HR-EGG in Medically Refractory Gastroparesis

Study Overview
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Brief Summary
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The goal of this observational study is to utilize a novel high resolution electrogastrography device to gauge if identification of gastric dysarrythmias can reliably identify patients that will respond to or will require definitive pyloric interventions such as a G-POEM procedure in patients with medically refractory gastroparesis Aims: Assess for the presence of gastric dysarrythmias in lung transplantation population as compared to alternative etiologies of gastroparesis Assess if presence or absence of gastric dysarrythmias is predictive of response or need of Gastric -per-oral endoscopic myotomy Assess alterations in gastric dysarrthmias following pyloric interventions including G-POEM. Patients will undergo two surface body surface gastric mapping via the HR-EGG before and after undergoing a gastric per oral endoscopic myotomy as standard clinical care for the treatment of medically refractory gastroparesis

Detailed Description
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Gastroparesis is a chronic digestive disorder defined by the symptoms of nausea, vomiting, bloating, and abdominal pain in the setting of objectively delayed gastric emptying without mechanical gastric outlet obstruction. Gastroparesis is frequently identified after lung transplantation with incidence rates as high as 44%. Gastroparesis after lung transplantation is of significant concern as complications directly related to gastroparesis, specifically gastroesophageal reflux and aspiration, have been linked to the development of bronchiolitis obliterans syndrome, the primary cause of graft failure and the main cause of late morbidity and mortality following lung transplantation. Effective long-term therapy for medically refractory post-lung transplant gastroparesis represents a significant therapeutic challenge. Current therapies (such as botulinum toxin injection or surgical pyloromyotomy/bypass) are either limited by inconsistent efficacy or by their invasiveness. However, recent advances in endoscopic tunneling techniques have led to the development of gastric per-oral endoscopic myotomy (G-POEM). Initial reports of this technique for treatment of post-lung transplant gastroparesis are encouraging, with excellent preliminary safety and efficacy data. However, currently there are no clinical, endoscopic, or radiographic parameters that reliably predict which patients will respond to G-POEM. This is likely secondary to the multifactorial pathophysiology of gastroparesis. Secondary to this there is an unmet need to develop a widely deployable screening tool that is i) non-invasive, ii) able to reliably divide gastroparesis into pathophysiologic subgroups and iii) be able to guide effective treatments. In a similar fashion to that of the brain and heart, waves generated at the stomach's surface propagate to the skin via volume conduction. These voltages can be measured with cutaneous electrodes, via gastric electrophysiology (EGG) noninvasively. However, the EGG has not encountered widespread clinical adoption as the ability to both reliably and consistently differentiate gastrocutaneous spatial dysrhythmias has not been possible. However, a novel 'high-resolution EGG' (HR-EGG), a multi-electrode array of 25 or more electrodes, has been shown to capture slow waves with high spatial resolution and extract meaningful spatial (as opposed to spectral) features, including the instantaneous slow wave direction at any given point in space. This coupled with novel deep convolutional neural network (CNN) frameworks and artifact rejection methods, have been able to reliably capture gastric myoelectricspatial abnormalities that correlate with symptom incidence and severity in gastroparesis patients. Currently, a new generation of high-resolution electrogastrograms recording technology with 64-channel electrode array is being developed by Alimetry Limited that is able to provide body surface gastric mapping (BSGM). This BSGM is able to provide a more complete understanding of the origin and propagation of human gastric slow-wave activity non-invasively, such as frequency and pattern, in high spatiotemporal detail. The system also includes an App for tracking patient-reported symptoms throughout the test. Our goal is to utilize this proprietary device to gauge if identification of gastric dysarrythmias can reliably identify patients that will respond to or will require definitive pyloric interventions such as a G-POEM procedure.

Official Title
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High Resolution Electrogastrography (HR-EGG) Assessment in Medically Refractory Gastroparesis

Conditions
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Gastroparesis, Lung Transplant; Complications

Intervention / Treatment
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* Device: High Resolution Electrogastography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients (age >17 years old) with medically refractory gastroparesis Exclusion Criteria: Females who are pregnant or lactating (self-reported) History of skin allergies to skin adhesives or hydrogels History of extreme sensitivity to cosmetics or lotions Fragile skin vulnerable to skin tears Damaged epigastric skin (open wounds, rash, inflammation) Patients unable to remain in a relaxed reclined position for the test duration BMI > 35 obtained via chart review

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Medically refractory Non-transplanted gastroparesis<br>Etiology of gastroparesis deemed on clinical grounds to NOT be secondary to lung transplantation process ( diabetes, post-surgery, idiopathic, neuromuscular etc.) Gastroparesis defined as > 10% radiotracer remains in the stomach after 4 hour gastric scintigraphy study. Medically refractory is defined as lack of clinical response to trial of diet and lifestyle modifications such as small frequent low fat and low fiber meals and trial or contraindications to prokinetic medications for the treatment of gastroparesis Case Cohort: Assessment of HR-EGG comparing controls (non lung transplant induced gastroparesis) vs lung transplant induced gastroparesis Investigators will further categorize patients into sub- groups based on HR-EGG phenotypes:, such as High Frequency, Low Frequency, High Amplitude, Low Amplitude, Continuous Symptoms, Sensorimotor Symptoms, Mixed Symptoms and Normal on Day. | Device: High Resolution Electrogastography<br>* a new generation 64- channel high-resolution electrogastrography recording technology by Alimetry Limited that is able to record and analyze body surface gastric mapping/ HR-EGG<br>* Other names: body surface gastric mapping;|
| Medically refractory Post Lung transplant gastroparesis<br>Etiology of gastroparesis deemed on clinical grounds to be secondary to lung transplantation process. Gastroparesis defined as > 10% radiotracer remains in the stomach after 4 hour gastric scintigraphy study. Medically refractory is defined as lack of clinical response to trial of diet and lifestyle modifications such as small frequent low fat and low fiber meals and trial or contraindications to prokinetic medications for the treatment of gastroparesis Case Cohort: Assessment of HR-EGG comparing controls (non lung transplant induced gastroparesis) vs lung transplant induced gastroparesis Investigators will further categorize patients into sub- groups based on HR-EGG phenotypes:, such as High Frequency, Low Frequency, High Amplitude, Low Amplitude, Continuous Symptoms, Sensorimotor Symptoms, Mixed Symptoms and Normal on Day. | Device: High Resolution Electrogastography<br>* a new generation 64- channel high-resolution electrogastrography recording technology by Alimetry Limited that is able to record and analyze body surface gastric mapping/ HR-EGG<br>* Other names: body surface gastric mapping;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assess the presence of gastric dysarrythmias in lung transplantation population compared to alternative etiologies of gastroparesis | Investigators will categorize patients into sub- groups based on HR-EGG phenotypes:, such as Low GA-RI, High Frequency, Low Frequency, High Amplitude, Low Amplitude, Continuous Symptoms, Sensorimotor Symptoms, Mixed Symptoms and Normal on Day. | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sub-type the specific bioelectrical abnormalities to assess which patterns are associated with symptoms and abnormal emptying across all subjects |  | 2 years | 
| Assess if presence or absence of gastric dysarrythmias is predictive of response or need of Gastric -per-oral endoscopic myotomy |  | 2 years | 
| Assess alterations in gastric dysarrythmias following pyloric interventions including G-POEM |  | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Gastroparesis, Post- Lung Transplant