Dustin A. Carlson

Refining the criterion for an abnormal Integrated Relaxation Pressure in esophageal pressure topography based on the pattern of esophageal contractility using a classification and regression tree model

Background  The Integrated Relaxation Pressure (IRP) is the esophageal pressure topography (EPT) metric used for assessing the adequacy of esophagogastric junction (EGJ) relaxation in the Chicago Classification of motility disorders. However, because the IRP value is also influenced by distal esophageal contractility, we hypothesized that its normal limits should vary with different patterns of contractility.

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.

Diagnosis of esophageal motility disorders: Esophageal pressure topography vs. conventional line tracing

OBJECTIVES:Enhanced characterization of esophageal peristaltic and sphincter function provided by esophageal pressure topography (EPT) offers a potential diagnostic advantage over conventional line tracings (CLT). However, high-resolution manometry (HRM) and EPT require increased equipment costs over conventional systems and evidence demonstrating a significant diagnostic advantage of EPT over CLT is limited. Our aim was to investigate whether the inter-rater agreement and/or accuracy of esophageal motility diagnosis differed between EPT and CLT.METHODS:Forty previously completed patient HRM studies were selected for analysis using a customized software program developed to perform blinded independent interpretation in either EPT or CLT (six pressure sensors) format. Six experienced gastroenterologists with a clinical focus in esophageal disease (attendings) and six gastroenterology trainees with minimal manometry experience (fellows) from three academic centers interpreted each of the 40 studies using both EPT and CLT formats. Rater diagnoses were assessed for inter-rater agreement and diagnostic accuracy, both for exact diagnosis and for correct identification of a major esophageal motility disorder.RESULTS:The total group agreement was moderate (κ=0.57; 95% CI: 0.56–0.59) for EPT and fair (κ=0.32; 0.30–0.33) for CLT. Inter-rater agreement between attendings was good (κ=0.68; 0.65–0.71) for EPT and moderate (κ=0.46; 0.43–0.50) for CLT. Inter-rater agreement between fellows was moderate (κ=0.48; 0.45–0.50) for EPT and poor to fair (κ=0.20; 0.17–0.24) for CLT. Among all raters, the odds of an incorrect exact esophageal motility diagnosis were 3.3 times higher with CLT assessment than with EPT (OR: 3.3; 95% CI: 2.4–4.5; P<0.0001), and the odds of incorrect identification of a major motility disorder were 3.4 times higher with CLT than with EPT (OR: 3.4; 2.4–5.0; P<0.0001).CONCLUSIONS:Superior inter-rater agreement and diagnostic accuracy of esophageal motility diagnoses were demonstrated with analysis using EPT over CLT among our selected raters. On the basis of these findings, EPT may be the preferred assessment modality of esophageal motility.

Flow time through esophagogastric junction derived during high-resolution impedance-manometry studies: a novel parameter for assessing esophageal bolus transit

This study aimed to develop and validate a method to measure bolus flow time (BFT) through the esophagogastric junction (EGJ) using a high-resolution impedance-manometry (HRIM) sleeve. Ten healthy subjects were studied with concurrent HRIM and videofluoroscopy; another 15 controls were studied with HRIM alone. HRIM studies were performed using a 4.2-mm-outer diameter assembly with 36 pressure sensors at 1-cm intervals and 18 impedance segments at 2-cm intervals (Given Imaging, Los Angeles, CA). HRIM and fluoroscopic data from four barium swallows, two in the supine and two in the upright position, were analyzed to create a customized MATLAB program to calculate BFT using a HRIM sleeve comprising three sensors positioned at the crural diaphragm. Bolus transit through the EGJ measured during blinded review of fluoroscopy was almost identical to BFT calculated with the HRIM sleeve, with the nadir impedance deflection point used as the signature of bolus presence. Good correlation existed between videofluoroscopy for measurement of upper sphincter relaxation to beginning of flow [R = 0.97, P < 0.001 (supine) and R = 0.77, P < 0.01 (upright)] and time to end of flow [R = 0.95, P < 0.001 (supine) and R = 0.82, P < 0.01 (upright)]. The medians and interquartile ranges (IQR) of flow time though the EGJ in 15 healthy subjects calculated using the virtual sleeve were 3.5 s (IQR 2.3-3.9 s) in the supine position and 3.2 s (IQR 2.3-3.6 s) in the upright position. BFT is a new metric that provides important information about bolus transit through the EGJ. An assessment of BFT will determine when the EGJ is open and will also provide a useful method to accurately assess trans-EGJ pressure gradients during flow.

