Mechanisms of Action for the Enterra Medical Gastric Electrical Stimulator
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18+
SponsorUniversity of Aarhus
About this trial
Background: Gastric electrical stimulation applied by a surgically implanted device effectively alleviates upper gastrointestinal symptoms in the majority of individuals with medically refractory gastroparesis. Despite its efficacy, the mechanisms of action have been minimally explored in previous studies, and it is unknown why some individuals experience limited symptom-lowering effects.
Aim: The investigators aim to investigate two of the potential mechanisms of action leading to symptom-reducing effects of gastric electrical stimulation: 1) possible central effects in the brainstem and brain by enhanced parasympathetic vagal activity, and 2) peripheral effects in the stomach by improved gastric accommodation.
Methods: Up to thirty individuals with drug-refractory gastroparesis having an implanted gastric electrical stimulator will be enrolled in this cross-sectional and observational study. Of these, 15 will be responders (substantial symptomatic improvement) and 15 non-responders (minor symptomatic improvement). Electroencephalography (EEG) will evaluate the stimulation-induced activity in the brain and brainstem to assess whether the gastric stimulation generates evoked potentials. Electrocardiography (ECG) will investigate stimulation-induced changes in the autonomic regulation of the heart. Gastric ultrasound will investigate the effect of stimulation on stomach accommodation, contractions, and wall tension. These central and peripheral measures will be assessed during one study day before and after activating the gastric electrical stimulator, following an increase in stimulation intensity and post-meal consumption. Furthermore, results will be compared between responders and non-responders.
Perspectives: Adjusting the parameters of gastric electrical stimulation based on objective markers in the brain, heart, or stomach, rather than relying on symptom fluctuations, may enhance the effectiveness of symptom improvement. In the future, these objective markers may aid in differentiating between responders and non-responders, which may lead to optimised selection criteria for surgery.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Age 18 and above
Able to read and understand Danish
Have an implanted gastric electrical stimulator for treating gastroparesis
Answering 0 or 1 (non-responders) or 3 or 4 (responders) on the Likert scale describing the symptom improvement gained by gastric electrical stimulation.
Disqualifiers
Previous surgery on the vagus nerve, including cervical vagotomy
Prior thoracic, abdominal or brain surgeries that, in the opinion of the investigator, could limit data collection or interpretation.
Previous diagnosis or history of orthostatic intolerance, e.g. POTS, neurocardiogenic syncope, orthostatic hypotension or autonomic dysfunction.
Patients with an implanted cardiac device (e.g. pacemaker, CRT, etc.) or vagal nerve stimulator (VNS).
Trial population
Individuals having an implanted Enterra gastric electrical stimulator for treating gastroparesis. 15 will be included as "responders" and 15 as "non-responders". Using a 5-point Likert scale, each participant will evaluate the experienced symptom-reducing effect of the gastric electrical stimulation. The individuals answering 0 or 1 (minor or no symptom improvement) are defined as responders, while individuals answering 3 or 4 (substantial or full symptom improvement) are defined as responders. Individuals answering 2 will not be included in the study.
Trial design
Design model
Cohort
Time perspective
Cross-sectional
Treatments tested in this trial
Effect of different gastric electrical stimulator stimulation paragdimes on brain, heart, and stomach.
Diagnostic testMeasuring EEG, ECG, and ultrasound in both groups during different stimulation intensities provided by the previously implanted gastric electrical stimulator.
Treatment groups
30 Participants
are divided into 2 treatment groupsGroup A: Responders1 intervention
Group B: Non-responders1 intervention
Trial outcomes
Primary outcomes
1
Evoked brain potentials
Amplitude of evoked brain potentials induced by gastric electrical stimulation
Time frame
5min during maximum stimulation intensitySecondary outcomes
1
EEG measures between ON/OFF stimulation
EEG frequency distribution when comparing the OFF and ON stimulation modes
Time frame
5min2
Meal-related EEG measures
EEG frequency distribution in response to an ingested meal when comparing the OFF and ON stimulation modes.
Time frame
5min3
ECG measures between ON/OFF stimulation
Heart rate variability, periodic repolarisation dynamic, and the deceleration capacity of the heart rate when comparing the OFF and ON stimulation modes.
Time frame
5min4
ECG measures between stimulation intensities
Heart rate variability, periodic repolarisation dynamic, and the deceleration capacity of the heart rate following different stimulation intensities.
Time frame
5minSponsors and contacts
Click on the lead sponsor to view all of their trials.
University of Aarhus
Lead sponsor
Aalborg University Hospital
Collaborator
Aarhus University Hospital
Collaborator
Source ClinicalTrials.gov