Functional Lumen Imaging Probe for the Management of Esophageal Disorders: Expert Review From the Clinical Practice Updates Committee of the AGA Institute

Enhancing Chicago Classification diagnoses with functional lumen imaging probe-mechanics (FLIP-MECH)

BACKGROUND

Esophageal motility disorders can be diagnosed by either high-resolution manometry (HRM) or the functional lumen imaging probe (FLIP) but there is no systematic approach to synergize the measurements of these modalities or to improve the diagnostic metrics that have been developed to analyze them. This work aimed to devise a formal approach to bridge the gap between diagnoses inferred from HRM and FLIP measurements using deep learning and mechanics.

METHODS

The "mechanical health" of the esophagus was analyzed in 740 subjects including a spectrum of motility disorder patients and normal subjects. The mechanical health was quantified through a set of parameters including wall stiffness, active relaxation, and contraction pattern. These parameters were used by a variational autoencoder to generate a parameter space called virtual disease landscape (VDL). Finally, probabilities were assigned to each point (subject) on the VDL through linear discriminant analysis (LDA), which in turn was used to compare with FLIP and HRM diagnoses.

RESULTS

Subjects clustered into different regions of the VDL with their location relative to each other (and normal) defined by the type and severity of dysfunction. The two major categories that separated best on the VDL were subjects with normal esophagogastric junction (EGJ) opening and those with EGJ obstruction. Both HRM and FLIP diagnoses correlated well within these two groups.

CONCLUSION

Mechanics-based parameters effectively estimated esophageal health using FLIP measurements to position subjects in a 3-D VDL that segregated subjects in good alignment with motility diagnoses gleaned from HRM and FLIP studies.

Esophageal Dysphagia in Adults: When It Sticks

Esophageal dysphagia is a common yet difficult to diagnose condition. This article underscores the role of detailed patient history and physical examinations, including prompt endoscopic evaluation, for accurate differentiation between esophageal and oropharyngeal dysphagia. The authors discuss the heightened importance of early intervention in certain patient groups, such as elderly individuals and patients with head and neck cancer, to mitigate the risk of malnutrition and infection. The authors delve into etiologic factors highlighting the complexity of clinical presentations and the significance of tailored management strategies.

Research gap in esophageal achalasia: a narrative review

In recent years, new translational evidence, diagnostic techniques, and innovative therapies have shed new light on esophageal achalasia and revamped the attention on this relatively rare motility disorder. This narrative review aims to highlight the most recent progress and the areas where further research is needed. The four senior authors identified five topics commonly discussed in achalasia management: i.e. pathogenesis, role of functional lumen imaging probe in the diagnostic flow chart of achalasia, how to define the outcome of achalasia treatments, how to manage persistent chest pain after the treatment, and if achalasia patients' may benefit from a regular follow-up. We searched the bibliographic databases to identify systematic reviews, meta-analyses, randomized control trials, and original research articles in English up to December 2023. We provide a summary with the most recent findings in each of the five topics and the critical points where to address future research, such as the immune-genetic patterns of achalasia that might explain the transition among the different phenotypes, the need for a validated clinical definition of treatment success, the use of neuromodulators to manage chest pain, and the need for identifying achalasia patients at risk for cancer and who may benefit of long-term follow-up. Although undoubtedly, progress has been made on the definition and management of achalasia, unmet needs remain. Debated aspects range from mechanistic insights, symptoms, objective measure relationships, and accurate clinical responses to therapeutic interventions. Translational research is eagerly awaited to answer these unresolved questions.

Perioperative management protocol for pediatric endoluminal functional lumen imaging probe in esophageal motility disorders

OBJECTIVES

Lower esophageal sphincter achalasia is associated with a higher risk of aspiration during anesthesia. Endoluminal Functional Lumen Imaging Probe (EndoFLIP) is used as an adjunctive tool in both the diagnosis and treatment of achalasia, for which all children require anesthesia. Anesthesia may affect the parameters of the EndoFLIP due to its effect on gut motility. There are no standard anesthesia protocols to help decrease the risk of aspiration and the undesirable effect of anesthesia on EndoFLIP parameters. This study aims to standardize an anesthesia protocol to target both goals.

METHODS

A protocol was developed to address perioperative management in patients undergoing EndoFLIP for any indication to minimize both anesthetic effect on the esophageal motility as well as perioperative complications. A retrospective data analysis was conducted on patients who underwent EndoFLIP at Cincinnati Children's Hospital Medical Center; pre- and post-protocol implementation data including adverse events was compared.

RESULTS

Pre-protocol implementation: 60 cases (median age of 13.8 years, 30 [50%] females) with 2 cases of adverse events (3.3%). Post-protocol implementation: 71 cases (median age of 14.6 years, 37 [52.1%] females) with no adverse events (0/71 = 0%). In comparison between pre- and post-protocol cases, no significant difference was noted in gender, age, and adverse events. Post-protocol procedures were found to be significantly shorter (median time of 89 vs. 79 min, p = 0.004).

CONCLUSIONS

Our anesthesia protocol provides a standardized way of administering anesthesia minimizing impact on EndoFLIP parameters and aspiration for patients with achalasia.

Functional lumen imaging probe use in a high-volume practice: Practical and technical implications

BACKGROUND

The functional lumen imaging probe (FLIP) is a Food and Drug Administration approved tool to aid the diagnosis and management of esophageal disorders. However, widespread adoption of FLIP remains limited and its utility in high-volume practices remains unclear.

AIM

To analyze large sample data on clinical use of FLIP and provide insight on several technical aspects when performing FLIP.

METHODS

We conducted a retrospective comparative and descriptive analysis of FLIP procedures performed by a single provider at an academic medical center. There was a total of 398 FLIP procedures identified. Patient medical records were reviewed and data regarding demographics and procedural details were collected. Statistical tests, including chi-squared, t-test, and multivariable logistic and linear regression, were performed.

RESULTS

There was an increase in FLIP cases with each successive time period of 13 months (n = 68, 146, 184, respectively) with notable rises specifically for indications of dysphagia and gastroesophageal reflux disease. There was a shift toward use of the longer FLIP balloon catheter for diagnostic purposes (overall 70.4% vs 29.6%, P < 0.01). Many cases (42.8%) were performed in conjunction with other diagnostics/interventions, such as dilation and wireless pH probe placement. Procedures were nearly equally performed with anesthesia vs moderate sedation (51.4% anesthesia), with no major complications. Patients who had anesthesia were less likely to have recurrent antegrade contractions [odds ratio (OR) = 0.4, 95%CI: 0.3-0.8] and were also more likely to have absent contractility (OR = 2.4, 95%CI: 1.3-4.4).

CONCLUSION

FLIP cases have increased in our practice with expanding indications for its use. Given limited normative data, providers should be aware of several potential technical issues, including the possible impact of sedation choice when assessing esophageal motility patterns.

A Review of In Vitro and In Silico Swallowing Simulators: Design and Applications

Swallowing is a primary and complex behaviour that transports food and drink from the oral cavity, through the pharynx and oesophagus, into the stomach at an appropriate rate and speed. To understand this sophisticated behaviour, a tremendous amount of research has been carried out by utilising the in vivo approach, which is often challenging to perform, poses a risk to the subjects if interventions are undertaken and are seldom able to control for confounding factors. In contrast, in silico (computational) and in vitro (instrumental) methods offer an alternate insight into the process of the human swallowing system. However, the appropriateness of the design and application of these methods have not been formally evaluated. The purpose of this review is to investigate and evaluate the state of the art of in vitro and in silico swallowing simulators, focusing on the evaluation of their mechanical or computational designs in comparison to the corresponding swallowing mechanisms during various phases of swallowing (oral phase, pharyngeal phase and esophageal phase). Additionally, the potential of the simulators is also discussed in various areas of applications, including the study of swallowing impairments, swallowing medications, food process design and dysphagia management. We also address current limitations and recommendations for the future development of existing simulators.

Eosinophil Depletion with Benralizumab for Eosinophilic Esophagitis

BACKGROUND

Benralizumab is an eosinophil-depleting anti-interleukin-5 receptor α monoclonal antibody. The efficacy and safety of benralizumab in patients with eosinophilic esophagitis are unclear.