High-Resolution Manometry and Esophageal Pressure Topography: Filling the Gaps of Convention Manometry

Although conventional manometry set the basis for the diagnosis of esophageal motility disorders, the large axial spacing between recording sites leaves large portions of the esophagus unevaluated and vulnerable to movement artifact. However, continuous spatiotemporal representations of pressure through the esophagus recorded with high-resolution manometry offers greater detail and improved accuracy for many of the most important measurements of esophageal motor function. This review describes how the new classification schemes for esophageal pressure topography have evolved from conventional criteria and focuses on how esophageal pressure topography has improved the ability to subcategorize conventional manometric diagnoses into new functional phenotypes.

The Chicago Criteria for esophageal motility disorders: What has changed in the past 5 years?

Purpose of review The Chicago Classification for esophageal motility disorders was developed to complement the enhanced characterization of esophageal motility provided by high-resolution esophageal pressure topography (HREPT) as this new technology has emerged within clinical practice. This review aims to summarize the evidence supporting the evolution of the classification scheme since its inception. Recent findings Studies examining the specific esophageal motility disorders in regards to HREPT metrics, clinical characteristics, and responses to treatments have facilitated updates of the diagnostic scheme and criteria. These studies have demonstrated variation in treatment responses associated with subclassification of achalasia, the use of distal latency in the diagnosis of distal esophageal spasm, and the development of diagnoses including esophagogastric junction outflow obstruction and hypercontractile esophagus. Summary The diagnostic criteria described in the Chicago Classification have evolved to demonstrate a greater focus on distinct clinical phenotypes. Future evaluation of the natural history and treatment outcomes will assist in further refinement of this diagnostic scheme and management of esophageal motility disorders.

Incidence and Prevalence of Achalasia in Central Chicago, 2004–2014, Since the Widespread Use of High-Resolution Manometry

BACKGROUND & AIMS Reported global incidence and prevalence values for achalasia vary widely, from 0.03 to 1.63 per 100,000 persons per year and from 1.8 to 12.6 per 100,000 persons per year, respectively. This study aimed to reconcile these low values with findings from a major referral center, in central Chicago (which began using high‐resolution manometry in 2004 and used it in all clinical studies since 2005), and has determined the incidence and prevalence of achalasia to be much greater. METHODS We collected data from the Northwestern Medicine Enterprise Data Warehouse database (tertiary care setting) of adults residing in Chicago with an encounter diagnosis of achalasia from 2004 through 2014. Patient files were reviewed to confirm diagnosis and residential address. US Census Bureau population data were used as the population denominator. We assumed that we encountered every incident case in the city to calculate incidence and prevalence estimates. Data were analyzed for the city at large and for the 13 zip codes surrounding the Northwestern Memorial Hospital (NMH), the NMH neighborhood. RESULTS We identified 379 cases (50.9% female) that met the full inclusion criteria; of these, 246 were incident cases. Among these, 132 patients resided in the NMH neighborhood, 89 of which were incident cases. Estimated yearly incidences were stable over the study period, ranging from 0.77 to 1.35 per 100,000 citywide (average, 1.07 per 100,000) and from 1.41 to 4.60 per 100,000 in the NMH neighborhood (average, 2.92 per 100,000). The corresponding prevalence values increased progressively, from 4.68 to 14.42 per 100,000 citywide and from 15.64 to 32.58 per 100,000 in the NMH neighborhood. CONCLUSIONS The incidence and prevalence of achalasia in central Chicago diagnosed using state‐of‐the‐art technology and diagnostic criteria are at least 2‐ to 3‐fold greater than previous estimates. Additional studies are needed to determine the generalizability of these data to other regions.

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.

Advances in the Evaluation and Management of Esophageal Disease of Systemic Sclerosis

Symptoms of heartburn and dysphagia as well as objective findings of abnormal esophageal acid exposure and esophageal dysmotility are common in patients with systemic sclerosis (SSc). Treatments for SSc esophageal disease are generally limited to gastroesophageal reflux disease (GERD) treatment with proton pump inhibitors. Progresses made in esophageal diagnostic testing offer the potential for improved clinical characterization of esophageal disease in SSc that may help direct management decisions. In addition to reviewing GERD management in patients with SSc, present and potential uses of endoscopy, reflux monitoring, manometry, impedance planimetry, and endoscopic ultrasound are discussed.

Evaluation of esophageal distensibility in eosinophilic esophagitis: an update and comparison of functional lumen imaging probe analytic methods

Distensibility evaluation of the esophageal body using the functional lumen imaging probe (FLIP) offers an objective measure to characterize patients with eosinophilic esophagitis (EoE), though this analysis may be limited by unrecognized catheter movement and esophageal contractility. The aims of this study were to report novel FLIP analytic methods of esophageal distensibility measurement in EoE and to assess the effect of contractility.