For his analysis, Davis prospectively reviewed the records of 108 Duke lung transplant patients. Of those patients, 70 (65 percent) had documented cases of GERD, and 34 of those went on to receive the fundoplication surgery. Of those receiving the surgery, 21 had signs of BOS, which is rated on a scale of BOS-0 to BOS-3, depending on the seriousness of the damage. BOS-3 is the most advanced stage.
Of those 21 patients, 11 showed improvements in their BOS scores, with two improving two grades (from BOS-2 to BOS-0)," Davis said. "It appears that we now have a potential treatment for an untreatable condition that seems to work. What we still need to determine is the timing of the surgery."
Davis said that it is seems logical the patients with documented GERD should receive the surgery earlier rather than later.
"Earlier detection and treatment may prevent irreversible damage to the transplanted lung caused by the aspiration of gastric contents," he said.
While the study showed a clear benefit of the fundoplication surgery for lung transplant patients, what is still not clear is the mechanism by which GERD impacts the BOS, Davis said.
One theory is straightforward the caustic gastric contents actually damage or destroy cells lining the lung, Davis said. Since the process of transplantation severs all nerves, transplant patients do not have the normal cough reflex, so any aspiration materials are not quickly cleared. Also, the tiny hairs known as cilia that line lung passages do not function properly in transplant patients.
Another explanation, according to Davis, is that the acid causes cells on the transplanted lungs to slough off, causing more donor materials to be presented to the immune system, causing inflammation.
"A more intriguing explanation revolves not so much on how the immune system responds to the transplanted organ itself, but how it responds to
Contact: Richard Merritt
Duke University Medical Center