METHODS

In a phase 3, multicenter, double-blind, randomized, placebo-controlled trial, we assigned patients 12 to 65 years of age with symptomatic and histologically active eosinophilic esophagitis in a 1:1 ratio to receive subcutaneous benralizumab (30 mg) or placebo every 4 weeks. The two primary efficacy end points were histologic response (≤6 eosinophils per high-power field) and the change from baseline in the score on the Dysphagia Symptom Questionnaire (DSQ; range, 0 to 84, with higher scores indicating more frequent or severe dysphagia) at week 24.

RESULTS

A total of 211 patients underwent randomization: 104 were assigned to receive benralizumab, and 107 were assigned to receive placebo. At week 24, more patients had a histologic response with benralizumab than with placebo (87.4% vs. 6.5%; difference, 80.8 percentage points; 95% confidence interval [CI], 72.9 to 88.8; P<0.001). However, the change from baseline in the DSQ score did not differ significantly between the two groups (difference in least-squares means, 3.0 points; 95% CI, -1.4 to 7.4; P = 0.18). There was no substantial between-group difference in the change from baseline in the Eosinophilic Esophagitis Endoscopic Reference Score, which reflects endoscopic abnormalities. Adverse events were reported in 64.1% of the patients in the benralizumab group and in 61.7% of those in the placebo group. No patients discontinued the trial because of adverse events.

CONCLUSIONS

In this trial involving patients 12 to 65 years of age with eosinophilic esophagitis, a histologic response (≤6 eosinophils per high-power field) occurred in significantly more patients in the benralizumab group than in the placebo group. However, treatment with benralizumab did not result in fewer or less severe dysphagia symptoms than placebo. (Funded by AstraZeneca; MESSINA ClinicalTrials.gov number, NCT04543409.).

Clinical issues and challenges in imaging of gastrointestinal diseases: A minireview and our experience

Imaging techniques play a crucial role in the modern era of medicine, particularly in gastroenterology. Nowadays, various non-invasive and invasive imaging modalities are being routinely employed to evaluate different gastrointestinal (GI) diseases. However, many instrumental as well as clinical issues are arising in the area of modern GI imaging. This minireview article aims to briefly overview the clinical issues and challenges encountered in imaging GI diseases while highlighting our experience in the field. We also summarize the advances in clinically available diagnostic methods for evaluating different diseases of the GI tract and demonstrate our experience in the area. In conclusion, almost all imaging techniques used in imaging GI diseases can also raise many challenges that necessitate careful consideration and profound expertise in this field.

Use of Impedance Planimetry in the Diagnosis of Gastric Sleeve Stenosis: The Establishment of New Benchmark Values

INTRODUCTION

Gastric sleeve stenosis (GSS) is an increasingly common adverse event following sleeve gastrectomy for which objective diagnostic criteria are lacking. Impedance planimetry measurements show promise in characterizing GSS, though normal and abnormal benchmark values have never been established.

METHODS

This was a retrospective analysis of upper endoscopies performed with impedance planimetry for suspected GSS. A bariatric endoscopist, blind to impedance planimetry measurements, assessed gastric sleeve anatomy and graded GSS severity. Impedance planimetry of diameter and distensibility index (DI) were obtained using 3 different balloon volumes (30, 40, and 50 mL).

RESULTS

A total of 110 upper endoscopies were included. Distribution of GSS was graded as none, mild, moderate, and severe in 19 (17%), 27 (25%), 34 (31%), and 30 (27%) procedures, respectively. In normal gastric sleeve anatomy, mean (±SD) diameter and DI measurements using consecutive balloon volumes ranged from 19.1 (±5.5) to 23.2 (±1.7) and 16.8 (±4.9) to 23.1 (±10.9), respectively. In severe GSS, mean diameter and DI measurements ranged from 10.3 (±3.0) to 16.6 (±2.1) and 7.5 (±2.4) to 7.7 (±2.4), respectively. When stratified by severity, impedance planimetry measurements of diameter and DI were significantly lower with each subsequent increase in GSS grade regardless of balloon fill volumes ( P ≤ 0.001).

DISCUSSION

Impedance planimetry measurements provide objective assessment in the diagnosis of GSS and correlate with luminal narrowing. A diameter ≥20 mm and a DI ≥15 mm 2 /mm Hg, as measured by impedance planimetry, are predictive of normal gastric sleeve anatomy. This study provides new benchmark values for the diagnosis and severity of GSS.

Anesthesia choice and its potential impact on endoluminal functional lumen imaging probe measurements in esophageal motility disorders

BACKGROUND AND AIMS

The widespread use of peroral endoscopic myotomy (POEM) has revolutionized the management of esophageal motility disorders (EMDs). The introduction of an endoluminal functional lumen imaging probe (EndoFLIP, Medtronic, Dublin, Ireland) can serve as a complementary diagnostic tool to assess the mechanical properties (ie, pressure, diameter, distensibility, topography) of the esophagus. During EndoFLIP measurements, different anesthesia techniques may induce variable degrees of neuromuscular blockade, potentially affecting esophageal motility and altering the results of EndoFLIP metrics. The aim of this study was to compare the impact of using total intravenous anesthesia (TIVA) versus general anesthesia with inhalational anesthetics (GAIA) on diagnostic EndoFLIP measurements.

METHODS

This retrospective study included all adult patients (≥18 years) undergoing EndoFlip during the POEM procedure at our institution between February 2017 and February 2022. Differences in pressure, diameter, and distensibility index were obtained by using propofol-based TIVA versus sevoflurane-based GAIA with a 30 mL and a 60 mL balloon. The differences were divided into terciles and compared between diagnoses by using univariate comparisons and logistic regression models.

RESULTS

A total of 49 patients were included (39% type I achalasia, 43% type II or III achalasia, and 18% jackhammer esophagus [JE]). Compared with spastic disorders (types II and III achalasia and JE), type I had lower values of pressure differences at 60 mL in univariate (3.75 vs 15.20, P = .001) and multivariate (adjusted odds ratio, .89; 95% confidence interval, .82-.978) analyses. Compared with type I, types II and III achalasia had higher rates of pressure differences at 60 mL in the univariate (9.85 vs 3.75, P = .04) analysis and nearly reached significance in the multivariate analysis (1.09; 95% confidence interval, 1-1.20). Compared with type I achalasia, JE exhibited higher values in pressure differences at 60 mL (27.7 vs 3.75, P < .001).

CONCLUSIONS

Esophageal pressure, as measured by EndoFLIP, was significantly reduced when patients were sedated with sevoflurane-based GAIA. The use of sevoflurane-based GAIA for diagnostic EndoFLIP may potentially lead to the misclassification of spastic disorders as type I achalasia. Propofol-based TIVA should therefore be considered over sevoflurane-based GAIA for sedation during the diagnostic test.

Endoscopic Features of Eosinophilic Gastrointestinal Diseases

Endoscopic evaluation with biopsies is a mainstay of the diagnosis of eosinophilic esophagitis (EoE) and non-EoE eosinophilic gastrointestinal diseases (EGIDs). Increasing knowledge has resulted in the development of 2 standardized scoring systems: the Endoscopic REFerence Score (EREFS) for EoE and the EG-REFS for eosinophilic gastritis, although the latter has not been validated. In EGIDs, diagnosis and follow-up focus on eosinophil infiltration in biopsies. In this article, we will discuss the most commonly used endoscopic scores in EoE and non-EoE EGIDs, their validity for the diagnosis and follow-up of disease activity, as well as endoscopic interventions and areas of uncertainty.

Expert Recommendations on the Diagnosis of Eosinophilic Esophagitis in the United Arab Emirates

Eosinophilic esophagitis (EoE) is a chronic, progressive, type 2 inflammatory esophageal disease presenting as dysphagia to solid food and non-obstructive food impaction. Knowledge gaps exist in its diagnosis and management. These expert recommendations focused on the diagnosis of EoE in the United Arab Emirates. An electronic search of PubMed and Embase databases was used to gather evidence from systematic reviews, randomized controlled trials, consensus papers, and expert opinions from the last five years on the diagnosis of EoE. The evidence was graded using the Oxford system. Literature search findings were shared with the expert panel. A 5-point scale (strongly agree, agree, neither agree nor disagree, disagree, and strongly disagree) was used, and a concordance rate of >75% among experts indicated agreement. Using a modified Delphi technique, 18 qualified experts provided 17 recommendations. Eleven statements achieved high agreement, four got moderate agreement, and two got low agreement. Challenges exist in diagnosing EoE, particularly in children. Esophageal biopsies were crucial in diagnosis, irrespective of visible mucosal changes. Further research on diagnostic tools like endoscopic mucosal impedance and biomarkers is needed. Diagnosis relies on esophageal biopsies and symptom-histology correlation; however, tools like EoE assessment questionnaires and endoscopic mucosal impedance could enhance the accuracy and efficiency of EoE diagnosis. The diagnosis of EoE is challenging since the symptoms seldom correlate with the histological findings. Currently, diagnosis is based on patient symptoms and endoscopic and histological findings. Further research into mucosal impedance tests and the role of biomarkers is needed to facilitate diagnosis.

