RetiredUnitedHealthcarePolicy CS046LA.P

Medical Policy — Gastric electrical stimulation and related gastrointestinal motility diagnostic procedures

This medical policy governs coverage and medical necessity determinations for gastric electrical stimulation (GES) therapy and several gastrointestinal motility diagnostic procedures for members in Louisiana. It affects providers seeking authorization or reimbursement for GES implantation and specified diagnostic tests.

Policy Summary

PayerUnitedHealthcare

PolicyGastric electrical stimulation and related gastrointestinal motility diagnostic procedures

Policy CodePolicy CS046LA.P

Change TypeRetirement with coding and coverage clarifications

Effective DateNov 1, 2025

Next Review DateN/A

Key ActionObtain prior authorization and document medically refractory gastroparesis with objective delayed gastric emptying and prior failed therapies before requesting GES.

SourceLink

POLICY UPDATE CHANGES

Added language that Esophageal Mucosal Integrity Testing by electrical impedance (e.g., MiVu™ Mucosal Integrity Testing System) for diagnosis of GERD, EoE, and nonacid reflux or for monitoring treatment response is unproven and not medically necessary due to insufficient evidence.

Removed language indicating rectal manometry, rectal sensation, tone, and compliance test, conventional defecography, and anorectal manometry are proven and medically necessary for evaluation of colorectal function.

Removed language that colonic manometry for evaluating colon motility is unproven and not medically necessary.

Removed language that ingestible vibrating capsule devices (e.g., the Vibrant® System) for constipation are unproven and not medically necessary.

Added CPT codes 43499 and 76498 to Applicable Codes.

Removed CPT/HCPCS codes 74270, 76496, 91117, 91120, 91122, A9286, A9900, A9999, and E1399 from Applicable Codes.

Added definition of 'Esophageal Mucosal Integrity Testing'.

Removed definitions of Anorectal Manometry, Colonic Manometry, and Defecography.

Retired policy for Louisiana plan membership disenrolled on Apr. 1, 2026.

04/01/2026Policy retirement date (LA)

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

9CPT/HCPCS codes removed

Louisiana onlyGeographic applicability

12Studies in Hayes HTA for GES

Coverage Criteria and Medical Necessity

GES — Medically Necessary Indication

Covered when ALL of the following are met

GES coverage criteria: GES therapy is proven and medically necessary for treating refractory gastroparesis that has failed other therapies, or chronic intractable (drug-refractory) nausea and vomiting secondary to gastroparesis of diabetic or idiopathic etiology.

Implied requirement: prior failure of other therapies

Conditional coverage considerations for GES

Covered when ALL of the following are met (guidance-derived conditional criteria):

Refractory disease: Patient has medically refractory gastroparesis or intractable nausea and vomiting after standard therapies have failed.

Supported by ACG/AGA statements that GES may be considered for medically refractory diabetic or idiopathic gastroparesis and for patients who have failed standard therapy.

Documentation of objective and symptom assessments: Baseline and follow-up symptom severity assessments (e.g., TSS, GCSI/PAGI-SYM) and prior therapy documentation are available.

Needed because studies and systematic reviews emphasize symptom scores and prior therapy details in assessing benefit.

Patient selection considerations: Selected patient characteristics (for example, diabetic or postsurgical etiology) may be preferred because some studies showed greater benefit in these subgroups compared with idiopathic cases.

Observed in cohort and case series findings and highlighted in guideline discussions.

Appropriate use criteria for MR defecography

Use of MR defecography is appropriate when ALL of the following are met:

Indication for MRD: Clinical features suggest a pelvic floor structural or evacuation disorder and initial anorectal manometry (ARM) and balloon expulsion testing (BET) are inconclusive or further anatomic detail is needed for preoperative planning.

Consistent with AGA/AGA/ASCRS guidance that MRD is useful when results are inconclusive or for preoperative anatomical assessment.

