New Endoscopic Method for GERD Diagnosis Shows High Accuracy

The gold standard for diagnosing gastroesophageal reflux disease (GERD) is impedance-pH monitoring. This test is particularly valuable when endoscopy doesn’t reveal esophagitis yet patients continue to experience refractory or recurrent symptoms or require invasive therapy.

This method comes with challenges, however. It’s costly, not always widely available, and requires the patient to wear a transnasal catheter for 24 hours. To address these drawbacks, international studies have explored a less intrusive alternative: Assessing esophageal mucosal impedance via catheter during endoscopy. This method was tested for the first time in Brazil, and promising results were published in July in the Journal of Neurogastroenterology and Motility.

The study was a part of Dr Rafael Bandeira Lages’ doctoral research in gastroenterology at the University of São Paulo under the supervision of Tomás Navarro Rodriguez.

Lages, Rodriguez, and their team evaluated 60 patients with typical GERD symptoms (eg, heartburn or regurgitation). All patients underwent impedance-pH monitoring, which was used as a reference to assess esophageal mucosal impedance via catheter during endoscopy. Measurements were taken at 2, 5, 10, and 18 cm above the esophagogastric junction.

Impedance: Diagnostic Thresholds

Patients without GERD, as determined by impedance-pH monitoring (acid exposure time ≤ 4%), exhibited significantly higher mucosal impedance values when measured during endoscopy at 2 and 5 cm above the esophagogastric junction. The highest sensitivity (96.4%) and specificity (87.5%) for ruling out GERD came from measurements taken at 2 cm.

In an interview with Medscape Medical News, Lages explained that impedance reflects the tissue’s resistance to electrical current. “The lower the mucosal impedance, the greater the tissue permeability, which likely indicates more damage from reflux in that region,” he noted.

The study indicated that impedance values higher than 2970 Ω at 2 cm from the esophagogastric junction were indicative of excluding GERD. These findings suggest this method as a promising alternative for diagnosing the condition.

In addition to being more comfortable for patients, this strategy may offer potential advantages. Lages noted that traditional methods, like impedance-pH and pH monitoring, assess a patient’s condition on the day of the test, which may slightly affect sensitivity. In contrast, mucosal impedance during endoscopy can identify chronic damage-related permeability, providing a more consistent diagnostic tool.

Clinical Application

While promising, direct evaluation of esophageal mucosal impedance measurement during endoscopy is not yet ready for widespread clinical use. “This is a concept gaining international traction, but it’s not fully validated yet,” Lages explained. He emphasized the need for further adaptations, especially to the system’s design, to ensure that it can be scaled up for everyday clinical use.

The researcher also noted the importance of other research groups replicating and validating the method to prove its applicability and effectiveness for diagnosing GERD.

This story was translated from the Medscape Portuguese edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.