Chronic Abdominal Pain, Gastroparesis
Conditions
Keywords
Gastric Electrical Stimulation, Enterra, Visceral pain, Gastroparesis pain, Neuromodulation
Brief summary
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.
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.
Interventions
DEVICEEnterra™ neurostimulator
Gastric Electrical Stimulation using implanted Enterra™ neurostimulator with protocol-specified programming parameters.
Sponsors
University of Louisville
National Institutes of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Masking description
Device programming assignments are coded and implemented by an independent unblinded technician. Participants and study personnel remain blinded during the randomized treatment phase.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Abdominal Pain Score | 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). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Brief Pain Inventory Score | 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. |
| Change in Gastroparesis Cardinal Symptom Index score | 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. |
| Change in Pain Medications | During the 8-week randomized treatment period. | Change in use of opioid and non-opioid pain medications during the 8-week randomized treatment period. |
| Percent Reduction in Pain Score | 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. |
| Change in Inflammatory Cytokines | Baseline to 8 weeks. | Measured via serum testing including including IL-6, TNF-α, IL-1β, IL-8, and IFN-γ. |
| Change in Autonomic Function | 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. |
| Change in Gastric Electrophysiology | 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. |
Countries
United States
Contacts
CONTACTThomas L Abell, MD
Outcome results
None listed