Medical Policy: 02.01.03
Original Effective Date: September 2004
Reviewed: September 2018
Revised: September 2018
Benefit determinations are based on the applicable contract language in effect at the time the services were rendered. Exclusions, limitations or exceptions may apply. Benefits may vary based on contract, and individual member benefits must be verified. Wellmark determines medical necessity only if the benefit exists and no contract exclusions are applicable. This medical policy may not apply to FEP. Benefits are determined by the Federal Employee Program.
This Medical Policy document describes the status of medical technology at the time the document was developed. Since that time, new technology may have emerged or new medical literature may have been published. This Medical Policy will be reviewed regularly and be updated as scientific and medical literature becomes available.
Acid reflux is the cause of heartburn, acid regurgitation peptic esophagitis, and Barrett's esophagus, and can cause esophageal stricture, some cases of asthma, posterior laryngitis, chronic cough, dental erosions, chronic hoarseness, pharyngitis subglottic stenosis or stricture, nocturnal choking, and recurrent pneumonia.
Gastroesophageal reflux disease (GERD) is usually diagnosed by clinical history and endoscopy, and is treated empirically with a trial of medical management, of at least four weeks in adults and two weeks in infants, prior to the need for esophageal ph monitoring.
Esophageal monitoring is done through the use of a tube with a pH electrode attached to its tip, which is then passed to 5 cm above the upper margin of the lower esophageal sphincter (LES). The electrode is attached to a data logger worn on a waist belt or shoulder strap. Every instance of acid reflux as well as its duration and pH is recorded, indicating gastric acid reflux over a 24-hour period.
More recently, a catheter-free, temporarily implanted device (Bravo™ pH Monitoring System, marketed by Medtronic) has been approved by the U.S. Food and Drug Administration (FDA) for the purposes of esophageal monitoring in those 4 years old and greater. Using endoscopic or manometric guidance, the capsule is temporarily implanted in the esophageal mucosa using a pin. The capsule records pH levels for up to 96 hours and transmits them via radio frequency telemetry to a receiver worn in the patient's belt. Data from the recorder are uploaded to a computer for analysis by a nurse or doctor.
Another technology closely related to pH monitoring is impedance-pH monitoring, which incorporates pH monitoring with measurement of impedance, a method of measuring reflux of liquid or gas of any pH. Multiple electrodes are placed along the length of the esophageal catheter. The impedance pattern detected can determine the direction of flow and the substance (liquid or gas). Impedance monitoring is able to identify reflux events in which the liquid is only slightly acidic or non-acidic. The therapeutic treatment of an abnormal impedance test are unproven at this time. Therefore the need for testing is not proven at this time.
Multichannel Intraluminal Impedance (MII) technology was designed to allow characterization of bolus movement within the esophagus regardless of the pH level. It provides 2 testing modalities in the evaluation of GERD. Esophageal function testing (EFT) combines MII with standard pressure manometry.
The AGA's medical position statement on the management of Barrett's esophagus (2011) noted that "The guideline developers recommend against attempts to eliminate esophageal acid exposure (proton pump inhibitors [PPIs] in doses greater than once daily, esophageal pH monitoring to titrate PPI dosing, or antireflux surgery) for the prevention of esophageal adenocarcinoma (strong recommendation, moderate-quality evidence)".
In 2013, ACG published guidelines on the diagnosis and management of gastroesophageal reflux disease (GERD). The guidelines stated “ambulatory esophageal reflux monitoring is indicated before consideration of endoscopic or surgical therapy in patients with nonerosive disease, as part of the evaluation of patients refractory to PPI therapy, and in situations when the diagnosis of GERD is in question.” This was a strong recommendation based on a low level of evidence. The guidelines noted there is limited evidence and lack of clear consensus on how testing should be performed (eg, catheter-based pH, wireless pH, or impedance pH) for refractory GERD.
Esophageal manometry is recommended for preoperative evaluation, but has no role in the diagnosis of GERD (Strong recommendation, low level of evidence).
Ambulatory esophageal reflux monitoring is indicated before consideration of endoscopic or surgical therapy in patients with non-erosive disease, as part of the evaluation of patient’s refractory to PPI therapy, and in situations when the diagnosis of GERD is in question. (Strong recommendation, low level of evidence). Ambulatory reflux monitoring is the only test that can assess reflux symptom association (strong recommendation, low level of evidence).
Ambulatory reflux monitoring is not required in the presence of short or long-segment Barrett’s esophagus to establish a diagnosis of GERD (Strong recommendation, moderate level of evidence).
The ACG released practice guidelines on esophageal reflux testing. Impedance-pH monitoring was cited as “may be useful” for evaluation of patients with insufficient response to medical therapy. Current interpretation of impedance monitoring relies on use of symptom correlation measures (SI, SSI or SAP). The therapeutic implications of an abnormal impedance test are unproven at this time.
Ambulatory reflux monitoring is not required in the presence of short or long-segment Barrett’s esophagus to establish a diagnosis of GERD. (Strong recommendation, moderate level of evidence).
The National Institute for Health and Care Excellence released a technology appraisal guidance on catheterless esophageal pH monitoring in 2006. This guidance indicated catheterless esophageal pH monitoring appears to be safe and effective and is commonly indicated for GERD symptoms refractory to PPIs and for GERD symptom recurrence after antireflux surgery.
In 2015, the Institute published recommendations on the diagnosis and management of GERD in children and young people. The recommendations specific to esophageal pH monitoring included:
Consider performing an esophageal pH study (or combined esophageal pH and impedance monitoring if available) in infants, children and young people with:
Consider performing an esophageal pH study without impedance monitoring in infants, children and young people if, using clinical judgement, it is thought necessary to ensure effective acid suppression.”
Esophageal pH monitoring using a catheter-based system or catheter-free, wireless esophageal monitoring may be considered medically necessary for the following clinical indications in adults and adolescents, or children able to report symptoms:
24-hour catheter-based esophageal pH monitoring may be considered medically necessary in infants or children who are unable to report or describe symptoms of reflux with at least one of the following clinical indications:
The Bravo pH Monitoring System is considered investigational for evaluation in those under 4 years old, because it has not been FDA approved for use in this age group.
Esophageal pH monitoring is not medically necessary for all other indications, including, but not limited to any of the following indications because its effectiveness has not been established:
Regular use of catheter-based impedance-pH monitoring is considered not medically necessary. There is not evidence that the results of testing changes treatment. Currently only a very weak recommendation exists regarding further treatment after impedance-pH testing.
Esophageal impedance in combination with pH monitoring in the evaluation of GERD is not medically necessary. Given the lack of a criterion standard, evidence supporting the use of impedance-pH testing is inconclusive. Although impedance-pH testing may increase positive tests or diagnostic yield, the potentially increased sensitivity may be accompanied by a decrease in specificity and the net effect on patient management and patient outcomes is not certain. There is a lack of comparative studies showing that impedance-pH monitoring is more useful than existing techniques to diagnose and/or treat GERD. In patients with GERD symptoms refractory to PPI therapy, 24 hour pH testing, not impedance testing, is considered the gold standard method to diagnose/confirm reflux.
At this time, the limited studies on catheter based-pH monitoring are unable to show outcomes that prove there is an overall impact on clinical management as a first line surveillance tool.
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