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Scintigraphy finds oropharyngeal reflux, lung aspiration in GERD
Last Updated: 2015-04-01
By Larry Hand
NEW YORK (Reuters Health) - Scintigraphy is a simple, noninvasive way to detect subclinical oropharyngeal reflux and lung aspiration, Australian researchers say.
In 80 patients with gastroesophageal reflux disease (GERD) and 205 patients with laryngopharyngeal reflux (LPR), they found a surprising number with previously undetected pharyngeal contamination or pulmonary aspiration.
"We did not realize that reflux extending into the laryngopharyngeal region was so common and very often clinically silent," Dr. Hans Van der Wall, of Concord Nuclear Imaging in Sydney, told Reuters Health by email. "Silent lung aspiration of refluxate was also unexpectedly common, especially in patients with a chronic cough or change in voice where alternate causes could not be identified after more than two months of investigation by respiratory physicians."
As reported online March 3 in Nuclear Medicine Communications, researchers took dynamic gamma camera images with patients in the upright and supine positions after they had swallowed 100 ml of water and 40-60 MBq of the radiopharmaceutical Tc-DTPA.
Follow-up images taken two hours later showed that 22 patients in the GERD group (27.5%) had refluxed the tracer into the upper esophagus in the upright position and 41 (51.25%) did so in the supine position - including 39 with reflux into the pharynx. Eleven patients (13.75%) showed evidence of pulmonary aspiration.
In the LPR group, 84 patients (40.98%) refluxed the tracer into the upper esophagus during upright imaging, including 74 with reflux into the pharynx. On supine imaging, 142 patients (69.27%) refluxed into the upper esophagus, and 139 of these refluxed into the pharynx. Forty-eight patients (23.41%) had pulmonary aspiration.
Rates of lung aspiration were significantly lower in GERD than in LPR.
The authors also saw a significant 7.7-year age difference between GERD and LPR patients. "This suggests a much longer history of the disease in patients with LPR, which reflects the delay in diagnosis," they wrote. "Clinical awareness of the potential for silent LPR is a key factor just as it is in patients with ostensible GERD alone who may also have silent LPR."
"The significance in age difference between the groups is part of the problem of clinically identifying laryngopharyngeal reflux and lung aspiration," Dr. Van der Wall said. "We have published work indicating that the clinical history is not good at identifying these people early and the doctor must have a high index of suspicion of gastroesophageal reflux when considering a number of manifestations in other organ systems, especially in the lungs."
The findings have a number of implications, Dr. Van der Wall said. First, "A significant proportion of chronic cough and 'adult onset' asthma may be due to gastroesophageal reflux." Second, "A significant proportion of patients with bronciectasis may be aspirating refluxate, leading to lung damage." And third, "A significant proportion of patients with gastroesophageal reflux also have problems emptying the stomach of liquids."
"Gastroesophageal reflux is much more common than suspected," he concluded," and patients without an explanation for extra-esophageal symptoms such as sore throat, voice change, and cough should have this simple screening reflux test to evaluate the possibility of reflux. It has a low radiation exposure, is noninvasive and the only way of directly looking for laryngopharyngeal reflux and lung aspiration."
The study had no external funding.
Nucl Med Commun 2015.