High-resolution Manometry Analysis Research Articles

Four-dimensional impedance manometry volume metrics for predicting abnormal bolus retention.

The objective measurement for esophageal bolus volume and bolus clearance could classify abnormal high-resolution manometry (HRM) beyond the current Chicago classification. We aimed to compare the novel four-dimensional impedance manometry (4D HRM) volume metrics with timed barium esophagram (TBE). Adults with esophageal symptoms undergoing HRM and TBE were included. A custom-built program for 4D HRM analysis measured esophageal luminal cross-sectional area (CSA) from impedance and subsequently derived esophageal bolus volume and clearance. 4D HRM volume metrics included pre-swallow residual volume, maximal volume, retention volume, and clearance ratio defined as 1.0-retention volume divided by the maximal volume. An abnormal TBE was defined as a column height >5 cm at 1 min or 5 min. A total of 95 patients (normal motility: 33%; ineffective esophageal motility: 12%; absent contractility: 10%; esophagogastric junction outflow obstruction: 30%; type I achalasia: 5%; type II achalasia: 12%) were categorized into normal TBE (58%), abnormal TBE at 1 min (17%), and abnormal TBE at 5 min (25%). The AUROC demonstrated that, among all 4D HRM volume metrics, the clearance ratio had the best performance in predicting abnormal TBE at 5 min (AUROC, 95% confidence interval: 0.89, 0.82-0.96), and exhibited a strong negative correlation with TBE at 5 min (r = -0.65; p < 0.001). Novel 4D HRM volume metrics provide objective measurement of esophageal bolus volume and bolus clearance. The clearance ratio has a strong correlation with TBE and could potentially serve as a substitute for TBE to measure esophageal retention.

Tubularized and Effaced Gastric Cardia Mimicking Barrett Esophagus Following Sleeve Gastrectomy: Protocolized Endoscopic and Histological Assessment With High-resolution Manometry Analysis.

To describe expected endoscopic and histological changes at gastro-esophageal junction (GEJ) and define diagnostic paradigms for Barrett esophagus (BE) postsleeve gastrectomy (SG). De novo incidence of BE post SG was reported as high as 18.8%. A confounding factor is the lack of standardized definition of BE post SG, which may differ from the general population due to procedure-induced alterations of GEJ. Part 1 involved evaluating endoscopic changes of GEJ post SG (N = 567) compared to pre SG (N = 320), utilizing protocolized preoperative screening, postoperative surveillance and synoptic reporting. Part 2 involved dedicated studies examining causes of altered anatomical and mucosal GEJ appearance using histopathology (N = 55) and high-resolution manometry (HRM) (N = 15). Part 1 - A characteristic tubularized cardia segment projecting supra-diaphragmatically was identified and almost exclusive to post SG (0.6% vs.26.6%, P < 0.001). True BE prevalence was low (4.1%pre SG vs. 3.8%post SG, P = 0.756), esophagitis was comparable (32.1% vs. 25.9%, P = 0.056). Part 2 - Histologically-confirmed BE was found in 12/55 patients, but 70.8% had glandular-type gastric mucosa implying tubularized cardia herniation. HRM of tubularized cardia demonstrated concordance of supra-diaphragmatic cardia herniation between endoscopy and HRM (3 cm vs. 3.2 cm, P = 0.168), with frequent elevated isobaric intraluminal pressurizations in supra-and infra-diaphragmatic cardia compartments. A novel appearance of tubularized cardia telescoping supra-diaphragmatically with flattening of gastric folds is common post SG, likely associated with isobaric hyper-pressurization of proximal stomach. incidence of true BE post SG is low in short-intermediate term. These provided a clear framework for approaching endoscopic screening and surveillance, with correct anatomical and mucosal identifications, and clarified key issues of SG and BE.

200 mL Rapid Drink Challenge During High-resolution Manometry Best Predicts Objective Esophagogastric Junction Obstruction and Correlates With Symptom Severity.