A Mechanics-Based Perspective on the Function of Human Sphincters During Functional Luminal Imaging Probe Manometry

Functional luminal imaging probe (FLIP) is used to measure cross-sectional area (CSA) and pressure at sphincters. It consists of a catheter surrounded by a fluid filled cylindrical bag, closed on both ends. Plotting the pressure-CSA hysteresis of a sphincter during a contraction cycle, which is available through FLIP testing, offers information on its functionality, and can provide diagnostic insights. However, limited work has been done to explain the mechanics of these pressure-CSA loops. This work presents a consolidated picture of pressure-CSA loops of different sphincters. Clinical data reveal that although sphincters have a similar purpose (controlling the flow of liquids and solids by opening and closing), two different pressure-CSA loop patterns emerge: negative slope loop (NSL) and positive slope loop (PSL). We show that the loop type is the result of an interplay between (or lack thereof) two mechanical modes: (i) neurogenic mediated relaxation of the sphincter muscle or pulling applied by external forces, and (ii) muscle contraction proximal to the sphincter which causes mechanical distention. We conclude that sphincters which only function through mechanism (i) exhibition NSL whereas sphincters which open as a result of both (i) and (ii) display a PSL. This work provides a fundamental mechanical understanding of human sphincters. This can be used to identify normal and abnormal phenotypes for the different sphincters and help in creating physiomarkers based on work calculation.

A New Method to Evaluate Lower Esophageal Distension Capacity in Eosinophilic Esophagitis by Using Functional Lumen Imaging Probe (EndoFLIP™)

Endoluminal functional lumen impedance planimetry (EndoFLIPTM) has become the gold standard to evaluate esophageal distensibility, although the study itself and its analysis present challenges. We propose here a new method to assess lower esophageal distension capacity that overcomes several limitations of prior approaches, including incomplete and corrupted EndoFLIPTM recordings. Esophageal distension capacity was evaluated with a 16-channel EndoFLIPTM in 10 controls and 14 patients with eosinophilic esophagitis (EoE). Controls were evaluated once. EoE patients were evaluated at baseline and after at least six weeks of treatment with orodispersible budesonide tablets, 1 mg bd. Balloon volumes were increased by 5 mL stepwise, either reaching a maximum volume of 60 mL or a maximum balloon pressure of 60 mmHg. Recordings were analyzed with a homemade R script. The mean esophageal diameter at 60 mL, D (60 mL), was calculated or extrapolated depending on whether the 60 mL volume was reached. By fitting a Michaelis-Menten curve across all measured diameters throughout all constant volume steps, the mean D (60 mL) was estimated. For control subjects, the mean ± SD value of D (60 mL) was 17.08 ± 1.69 mm, and for EoE patients at baseline, D (60 mL) was 14.51 ± 2.68 mm. After six weeks of treatment of EoE patients, D (60 mL) significantly increased to 16.22 ± 1.86 mm (paired Wilcoxon signed test: p = 0.0052), although the values for control subjects were not reached. The estimated mean esophageal diameter at 60 mL is a good proxy for esophageal distension capacity, which correlates with clinical outcomes in EoE. The method presented in this study overcomes difficulties encountered during the standard measurement protocol, allowing the analysis of recordings from incomplete and corrupted registries.

A Comparison of Functional Luminal Imaging Probe With High-resolution Manometry, Timed Barium Esophagram, and pH Impedance Testing to Evaluate Functional Luminal Imaging Probe's Diagnostic Capabilities

OBJECTIVE

The aims of this study are to determine the functional luminal imaging probe's (FLIP) diagnostic utility by comparing FLIP measurements with results from other esophageal evaluation standards.

BACKGROUND

The FLIP is an esophageal evaluation technique performed at the time of endoscopy. Few studies have evaluated FLIP diagnostic capabilities compared with the established testing techniques, including high-resolution manometry (HRIM), time barium esophagram (TBE), and 24-hour impedance-pH monitoring.

PATIENTS AND METHODS

A retrospective review was performed for 413 preintervention patients who underwent FLIP testing during endoscopy. Data from HRIM, 24-hour pH monitoring, and TBE were compared.

RESULTS

Abnormal Distensibility Index (DI) was associated with abnormal integrated relaxation pressure (IRP; P = 0.003). Average DI was higher in patients with abnormal IRP (>15 mm Hg) when a hiatal hernia was present (P = 0.025). The total agreement between correlated diagnoses from FLIP and HRIM was 33.5%. DI was not associated with acid exposure time on pH monitoring. Agreement between FLIP and TBE was 49% with a sensitivity of 98.1% and a specificity of 36.5%. A 60 mL distension had a significantly lower detection rate than 40 mL and 50 mL for active peristalsis and was unaffected by pressure (P < 0.05).

CONCLUSIONS

FLIP as an adjunct to HRIM is supported by strong metric correlation. FLIP was not correlated to pH monitoring findings, suggesting FLIP is not useful in reflux assessment. The agreement between FLIP and TBE was lower than in previous studies. Hiatal hernia impacted the normality between DI and IRP, not between FLIP and TBE. We suggest analyzing peristaltic patterns on panometry at all fill volumes to optimize detection.

Utilizing a Functional Lumen Imaging Probe for Evaluation of the Pediatric Airway, A Pilot Study

OBJECTIVES

Accurate and reproducible measurements of the pediatric airway are critical for diagnostic evaluation and management of subglottic and tracheal stenosis. The endoluminal functional lumen imaging probe (EndoFLIP) is a catheter-based imaging probe which utilizes impedance planimetry to calculate luminal parameters, including cross-sectional area and compliance. Herein, we demonstrate the feasibility of this system for multidimensional evaluation of the pediatric airway.

METHODS

3D-printed pediatric laryngotracheal models were created based on computed tomography scans, then artificially deformed to simulate both circumferential and posterior subglottic stenosis. Two observers made six measurements of the minimum cross-sectional area (MCSA) and length of stenosis of each model with EndoFLIP. Agreement between observer measurements and model dimensions was evaluated using Lin's concordance correlation coefficient; inter-observer reliability was assessed using intraclass correlation.

RESULTS

Four models were created: two without pathology (MCSA: 132.4, 44.3 mm2 ) and two with subglottic stenosis (MCSA: 28.7, 59.7 mm2 , stenotic length 27.8, 24.4 mm). Observer measurements of MCSA and length of stenosis demonstrated high concordance with the models (r = 0.99, 0.95, p < 0.001) with a mean error of 4.5% and 18.2% respectively. There was a low coefficient of variation (0.6%-2.8%) for measurements, indicating high precision. Interrater reliability was high for both MCSA and stenotic length (ICC: 0.99, 0.98).

CONCLUSIONS

The EndoFLIP system allows for accurate and reproducible measurements of cross-sectional area and stenotic length in pediatric airway models. This method may provide further advantages in the evaluation of airway distensibility, as well as measurements of asymmetric airway pathology.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:108-112, 2024.

Current Approach to Dysphagia: A Review Focusing on Esophageal Motility Disorders and Their Treatment

Background

Dysphagia is a prevalent condition which may severely impact the patient's quality of life. However, there are still lacking standardized therapeutic options for esophageal motility disorders.

Summary

Dysphagia is defined as a subjective sensation of difficulty swallowing which can result from oropharyngeal or esophageal etiologies. Regarding esophageal dysphagia, after excluding structural causes and esophageal mucosal lesions, high-resolution manometry (HRM) is the gold standard for the diagnosis of esophageal motility disorders. HRM has not only improved the sensitivity for detecting achalasia but has also expanded our understanding of spastic and hypomotility disorders of the esophageal body. The Chicago Classification v4.0 uses a hierarchical approach and provides a standardized diagnosis of esophageal motility disorders, allowing a tailored therapeutic approach. Dysphagia is often a long-term health problem that broadly impacts health and well-being and leads to physical and psychosocial disability, namely, malnutrition and aspiration pneumonia, as well as social isolation, depression, and anxiety. Apart from achalasia, most esophageal motility disorders tend to have a benign long-term course with symptoms of dysphagia and noncardiac chest pain that can improve significantly over time. Patient-reported outcomes (PROs) are self-assessment tools that capture the patients' illness experience and help providers better understand symptoms from the patients' perspective. Therefore, PROs have a critical role in providing patient-centered care.

