New Lubricant Seen Reducing Surgical Risks : Man-Made Agent Helps in Healing of Wounds, Researchers Report

The long-term risks from cardiac, abdominal and gynecological surgery can be significantly reduced by use of a genetically engineered lubricating agent that minimizes tissue damage and improper healing, researchers said Monday at a meeting of the American Chemical Society.

Improperly healed surgical wounds, called adhesions, can be painful or life-threatening, and can greatly increase the risk of followup surgery.

Tests in animals show that the new agent, called hyaluronic acid, can sharply reduce the risk of adhesions occurring in some surgical procedures, according to chemist Eugene P. Goldberg of the University of Florida at Gainesville. “These are very significant improvements,” Goldberg said.

Firm Sees Big Savings

Hyaluronic acid for surgical purposes is now obtained from chickens at a cost of several million dollars per pound, but Genzyme Corp. of Boston has developed a genetic engineering process that promises to make it available at a substantially lower price.

Clinical trials of the substance in humans are scheduled to begin after the first of the year. Genzyme estimates that it could ultimately be used in as many as 7 million surgical procedures per year.

Surgical adhesions typically occur when heart, intestinal, uterine and other internal tissues dry out during surgery or become abraded, crushed, or infected during handling. Such damage triggers a disorganized healing process that results in the formation of excess scar tissue.

In the heart, adhesions can make subsequent operations--such as replacement of artificial heart valves--substantially more risky, producing extensive bleeding, damage to heart tissue and even death. In intestinal surgery, adhesions can cause constrictions and life-threatening blockages.

Can Produce Lifelong Pain

In gynecological surgery, adhesions can result in severe, lifelong pain in the affected areas. Typically, Goldberg said, surgeons avoid removing such adhesions because the risk of additional damage is greater than the benefit from pain relief.

Although surgeons normally wet incisions with a saline solution to minimize drying, there currently exist no drugs or other agents to prevent formation of adhesions.

Hyaluronic acid is a naturally occurring sugar molecule that is readily soluble in water. It is normally found in very low concentrations in “synovial” fluid in human joints and elsewhere in the body. For existing medical uses, it is extracted from rooster combs and highly purified.

When a small amount of hyaluronic acid is added to water, it causes the water to gel and become very slippery. A 1% solution, for example, forms a thick gel that is used to lubricate the eye during ophthalmologic surgery, such as cataract removal or the insertion of an artificial lens. The gel keeps the fragile eye tissues moist and its slippery “feel” prevents them from becoming abraded.

Need to Curb Costs

A syringe containing 0.4 milliliters of such a solution--less than a drop, but enough for one eye--now costs as much as $70. Any other type of surgery would require much more of the compound, making it prohibitively expensive.

But Genzyme, a biotechnology company founded eight years ago, has found a different way to produce hyaluronic acid. Molecular biologists at Genzyme altered some naturally occurring bacteria to produce much larger quantities of it than they normally do; the acid can then be purified more readily than that from rooster combs.

A Genzyme representative at the meeting refused to reveal the expected price of the material, but he predicted that it would be cheap enough to make its use in surgery feasible.

In medical use, a solution of the agent would be applied to the surface of internal organs that are to be handled during the operation as soon as a surgical incision has been made. It would also be applied to the surfaces of surgical gloves, gauze sponges and instruments. That coating would protect organs throughout the operation. After the operation, the body absorbs the gel.