Gastric Electrical Stimulation for Abdominal Pain in Patients With Gastroparesis (HEAL)

April 28, 2026 updated by: Thomas Abell, University of Louisville
Gastroparesis is a disorder characterized by delayed gastric emptying and symptoms including nausea, vomiting, and abdominal pain. Gastric electrical stimulation (GES) using the implanted Enterra™ neurostimulator is FDA-approved to treat nausea and vomiting but its impact on abdominal pain has not been well studied. This study evaluates whether alternative programming parameters of the Enterra™ device can reduce abdominal pain in patients with gastroparesis. Participants with an existing Enterra™ device will be randomized to one of three stimulation settings and followed for assessment of pain, gastrointestinal symptoms, quality of life, and medication use.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

This is a multicenter, randomized, double-blind, active-controlled, three-arm parallel clinical trial in adults with gastroparesis who have an implanted Enterra™ gastric neurostimulator. All participants will complete a two-week run-in period using their baseline clinical device settings prior to randomization. Participants will then be randomly assigned in a 1:1:1 ratio to one of three gastric electrical stimulation parameter sets: standard nominal parameters (active control), special short-cycle parameters, or modified Enterra parameters delivered continuously. Participants will remain on their assigned blinded settings for eight weeks, during which validated patient-reported measures of abdominal pain, gastroparesis symptoms, quality of life, and pain medication use will be collected. After completion of blinded endpoint assessments, participants may select their preferred settings for an additional eight-week follow-up period. Optional substudy assessments include gastric function testing, inflammatory biomarker analysis, and autonomic nervous system testing.

Study Type

Interventional

Enrollment (Estimated)

150

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Kentucky
      • Louisville, Kentucky, United States, 40202
        • University of Louisville Clinical Trials Unit
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged 18 years or older.
  • Diagnosed gastroparesis.
  • Implanted Enterra™ device for at least 8 weeks prior to enrollment.
  • Chronic daily abdominal pain of gastric origin lasting more than 2 months.
  • Average pain score ≥4 on a 0-10 scale.
  • Ability to provide informed consent.

Exclusion Criteria:

  • Daily opioid use.
  • Pregnancy or breastfeeding.
  • Abdominal pain not attributed to gastric/visceral origin.
  • Severe constipation or uncontrolled diabetes (HbA1c >10).
  • Other medical conditions that would interfere with study participation.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Nominal GES Parameters
Continuous 24-hour gastric electrical stimulation using participants' standard clinically prescribed Enterra™ settings.
Device: Enterra™ neurostimulator
Gastric Electrical Stimulation using implanted Enterra™ neurostimulator with protocol-specified programming parameters.
Experimental: Special Parameter GES
Short-cycle stimulation (0.3 seconds on / 0.2 seconds off; 0.24 ms pulse width; 100 Hz frequency; 4-6 mA amplitude) delivered for one hour every eight hours, with nominal settings used during remaining time.
Device: Enterra™ neurostimulator
Gastric Electrical Stimulation using implanted Enterra™ neurostimulator with protocol-specified programming parameters.
Experimental: Modified Enterra Parameters
Continuous 24-hour stimulation (3 seconds on / 2 seconds off; 0.33 ms pulse width; 14 Hz frequency; 15-20 mA amplitude).
Device: Enterra™ neurostimulator
Gastric Electrical Stimulation using implanted Enterra™ neurostimulator with protocol-specified programming parameters.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Abdominal Pain Score
Time Frame: Baseline to 8 weeks after randomization.
Change from baseline in seven-day average of daily worst abdominal pain score measured using an 11-point Numeric Rating Scale (0 = no pain, 10 = worst possible pain).
Baseline to 8 weeks after randomization.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Gastroparesis Cardinal Symptom Index score
Time Frame: From baseline to 8 weeks after randomization
Change in Gastroparesis Cardinal Symptom Index (GCSI) score from baseline to 8 weeks after randomization. The Gastroparesis Cardinal Symptom Index (GCSI) is a patient-reported tool measuring the severity of gastroparesis symptoms over 2 weeks, assessing 9 items group into 3 subclasses: nausea/vomiting, fullness/early satiety, and bloating on a 0-5 scale. A total GCSI score ≥18 generally indicates moderate to severe symptoms, with lower scores indicating better symptom control.
From baseline to 8 weeks after randomization
Change in Pain Medications
Time Frame: During the 8-week randomized treatment period.
Change in use of opioid and non-opioid pain medications during the 8-week randomized treatment period.
During the 8-week randomized treatment period.
Change in Inflammatory Cytokines
Time Frame: Baseline to 8 weeks.
Measured via serum testing including including IL-6, TNF-α, IL-1β, IL-8, and IFN-γ.
Baseline to 8 weeks.
Change in Brief Pain Inventory Score
Time Frame: Baseline to 8 weeks after randomization.