Technique requirement: MR defecography includes an evacuation-phase imaging component because inclusion of evacuation-phase imaging improves sensitivity for rectocele and enterocele.

Meta-analysis and comparative studies report higher sensitivity when evacuation-phase MRD is performed versus without evacuation.

Coverage stance for EGG/BSGM

Coverage stance for EGG/BSGM:

Not established clinical utility: Electrogastrography (EGG) and body surface gastric mapping (BSGM) lack convincing evidence that their diagnostic findings translate to improved patient-relevant outcomes; clinical utility and standardized protocols are not yet established.

ECRI and systematic reviews conclude very low to heterogeneous evidence and call for standardized procedures and further validation.

Evidence-based findings (no explicit coverage criteria provided in this document portion)

Evidence indicates the following findings from recent studies and systematic reviews:

EGG/BSGM evidence summary: Systematic reviews and multiple observational and validation studies report that patients with gastroparesis and related gastroduodenal disorders commonly have altered gastric myoelectrical activity (reduced normogastria; increased bradygastria/tachygastria; rhythm instability). BSGM demonstrates improved symptom correlations and higher patient-level classification accuracy compared with traditional cutaneous EGG and can enhance phenotyping versus gastric emptying testing (GET).

Clinical utility (improved patient outcomes) has not been demonstrated; studies are limited by heterogeneity, small cohorts, evolving reference values, and lack of outcome data.

Esophageal mucosal impedance evidence summary: Balloon and catheter-based mucosal impedance testing show distinct MI patterns that can differentiate GERD, EoE, and non-GERD in small prospective and retrospective studies, and the MiVu system has received De Novo clearance; however, evidence is limited and clinical utility (impact on outcomes) remains unproven.

Hayes and ECRI reviews call for additional clinical validity and utility studies despite promising diagnostic accuracy signals in small studies.

Unproven / Not Medically Necessary

Not medically necessary statements

Esophageal Mucosal Integrity Testing (electrical impedance): Esophageal Mucosal Integrity Testing by electrical impedance (e.g., MiVu™) for diagnosis of GERD, eosinophilic esophagitis (EoE), nonacid reflux, or for monitoring treatment response is unproven and not medically necessary due to insufficient evidence.

Added to Coverage Rationale and supported by evidence reviews noting limited, low-quality studies and lack of demonstrated clinical utility.

Other unproven procedures: Magnetic resonance defecography for evaluation of constipation and anorectal/pelvic floor disorders and cutaneous/mucosal/serosal electrogastrography, electroenterography, or body surface gastric mapping as standalone diagnostic tests to guide therapy are considered unproven and not medically necessary when intended to change management without evidence of improved patient outcomes.

Policy lists these procedures as unproven and not medically necessary due to insufficient evidence of efficacy.

Magnetic Resonance Imaging (MRI) defecography is listed in this policy as an unproven technique for the evaluation of constipation and anorectal or pelvic floor disorders when used as a substitute for established diagnostic pathways. The policy states that MRI defecography is among procedures deemed unproven and not medically necessary due to insufficient evidence of efficacy for these indications, and that fluoroscopic defecography or evacuation-phase testing remain the reference standards when those tests are available and indicated.

Electrogastrography (EGG) and Body Surface Gastric Mapping (BSGM) are excluded as standalone diagnostic tests to guide therapy when there is no evidence that their use improves patient-relevant outcomes. The policy explains that available studies do not demonstrate convincing diagnostic accuracy tied to improved management or outcomes, and that standardized recording, analysis, and interpretation protocols and clinical utility studies are needed before these tests can be recommended for routine clinical decision-making.

The Enterra™ gastric electrical stimulation system is an FDA Humanitarian Device Exemption (HDE)–labeled therapy for chronic, intractable (drug-refractory) nausea and vomiting secondary to diabetic or idiopathic gastroparesis in adults. Per the FDA labeling cited in this policy, the device should not be used in patients with gastric obstruction or pseudo-obstruction, prior gastric resection, fundoplication, eating disorders, history of seizures, primary swallowing disorders, chemical dependency, or psychogenic vomiting.

