Zoe Listernick

The Functional Lumen Imaging Probe Detects Esophageal Contractility Not Observed With Manometry in Patients With Achalasia

BACKGROUND & AIMS The functional lumen imaging probe (FLIP) could improve the characterization of achalasia subtypes by detecting nonocclusive esophageal contractions not observed with standard manometry. We aimed to evaluate esophageal contractions during volumetric distention in patients with achalasia using FLIP topography. METHODS Fifty-one treatment-naive patients with achalasia, defined and subclassified by high-resolution esophageal pressure topography, and 10 asymptomatic individuals (controls) were evaluated with the FLIP during endoscopy. During stepwise distension, simultaneous intrabag pressures and 16 channels of cross-sectional areas were measured; data were exported to software that generated FLIP topography plots. Esophageal contractility was identified by noting periods of reduced luminal diameter. Esophageal contractions were characterized further by propagation direction, repetitiveness, and based on whether they were occluding or nonoccluding. RESULTS Esophageal contractility was detected in all 10 controls: 8 of 10 had repetitive antegrade contractions and 9 of 10 had occluding contractions. Contractility was detected in 27% (4 of 15) of patients with type I achalasia and in 65% (18 of 26, including 9 with occluding contractions) of patients with type II achalasia. Contractility was detected in all 10 patients with type III achalasia; 8 of these patients had a pattern of contractility that was not observed in controls (repetitive retrograde contractions). CONCLUSIONS Esophageal contractility not observed with manometry can be detected in patients with achalasia using FLIP topography. The presence and patterns of contractility detected with FLIP topography may represent variations in pathophysiology, such as mechanisms of panesophageal pressurization in patients with type II achalasia. These findings could have implications for additional subclassification to supplement prediction of the achalasia disease course.

Evaluation of Esophageal Motility Utilizing the Functional Lumen Imaging Probe

Objectives:Esophagogastric junction (EGJ) distensibility and distension-mediated peristalsis can be assessed with the functional lumen imaging probe (FLIP) during a sedated upper endoscopy. We aimed to describe esophageal motility assessment using FLIP topography in patients presenting with dysphagia.Methods:In all, 145 patients (aged 18–85 years, 54% female) with dysphagia that completed upper endoscopy with a 16-cm FLIP assembly and high-resolution manometry (HRM) were included. HRM was analyzed according to the Chicago Classification of esophageal motility disorders; major esophageal motility disorders were considered “abnormal”. FLIP studies were analyzed using a customized program to calculate the EGJ-distensibility index (DI) and generate FLIP topography plots to identify esophageal contractility patterns. FLIP topography was considered “abnormal” if EGJ-DI was <2.8 mm2/mm Hg or contractility pattern demonstrated absent contractility or repetitive, retrograde contractions.Results:HRM was abnormal in 111 (77%) patients: 70 achalasia (19 type I, 39 type II, and 12 type III), 38 EGJ outflow obstruction, and three jackhammer esophagus. FLIP topography was abnormal in 106 (95%) of these patients, including all 70 achalasia patients. HRM was “normal” in 34 (23%) patients: five ineffective esophageal motility and 29 normal motility. In all, 17 (50%) had abnormal FLIP topography including 13 (37%) with abnormal EGJ-DI.Conclusions:FLIP topography provides a well-tolerated method for esophageal motility assessment (especially to identify achalasia) at the time of upper endoscopy. FLIP topography findings that are discordant with HRM may indicate otherwise undetected abnormalities of esophageal function, thus FLIP provides an alternative and complementary method to HRM for evaluation of non-obstructive dysphagia.

High-Resolution Impedance Manometry Metrics of the Esophagogastric Junction for the Assessment of Treatment Response in Achalasia

OBJECTIVES:We aimed to evaluate the value of novel high-resolution impedance manometry (HRIM) metrics, bolus flow time (BFT), and esophagogastric junction (EGJ) contractile integral (CI), as well as EGJ pressure (EGJP) and the integrated relaxation pressure (IRP), as indicators of treatment response in achalasia.METHODS:We prospectively evaluated 75 patients (ages 19–81, 32 female) with achalasia during follow-up after pneumatic dilation or myotomy with Eckardt score (ES), timed-barium esophagram (TBE), and HRIM. Receiver-operating characteristic (ROC) curves for good symptomatic outcome (ES≤3) and good radiographic outcome (TBE column height at 5 min<5 cm) were generated for each potential predictor of treatment response (EGJP, IRP, BFT, and EGJ-CI).RESULTS:Follow-up occurred at a median (range) 12 (3–291) months following treatment. A total of 49 patients had good symptomatic outcome and 46 had good radiographic outcome. The area-under-the-curves (AUCs) on the ROC curve for symptomatic outcome were 0.55 (EGJP), 0.62 (IRP), 0.77 (BFT) and 0.56 (EGJ-CI). The AUCs for radiographic outcome were 0.64 (EGJP), 0.48 (IRP), 0.73 (BFT), and 0.65 (EGJ-CI). Optimal cut-points were determined as 11 mm Hg (EGJP), 12 mm Hg (IRP), 0 s (BFT), and 30 mm Hg•cm (EGJ-CI) that provided sensitivities/specificities of 57%/46% (EGJP), 65%/58% (IRP), 78%/77% (BFT), and 53%/62% (EGJ-CI) to predict symptomatic outcome and 57%/66% (EGJP), 57%/41% (IRP), 76%/69% (BFT), and 57%/66% (EGJ-CI) to predict radiographic outcome.CONCLUSIONS:BFT, a novel HRIM metric, provided an improved functional assessment over manometric measures of EGJP, IRP, and EGJ-CI at follow-up after achalasia treatment and may help direct clinical management.