Background/AimsSingle swallow integrated relaxation pressure (IRP) on high-resolution manometry (HRM) does not always accurately predict esophagogastric outflow obstruction on timed barium esophagogram (TBE). Furthermore, neither single swallow IRP or TBE is reliable in predicting symptoms, particularly after treatment with dilatation or myotomy. A 200 mL rapid drink challenge (RDC) has been proposed as an adjunctive test during HRM. This serves as a “stress-test” to the esophagogastric junction, and may yield clinically useful parameters. We aim to assess HRM parameters during RDC, and their ability to predict outflow obstruction on TBE in patients with dysphagia, and to correlate with symptoms in patients’ achalasia.MethodsThirty patients with dysphagia were recruited. All underwent standard single swallow HRM analysis, 200 mL RDC, then TBE. RDC parameters, including esophagogastric pressure gradient, IRP, and RDC duration were evaluated. Multiple regression analysis was performed to assess the best predictive parameter for obstruction on TBE. A further 21 patients with achalasia were evaluated with Eckhardt score, single swallow HRM, RDC, and TBE. Parameter correlation with Eckhardt score was evaluated.ResultsMean IRP during RDC was the best HRM parameter at predicting outflow obstruction on TBE. This performed much better in untreated patients (sensitivity 100% and specificity 85.5%) than in previously treated patients (sensitivity 50% and specificity 66%). In patients with achalasia, mean IRP during RDC was the only parameter that correlated with symptom score.ConclusionMean IRP during RDC appears to be a clinically useful “stress test” to the esophagogastric junction during HRM.

Mo1486 - 200ml Rapid Drink Challenge During High Resolution Manometry Predicts Oesophago-Gastric-JunctionObstruction Detected by Timed Barium Oesophagogram with High Sensitivity and Specificity

Introduction In patients with dysphagia, confirmation of obstruction at the oesophago-gastric junction (OGJ) is used to decide further endoscopic or surgical therapy. This is true for both untreated and treated patients with persistent dysphagia. A 200 ml rapid drink challenge (RDC) during high resolution manometry (HRM) may aid diagnosis of oesophageal motility disorders (Marin &Serra NGM 2016). Timed barium oesophagogram (TBO) detects impaired oesophageal emptying of liquids. We hypothesised that O-G pressure parameters during RDC could predict pathologic barium column in TBO. We aimed to assess the ability of RDC to diagnose obstruction at the OGJ in a group of untreated and treated patients with dysphagia. Method 30 patients with dysphagia (mean age 50y) were prospectively included. All patients underwent HRM (Medtronic; Sandhill) with standard protocol plus RDC followed by TBO. HRM analysis was in accordance with the Chicago Classification v3.0. Analysis of RDC included all parameters described by Marin & Serra 2016; cutoff points for each were determined using a ROC curve analysis. During TBO, oesophageal emptying was assessed at minutes 1, 3 and 5. Persistent barium column at 5 min was diagnostic of OGJ obstruction. Results Of 30 patients, 19 patients were untreated; 11 patients were previously treated (5 dilation, 6 myotomy). HRM diagnoses: 3 normal, 23 achalasia (type I=4, II=18, III=1), 1 aperistalsis, 1 distal oesophageal spasm. Overall, the RDC parameter that best predicted OGJ obstruction during TBO was IRP/200 ml (cutoff >17mmHg: sensitivity=75%, specificity=90%). Subgroup analysis: Prediction of obstruction during TBO by the RDC test further improved in the untreated group (sensitivity 100%; specificity 85.5%) but not for the treated group (sensitivity 50%; sensitivity 66%). Abstract PTH-138 Table 1 All patients (n=30) Abstract PTH-138 Table 2a Untreated population (n=19) Abstract PTH-138 Table 2b Treated population (n=11) Conclusion RDC during HRM is a useful adjuvant to improve diagnosis of OGJ obstruction, particularly in untreated dysphagia. Disclosure of Interest S. Sonmez: None Declared, J Arguero: None Declared, J Ooi: None Declared, K Nakagawa: None Declared, E Glasinovic: None Declared, P Woodland: None Declared, E Yazaki: None Declared, D Sifrim Conflict with: Reckitt Benckiser (Hull, UK); Sandhill Scientific (CO, USA)