This policy segment was retired for Louisiana plan membership effective 04/01/2026; Louisiana plan membership was disenrolled on that date as noted in the policy history and revision information.

The policy explicitly lists several diagnostic procedures as unproven and not medically necessary because the available evidence is insufficient to demonstrate effectiveness. Examples named in the coverage rationale include MRI defecography; cutaneous, mucous, or serosal electrogastrography, electroenterography, or body surface gastric mapping for diagnosing intestinal or gastric disorders (including gastroparesis); and esophageal mucosal integrity testing by electrical impedance (e.g., MiVu™) for diagnosis or monitoring of GERD, EoE, or nonacid reflux.

Gastric Electrical Stimulation (GES) remains of uncertain effectiveness in some respects because randomized, blinded trial data are limited and inconsistent. The policy notes that while many nonrandomized studies report symptom improvement, randomized evidence is small and heterogeneous; therefore, GES may be considered not medically necessary when the policy’s criteria for refractory disease and required documentation are not met or when evidence does not support consistent patient benefit.

Evidence reviewers concluded that clinical utility for Gastric Electrical Stimulation and related electrophysiologic diagnostic tests is unproven for many indications because studies have not consistently demonstrated improvements in patient-relevant outcomes. The policy summarizes HTA and systematic review findings that emphasize low-to-moderate quality evidence, methodological heterogeneity, and a need for additional randomized and clinical utility studies before routine coverage can be supported.

Esophageal Mucosal Integrity Testing by electrical impedance (for example, the MiVu™ Mucosal Integrity Testing System) is described in this policy as an emerging technology without convincing evidence of clinical effectiveness. The policy states that current studies are limited and do not establish that MI testing is safe and effective for diagnosing GERD, eosinophilic esophagitis (EoE), or nonacid reflux, or for monitoring treatment response, and therefore classifies this testing as unproven and not medically necessary.

Applicable Procedure and Billing Codes

Applicable procedure codesCPT

0779T	Gastrointestinal myoelectrical activity study, stomach through colon, with interpretation and report.
0868T	High-resolution gastric electrophysiology mapping with simultaneous patient-symptom profiling, with interpretation and report.
43499	Unlisted procedure, esophagus.
43647	Laparoscopy, surgical; implantation or replacement of gastric neurostimulator electrodes, antrum.
43648	Laparoscopy, surgical; revision or removal of gastric neurostimulator electrodes, antrum.
43881	Implantation or replacement of gastric neurostimulator electrodes, antrum, open.
43882	Revision or removal of gastric neurostimulator electrodes, antrum, open.
64590	Insertion or replacement of peripheral, sacral, or gastric neurostimulator pulse generator or receiver, requiring pocket creation and connection between electrode array and pulse generator or receiver.
64595	Revision or removal of peripheral, sacral, or gastric neurostimulator pulse generator or receiver, with detachable connection to electrode array.
72195	Magnetic resonance (e.g., proton) imaging, pelvis; without contrast material(s).

1–10 of 15

1/2

Added CPT CodesCPT

43499	CPT code added (unspecified procedure, digestive system)
76498	CPT code added (unspecified diagnostic radiology procedure)

Removed CPT/HCPCS Codesmixed

74270	Removed CPT/HCPCS code
76496	Removed CPT/HCPCS code
91117	Removed CPT/HCPCS code
91120	Removed CPT/HCPCS code
91122	Removed CPT/HCPCS code
A9286	Removed HCPCS code
A9900	Removed HCPCS code
A9999	Removed HCPCS code
E1399	Removed HCPCS code

Provider Requirements, Prior Authorization, and Documentation

Prior Authorization

Prior Authorization Required

Prior authorization may be required for gastric electrical stimulation (GES) implantation, related neurostimulator device procedures, and specialized gastric electrophysiology testing. When prior authorization is required, documentation should demonstrate medically refractory gastroparesis, failure of standard therapies (step therapy), and objective supportive testing.