Key Messages

Motility disorders should be ruled out in the presence of nonobstructive esophageal dysphagia, and treatment options should be considered according to the severity of symptoms reported by the patient.

Interventional functional diagnostics in gastrointestinal endoscopy: Combining diagnostic and therapeutic tools in the endoscopy suite with the functional lumen imaging probe

With technical progress of gastrointestinal functional testing, there has been a demand for more comprehensive examination of esophageal physiology and pathophysiology beyond high-resolution manometry. A new interventional technology based on impedance planimetry, the functional lumen imaging probe (FLIP), enables intraluminal measurement of distensibility and compliance of hollow organs. EndoFLIP uses balloon catheters to measure diameter and distension pressure to calculate cross-sectional area and distensibility in different organs (mostly esophagus, stomach, anorectal region) and can be used in wide variety of indications (diagnostics, pre- and post-treatment evaluation) and currently serves as a helpful adjunctive tool in ambiguous clinical cases. EsoFLIP is a therapeutic variation that uses a stiffer balloon catheter allowing for dilation. The trend to simplify the clinical process from diagnosis to treatment tends to a one-session procedure combining diagnostics and therapeutic interventions. In specified conditions like e.g. achalasia or gastroparesis, a combination of EndoFLIP and EsoFLIP procedures may therefore be useful. The aim of this narrative review is to introduce the clinical use of FLIP and its potential benefit in combined diagnostic-therapeutic procedures.

Mini-review: Tailored per-oral endoscopic myotomy for type III achalasia

This mini-review summarizes the most recent literature regarding per-oral endoscopic myotomy for type III achalasia, emphasizing the poorly understood science of tailoring myotomy length during this procedure. In addition, special attention will be placed on the current subjective and objective biomarkers, such as the Eckardt score, used to evaluate treatment outcomes in this population to better contextualize the existing data on patient outcomes, as proposed by Low et al in the current issue of the Journal. Understanding the current treatment landscape for type III achalasia and identifying the key areas of research deficiencies will guide future investigation and management of this disease.

Esophageal biomechanics assessed by impedance planimetry (EndoFLIPTM) in healthy subjects and in patients with eosinophilic esophagitis. Normality values

BACKGROUND

active eosinophilic esophagitis is associated with esophageal caliber, distensibility and motility changes that may be reversed with treatment.

OBJECTIVES

to study esophageal diameter, distensibility and contractility in healthy subjects compared to patients with eosinophilic esophagitis, both before and after treatment.

METHODS

a quasi-experimental study, EndoFLIP™, was used to analyze the esophageal body and esophago-gastric junction (EGJ) in all three groups, and a program was designed to obtain esophageal diameter, distensibility and contractility values.

RESULTS

ten healthy volunteers (24-61 years, six men) and nine patients with eosinophilic esophagitis (21-52 years, seven men) were included. The esophagogastric junction distensibility index was 5.07 mm2/Hg in the control subjects, 2.40 mm2/Hg in the subjects with eosinophilic esophagitis before treatment and 2.46 mm2/Hg after treatment. The distensibility plateau was 20.02 mm, 15.43 mm and 17.41 mm, respectively, and the diameter was 21.90 mm, 17.73 mm and 18.30 mm, showing significant differences (p < 0.05), except between control subjects and patients after treatment (p = 0.079). Repetitive antegrade contractions developed in 90 % of control subjects, 66.7 % of eosinophilic esophagitis patients before treatment and 88.9 % of the latter after treatment (p > 0.05).

CONCLUSIONS

esophago-gastric junction distensibility index, distensibility plateau and diameter values were higher in controls than in patients, although six weeks of treatment seems a short period to observe significant changes in esophageal biomechanics. Repetitive antegrade contractions are the predominant pattern in healthy subjects and eosinophilic esophagitis. We provide normality values for esophageal biomechanics, measured by impedance planimetry in our setting.

Intraoperative distensibility measurement in POEM for achalasia: impact on patient outcome and associations with other outcome variables at 1-year follow-up

BACKGROUND AND AIMS

The functional luminal imaging probe (FLIP) can provide measurements of lower esophageal sphincter (LES) distensibility. Studies report that use of intraoperative FLIP examination during peroral endoscopic myotomy (POEM) for achalasia is associated with treatment success, but evidence is limited and inconsistent. The main aim of the present study was to assess associations between intraoperative FLIP values and 1-year outcomes. Additionally, associations between 1-year FLIP measurements and other 1-year outcome variables were studied.

METHODS

We performed a single-center prospective study of consecutive achalasia patients treated with POEM with a standardized 1-year follow-up. The inclusion period was from June 2017 to January 2020. We compared 1-year outcomes (FLIP measurement values, Eckardt score (ES), reflux esophagitis, timed barium esophagogram (TBE), and lower esophageal sphincter resting pressure (LES-rp)) in patients with and without intraoperative FLIP examination. We also assessed associations between intraoperative FLIP values, 1-year FLIP values, and other 1-year outcomes. Results are given as median (IQR), and non-parametrical statistical analyses were applied.

RESULTS

Sixty-two patients (27 females) with median age 45 years (35-54) were included. Baseline characteristics were similar in patients with (n = 32) and without (n = 30) intraoperative FLIP examination. In patients with intraoperative FLIP, ES was 2 (1-3) and LES distensibility index (DI) 3.7 (2.6-5.4) after 1 year, compared with ES 2 (1-3) and DI 4.0 (3.1-6.8)) in patients without intraoperative FLIP (ns). Intraoperative DI was not correlated with 1-year ES or DI. One-year DI correlated significantly with 1-year ES (rs - 0.42), TBE (rs - 0.34), and LES-rp (rs - 0.29).

CONCLUSIONS

Use of intraoperative FLIP measurements in POEM for achalasia is not associated with improved 1-year outcome, and the clinical value of intraoperative FLIP in POEM for achalasia is questioned. Follow-up FLIP measurements are moderately associated with symptomatic outcome, and may serve as an additional diagnostic modality in post-treatment evaluation.

Histological Phenotyping in Eosinophilic Esophagitis: Localized Proximal Disease Is Infrequent but Associated with Less Severe Disease and Better Disease Outcome

INTRODUCTION

It is still unknown whether eosinophilic esophagitis (EoE) patients with localized disease are different from those with extended disease.

METHODS

We evaluated prospectively included patients in the Swiss EoE cohort. Data on all patients with active disease at baseline, no concomitant gastroesophageal reflux disease, no strictures at baseline, and at least one follow-up visit were analyzed. We compared patients with histologically localized proximal versus distal versus extended (=proximal and distal) disease with regard to patient, disease characteristics, disease presentation, and development of complications.

RESULTS

We included 124 patients with a median of 2.5 years of follow-up (73.4% males, median age 35.0 years). Ten patients had proximal (8.1%), 46 patients had distal (37.1%), and 68 patients had extended disease (54.8%). Patients with proximal disease were significantly more often females (80%) compared with patients with distal (26.1%, p = 0.002) or extended disease (19.1%, p < 0.001) and reported less severe symptoms (VAS 0 vs. VAS 1, p = 0.001). Endoscopic and histological disease was less pronounced in the proximal esophagus of proximal EoE compared to extended disease (EREFS 1.0 vs. 3.0, p = 0.001; 27.0 eos/hpf vs. 52.5 eos/hpf, p = 0.008). Patients with proximal disease were less likely to undergo dilation compared to patients with distal disease in the follow-up (3.3% vs. 23.3%, p = 0.010). In a multivariate Cox regression model, proximal eosinophilia was less likely to be associated with treatment failure compared to distal eosinophilia.

CONCLUSION

Although isolated proximal EoE is infrequent, it is associated with less severe disease and better disease outcome. Proximal disease appears to present a unique EoE phenotype.

