A patient at the University of Alabama at Birmingham 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.”
The procedure, which takes about 45 minutes, is done under light anesthesia. Patients typically stay in the hospital overnight to monitor their reaction. Three months after his injection, Waldrop said he sees improvement, but it will be another couple of months and the arrival of drier weather before he is truly able to gauge the benefit.
Dransfield said his expectation is that the procedure will prove to be much safer than surgery, with similar results.
“We don’t yet know the balance of risks and benefits for this procedure as well as we do for surgery,” Dransfield said. “Certainly the hope is the risk will be far lower, and the preliminary data from Europe indicates that that is true. The risk of major cardio- or pulmonary complications is quite low. I think having a safer option that is as effective or almost as effective as surgery will greatly improve our ability to take care of these folks.”
So far, the major complication is an immune system inflammatory response with flu-like symptoms that typically resolves over the course of two or three days.
Waldrop, who is on supplemental oxygen, would like to one day leave that oxygen tank at home.
“I want to play golf,” he said. “I’d like to just be able to go play golf, or just enjoy something every once in a while and not have to worry about running out of energy. Quality of life is everything, and I’d like my quality of life to come back up to where I can do things and not have to worry so much – and not have my wife worry about me so much.”
UAB is part of an international phase III trial of the AeriSeal System treatment aiming to enroll 300 patients in Europe, Israel and the United States.