Correlation of High-Resolution Manometric Findings with Symptoms of Dysphagia and Endoscopic Features in Adults with Eosinophilic Esophagitis

Background: Eosinophilic esophagitis (EoE) presents with dysphagia, but data about motility patterns using high-resolution manometry (HRM) are rare. We aimed at evaluating esophageal motility patterns in EoE and their correlation to endoscopic and dysphagia scores. Methods: Twenty-six EoE patients and 23 controls were included after 4 weeks of treatment with proton pump inhibitors. Dysphagia and endoscopic scores were evaluated before performing HRM. EoE patients were classified to have fibrostenotic (FS) or inflammatory (IF) type. HRM analysis was performed according to the Chicago classification (CC) system. Results: According to the CC, the HRM findings in EoE and controls were normal in 11 (42%) and 20 (88.5%), p < 0.0001. Weak and failed peristaltic integrity was only seen in EoE patients (failed 1/2.7%, weak 7/26.9%, p = 0.004). Of the EoE patients, 17 had IF and 9 presented with FS type. HRM parameters showed no differences according to the EoE subtype. The endoscopic score in the FS subtype was significantly higher than in EoE with IF subtype (5.33 vs. 3.58, p = 0.001). No significant difference was seen in dysphagia scores in EoE subtypes. Discussion: HRM findings in EoE are often diagnostic, but they are non-specific and do not correlate with the severity of dysphagia or endoscopic appearance. The clinical impact of HRM in EoE needs further evaluation.

High Resolution Manometry Analysis of a Patient With Dysphagia After Occiput-C3/4 Posterior Fusion Operation.

Many reports of changes in cervical alignment after posterior occipitocervical (O-C) fusion causing dysphagia are available. The clinical course can range from mild discomfort to severe aspiration. However, the underlying pathogenesis is not well known. We report an 80-year-old female with videofluoroscopic swallowing study evidence of aspiration that developed after occiput-C3/4 posterior fusion. Pharyngeal pressure was analyzed using high resolution manometry (HRM). Impaired upper esophageal sphincter opening along with diminished peristalsis and pharyngeal pressure gradient were revealed by HRM to be the main characteristics in such patients. The patient fully recovered after a revision operation for cervical angle correction. Distinct pressure patterns behind reversible dysphagia caused by a change in cervical alignment were confirmed using HRM analysis.

High resolution manometry analysis of esophageal motility characteristics in patients with different subtypes of achalasia

High resolution manometry analysis of esophageal motility characteristics in patients with different subtypes of achalasia

Reliability of an automated high-resolution manometry analysis program across expert users, novice users, and speech-language pathologists.

The purpose of this study was to investigate inter- and intrarater reliability among expert users, novice users, and speech-language pathologists with a semiautomated high-resolution manometry analysis program. We hypothesized that all users would have high intrarater reliability and high interrater reliability. Three expert users, 15 novice users, and 5 speech-language pathologists participated in this study. Following a 20-min training session, users analyzed 30 high-resolution manometry plots using an automated analysis program. Output parameters included 2- and 3-dimensional pressure integrals over 5 anatomical regions of interest. Intraclass correlations were used to examine inter- and intrarater reliability. An analysis of variance was also performed to determine any differences in mean output parameter values. Within-group interrater reliability ranged from 0.54 to 0.99, and intergroup reliability ranged from 0.92 to 0.99. Intrarater reliability ranged from 0.67 to 1.00 across all groups. There were no significant differences of output parameters among groups. The high reliability observed after a short training session demonstrates that individuals with little to no prior knowledge of swallowing physiology can perform at a similar level as those with expertise. Given the quickness and ease of training in the use of this program, it has the potential for research and clinical utility.