Use of endolumenal functional lumen imaging probe in investigating paediatric gastrointestinal motility disorders

Investigating gastrointestinal (GI) motility disorders relies on diagnostic tools to assess muscular contractions, peristalsis propagation and the integrity and coordination of various sphincters. Manometries are the gold standard to study the GI motor function but it is increasingly acknowledged that manometries do not provide a complete picture in relation to sphincters competencies and muscle fibrosis. Endolumenal functional lumen imaging probe (EndoFLIP) an emerging technology, uses impedance planimetry to measure hollow organs cross sectional area, distensibility and compliance. It has been successfully used as a complementary tool in the assessment of the upper and lower oesophageal sphincters, oesophageal body, the pylorus and the anal canal. In this article, we aim to review the uses of EndoFLIP as a tool to investigate GI motility disorders with a special focus on paediatric practice. The majority of EndoFLIP studies were conducted in adult patients but the uptake of the technology in paediatrics is increasing. EndoFLIP can provide a useful complementary data to the existing GI motility investigation in both children and adults.

The utility of Endoscopic Functional Luminal Imaging (EndoFLIP) in the diagnosis and management of children with achalasia

BACKGROUND

Per-oral endoscopic myotomy (POEM) has is an alternative treatment to laparoscopic Heller myotomy for children with achalasia. The EndoFLIP functional luminal imaging system is used to measure esophagogastric junction (EGJ) distensibility pre- and post-POEM. Previous adult studies have established a correlation between obstructive symptoms and Distensibility Index (DI). Here we analyze the utility of EndoFLIP in diagnosis and management of achalasia in the largest study on pediatric POEM patients and hypothesize that DI may aid diagnosis and treatment of pediatric achalasia.

METHODS

Demographics, preoperative basal and residual pressures measured on manometry, and EndoFLIP measurements pre- and post-POEM were recorded for children that underwent POEM. Pearson correlation coefficient and T-scores were used to assess for correlation between manometry measurements and pre-POEM DI. Linear regression was conducted to analyze the relationship between pre-POEM DI, Eckardt scores, and manometry pressures.

RESULTS

Of 33 patients that underwent POEM and EndoFLIP since 2014 (21 male, 12 female), the median pre-POEM Eckardt score decreased from 7 to 1 post-POEM. The median basal pressure was 50 ± 25 mmHg, pre-POEM DI was 0.9 (0.8-1.6) mm²/mmHg and the post-POEM DI was 3.8 (3.2-4.4) mm²/mmHg. There was no correlation between DI and basal pressure or residual pressure, though there was a strong negative correlation between Eckardt scores and DI.

CONCLUSION

The EndoFLIP system is a valuable tool in adult patients in diagnosing achalasia and defining the endpoint of the POEM procedure. We find that there is a role for EndoFLIP in the pediatric population in diagnosis and management of the disease.

TYPE OF STUDY & LEVEL OF EVIDENCE

Study of diagnostic test; Level IV.

Eosinophilic Esophagitis—What Do We Know So Far?

Eosinophilic esophagitis is a Th-2 antigen-mediated disease in which there is an influx of eosinophils to all layers of the esophagus, triggering an inflammatory response. Chronic inflammatory process causes esophageal remodeling, leading to difficulties in swallowing. Food impaction, heartburn, and chest pain are other characteristic (but not pathognomonic) symptoms in adults. Although the disease has only been described since in the early 1970s, its incidence and prevalence are rapidly growing, especially in Western countries. According to the diagnostic guidelines, there should be at least 15 eosinophils visible per high-power field in biopsies obtained from different sites in the esophagus upon endoscopy with relevant esophageal symptoms. Other diseases that can cause esophageal eosinophilia should be ruled out. Eosinophilic esophagitis treatment may be challenging; however, new methods of management have recently emerged. The currently used proton pump inhibitors, topical corticosteroids, and elimination diet are combined with biological treatment. New methods for disease diagnostics and clinical course assessment are also available. This review presents current knowledge about the disease, supported by the latest research data.

Impedance planimetry (EndoFLIP) assisted laparoscopic esophagomyotomy in pediatric population

INTRODUCTION

Functional lumen imaging probe (EndoFLIP) is a diagnostic technology that assesses esophageal cross-sectional area via impedance planimetry during controlled volumetric distention. The purpose of this study is to evaluate the utility of EndoFLIP intraoperatively during laparoscopic esophagomyotomy.

METHODS

We performed a retrospective cohort study reviewing all patients undergoing EndoFLIP assisted laparoscopic esophagomyotomy for achalasia between January and December 2021 (n = 10). Twenty-two patients with achalasia that underwent traditional laparoscopic esophagomyotomy between July 2014 and September 2019 served as a comparison. Primary outcome evaluated was resolution of symptoms at discharge. Secondary outcomes included change in distensibility index (DI), operative time, length of stay, time to regular diet, and reinterventions.

RESULTS

All patients managed with EndoFLIP assistance had resolution of dysphagia and postprandial vomiting following intervention. Mean change in DI was 5.32 mm²/mmHg with a myotomy length of 3.6 cm. Operative time was shorter in the EndoFLIP cohort (97 min versus 185 min, p = <0.001). Study patients did not undergo an antireflux operation. There was no difference in length of stay or time to soft diet between groups. All patients were discharged on postoperative day 1 tolerating a mechanical soft diet. No acid suppressive medications were prescribed during the observation period. One patient required dilation for recurrent symptoms and one required reoperation for mucosal leak.

CONCLUSION

EndoFLIP assisted laparoscopic esophagomyotomy results in similar short-term outcomes to traditional surgical technique. EndoFLIP allows for focused myotomy length and a shorter operative time.

LEVEL OF EVIDENCE

III.

Virtual disease landscape using mechanics-informed machine learning: Application to esophageal disorders

Esophageal disorders are related to the mechanical properties and function of the esophageal wall. Therefore, to understand the underlying fundamental mechanisms behind various esophageal disorders, it is crucial to map mechanical behavior of the esophageal wall in terms of mechanics-based parameters corresponding to altered bolus transit and increased intrabolus pressure. We present a hybrid framework that combines fluid mechanics and machine learning to identify the underlying physics of various esophageal disorders (motility disorders, eosinophilic esophagitis, reflux disease, scleroderma esophagus) and maps them onto a parameter space which we call the virtual disease landscape (VDL). A one-dimensional inverse model processes the output from an esophageal diagnostic device called the functional lumen imaging probe (FLIP) to estimate the mechanical "health" of the esophagus by predicting a set of mechanics-based parameters such as esophageal wall stiffness, muscle contraction pattern and active relaxation of esophageal wall. The mechanics-based parameters were then used to train a neural network that consists of a variational autoencoder that generated a latent space and a side network that predicted mechanical work metrics for estimating esophagogastric junction motility. The latent vectors along with a set of discrete mechanics-based parameters define the VDL and formed clusters corresponding to specific esophageal disorders. The VDL not only distinguishes among disorders but also displayed disease progression over time. Finally, we demonstrated the clinical applicability of this framework for estimating the effectiveness of a treatment and tracking patients' condition after a treatment.

Use of an intragastric trocar to perform a novel stapling procedure for reflux disease

Background and study aims  A percutaneous intragastric trocar (PIT) enables intraluminal use of laparoscopic tools and helps overcome traditional limitations of endoscopy. The aim of this study was to determine the efficacy of using a PIT to perform an anti-reflux stapling procedure. Materials and methods  Trocars were placed in four animals and an articulating stapler was used to perform fundoplication under endoscopic guidance. Animals were monitored for 14 days post-procedure. Functional lumen imaging of the esophagogastric junction (EGJ) was performed at baseline, immediately post-intervention, and at 14 days. Results  The procedure was successful in all animals who survived to day 14 without distress or significant adverse events. Baseline EGJ distensibility was 5.0 ± 1.2 mm ² /mmHg, 2.7 ± 0.7 mm ² /mmHg post-procedurally, and 3.0 ± 0.8mm ² /mmHg on day 14. Average change in distensibility pre- and post-procedure was -2.3 ± 1.8 mm ² /mmHg (95 % confidence interval [CI] -0.5 to 5.1, P  = 0.08) while change in pre- and day 14 distensibility was -2.0 ± 1.4 mm ² /mmHg (95 % CI -0.1 to 4.2, P  = 0.06). Conclusions  An intragastric trocar allows for use of large-diameter laparoscopic instruments to safely and effectively perform endoluminal fundoplication with anti-reflux properties that persist for at least 14 days.