GES implantation and neurostimulator procedures (e.g., CPT 43647, 43648, 43881, 43882, 64590, 64595) may require prior authorization
Specialized electrophysiology tests (e.g., CPT 0779T, 0868T, 91132–91133) may require prior authorization

Documentation Required

GES Prior Authorization Documentation Expectations

Prior authorization requests for GES should include evidence of medically refractory gastroparesis: failed standard medical therapies, symptom severity scales, and objective testing demonstrating delayed gastric emptying per validated protocols.

Definitions and Terminology

Electrogastrography (EGG)

DefinitionElectrogastrography (EGG) is a non-invasive method for recording gastric myoelectrical activity using cutaneous abdominal electrodes; the surface recording is called an electrogastrogram.

PurposeUsed to identify abnormalities in gastric slow waves (dysrhythmia, abnormal propagation) and to phenotype gastric myoelectrical activity in motility disorders.

LimitationsThere is lack of one-to-one correlation between myoelectrical spikes and contractions; EGG does not reliably detect contractile abnormalities and clinical utility to improve patient outcomes is unproven.

Gastroparesis

DefinitionGastroparesis is a digestive disorder in which stomach motility is abnormal or absent; also known as delayed gastric emptying.

Clinical features

Background and Clinical Context

Gastroparesis is a disorder of delayed gastric emptying that commonly causes nausea, vomiting, early satiety, bloating, and abdominal pain and is frequently seen in patients with diabetes. Diagnosis requires objective demonstration of delayed gastric emptying (radioscintigraphy is the reference standard in studies cited) and adherence to validated, standardized testing protocols. The policy emphasizes that invasive therapies such as GES are intended for selected patients with documented, medically refractory disease after conservative therapies have failed, and that appropriate diagnostic documentation and follow-up measures (symptom scores, gastric emptying testing) are necessary to support treatment decisions.

Policy Changes and Revision History

2026-04-01retirementLatest

Policy retired for Louisiana plan membership (membership disenrolled).

2025-11-01material_revision

Added statement that Esophageal Mucosal Integrity Testing by electrical impedance (e.g., MiVu™) for diagnosis of GERD, EoE, and nonacid reflux or for monitoring treatment response is unproven and not medically necessary; removed multiple prior coverage statements and several procedure definitions; added CPT codes 43499 and 76498 and removed CPT/HCPCS codes 74270, 76496, 91117, 91120, 91122, A9286, A9900, A9999, and E1399; updated Description of Services, Clinical Evidence, FDA, and References sections.

Policy Summary

PayerUnitedHealthcare

PolicyGastric electrical stimulation and related gastrointestinal motility diagnostic procedures

Policy CodePolicy CS046LA.P

Change TypeRetirement with coding and coverage clarifications

Effective DateNov 1, 2025

Next Review DateN/A

Key ActionObtain prior authorization and document medically refractory gastroparesis with objective delayed gastric emptying and prior failed therapies before requesting GES.

SourceLink

On This Page

Documentation of failed standard therapies and stepwise treatment attempts prior to GES
Objective evidence of delayed gastric emptying (scintigraphy GET per standardized protocol)
Symptom severity scores (e.g., Total Symptom Score [TSS], GCSI), vomiting/nausea frequency, and prior hospitalization days

Prior Authorization

Enterra HDE Oversight and Authorization

Enterra Therapy is marketed under an FDA Humanitarian Device Exemption (HDE) and may only be used in facilities with Institutional Review Board (IRB) oversight per FDA HDE requirements. Prior authorization and facility oversight checks should reflect the HDE labeling and IRB requirements.