A New Approach Is Needed to Analyze the Upper Esophageal Sphincter Because Currently Incorporated High-resolution Manometry Analysis Software Package Is Not Perfect

A New Approach Is Needed to Analyze the Upper Esophageal Sphincter Because Currently Incorporated High-resolution Manometry Analysis Software Package Is Not Perfect

A New Approach Is Needed to Analyze the Upper Esophageal Sphincter Because Currently Incorporated High-resolution Manometry Analysis Software Package Is Not Perfect.

TO THE EDITOR: I read with interest the review article by Wang et al1 regarding “High-resolution manometry (HRM) analysis of upper esophageal sphincter (UES) not addressed by the ‘Chicago classification’” disorders of the UES may include pharyngeal dysphagia and other cervical symptoms such as globus. Currently automated analysis of HRM provides the details of information such as mean basal UES pressure, mean residual UES pressure, UES relaxation time-to-nadir, UES relaxation duration, UES recovery time, and peak pharyngeal pressure. We have been evaluating whether HRM plays some roles in the assessment of the disorders of the UES with special interest for 4 years.2–4 To our experience, the information obtained by the software analysis often is not perfect as well as occasionally being wrong. Figure 1A shows erroneous locations of pharyngeal/UES wave markers, which are occurring despite of adequate setting thermal compensation and adjusting the spatial markers. Therefore it should be noted that it is very important to adjust the locations of the pharyngeal/UES wave markers correctly before the assessment of oropharyngeal dysphagia or globus. This problem frequently occurs in the setting of incomplete UES relaxation (Fig. 1B) and then gives misinformation regarding the duration of UES relaxation. However, it is very hard to correctly adjust UES wave markers under these circumstances. Given that, another new approach for quantitative assessment of UES relaxation should be considered. When we evaluate esophagogastric junction (EGJ) relaxation in the HRM examination, 4-second integrated relaxation pressure (IRP) is one of the best measures of EGJ relaxation, compared to nadir pressure and 3-second IRP.5 The opening time of UES is a lot shorter than that of EGJ. This suggests that IRP concept may be inappropriate in the assessment of UES relaxation. In HRM analysis, isobaric contours of 20 mmHg and 30 mmHg are currently used to assess distal contractile integral and distal segment contraction, respectively.5 These isobaric contours might be helpful for a more robust localization of these wave markers and then provide additional new concept regarding a measure of UES relaxation. To our experience, duration of UES relaxation on automated analysis seems to correlate well with the shortest horizontal distance from ending contour of pre-swallow UES peak to starting contour of post-swallow UES peak with 20 mmHg isobaric contour applied in this analysis (Fig. 2). This issue, however, should be further validated by larger study. In conclusion, we believe that the new approach should be introduced for better evaluation of disorders of the UES. Figure 1. Wrong location of pharyngeal/upper esophageal sphincter wave markers is noted. (A) Starting and ending points of UES relaxation wave makers are improperly located. (B) Starting, center and ending points of UES relaxation wave markers in third swallow ... Figure 2. Comparison of duration of the upper esophageal sphincter relaxation between automated analysis and new approach (using 20 mmHg isobaric contours).

High-resolution Manometry and Globus: Comparison of Globus, Gastroesophageal Reflux Disease and Normal Controls Using High-resolution Manometry