Current and future perspectives on the utility of provocative tests of anal sphincter function: A state-of-the-art summary

BACKGROUND

The maintenance of fecal continence depends upon coordinated interactions between the pelvic floor, anorectum, and anal sphincter complex orchestrated by central and peripheral neural activities. The current techniques to objectively measure anorectal function rely on fixed diameter catheters placed inside the anal canal with a rectal balloon to obtain measurements of anal resting and squeeze function, and rectal compliance. Until recently it had not been possible to measure the distensibility of the anal canal, or in other words its ability to resist opening against an increasing pressure, which has been proposed as the main determinant of a biological sphincter's function. Anal acoustic reflectometry (AAR) and the functional lumen imaging probe (FLIP) are two novel, provocative techniques that dynamically assess the anal sphincter complex under volume-controlled distension. In doing so, both provide information on the viscoelastic properties of the anal canal and offer new insights into its function.

PURPOSE

This review details the current and potential future applications of AAR and FLIP and highlights the unanswered questions relevant to these new technologies.

Normative values for esophageal functional lumen imaging probe measurements: A meta-analysis

BACKGROUND

The functional lumen imaging probe (Endoflip™) is increasingly used for evaluation of patients with esophageal symptoms. To improve the interpretation of Endoflip™ in clinical practice, normative values with appropriate cut-off values are required.

METHODS

Original clinical studies describing Endoflip™ use for measurements of esophageal motility in healthy adults were considered. Meta-analysis was performed based on published values.

RESULTS

A total of 17 articles were included in the systematic review, 15 of which were included in the meta-analysis, representing 154 unique subjects. At 40 ml distention, the 5th-95th and 10th-90th percentiles for esophagogastric junction distensibility index (EGJ-DI) were 1.96-10.95 mm² /mmHg and 2.36-8.95 mm² /mmHg, respectively. An EGJ-DI below 2 mm² /mmHg was found in 5.4%, and below 3 mm² /mmHg in 20.1% of healthy subjects. At 50 ml distention, the 5th-95th and 10th-90th percentiles for EGJ-DI are 2.86-10.66 mm² /mmHg and 3.28-9.12 mm² /mmHg, respectively (below 2 mm² /mmHg: 0.6%, 3 mm² /mmHg: 6.3%). The 5th-95th and 10th-90th percentiles for EGJ-DI at 60 ml distention were 3.06-8.14 mm² /mmHg and 3.33-7.18 mm² /mmHg, respectively (below 2 mm² /mmHg: 0.0%, 3 mm² /mmHg: 7%). A clear cut-off for lower values was identified while a large spread in values was observed for upper limits of normal for EGJ-DI for all filling volumes.

CONCLUSIONS

Given these observations, we recommend using a cut-off of 2 mm² /mmHg for clinical practice, values below can be considered abnormal. Given that 5.4% of the healthy subjects will have an EGJ-DI below 2 mm² /mmHg at 40 ml, we recommend using the 50 and 60 ml distention volumes. The clinical use of an upper limit for normality of EGJ-DI seems questionable.

Endoscopic approach to eosinophilic esophagitis: American Society for Gastrointestinal Endoscopy Consensus Conference

Endoscopy plays a critical role in caring for and evaluating the patient with eosinophilic esophagitis (EoE). Endoscopy is essential for diagnosis, assessment of response to therapy, treatment of esophageal strictures, and ongoing monitoring of patients in histologic remission. To date, less-invasive testing for identifying or grading EoE severity has not been established, whereas diagnostic endoscopy as integral to both remains the criterion standard. Therapeutic endoscopy in patients with adverse events of EoE may also be required. In particular, dilation may be essential to treat and attenuate progression of the disease in select patients to minimize further fibrosis and stricture formation. Using a modified Delphi consensus process, a group of 20 expert clinicians and investigators in EoE were assembled to provide guidance for the use of endoscopy in EoE. Through an iterative process, the group achieved consensus on 20 statements yielding comprehensive advice on tissue-sampling standards, gross assessment of disease activity, use and performance of endoscopic dilation, and monitoring of disease, despite an absence of high-quality evidence. Key areas of controversy were identified when discussions yielded an inability to reach agreement on the merit of a statement. We expect that with ongoing research, higher-quality evidence will be obtained to enable creation of a guideline for these issues. We further anticipate that forthcoming expert-generated and agreed-on statements will provide valuable practice advice on the role and use of endoscopy in patients with EoE.

Utility of Functional Lumen Imaging Probe in Long-Term Follow-Up of Children with Esophageal Atresia: A Single-Center Retrospective Study

Long term follow-up of patients with esophageal atresia (EA) may be hampered by esophageal dysmotility, which affects quality of life and might lead to late complications. The endoluminal functional lumen imaging probe (EndoFlip™ Medtronic, Crospon Inc.) is an innovative diagnostic tool that assesses esophageal distensibility. Our aim was to report the use of EndoFlip™ in an EA follow-up, in order to describe distensibility patterns and to determine its possible role for functional evaluation of patients. We retrospectively collected data of EA patients, with a minimum follow-up of 9 years, who required endoscopic evaluation and underwent EndoFlip™. An adaptation of the Medtronic EF-322 protocol was applied and distensibility data were compared to those reported by Pandolfino et al. Nine patients (median age 13 years) were included in the study. The median minimum distensibility was 2.58 mm²/mmHg. Signs of peristalsis were observed in three patients. In one case, the esophagogastric junction (EGJ) after Toupet fundoplication showed low distensibility. EGJ distensibility values of 2.58 mm²/mmHg (median) confirmed both good esophagogastric continence and compliance. Esophagitis and absent peristalsis were found in one patient together with partial stenosis of the fundoplication, confirming the importance of surgical adaptation. Esophageal body distensibility was higher than that of the EGJ. Considering the presence of symptoms, the EndoFlip™ results seem to correlate better with the clinical picture. EndoFlip™ use was safe and feasible in children. It allowed for the measurement of esophageal distensibility and diameter and the acquisition of indirect information on motility with clinical implications. The routine use of EndoFlip™ could be part of EA follow-up, although considerable research is needed to correlate Endoflip™ system measurements to EA patient outcomes.

Nasal Continuous Positive Airway Pressure as a Preferred Airway Management During IV Sedation of Obese Patients With Obstructive Sleep Apnea Undergoing Functional Luminal Imaging Probe Panometry

The functional luminal imaging probe (FLIP) utilizes high-resolution planimetry to provide information regarding esophagogastric junction (EGJ) diameter, EGJ distensibility, and reactive contractile patterns of the esophageal body. This is an FDA-approved measurement tool utilized to both diagnose and measure various upper gastrointestinal disorders. While patients are sedated during FLIP panometry, significant respiratory variations can affect the quality of FLIP panometry results. Nasal continuous positive airway pressure (CPAP) can be utilized to prevent intraoperative or postoperative hypoxia in obese patients as well as those with obstructive sleep apnea (OSA). In this retrospective chart review, we compared obese patients with a diagnosis of OSA who underwent FLIP panometry utilizing nasal CPAP as airway management against a group who underwent the same procedure with a nasal cannula to evaluate the incidence of hypoxia, hypercapnia, variation in cardiovascular dynamics, and the quality of FLIP panometry readings.

Advances in Pediatric Diagnostic Endoscopy: A State-of-the-Art Review

Pediatric endoscopy has revolutionized the way we diagnose and treat gastrointestinal disorders in children. Technological advances in computer processing and imaging continue to affect endoscopic equipment and advance diagnostic tools for pediatric endoscopy. Although commonly used by adult gastroenterologists, modalities, such as endomicroscopy, image-enhanced endoscopy, and impedance planimetry, are not routinely used in pediatric gastroenterology. This state-of-the-art review describes advances in diagnostic modalities, including image-enhanced endoscopy, confocal laser endomicroscopy, optical coherence tomography, endo functional luminal imaging probes, wireless motility/pH capsule, wireless colon capsule endoscopy, endoscopic ultrasound, and discusses the basic principles of each technology, including adult indications and pediatric applications, safety cost, and training data.

Relationship between dysphagia, lower esophageal sphincter relaxation, and esophagogastric junction distensibility

BACKGROUND

It is debated whether high-resolution manometric (HRM) integrated relaxation pressure (IRP) or functional lumen imaging probe (FLIP) distensibility index (DI) is the superior measure of esophagogastric junction (EGJ) opening. We examined the relationship between the DI and IRP and assessed correlations with dysphagia symptoms in patients with achalasia and EGJ outflow obstruction (EGJOO).

