Pyloric Sphincter Abnormalities in Patients With Gastroparesis Symptoms

Study Overview
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Brief Summary
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The overall objective of this study is to determine if there are pyloric sphincter abnormalities in patients with gastroparesis symptoms and determine how prevalent these abnormalities are using three tests to assess the pyloric sphincter - endoluminal functional luminal imaging probe (Endoflip™), high resolution electrogastrography (hrEGG) using Gastric Alimetry™ System and water load satiety testing (WLST).

Detailed Description
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There have been several published studies using Endoflip™ to assess the pyloric sphincter in small number of participants. In the first study, Gourcerol et al showed that pyloric compliance is decreased in gastroparesis patients compared to 21 healthy controls and associated with the T1/2 of gastric emptying and symptoms of gastroparesis (Gourcerol 2015). From this study, pyloric distensibility <10 appeared to be abnormal. In the second study, Malik et al found that the pyloric sphincter contour was seen best at distention with 40 cc. Symptoms of early satiety and postprandial fullness were inversely correlated with pyloric diameter and cross-sectional area of the pyloric sphincter (Malik 2015). Pyloric distensibility <9.2 was associated with improvement in symptoms with endoscopic pyloromyotomy. A recent study showed similar patterns for improvement in symptoms with botulinum toxin injection in the pylorus. The pyloric sphincter is at the distal end of the stomach, whereas the lower esophageal sphincter (LES) is at the proximal portion of the stomach. How abnormalities of the pyloric sphincter relate to abnormalities of the LES is not known but will be addressed in this study. Our prior studies have shown that diffuse transit abnormalities may occur in patients with gastroparesis. In addition, patients with gastroparesis can have symptoms of gastroesophageal reflux disease. This study will ascertain if there are LES abnormalities in patients with gastroparesis as determined by Endoflip™, such as LES distensibility and how LES distensibility relates to pyloric distensibility. This study protocol will assess lower esophageal and pyloric sphincter diameter, CSA, pressure, distensibility, and compliance in patients with symptoms of gastroparesis and delayed gastric emptying, patients with symptoms of gastroparesis but with normal gastric emptying, and normal control participants. The protocol will also include a water load satiety test and use Gastric Alimetry™ System that assesses gastric myoelectrical activity in symptomatic participants but not control participants.

Official Title
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Pyloric Sphincter Abnormalities in Patients With Gastroparesis Symptoms

Conditions
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Gastroparesis, Idiopathic Gastric Motility Disorder, Diabetic Gastroparesis

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria FOR SYMPTOMATIC PARTICIPANTS: Provision of signed and dated informed consent form Stated willingness to comply with all study procedures and availability for the duration of the study Male or female, aged 18 - 85 Symptoms of gastroparesis, either diabetic or idiopathic etiology Individual will have had a prior 4-hour gastric emptying scintigraphy test performed for clinical evaluation within the last 6 months. This gastric emptying test would be done for clinical evaluation and is not part of the research study. From these participants with gastroparesis symptoms, we will include those with delayed gastric emptying as well as those with normal gastric emptying. Symptoms of gastroparesis with minimum GCSI score of 2.0 (18/45 x 5) Participant must not initiate any new treatments until completion of the study procedures. Willingness to: Stop histamine 2 antagonists, prokinetics (e.g., metoclopramide, erythromycin, domperidone, prucalopride), narcotics, anticholinergics, constipation medications (over the counter laxatives, isotonic polyethylene glycol (PEG) electrolyte preparations (e.g. MiraLax), and prescription laxatives (e.g. lubiprostone), proton pump inhibitors, cannabinoids, and CBD for 3 days prior to the each visit; Abstain from food and water after midnight (at least for 8 hours) before the start of each visit until after the visit. INCLUSION CRITERIA FOR CONTROL PARTICIPANTS Provision of signed and dated informed consent form Male or female, aged 18 or older Undergoing an upper endoscopy for their clinical evaluation of diarrhea, GI bleed, or iron-deficiency anemia, or evaluation for bariatric surgery. Do not have upper GI symptoms greater than 1 as assessed by the Gastroparesis Cardinal Symptom Index (GCSI) of PAGI-SYM questionnaire. EXCLUSION CRITERIA: Prior gut lumen surgery on the esophagus or the stomach, including Nissen fundoplication. Prior surgery on the pylorus (G-POEM, surgical pyloroplasty, surgical pyloromyotomy) Known history of achalasia or esophageal stricture Known history of physiological or mechanical GI obstruction Abnormalities seen on a prior upper endoscopy placing patient at increased risk: Ulcer of the esophagus, stomach, or duodenum Esophageal varices Individuals at risk for prolonging the endoscopy procedure: severe chronic pulmonary disease, severe food retention in the stomach on endoscopy Individuals with a history of other chronic disease potentially causative of gastrointestinal symptom: Acute or chronic renal insufficiency Current eating disorders Women who are pregnant. A urine pregnancy test is routinely obtained on all females immediately prior to endoscopic procedures. Individuals with contraindications for endoscopy, including bleeding abnormalities Allergy to eggs preventing sedation with propofol Significant dysphagia Prior inflammatory bowel disease Presence or prior use of gastric stimulator History of any gastric/pyloric injection of botulinum toxin Use of opioids greater than 3 days per week

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Symptoms of gastroparesis<br>Participants with symptoms of gastroparesis with minimum Gastroparesis Cardinal Symptom Index (GCSI) score of 2.0 (18/45 x 5) | |
| Control participants<br>Participants undergoing endoscopy for evaluation but without gastroparesis symptoms or gastroesophageal reflux symptoms. Score 1.0 or less (≤ 1 ) on the GCSI of Patient Assessment of Upper Gastrointestinal Symptom Severity Index (PAGI-SYM) questionnaire | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Distensibility of the pylorus | Distensibility of the pylorus will be calculated as the median of three measurements (not three different inflations) of distensibility (mm2/mmHg) of the pylorus pressure using the Endoflip balloon catheter at 50 mL volume | Baseline | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Opening diameter (mm) of the pylorus when 40 mL volume is introduced into the EF325N Endoflip™ measurement catheter. | diameter (mm) of the pylorus | Baseline | 
| Opening diameter (mm) of the pylorus when 50 mL volume is introduced into the EF325N Endoflip™ measurement catheter. | diameter (mm) of the pylorus | Baseline | 
| Cross Sectional Area(mm2) of the pylorus with 40 mL balloon volume | Cross Sectional Area (mm2) of the pylorus | Baseline | 
| Cross Sectional Area(mm2) of the pylorus with 50 mL balloon volume | Cross Sectional Area (mm2) of the pylorus | Baseline | 
| Compliance (mm3/mmHg) of the pylorus with 40 mL balloon volume | Compliance (mm3/mmHg) of the pylorus | Baseline | 
| Compliance (mm3/mmHg) of the pylorus with 50 mL balloon volume | Compliance (mm3/mmHg) of the pylorus | Baseline | 
| Pressure (mmHg) of the pyloric sphincter | Pressure (mmHg) of the pyloric sphincter | Baseline |