.

The FDA approval is a victory for Dr. Lyman Smith of Elgin, Ill., an orthopedist who developed and promoted use of the enzyme to treat herniated discs. Smith had been fascinated with a 1956 paper by Dr. Lewis Thomas, author of Lives of a Cell and now Chancellor of Memorial-Sloan Kettering Cancer Center. Thomas had been trying to see if various enzymes could alter concentrations of proteins in the blood. One evening, he gave adolescent rabbits intravenous injections of papain. Next morning, he found that the rabbits' normally erect ears had flopped; the papaya enzyme had dissolved the gelatinous protein of their cartilage.

Smith, now 70, became determined to find out if chymopapain, another papaya enzyme, could be used to dissolve the similarly gelatinous core of herniated discs. From 1964 until 1978 more than 15,000 patients had chymopapain injected into their discs in FDA-approved experiments. The chemical proved to be as successful as a laminectomy in relieving pain: about 70% of patients improved with either therapy. In 1971, chymopapain was approved for use in Canada, Britain and Australia. But a study of almost 100 patients in the U.S. showed that placebo injections were just as effective as chymopapain. That controversial experiment led the FDA to withhold approval in 1974, and U.S. patients began visiting Canada. A new series of trials, begun in 1979, led to the final FDA approval.

The use of chymopapain does have one drawback. Injection of the chemical can trigger a potentially fatal response known as anaphylactic shock. The reaction, which cannot be predicted in an individual, can lead to the collapse of the respiratory and cardiovascular systems. The FDA points out, however, that in the new clinical trials with more than 1,400 patients, anaphylaxis occurred in only 1% of cases, and of these just two patients died. The mortality rate of .14% for chymopapain is about the same as that for lumbar disc surgery. Still, surgeons are cautioning patients that chymopapain is a last-ditch therapy short of surgery. In 95% of the millions of patients with herniated discs, the pain can be relieved by bed rest and aspirin.

This file is automatically generated by a robot program, so viewer discretion is required.