Endoflip® diagnostic technology offers a more complete view of digestive diseases than existing diagnostic procedures. You may find the following article useful in explaining to your patients what Endoflip® is and how is it used by clinicians to diagnose and treat symptoms of achalasia, dysphasia and GERD?
The following article has been adapted from the original, with the kind permission of Joel Rubenstein, M.D., M.Sc., Associate Professor, Division of Gastroenterology, University of Michigan.
Endoflip® (endolumenal functional lumen imaging probe) is a newer, minimally invasive device created to complement traditional diagnostic tests, such as high resolution esophageal manometry (HRM) and barium esophagram.
Both of the traditional diagnostic tests are useful in most cases. The esophagram visually demonstrates the clearance of the bolus – swallowed material – from the esophagus. And while manometry measures the strength of contraction in the esophagus, the probe is very thin and may not accurately represent the mechanics of the esophagus in response to a bolus of food.
Endoflip® uses a balloon mounted on a thin catheter placed transorally at the time of a sedated endoscopy. In comparison to the traditional diagnostic tests, Endoflip® offers the additional capability of measuring the cross-sectional area and intraluminal pressure of the esophagus while under distension (as if a solid bolus was present). The technology uses impedance planimetry to estimate cross-sectional area.
How it works
During an upper endoscopy (EGD), a catheter is passed transorally into the stomach. A balloon attached to the catheter is inflated with a specific concentration of solution with known ionic properties to various volumes.
A small electrical current is passed through an electrode located on the catheter inside the balloon. The current can only pass to its paired electrode through the solution to the balloon. The voltage gradient between the pair of electrodes is inversely proportional to the cross-sectional area at the midpoint between the pair of electrodes.
The catheter has multiple pairs of electrodes along its length which are sequentially activated.
Simultaneously, the pressure in the balloon is measured. Software calculates the distensibility index (the ratio of the cross-sectional area to the pressure). Data is manually revised after the procedure.
The University of Michigan presented its results of a systematic review at Digestive Diseases Week 2015 on what thresholds of distensibility of the esophagogastric junction should be used for diagnosing achalasia.
Importantly, they found that the distensibility of the esophagogastric junction in patients following successful fundoplication for gastroesophageal reflux disease (GERD) is similar to that in patients with achalasia. This means that the distensibility of the esophagogastric junction needs to be interpreted in the context of the demonstrated motility of the body of esophagus. This highlights the clinical pearl that patients being considered for fundoplication for regurgitation symptoms should routinely undergo esophageal manometry pre-operatively to exclude aperistalsis in the body of the esophagus, as such patients would be at high risk for dysphagia following fundoplication.