METHODS

Patients with achalasia and those with barium tablet retention at the EGJ were grouped as follows: Group 1:Achalasia (IRP ≥ 15 mmHg + complete absence of normal peristalsis); Group 2: Manometric +FLIP EGJOO (IRP ≥ 15 mmHg with some intact peristalsis + DI ≤ 2.8 mm2 /mmHg); Group 3: Abnormal DI only (DI ≤ 2.8 mm2 /mmHg + IRP <15 mmHg); and Group 4: Normal IRP and DI (IRP ≥ 15 mmHg + DI > 2.8 mm2 /mmHg). Correlation between the DI, baseline lower esophageal sphincter pressure (BLESP), IRP, and dysphagia (Eckardt score) was assessed. Multivariable analysis was used to assess variables associated with dysphagia score ≥2.

KEY RESULTS

A total of 79 patients were included: Group 1 (n = 31), Group 2 (n = 33), Group 3 (n = 14), and Group 4 (n = 1). DI did not correlate with BLESP or IRP in the whole sample or subgroups. DI was the only variable associated with dysphagia score ≥2 (p = 0.006). DI < 1.25 mm2 /mmHg had sensitivity of 87% and specificity of 52% (p = 0.0003) for dysphagia score ≥2.

CONCLUSIONS & INFERENCES

DI does not correlate with HRM EGJ measurements and is the metric with the strongest effect on dysphagia severity. The various biological elements that may cause restrictive EGJ function should be the subject of future studies.

Kyoto international consensus report on anatomy, pathophysiology and clinical significance of the gastro-oesophageal junction

OBJECTIVE

An international meeting was organised to develop consensus on (1) the landmarks to define the gastro-oesophageal junction (GOJ), (2) the occurrence and pathophysiological significance of the cardiac gland, (3) the definition of the gastro-oesophageal junctional zone (GOJZ) and (4) the causes of inflammation, metaplasia and neoplasia occurring in the GOJZ.

DESIGN

Clinical questions relevant to the afore-mentioned major issues were drafted for which expert panels formulated relevant statements and textural explanations.A Delphi method using an anonymous system was employed to develop the consensus, the level of which was predefined as ≥80% of agreement. Two rounds of voting and amendments were completed before the meeting at which clinical questions and consensus were finalised.

RESULTS

Twenty eight clinical questions and statements were finalised after extensive amendments. Critical consensus was achieved: (1) definition for the GOJ, (2) definition of the GOJZ spanning 1 cm proximal and distal to the GOJ as defined by the end of palisade vessels was accepted based on the anatomical distribution of cardiac type gland, (3) chemical and bacterial (Helicobacter pylori) factors as the primary causes of inflammation, metaplasia and neoplasia occurring in the GOJZ, (4) a new definition of Barrett's oesophagus (BO).

CONCLUSIONS

This international consensus on the new definitions of BO, GOJ and the GOJZ will be instrumental in future studies aiming to resolve many issues on this important anatomic area and hopefully will lead to better classification and management of the diseases surrounding the GOJ.

Role of functional luminal imaging probe in the management of postmyotomy clinical failure

BACKGROUND AND AIMS

A small percentage of patients with esophageal dysmotility disorders (EDDs) fail to improve or relapse after management by laparoscopic Heller myotomy (LHM) and peroral endoscopic myotomy (POEM). In this study, we aimed to describe the role of functional luminal imaging probe (FLIP) in identifying patients who might benefit from lower esophageal sphincter (LES)-directed retreatment.

METHODS

This was a retrospective study at 6 tertiary care centers (United States, 4; Europe, 1; Asia, 1) between January 2015 and April 2021 involving patients with prior failed myotomy. The primary outcome was the impact of the use of FLIP on the management of patients with prior failed myotomy.

RESULTS

One hundred twenty-three patients (62 women [50%]; mean age, 53 ± 21.1 years) who underwent LHM (n = 53, 43%) or POEM (n = 70, 57%) for the management of achalasia (n = 98) or other EDDs (n = 25) had clinical failure at a median time of 10.8 months (interquartile range, .8-17.3) postprocedure. Twenty-nine patients had apposing "abnormal" diagnoses in terms of integrated relaxation pressure (IRP) >15 mm Hg on HRM and distensibility index (DI) <2.8 mm²/mm Hg on FLIP, with ultimate change in management noted in 15 patients (10 directed toward conservative management, 5 directed toward LES-directed retreatment). The impact of FLIP on both diagnosis and management was noted in 15 of 29 patients (52%). In the subgroup analysis of 44 patients who underwent LES-directed retreatment, clinical success was highest among patients with both abnormal IRP and DI (21/25 [84%]) versus patients with only abnormal IRP (8/14 [57%]) or only abnormal DI (3/5 [60%], P = .04), with DI at 40-mL distension volume on FLIP identified as an independent predictor of clinical success (odd ratio, 1.51; 95% confidence interval, 1.02-2.1; P = .03).

CONCLUSIONS

The finding of this study further suggests the important role of using FLIP in addition to HRM in evaluating patients with clinical failure postmyotomy.

A Comparative Assessment of the Diagnosis of Swallowing Impairment and Gastroesophageal Reflux in Canines and Humans

Swallowing impairment is a highly prevalent and clinically significant problem affecting people and dogs. There are myriad causes of swallowing impairment of which gastroesophageal reflux is the most common in both species. Similarities in anatomy and physiology between humans and canines results in analogous swallowing disorders including cricopharyngeus muscle achalasia, esophageal achalasia, hiatal herniation, and gastroesophageal reflux with secondary esophagitis and esophageal dysmotility. Accordingly, the diagnostic approach to human and canine patients with swallowing impairment is similar. Diagnostic procedures such as swallowing fluoroscopy, high-resolution manometry, pH/impedance monitoring, and endolumenal functional luminal imaging probe can be performed in both species; however, nasofacial conformation, increased esophageal length, and the difficulty of completing several of these procedures in awake dogs are inherent challenges that need to be considered. Human patients can convey their symptoms and respond to verbal cues, whereas veterinarians must rely on clinical histories narrated by pet owners followed by comprehensive physical examination and observation of the animal eating different food consistencies and drinking water. Dogs may also be unwilling to drink or eat in the hospital setting and may be resistant to physical restraint during diagnostic procedures. Despite the species differences and diagnostic challenges, dogs are a natural animal model for many oropharyngeal and esophageal disorders affecting people, which presents a tremendous opportunity for shared learnings. This manuscript reviews the comparative aspects of esophageal anatomy and physiology between humans and canines, summarizes the diagnostic assessment of swallowing impairment in both species, and discusses future considerations for collaborative medicine and translational research.

Endoluminal Functional Lumen Imaging Probe Is Safe in Children Under Five Years Old

BACKGROUND

Endoluminal functional lumen imaging probe (EndoFLIP) is a minimally invasive, novel device that uses high-resolution impedance planimetry to measure important parameters of the gastrointestinal lumen that aid in the diagnosis of esophageal disorders. EndoFLiP is approved by the US Food and Drug Administration (FDA) for children 5 years and older. We sought to compare its safety and luminal characteristics between children under 5 years of age with children 5 years and older.

METHODS

A single-center retrospective review was performed to identify all patients < 21 years of age who underwent esophagogastroduodenoscopy (EGD) with EndoFLIP between October 2017 and November 2020. Results: Sixty-seven EGDs with EndoFLIP were performed in 56 patients, including 14 that were done in children < 5 years and 53 in children ≥5years. The median age in the < 5-year group was 1.7years (interquartile range [IQR], 0.9-4.4) and the youngest patient was 1 month old. The median age in ≥5-year group was 14.3 years (IQR, 8.2-16.2). Median procedure times were similar (32 minutes [IQR, 25-48] for the < 5-year group; 28 minutes [IQR, 20-33] for ≥5-year group; P  = 0.08). There were no adverse events or unplanned hospitalizations in either group. At 30 mL inflation, the pressure of the lower esophageal sphincter (LES) was statistically different between the 2 groups (P = 0.02).

CONCLUSION

EndoFLIP appears to be safe for use in our small cohort of children < 5 years of age and may be an important tool in the management of esophageal disorders in this age group. There was no difference in procedure time between our 2 age groups and there were no procedure-related complications.