Change in Brief Pain Inventory (BPI) score from baseline to 8 weeks after randomization. The investigators will be using the Brief Pain Inventory (BPI) short form.

The Brief Pain Inventory (BPI) scoring assesses pain severity and its interference with daily life using an 11-point numeric rating scale (0 = "no pain/interference", 10 = "worst pain/complete interference").

It provides two main scores: a Pain Severity Score (average of 4 items) and a Pain Interference Score (average of 7 items), where higher scores indicate greater impairment.
Baseline to 8 weeks after randomization.
Percent Reduction in Pain Score
Time Frame: Baseline to 8 weeks.

Percent of responders defined as ≥30% reduction in pain score at 8 weeks.

The investigators will be using the Brief Pain Inventory (BPI) short form. The Brief Pain Inventory (BPI) scoring assesses pain severity and its interference with daily life using an 11-point numeric rating scale (0 = "no pain/interference", 10 = "worst pain/complete interference"). It provides two main scores: a Pain Severity Score (average of 4 items) and a Pain Interference Score (average of 7 items), where higher scores indicate greater impairment.
Baseline to 8 weeks.
Change in Autonomic Function
Time Frame: Baseline to 8 weeks

For measurements of autonomic function, participants will undergo traditional autonomic testing, an established technique that has been extensively applied. This testing is reported a two main components: Vagal Cholinergic, via RR variation with deep breathing and Valsalva Ratio as well as Sympathetic Adrenergic, via postural adjustment ratio and vasoconstriction to cold stress.

The normal values for these are derived from extensive experience of nearly 3000 patients as well as normal controls. This testing is also performed with cutaneous electrograms, used as a combined autonomic enteric tool, for baseline, and response to cold and posture.
Baseline to 8 weeks
Change in Gastric Electrophysiology
Time Frame: baseline to 8 weeks
Measured via electrogastrogram (EGG). The investigators will record mucosal and serosal measures at the time of placement of temporary GES electrodes, and before a temporary GES device is connected to the leads. The technique of mucosal electrogram recordings uses 2 leads, a proximal one in the upper gastric body and a distal one near the body antral junction, which allows for low resolution mapping of the stomach. The recordings will be analyzed by signal averaging and reported as frequency, amplitude and their ratio. All patients will also have baseline cutaneous electrograms as well, for reference, analyzed in a similar manner.
baseline to 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Louisville

Collaborators

National Institute of Neurological Disorders and Stroke (NINDS)
National Institutes of Health (NIH)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 1, 2026

Primary Completion (Estimated)

July 1, 2030

Study Completion (Estimated)

July 1, 2030

Study Registration Dates

First Submitted

April 9, 2026

First Submitted That Met QC Criteria

April 21, 2026

First Posted (Actual)

April 29, 2026

Study Record Updates

Last Update Posted (Actual)

May 4, 2026

Last Update Submitted That Met QC Criteria

April 28, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 26.0165
  • 1UG3NS140971-01 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

De-identified individual participant data will not be shared outside the investigative team.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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