Esophageal Functional Lumen Imaging Probe (FLIP): How Can FLIP Enhance Your Clinical Practice?

Utilizing Esophageal Motility Tests in Diagnosing and Evaluating Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD), a prevalent clinical condition, is often attributed to aberrant esophageal motility, leading to gastric content reflux and associated symptoms or complications. The rising incidence of GERD presents an escalating healthcare challenge. Endoscopic and esophageal reflux monitoring can provide a basis for the diagnosis of patients with gastroesophageal reflux disease, but when the diagnostic basis is at an inconclusive value, some additional supportive evidence will be needed. Advanced technology is the key to improving patient diagnosis, accurate assessment, and the development of effective treatment strategies. High-resolution esophageal manometry (HREM) and endoscopic functional lumen imaging probe (EndoFLIP) represent the forefront of esophageal motility assessment. HREM, an evolution of traditional esophageal manometry, is considered the benchmark for identifying esophageal motility disorders. Its widespread application in esophageal dynamics research highlights its diagnostic significance. Concurrently, EndoFLIP's emerging clinical relevance is evident in diagnosing and guiding the treatment of coexisting esophageal motility issues. This review integrates contemporary research to delineate the contributions of HREM, EndoFLIP, and novel technologies in GERD. It examines their efficacy in facilitating an accurate diagnosis, differentiating similar gastrointestinal disorders, quantifying the extent of reflux, assessing the severity of the disease, forecasting patient responsiveness to proton pump inhibitor therapy, and guiding decisions for surgical interventions. The overarching aim is to deepen the understanding of GERD's underlying mechanisms and advance the formulation of holistic, efficacious treatment approaches.

Identification of Achalasia Within Absent Contractility Phenotypes on High-Resolution Manometry: Prevalence, Predictive Factors, and Treatment Outcome

INTRODUCTION

Absent contractility on high-resolution manometry (HRM) defines severe hypomotility but needs distinction from achalasia. We retrospectively identified achalasia within absent contractility using HRM provocative maneuvers, barium esophagography, and functional lumen imaging probe (FLIP).

METHODS

Adult patients with absent contractility on HRM during the 4-year study period were eligible for inclusion. Inadequate studies, achalasia after therapy, or prior foregut surgery were exclusions. Upright integrated relaxation pressure (IRP) >12 mm Hg, panesophageal pressurization, and/or elevated IRP on multiple rapid swallows and rapid drink challenge (RDC) were considered abnormal. Esophageal barium retention and abnormal esophagogastric junction distensibility index (<2.0 mm 2 /mm Hg) on FLIP defined achalasia. Clinical, endoscopic, and motor characteristics of patients with achalasia were compared with absent contractility without obstruction.

RESULTS

Of 164 patients, 20 (12.2%) had achalasia (17.9% of 112 patients with adjunctive testing), while 92 did not, and 52 did not undergo adjunctive tests. Achalasia was diagnosed regardless of IRP value, but the median supine IRP was higher (odds ratio 1.196, 95% confidence interval 1.041-1.375, P = 0.012). Patients with achalasia were more likely to present with dysphagia (80.0% vs 35.9%, P < 0.001), with obstructive features on HRM maneuvers (83.3% vs 48.9%, P = 0.039), but lower likelihood of GERD evidence (20.0% vs 47.3%, P = 0.027) or large hiatus hernia (15.0% vs 43.8%, P = 0.002). On multivariable analysis, dysphagia presentation ( P = 0.006) and pressurization on RDC ( P = 0.027) predicted achalasia, while reflux and presurgical evaluations and lack of RDC obstruction predicted absent contractility without obstruction.

DISCUSSION

Despite HRM diagnosis of absent contractility, achalasia is identified in more than 1 in 10 patients regardless of IRP value.

Novel Diagnostic Techniques in the Evaluation of Gastroesophageal Reflux Disease (GERD)

In our present clinical paradigm, patient symptoms and presentation in the setting of traditional findings from endoscopy (erosive esophagitis, Barrett's esophagus, reflux-mediated stenosis), esophageal high-resolution manometry, and/or ambulatory reflux monitoring (distal esophageal acid exposure time, numbers of reflux events, reflux-symptom association) guide the care of patients with suspected GERD. However, novel metrics and techniques acquired from or performed at endoscopy, manometry, or pH-impedance monitoring, beyond conventional evaluation, are of great interest to the gastroenterology community given the frequent (and sometimes challenging) presentation of suspected GERD. These novel and evolving diagnostic approaches have the potential to enhance the evaluation of these patients and optimize their management. In this invited review, we discuss the present evidence and potential clinical utility of selected GERD metrics and techniques of interest at endoscopy (dilated intercellular spaces, mucosal impedance), manometry (contractile integral, impedance analysis, straight leg raise, multiple rapid swallow maneuvers), and reflux monitoring (mean nocturnal baseline impedance, post-reflux swallow-induced peristaltic wave indices), and how these tools may be most optimally adopted and utilized for clinical care (Fig. 1).

The Outcomes of Performing Partial Fundoplication Based on Endoflip Versus Manometric Findings

BACKGROUND

The surgical management of gastroesophageal reflux disease (GERD) involves extensive diagnostic studies and sophisticated surgical techniques. The workup should be comprehensive and purposeful. High resolution impedance manometry (HRIM) provides valuable information regarding peristalsis and lower esophageal sphincter relaxation. The disadvantages of HRIM such as intolerance or inability to pass the catheter led to its selective use or even omission especially in laparoscopic hiatal hernia repair with partial fundoplication. This pragmatic approach risks missing motility disorders in patients with secondary reflux symptoms related to achalasia or scleroderma. Endolumenal functional lumen imaging probe (endoFLIP) can fill this void as it evaluates the dynamics of the esophagogastric junction under sedation. This study aims to compare the outcomes of preoperative use of HRIM vs endoFLIP for laparoscopic repair of hiatal hernia with partial fundoplication.

METHODS

This is a retrospective cohort study for consecutive patients who underwent antireflux surgery with partial fundoplication between July 2018 and February 2021. Preoperative and postoperative outcomes were compared between two cohorts of patients: those with preoperative HRIM and those with preoperative endoFLIP.

RESULTS

A total of 72 patients were evaluated, 41 had preoperative HRIM and 31 had endoFLIP. There was no statistically significant difference in their age, sex, BMI, duration of GERD symptoms, or proton pump inhibitors use. The endoscopic findings of esophagitis, hiatal hernia, and Hill's grade were comparable. There was no difference in the American Society of Anesthesiology classification or the choice of antireflux surgery. The improvement of postoperative GERD scores and dysphagia subscore was similar between the two groups.

CONCLUSION

Performing partial fundoplication based on endoFLIP evaluation of the dynamics of the esophagogastric junction is safe and does not increase postoperative dysphagia compared to preoperative manometric use. Randomized prospective studies are needed to confirm the findings of this study.