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 use Gastric Alimetry™ System that assesses gastric myoelectrical activity and water load satiety testing (WLST).
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).