Medical Policy: 02.01.03
Original Effective Date: September 2004
Reviewed: September 2020
Revised: September 2020
This policy contains information which is clinical in nature. The policy is not medical advice. The information in this policy is used by Wellmark to make determinations whether medical treatment is covered under the terms of a Wellmark member's health benefit plan. Physicians and other health care providers are responsible for medical advice and treatment. If you have specific health care needs, you should consult an appropriate health care professional. If you would like to request an accessible version of this document, please contact customer service at 800-524-9242.
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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.
When acid repeatedly refluxes from the stomach into the esophagus alone, it is known as gastroesophageal reflux disease (GERD). However, if the stomach acid travels up the esophagus and spills into the throat or pharynx/larynx, is known as laryngopharyngeal reflux (LPR).
Gastroesophageal reflux disease (GERD) is usually diagnosed by clinical history and endoscopy, it 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 is 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. Combined multichannel intraluminal impedance with esophageal manometry (MII-EM) is a test of esophageal function as it provides information about both pressures and bolus transit within the esophagus. In context of esophageal bolus transit, measurement of bolus clearance with internal impedance does not determine the abnormal functioning of the esophagus, especially in terms of minor malformations. The role of MII-EM in the diagnosis of extra-esophageal disorders related to gastroesophageal reflux disease has not been established.
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 functional luminal imaging probe is a Food and Drug Administration–approved measurement tool used to measure simultaneous pressure and diameter to guide management of various upper gastrointestinal disorders. Additionally, this tool is also approved to guide therapy during bariatric procedures and specialized esophageal surgery. Although it has been commercially available since 2009 as the endolumenal functional lumen imaging probe (EndoFLIP), the functional luminal imaging probe has had limited penetrance into clinical settings outside of specialized centers. This is primarily because of a paucity of data supporting its utility in general practice and a lack of standardized protocols and data analysis methodology. However, data are accumulating that are providing guidance regarding emerging applications in the evaluation and management of foregut disorders. This clinical practice update describes the technique and reviews potential indications in achalasia, eosinophilic esophagitis, and gastroesophgeal reflux disease.
Best Practice Advice 1: Clinicians should not make a diagnosis or treatment decision based on functional lumen imaging probe (FLIP) assessment alone.
Best Practice Advice 2: FLIP assessment is a complementary tool to assess esophagogastric junction opening dynamics and the stiffness of the esophageal wall.
Best Practice Advice 3: Utilization should follow distinct protocols and analysis paradigms based on the disease state of interest.
Best Practice Advice 4: Clinicians should not utilize FLIP in routine diagnostic assessments of gastroesophageal reflux disease.
Best Practice Advice 5: FLIP should not be used to diagnose eosinophilic esophagitis but may have a role in severity assessment and therapeutic monitoring.
The American College of Gastroenterology (ACG; 2007) released practice guidelines on esophageal reflux testing informed by a review of the literature up to 2006. Although the literature on wireless pH testing was extensively reviewed, the recommendations for testing made no distinction between wireless and traditional pH monitoring. An indirect endorsement of wireless monitoring might be inferred from a statement that a 48-hour study would produce a greater diagnostic yield from a symptom-association test. Symptom-association tests require statistical testing of the data, and a 48-hour test produces more data points. However, these statistical correlation tests are not perfect, because the guidelines stated that such measures “do not ensure a response to either medical or surgical antireflux therapies.” No studies were cited that indicated superior outcomes for patients for treatment guided by wireless pH testing vs traditional pH testing. The major advantage for the wireless system cited was patient tolerability.
Impedance pH monitoring was cited as “may be useful” (a lower category of recommendation than for pH monitoring) for evaluation of patients with insufficient response to medical therapy in whom documentation of nonacid reflux would alter clinical management. Moreover, ACG suggested that impedance monitoring has a greater yield for findings than pH monitoring when performed on proton pump inhibitor (PPI) therapy. The last statement of the guidelines specified that the implications of an abnormal impedance test are unproven at this time.
ACG (2013) 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 ACG guidelines noted there was 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.
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).
In terms of objective investigations for OD, there are 5 main exams cited in the literature (functional endoscopic evaluation of swallowing (FEES), video fluoroscopic swallowing study (VFSS), esophageal manometry, pharyngeal pH monitoring, esophageal impedance pH monitoring). FEES and VFSS are considered the 2 most informative exams, allowing the identification of patients at risk for aspiration pneumonia. FEES is more practical to perform in the clinical setting given that the only material requirement is a fiberoptic laryngoscope.
Recommendation 1: for the objective investigation of OD, it is recommended to systematically perform either a FEES or VFSS, FEES being the preferred initial investigation given its increased ease of use.
There is no further mention or recommendation of the use of impedance monitoring in the assessment of dysphagia.
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 electrodes are considered class I devices by the U.S. Food and Drug Administration (FDA) and are exempt from 510(k) requirements. A catheter-free, temporarily implanted device (Bravo™ pH Monitoring System; Medtronic, now Given Imaging) was cleared for marketing by FDA through the 510(k) process for the purpose of “gastroesophageal pH measurement and monitoring of gastric reflux in adults and children from 4 years of age.”
Several wireless and catheter-based (wired) esophageal pH monitoring devices have been cleared for marketing by FDA through the 510(k) process. Examples include the Bravo™ pH Monitoring System (Given Imaging), the Sandhill Scientific PediaTec™ pH Probe (Sandhill Scientific), the ORION II Ambulatory pH Recorder (MMS, Medical Measurement Systems), and the TRIP CIC Catheter (Tonometrics).
Esophageal pH monitoring (91034/91035) 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 (91037/91038) 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. There is lack of literature to support the use of impedance testing.
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.
Multichannel intraluminal impedance (MII) in the evaluation of GERD, achalasia, and laryngo-pharyngeal reflux is considered not medically necessary because there is inadequate evidence in the peer-reviewed published literature proving its effectiveness in management or treatment recommendations.
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