A System to Assess the Competency for Interpretation of Esophageal Manometry Identifies Variation in Learning Curves

BACKGROUND & AIMS: Quality esophageal high‐resolution manometry (HRM) studies require competent interpretation of data. However, there is little understanding of learning curves, training requirements, or measures of competency for HRM. We aimed to develop and use a competency assessment system to examine learning curves for interpretation of HRM data. METHODS: We conducted a prospective multicenter study of 20 gastroenterology trainees with no experience in HRM, from 8 centers, over an 8‐month period (May through December 2015). We designed a web‐based HRM training and competency assessment system. After reviewing the training module, participants interpreted 50 HRM studies and received answer keys at the fifth and then at every second interpretation. A cumulative sum procedure produced individual learning curves with preset acceptable failure rates of 10%; we classified competency status as competency not achieved, competency achieved, or competency likely achieved. RESULTS: Five (25%) participants achieved competence, 4 (20%) likely achieved competence, and 11 (55%) failed to achieve competence. A minimum case volume to achieve competency was not identified. There was no significant agreement between diagnostic accuracy and accuracy for individual HRM skills. CONCLUSIONS: We developed a competency assessment system for HRM interpretation; using this system, we found significant variation in learning curves for HRM diagnosis and individual skills. Our system effectively distinguished trainee competency levels for HRM interpretation and contrary to current recommendations, found that competency for HRM is not case‐volume specific.

High‐resolution manometry assessment of the lower esophageal sphincter after‐contraction: Normative values and clinical correlation

The Chicago Classification v3.0 proposed extending the distal contractile integral (DCI) measurement domain to include the lower esophageal sphincter (LES) to enhance the detection of esophageal hypercontractility. However, normative and clinical data for this approach are unreported. We aimed to describe the application of an extended DCI measurement in asymptomatic controls and patients.

Tu1141 Esophageal Body Response to Volumetric Distension in Patients With Achalasia: A Study Utilizing the Functional Lumen Imaging Probe

Background: Achalasia subtypes are differentiated by esophageal body pressurization patterns identified with esophageal pressure topography (EPT). The functional lumen imaging probe (FLIP), which measures cross-sectional area (CSA) as a function of pressure during volume distension, may enhance characterization of achalasia subtypes by detection of non-occlusive esophageal contractions not appreciated with standard manometric assessment. Our aim was to evaluate the esophageal body response to volumetric distention in achalasia patients using a new analysis paradigm, FLIP topography. Methods: Treatment-naive patients with achalasia defined and sub-classified by EPT were evaluated with the FLIP (Crospon, Inc, Gallway, Ireland) during endoscopy. The FLIP consisted of an infinitely compliant cylindrical bag with 17 ring impedance-planimetry electrodes spaced 1 cm apart and a solid-state transducer for simultaneous measurements of 16 channels of CSA and intra-bag pressure. The distal end of the FLIP was positioned across the esophagogastric junction to allow three intragastric channels. Stepwise bag distension from 5 to 60 mL was conducted and CSA and intrabag pressure data was exported to MATLABTM (The Math Works, Natick, MA). A customized MATLAB program generated FLIP topography plots (Figure) of CSA by axial position over time. Esophageal reactivity was identified by noting periods of reduced CSA as a surrogate for contractions. The intrabag pressure and distension volume at the onset of esophageal body contraction was measured and compared between achalasia subtypes using non-parametric tests. Results: 19 patients (ages 19-72; 6 female) with achalasia (2 type I, 11 type II, and 6 type III) were studied. Esophageal reactivity was observed in 0/2 type I, 6/11 (55%) type II, and 6/6 type III patients. Of patients that exhibited reactivity, numerically, but not statistically significantly, higher pressures at reactivity onset were seen in type II [median (IQR): 18.8mmHg (8.8-32.4)] than type III [10.2 (10-13.2), p =0.42] achalasia patients. The distension volumes at the onset of reactivity between subtypes were similar [type II: 27.5mL (25-30); type III: 27.5 (21.25-30); p =0.74]. Retrograde contractions were observed in 4/6 type II patients and 5/6 type III patients demonstrating reactivity. Conclusions: Assessment with FLIP topography detected variable reactivity to esophageal body distension between achalasia subtypes and among patients with type II achalasia. In approximately half of our studied type II achalasia patients, FLIP topography demonstrated some degree of preserved esophageal body contractility. Subclassification by esophageal body reactivity may help predict symptom development and/or response to treatment.