A study published today in JAMA Surgery (formerly the Archives of Surgery) by esophageal disease specialists from the West Penn Allegheny Health System (WPAHS) provides further evidence the disease also poses significant pulmonary health risks and is a primary cause of adult-onset asthma.
Blair Jobe, MD, Director of West Penn Allegheny’s Institute for the Treatment of Esophageal and Thoracic Disease, and colleagues Yoshihiro Komatsu, MD, and Toshitaka Hoppo, MD, PhD, focused their research on a novel GERD diagnostic technique they helped develop – called hypopharyngeal multichannel intraluminal impedance (HMII). In their study, the procedure proved to be significantly more accurate than conventional diagnostic approaches for identifying patients with GERD-induced asthma.
Furthermore, the study also showed that the vast majority of patients with confirmed GERD-induced asthma experienced significant relief from their asthmatic symptoms after undergoing anti-reflux surgery.
Gastroesophageal reflux occurs when the amount of gastric fluid (acid and bile from the stomach) that refluxes into the esophagus exceeds the normal limit. Common symptoms of the disease include frequent heartburn, chest discomfort, dry cough, hoarseness or sore throat, difficulty swallowing and regurgitation of food. It is estimated that 25-40% of adult Americans experience symptomatic GERD and 10-20% suffer from it daily.
“We have observed for some time a strong association between GERD and certain pulmonary diseases, including adult-onset asthma. The real challenge, however, has been our limited ability to effectively diagnosis these patients and determine who precisely may benefit from surgical intervention,” said Dr. Jobe.
“This study suggests that hypopharyngeal impedance testing is much more sensitive as means of detecting GERD in asthmatic patients than what we have traditionally relied upon to make the diagnosis.”
According to Dr. Jobe, the standard evaluation for GERD is a test called esophageal pH monitoring which measures how often and for how long stomach acid enters the esophagus. The procedure involves introducing a small thin tube through the nose or mouth and into the stomach, which is then drawn back up into the esophagus. The tube is attached to a monitor that records the level of acidity in the esophagus over a period of time.
The problem with pH testing in this particular group of patients, Dr. Jobe said, is that the nature of their reflux is considerably different. Instead of gastric juices gurgling into the esophagus, reflux in patients with GERD-induced asthma occurs as more of a projectile squirt of fluid that reaches higher into the esophagus. As a result, the fluid bypasses the pH monitor and the test is read as normal.
Once gastric fluid is projected into a patient’s mouth it can become aerosolized and then inhaled into the lungs where it causes constriction of the bronchial tubes, which leads to asthma.
HMII testing is performed using a specially designed catheter that enables physicians to measure the level of reflux exposure to a patient’s airway. In Dr. Jobe’s study, 27 patients with adult-onset asthma were evaluated using the HMII procedure.
Despite previous negative pH monitoring study results, 19 (70%) of the study participants demonstrated abnormal reflux exposure to their airway upon evaluation with HMII. Of 20 patients who subsequently underwent anti-reflux surgery, asthma symptoms improved in 18 (90%), and six of them ultimately discontinued or reduced pulmonary medications.
Anti-reflux surgery is a procedure – most often performed laparoscopically – which restores proper function to the lower esophageal sphincter (the valve between the esophagus and stomach), preventing or minimizing the reflux of fluids in to the esophagus.
Dr. Jobe said the study results are convincing enough to warrant consideration of HMII testing in patients with adult-onset asthma who are not responding to asthma medications or who are experiencing concomitant GERD symptoms.
“In our esophageal clinic, we assume reflux is the cause of adult-onset asthma until it’s proven otherwise and we now appear to have a much better tool to make that determination. Unfortunately, there are a lot of patients suffering with this condition who either never see a GERD specialist or have their condition misdiagnosed by conventional pH monitoring,” Dr. Jobe said.
“Hopefully this study will generate greater awareness among both patients and physicians about the role of GERD in adult-onset asthma , the availability of a potentially more reliable diagnostic therapy, and perhaps most importantly, the possibility of a surgical remedy for their condition,” he said.
Editors Note: This research was conducted by Dr. Jobe and his team while they were on staff at the University of Pittsburgh. They left the University in March, 2012 to join WPAHS.