Background/AimsGlobus is a foreign body sense in the throat without dysphagia, odynophagia, esophageal motility disorders, or gastroesophageal reflux. The etiology is unclear. Previous studies suggested that increased upper esophageal sphincter pressure, gastroesophageal reflux and hypertonicity of esophageal body were possible etiologies. This study was to quantify the upper esophageal sphincter (UES) pressure, contractile front velocity (CFV), proximal contractile integral (PCI), distal contractile integral (DCI) and transition zone (TZ) in patient with globus gastroesophageal reflux disease (GERD) without globus, and normal controls to suggest the correlation of specific high-resolution manometry (HRM) findings and globus.MethodsFifty-seven globus patients, 24 GERD patients and 7 normal controls were studied with HRM since 2009. We reviewed the reports, and selected 5 swallowing plots suitable for analysis in each report, analyzed each individual plot with ManoView. The 5 parameters from each plot in 57 globus patients were compared with that of 24 GERD patients and 7 normal controls.ResultsThere was no significant difference in the UES pressure, CFV, PCI and DCI. TZ (using 30 mmHg isobaric contour) in globus showed significant difference compared with normal controls and GERD patients. The median values of TZ were 4.26 cm (interquartile range [IQR], 2.30-5.85) in globus patients, 5.91 cm (IQR, 3.97-7.62) in GERD patients and 2.26 cm (IQR, 1.22-2.92) in normal controls (P = 0.001).ConclusionsHRM analysis suggested that UES pressure, CFV, PCI and DCI were not associated with globus. Instead increased length of TZ may be correlated with globus. Further study comparing HRM results in globus patients within larger population needs to confirm their correlation.

Fragmented esophageal smooth muscle contraction segments on high resolution manometry: a marker of esophageal hypomotility

Esophageal peristalsis consists of a chain of contracting striated and smooth muscle segments on high resolution manometry (HRM). We compared smooth muscle contraction segments in symptomatic subjects with reflux disease to healthy controls. High resolution manometry Clouse plots were analyzed in 110 subjects with reflux disease (50 ± 1.4 years, 51.5% women) and 15 controls (27 ± 2.1 years, 60.0% women). Using the 30 mmHg isobaric contour tool, sequences were designated fragmented if either smooth muscle contraction segment was absent or if the two smooth muscle segments were separated by a pressure trough, and failed if both smooth muscle contraction segments were absent. The discriminative value of contraction segment analysis was assessed. A total of 1115 swallows were analyzed (reflux group: 965, controls: 150). Reflux subjects had lower peak and averaged contraction amplitudes compared with controls (P < 0.0001 for all comparisons). Fragmented sequences followed 18.4% wet swallows in the reflux group, compared with 7.5% in controls (P < 0.0001), and were seen more frequently than failed sequences (7.9% and 2.5%, respectively). Using a threshold of 30% in individual subjects, a composite of failed and/or fragmented sequences was effective in segregating reflux subjects from control subjects (P = 0.04). Evaluation of smooth muscle contraction segments adds value to HRM analysis. Specifically, fragmented smooth muscle contraction segments may be a marker of esophageal hypomotility.

Analysis of Intersegmental Trough and Proximal Latency of Smooth Muscle Contraction Using High-resolution Esophageal Manometry

Intersegmental troughs (ISTs) between striated and smooth muscle contraction segments on high-resolution manometry (HRM) have been linked to hypomotility disorders. We investigated the relationship between ISTs, latency of initiation of smooth muscle contraction, and motor patterns in symptomatic patients and normal controls. HRM Clouse plots were analyzed in 199 participants (47.2±1.2 y, 112F/87M), categorized into 110 participants with gastroesophageal reflux disease (GERD), 74 symptomatic participants without GERD, and 15 healthy controls. IST length was measured in centimeters and percentage esophageal length, designated extended when ≥20% esophageal length on >30% swallows. Proximal latency was measured as the time interval between onset of skeletal and smooth muscle contraction segments, and designated prolonged when ≥4s in ≥50% of swallows. ISTs of any length were noted in 74.6% swallows and in 92.5% of participants, with a similar frequency across the 3 groups. ISTs and proximal latency were both longer in the GERD group, especially when Barrett esophagus was present, compared with non-GERD patients or controls (P≤0.03 across groups); extended IST and prolonged proximal latency followed similar trends. On multivariate logistic regression, extended IST predicted GERD [odds ratio (OR), 2.30; 95% confidence intervals (CI) 1.18-4.47], as did lower esophageal sphincter pressure <5 mm Hg (OR, 3.79-3.96; 95% CI 1.77-8.49), after controlling for age and sex; prolonged proximal latency predicted both GERD (OR, 2.03; 95% CI 1.01-4.12) and Barrett esophagus (OR 1.91, 95% CI 1.24-2.94). Measurement of IST and proximal latency add value to HRM analysis, and may be markers of esophageal hypomotility.