Enterra™ is approved under an HDE for chronic intractable (drug-refractory) nausea and vomiting secondary to diabetic or idiopathic gastroparesis (ages 18–70)
Facilities must have IRB approval to use HDE devices and document IRB oversight when seeking authorization

Note

Verify Prior Authorization per Plan

Verify prior authorization requirements and any external utilization management criteria (e.g., InterQual®) for the specific member and benefit plan before proceeding. Federal, state, or contractual plan terms override this policy when conflicts exist.

Check the member’s benefit plan and any third-party tools used by UnitedHealthcare (for example, InterQual) prior to scheduling
In case of conflict, federal, state, or contractual benefit requirements govern coverage decisions

Denial Risk

Denial Risk for Unproven Procedures

Some procedures and tests described in this policy are considered unproven or not medically necessary and are at risk for denial. Claims lacking evidence of clinical benefit or failing to meet established coverage criteria may be denied.

Unproven/not medically necessary examples include MRI defecography for constipation/pelvic floor disorders, cutaneous/mucosal/serosal electrogastrography or body surface gastric mapping for diagnosis, and certain manometry modalities
Esophageal Mucosal Integrity Testing by electrical impedance (e.g., MiVu™) is listed as unproven and not medically necessary

Denial Risk

Evidence Uncertainty May Trigger Denial

When the evidence base is limited, inconsistent, or of low quality, reviewers may deny authorization. For GES, uncertainty about consistent clinical benefit and device-related complications are grounds to require additional documentation or to deny coverage.

Limited randomized blinded data and inconsistent findings for GES efficacy may trigger denial or conditional approval
Device-related risks (e.g., lead/stimulator migration, infection, device removal rates) should be addressed in authorization requests

Denial Risk

Denial Risk for Electrophysiology and Impedance Testing

Tests described as investigational or lacking demonstrated clinical utility (for example, electrogastrography/BSGM and impedance mucosal testing) are at higher risk of denial unless clear evidence shows that their use changes management and improves outcomes.

Electrogastrography/BSGM: clinical utility and effect on outcomes are not established; lack of demonstrated benefit may lead to non-coverage or conditional coverage only
Esophageal mucosal electrical impedance testing (e.g., MiVu™) is unproven and may be denied

Documentation Required

BSGM/EGG Testing Expectations

Studies of body surface gastric mapping (BSGM) and electrogastrography (EGG) typically include pretest clinical work-up and standardized pretest preparation; authorization or documentation should mirror these expectations when such testing is considered.

Pretest work-up often includes upper endoscopy to exclude alternative pathology
Patients in studies withheld motility-altering medications for ~48 hours, completed overnight fasting, and avoided caffeine, nicotine, opioids, and cannabis on the test day
Testing protocols in studies included baseline fasting recordings, standardized meals (e.g., 99mTc-labelled egg or specified caloric meal), and multi-hour postprandial recordings

Step Therapy

Step Therapy and Patient Selection Prior to GES

Stepwise treatment is expected before considering GES. GES is generally considered medically necessary only for refractory gastroparesis after failure of standard medical therapy and in selected patients with chronic intractable, drug-refractory symptoms.

Document prior trials of dietary modifications, prokinetic agents, antiemetics, and other standard therapies
Exclude opioid-related causes of symptoms when considering GES (per AGA guidance)

Documentation Required

Suggested Documentation Elements for GES

Authorization and follow-up documentation for GES should include longitudinal outcome measures and device safety information to support continued coverage decisions.

Long-term follow-up data, including duration of benefit and device-related complications
Symptom severity scores (TSS, GCSI), vomiting/nausea frequency, changes in hospitalization days, nutritional status, and medication use
Documentation of device removals, infections, lead migration, and other adverse events

Note

AGA Guidance on EGG/BSGM

UnitedHealthcare and guideline bodies note that AGA does not recommend routine use of EGG for diagnosis of gastroparesis; the 2004 position and 2022 update remove prior endorsement of EGG, so use EGG/BSGM cautiously and document how results will change management.

