A patient at the University of Alabama at Birmingham (UAB) became the first person in America to undergo an investigational therapy for emphysema that uses a foam sealant sprayed into the lungs.
On Oct. 29, 2012, Perry Waldrop, 55, of Cullman, Ala., was treated in a late-stage clinical trial of the AeriSeal System. The therapy, approved for use in parts of Europe and Israel, is undergoing investigation in the United States as a potential method of reducing lung volume in patients with severe emphysema.
About 4.9 million Americans have been diagnosed with emphysema, a lung disease usually caused by smoking. Emphysema damages air sacs in the lung called alveoli. The sacs fill with air that the body is unable to exhale, causing the lungs to expand. This in turn flattens the diaphragm, the primary muscle used for breathing. The flattened diaphragm is unable to function properly, making it extremely difficult for the individual to breathe.
The most common therapy is lung volume reduction surgery, first introduced in the 1950s. The over-inflated, diseased parts of the lung are cut away, allowing the lung to return to a more normal size, which allows the diaphragm to return to normal function. Surgery is effective, but there are some risks involved.
"There is a 50-60 percent risk of pulmonary or cardiac complications and a small risk of perioperative death following lung volume reduction surgery," said Mark Dransfield, M.D., associate professor in the Division of Pulmonary, Allergy and Critical Care Medicine and principal investigator in the AeriSeal trial.
Dransfield said there are other techniques under investigation as well, including one-way valves or using steam to close off diseased parts of the lungs.
"The idea behind all lung volume reduction procedures is to reduce the volume in the lung and allow the diaphragm to return to its normal shape and function," he said. "We're looking for a less-invasive way to achieve that goal without the risks inherent in surgery."
The AeriSeal system uses a proprietary polymer that is injected into the lung. Similar to a two-part epoxy, the two liquid components are mixed at the time of injection, and they produce a foam when air is added. Within about 30 minutes of injection, the foam hardens to a rubbery consistency, blocking off the holes in the air sacs and sealing the damaged regions of lung. Over the course of several months, the air sacs deflate, and the lung shrinks in size, clearing the way for the diaphragm to return to normal function.
Perry Waldrop, who started smoking at an early age, was quick to agree to be the first U.S. patient.
"I just couldn't do anything," Waldrop said. "I had no energy, I couldn't even walk. When you can't breathe, anything is worth a try."