Comparison of Conventional and Segmental Analysis on High Resolution Manometry (HRM)

Purpose: HRM demonstration of three contraction segments in the esophageal body has added to our understanding of esophageal motor physiology. Despite this advance, pre-HRM parameters continue to be applied to HRM analysis. We investigated differences between conventional and segmental analysis of HRM Clouse plots in symptomatic subjects and normal controls. Methods: HRM contour plots were compared between a reflux group (n=110, 49±1.4 yr, 55F/55M) with abnormal pH study, erosive esophagitis on endoscopy or Barrett's esophagus on histopathology; a non-reflux group (n=74, 48±2.3 yr, 48F/26M) with esophageal symptoms but normal pH study and endoscopy; and controls (n=12, 30±0.9 yr, 7F/5M). Achalasia and its variants, aperistalsis and post surgical states were excluded. Peristaltic performance, peak contraction amplitude (PCA) in either smooth muscle segment, averaged contraction amplitude (ACA, 3 & 8 cm proximal to LES), segment anatomy, and end-expiratory lower esophageal sphincter pressure (LESP) were extracted. At 30 mmHg, sequences were designated fragmented if one smooth muscle segment was absent or if the two segments were separated by a pressure trough and failed if both smooth muscle segments were absent. Results: A total of 1827 swallows were analyzed in symptomatic subjects, and 120 in controls. As expected, reflux subjects had lower ACA (82.9 ±3.3 vs. 116.6 ±5.7 mmHg, p<0.0001) and LESP (7.8±0.7 vs. 16.2±1.6 mmHg, p<0.0001) compared to non-reflux group; similar findings were seen using PCA (119.7±1.5 vs. 161.3±2.6 mmHg, p<0.0001). PCA in controls (160± 3.7 mmHg) was comparable to non-reflux but significantly higher than reflux subjects. There were 44.4% (reflux) and 38.3% (non-reflux) gains in measured amplitude using PCA rather than ACA. Further, 41.1% fewer failed sequences (87 vs. 123) were seen in the reflux group with segment analysis (p=0.01); in the non-reflux group, the change from 20 to 15 failed was not significant; no change was noted in the controls. Fragmented contractions were significantly more prevalent in the reflux group (18.1%) compared to non-reflux (4.1%) or controls (7.5%, p<0.0001). Discordance between conventional and segmental analysis was 27.2% in the reflux group, but only 5.4% in the non-reflux group (p<0.001). Composite failed and fragmented sequences amounting to >30% of the evaluated wet swallows significantly segregated the reflux group from the non-reflux group (34.5% vs. 4.1%, OR 12.5, 95% CI 3.5-34.6, p<0.0001). Conclusion: New HRM analysis paradigms may provide novel insight into esophageal peristaltic function, especially in subjects with hypomotile patterns. Further studies are required to determine if these new parameters improve prediction of patient outcome.

M1148 Equivalency of Conventional and High-Resolution Manometry Analysis Parameters to Quantifying Esophageal Motility

M1148 Equivalency of Conventional and High-Resolution Manometry Analysis Parameters to Quantifying Esophageal Motility

94 Adaptive Responses of the Esophagogastric Junction High Pressure Zone: High Resolution Manometry Analysis in Normal Subjects and Patients with Hiatal Hernia

94 Adaptive Responses of the Esophagogastric Junction High Pressure Zone: High Resolution Manometry Analysis in Normal Subjects and Patients with Hiatal Hernia

Impaired deglutitive EGJ relaxation in clinical esophageal manometry: a quantitative analysis of 400 patients and 75 controls