AGA (2004; 2022 update) does not recommend routine EGG for gastroparesis diagnosis
If EGG/BSGM is ordered, include rationale linking test results to intended clinical management

Common symptoms include nausea, vomiting, early satiety, bloating, and abdominal pain; objective demonstration of delayed gastric emptying is required for diagnosis.

Diagnostic standardGastric emptying testing (e.g., standardized 2- and 4-hour scintigraphy after a low-fat meal) is used to demonstrate delayed gastric emptying.

MRI Defecography

DefinitionMagnetic Resonance (MR) Defecography is a noninvasive MRI-based test obtaining images at various stages of defecation to evaluate pelvic floor anatomy, dynamic motion, and rectal evacuation.

Clinical useUsed to assess structural and functional pelvic floor disorders and can evaluate anatomy and dynamic motion simultaneously for preoperative planning or when other tests are inconclusive.

Technique noteInclusion of an evacuation-phase imaging component increases sensitivity for detecting rectocele and enterocele compared with MRI without evacuation phase.

Humanitarian Use Device (HUD)

DefinitionHumanitarian Use Device (HUD): an FDA designation for devices intended to benefit patients with rare conditions; referenced for GES (Enterra) as an HUD for medically refractory diabetic or idiopathic gastroparesis.

Regulatory implicationHUD-labeled devices have specific indications and institutional oversight (e.g., IRB) requirements for use per FDA labeling and guidance.

Evidence contextACG guidance states GES may be considered as a HUD for medically refractory diabetic or idiopathic gastroparesis based on low-quality evidence.

Evacuation-phase MR defecography

DefinitionEvacuation-phase MR defecography refers to MR defecography performed with an evacuation-phase imaging component to capture dynamic evacuation.

Diagnostic advantageEvacuation-phase MRD has higher sensitivity for rectocele and enterocele detection than MRD without evacuation phase and approaches sensitivity of evacuation proctography for some findings.

RoleShould be included when MRD is performed to improve detection of posterior pelvic floor disorders and for preoperative anatomical assessment.

BSGM — Body Surface Gastric Mapping

DefinitionBody Surface Gastric Mapping (BSGM) is a high-resolution, noninvasive technique using multi-electrode surface arrays and analytics to record and map gastric myoelectrical activity and produce spectral and spatial biomarkers.

Clinical applicationBSGM is used to phenotype gastroduodenal disorders, improve symptom correlations, and detect motility abnormalities (higher detection rates vs GET in some studies).

LimitationsAlthough BSGM shows improved classification accuracy versus traditional EGG, clinical utility demonstrating improved patient outcomes remains unproven and protocols vary across studies.

MI testing (MiVu) — Mucosal integrity testing

DefinitionMucosal integrity (MI) testing (MiVu) refers to measurement of esophageal mucosal integrity by electrical impedance using balloon or catheter devices during endoscopy to assess epithelial integrity patterns associated with GERD and EoE.

Regulatory statusThe MiVu Mucosal Integrity Testing System received FDA De Novo clearance (Class II) in 2019 and a 510(k) in 2023 (K230056).

Evidence and limitationPublished studies are limited in number and quality; existing evidence does not convincingly demonstrate safety, effectiveness, or clinical utility for diagnosis or monitoring of GERD or EoE.

Esophageal Mucosal Integrity Testing

DefinitionEsophageal Mucosal Integrity Testing describes electrical impedance testing systems (e.g., MiVu™ Mucosal Integrity Testing System) used during endoscopy to assess esophageal mucosal/epithelial integrity as an adjunct to differentiate GERD, EoE, and nonacid reflux.

Clinical intentIntended as an adjunct alternative to prolonged pH monitoring and biopsies to speed diagnostic differentiation between GERD, non-GERD, and EoE.

Coverage stanceThis policy considers esophageal mucosal integrity testing by electrical impedance unproven and not medically necessary for diagnosing GERD, EoE, nonacid reflux, or for monitoring treatment response due to insufficient evidence.