The purpose of the study is to investigate the use of FLIP topography in patients undergoing evaluation for gastroesophageal reflux disease (GERD). This device allows the clinician to measure muscle activity in the esophagus during a routine upper endoscopy. The FLIP topography will be used to help detect movement disorders in the esophagus, and to examine differences in patient satisfaction between FLIP topography and the standard of care procedure, high resolution manometry (HRM).

The goal of the proposed research is to evaluate the endoscopic esophageal functional luminal imaging probe (FLIP) with topography (Endoflip® 2.0, Medtronic, USA) as a pre-operative diagnostic test to rule out significant esophageal dysmotility in patients with gastroesophageal reflux disease (GERD). Currently, the gold standard for pre-operative motility assessment is high resolution manometry (HRM), a trans-nasal catheter test performed in an awake patient that can be quite uncomfortable, and some patients cannot tolerate.1 Conversely, Endoflip can provide similar data in a sedated patient at the time of upper endoscopy, limiting discomfort and streamlining workup. While Endoflip has been used as a complimentary tool for clinical decision making in major motility disorders, its evaluation as a potential stand-alone pre-operative test in the GERD population has been limited. However, if FLIP topography reliably excludes major motility disorders, patients could proceed with fundoplication without undergoing the additional burden of high resolution manometry (HRM) testing. Unfortunately, as of now, there are insufficient data available to justify a change in clinical practice. As a result, FLIP topography has remained relegated to a purely complimentary role.

To investigate this question, the investigators will perform FLIP topography (Endoflip 2.0) analysis on all patients undergoing routine evaluation for gastroesophageal reflux disease at the time of their pre-operative EGD. Those patients with repetitive antegrade contractions (RACs) on FLIP topography will be classified as having normal motility, while any other pattern will be considered abnormal. All patients will additionally complete a standard pre-operative reflux evaluation including HRM, Upper GI series (UGI), 48-hour wireless pH testing, and baseline GERD quality of life surveys. The investigators will then compare the results of the FLIP topography measurements to the results of the gold standard high-resolution manometry (HRM) in terms of the ability of the FLIP topography to differentiate between normal and impaired esophageal function in GERD patients. Subjects will then be followed through their anti-reflux operations and post-operative outcomes will be tracked with standardized symptom questionnaires at 1, 2 and 6 months post-operatively to evaluate for post-operative dysphagia and quality of life.

The investigators hypothesize that FLIP topography (Endoflip 2.0) in GERD patients will reliably identify individuals with normal motility, which will predict good outcomes after anti-reflux surgery. If this proves to be the case, formal high resolution manometry (HRM) testing would not be necessary prior to proceeding with fundoplication, allowing a paradigm shift in the pre-operative workup of this large population of patients.

Inclusion Criteria:

• Suspected or known history of GERD
• Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria:

• Previous esophageal or gastric surgery (including failed anti-reflux operation)
• Hiatal Hernia > 5cm based on upper GI
• Patients with a known major motility disorder (achalasia)

All patients who present to our comprehensive esophageal clinic for evaluation of suspected GERD meeting the inclusion/exclusion criteria will be asked to participate in the study.