Esophageal Motility Disorders: Current Approach to Diagnostics and Therapeutics

Dysphagia is a common symptom with significant impact on quality of life. Our diagnostic armamentarium was primarily limited to endoscopy and barium esophagram until the advent of manometric techniques in the 1970s, which provided the first reliable tool for assessment of esophageal motor function. Since that time, significant advances have been made over the last 3 decades in our understanding of various esophageal motility disorders due to improvement in diagnostics with high-resolution esophageal manometry. High-resolution esophageal manometry has improved the sensitivity for detecting achalasia and has also enhanced our understanding of spastic and hypomotility disorders of the esophageal body. In this review, we discuss the current approach to diagnosis and therapeutics of various esophageal motility disorders.

POEM, GPOEM, and ZPOEM

Our tripartite narrative review discusses Peroral Endoscopic Myotomy (POEM), gastric POEM (GPOEM) and POEM for Zenker's diverticula (ZPOEM). POEM is the prototypical procedure that launched the novel "3rd space endoscopy" field of advanced endoscopy. It revolutionized achalasia therapy by offering a much less invasive version of the prior gold standard, the laparoscopic Heller myotomy (HM). We review in detail indications, outcomes, technique variations and comparative data between POEM and HM particularly with regard to the hotly debated issue of GERD. We then proceed to discuss two less illustrious but nevertheless important offshoots of the iconic POEM procedure: GPOEM for gastroparesis and ZPOEM for the treatment of hypopharyngeal diverticula. For GPOEM, we discuss the rationale of pylorus-directed therapies, briefly touch on GPOEM technique variations and then focus on the importance of proper patient selection and emerging data in this area. On the third and final part of our review, we discuss ZPOEM and expound on technique variations including our "ultra-short tunnel technique". Our review emphasizes that, despite the superiority of endoscopy over surgery for the treatment of hypopharyngeal diverticula, there is no clear evidence yet of the superiority of the newfangled ZPOEM technique compared to the conventional endoscopic myotomy technique practiced for over two decades prior to the advent of ZPOEM.

Achalasia Cardia: Balloon, Tunnel, or Knife?

Achalasia cardia is a rare esophageal motility disorder characterized by impaired relaxation of the lower esophageal sphincter during swallowing and aperistalsis of the esophageal smooth muscles. The treatment approaches to achalasia include nonsurgical treatment with medications (nitrates, calcium channel blockers), endoscopic treatment (balloon pneumatic dilation [PD], botulinum toxin injection [BTI], peroral endoscopic myotomy [POEM]), and surgery (laparoscopic Heller's myotomy [LHM]). The subtype of achalasia (the Chicago Classification) governs the ideal treatment. For the commonly encountered achalasia subtype I and II, PD, LHM, and POEM all have similar efficacy. However, for type III achalasia, POEM seems to be the best line of treatment. Among high-risk elderly patients or those with comorbidities, BTI is preferred. The choice of treatment should be minimally invasive therapy with good short-term and sustained long-term effects with negligible adverse events. POEM seems to be evolving as a first-line therapy among the available therapies. Here, we review the treatment options among achalasia cardia patients with special attention to post-POEM gastroesophageal reflux disease and its management.

Functional Luminal Imaging Probe in the Management of Pediatric Esophageal Disorders

BACKGROUND

Functional luminal imaging probe (FLIP) measures pressure-geometry relationships of digestive luminal space. When used in esophageal disorders, it provides several luminal parameters that help better understand the pathophysiology. Data about the potential utility of FLIP in pediatrics are scarce and there is no standardized use in children. We aim to describe the use of FLIP in our center, its safety, feasibility, and clinical impact in esophageal disorders in children.

METHODS

Consecutive FLIP recordings performed at the Centre Hospitalier Universitaire-Sainte-Justine, Montréal, Canada between February 2018 and January 2021 were extracted. A chart review was conducted for demographics and medical history. Symptomatology after the procedure was evaluated with validated dysphagia scores.

KEY RESULTS

Nineteen patients were included (11 girls, median age 16 years, range 3.2-19.6) with achalasia (n = 5), post-Heller's myotomy dysphagia (n = 3), esophagogastric junction outflow obstruction (n = 3), congenital esophageal stenosis (n = 2); post-esophageal atresia repair stricture (n = 3), and post-fundoplication dysphagia (n = 3). There was no significant correlation between integrated relaxation pressure measured with high resolution manometry and distensibility index (DI). The use of FLIP made it possible to differentiate between dysphagia related to an esophageal obstruction (DI < 2.8 mm2/mmHg) and dysphagia without major motility disorder (DI > 2.8 mm2/mmHg) that guided the indication for dilation. FLIP led to a change in management in 47% of the patients. Forty-seven percent of the patients were symptom free at the time of the evaluation.

CONCLUSIONS INFERENCES

FLIP provides key esophageal luminal values and therefore can play an important role in pediatric esophageal disorders management.

Eosinophilic esophagitis: A review of the pediatric population and consideration of upcoming therapies

Eosinophilic esophagitis (EoE) is a disease entity that has become increasingly recognized in the pediatric population over the last decade and was first recognized as early as 1990. EoE is a clinicopathologic diagnosis with signs and symptoms varying between age groups. The clinical presentation of EoE is variable ranging from milder nonspecific symptoms, such as abdominal pain, vomiting, and dyspepsia, to more severe presentations such as failure to thrive, dysphagia and even food impaction and is dependent on age of diagnosis 2. There is growing body of evidence with regards to the pathophysiology, diagnostic modalities, and treatment options for EoE in the past decade. In this review article, we aim to discuss the disease burden, pathophysiology, diagnostic strategies, and currently available treatment options for EoE based on existing literature.

Nonachalasic esophageal motor disorders, from diagnosis to therapy

INTRODUCTION

Investigations conducted using conventional manometry and, recently, using high-resolution manometry (HRM), allowed us to explore the field of esophageal motility and understand the potential link between motor features and gastroesophageal reflux disease (GERD) pathogenesis. The management of patients with nonachalasic esophageal motor disorders is often challenging, due to the clinical heterogeneous presentation and the multifactorial nature of the mechanisms underlying symptoms.

AREAS COVERED

Several studies, carried out using HRM, have better interpreted the esophageal motor function in patients with esophagogastric junction outflow obstruction (EGJOO), distal esophageal spasm (DES), hypertensive esophagus, and hypomotility disorders. Moreover, HRM studies have shown a direct correlation between reduced esophageal motility, disruption of the esophagogastric junction, and gastroesophageal reflux burden.

EXPERT OPINION

Pathogenesis, clinical presentation, diagnosis, and treatment of nonachalasic esophageal motor disorders still represent a challenging area, requiring future evaluation by multicenter outcome studies carried out in a large cohort of patients and asymptomatic subjects. However, we believe that an accurate clinical, endoscopic, and HRM evaluation is, nowadays, helpful in addressing patients with nonachalasic esophageal motor disorders to optimal treatment options.

Esophageal Motility Disorders: Are We Missing in Our Busy Endoscopy Practice?

Esophageal motility disorders (EMDs) form a significant part of a busy endoscopist's practice. Endoscopy plays an all-encompassing role in the diagnosis and management of EMDs including achalasia cardia. The focus on in-vogue third-space endoscopic procedures such as per-oral endoscopic myotomy often digresses the important role of endoscopy. Endoscopic evaluation forms the part of standard first-line evaluation of any dysphagia and serves to rule out a secondary cause such as an esophagogastric junction malignancy and eosinophilic esophagitis. Moreover, endoscopic evaluation may itself provide corroborative evidence that may contribute to the diagnosis of the motility disorder. Achalasia cardia may present with a wide spectrum of endoscopic findings from being entirely normal and the well-known and pathognomonic dilated sigmoid-shaped esophagus with food residue, to lesser-known ornate signs. The evidence on the role of endosonography in EMDs is conflicting and largely restricted to evaluation of pseudoachalasia. High-resolution manometry (HRM) remains the gold standard in the diagnosis of EMDs. Endoscopists must also keep abreast of the latest iteration of the Chicago classification version 4.0, which differs significantly from its predecessor in being more stringent in making diagnosis of esophagogastric junction outflow obstruction and disorders of peristalsis since these manometric findings may be seen in normal individuals and may be mimicked by opioid use and gastroesophageal reflux. The latest rendition also includes the use of provocative maneuvers and testing in both supine and sitting posture. Despite being the gold standard, there are certain lacunae in the use and interpretation of the Chicago classification of which the users should be well aware. Emerging technologies such as functional lumen imaging probe and planimetry, and timed barium esophagogram fill the lacuna in diagnosis of these motility disorders, which at times is beyond the resolution of HRM.