Assessing deglutitive esophagogastric junction (EGJ) relaxation is an essential focus of clinical manometry. Our aim was to apply automated algorithmic analyses to high-resolution manometry (HRM) studies to ascertain the optimal method for discriminating normal from abnormal deglutitive EGJ relaxation. All 473 subjects (73 controls) were studied with a 36-channel solid-state HRM assembly during water swallows. Patients were classified as: 1) achalasia, 2) postfundoplication, 3) nonachalasia with normal deglutitive EGJ relaxation, or 4) functional obstruction (preserved peristalsis with incomplete EGJ relaxation). Automated computer programs assessed the adequacy of EGJ relaxation by using progressively complex analysis routines to compensate for esophageal shortening, crural diaphragm contraction, and catheter movement, all potential confounders. The single-sensor method of assessing EGJ relaxation had a sensitivity of only 52% for detecting achalasia. Of the automated HRM analysis paradigms tested, the 4-s integrated relaxation pressure using a cutoff of 15 mmHg performed optimally with 98% sensitivity and 96% specificity in the detection of achalasia. We also identified a heterogeneous group of 26 patients with functional EGJ obstruction attributed to variant achalasia and other diverse pathology. Although further clinical experience will ultimately judge, it is our expectation that applying rigorous methodology such as described herein to the analysis of HRM studies will improve the consistency in the interpretation of clinical manometry and prove useful in guiding clinical management.

The authors reply

<h3>Introduction</h3> In patients with dysphagia, confirmation of obstruction at the oesophago-gastric junction (OGJ) is used to decide further endoscopic or surgical therapy. This is true for both untreated and treated patients with persistent dysphagia. A 200 ml rapid drink challenge (RDC) during high resolution manometry (HRM) may aid diagnosis of oesophageal motility disorders (Marin &amp;Serra NGM 2016). Timed barium oesophagogram (TBO) detects impaired oesophageal emptying of liquids. We hypothesised that O-G pressure parameters during RDC could predict pathologic barium column in TBO. We <b>aimed</b> to assess the ability of RDC to diagnose obstruction at the OGJ in a group of untreated and treated patients with dysphagia. <h3>Method</h3> 30 patients with dysphagia (mean age 50y) were prospectively included. All patients underwent HRM (Medtronic; Sandhill) with standard protocol plus RDC followed by TBO. HRM analysis was in accordance with the Chicago Classification v3.0. Analysis of RDC included all parameters described by Marin &amp; Serra 2016; cutoff points for each were determined using a ROC curve analysis. During TBO, oesophageal emptying was assessed at minutes 1, 3 and 5. Persistent barium column at 5 min was diagnostic of OGJ obstruction. <h3>Results</h3> Of 30 patients, 19 patients were untreated; 11 patients were previously treated (5 dilation, 6 myotomy). <i>HRM diagnoses:</i> 3 normal, 23 achalasia (type I=4, II=18, III=1), 1 aperistalsis, 1 distal oesophageal spasm. Overall, the RDC parameter that best predicted OGJ obstruction during TBO was IRP/200 ml (cutoff &gt;17mmHg: sensitivity=75%, specificity=90%). <i>Subgroup analysis:</i> Prediction of obstruction during TBO by the RDC test further improved in the untreated group (sensitivity 100%; specificity 85.5%) but not for the treated group (sensitivity 50%; sensitivity 66%). Abstract PTH-138 Table 1 All patients (n=30) Abstract PTH-138 Table 2a Untreated population (n=19) Abstract PTH-138 Table 2b Treated population (n=11) <h3>Conclusion</h3> RDC during HRM is a useful adjuvant to improve diagnosis of OGJ obstruction, particularly in untreated dysphagia. <h3>Disclosure of Interest</h3> S. Sonmez: None Declared, J Arguero: None Declared, J Ooi: None Declared, K Nakagawa: None Declared, E Glasinovic: None Declared, P Woodland: None Declared, E Yazaki: None Declared, D Sifrim Conflict with: Reckitt Benckiser (Hull, UK); Sandhill Scientific (CO, USA)