Intrabolus Pressure Research Articles

Morphologic Changes in Esophageal Body Movement During Bolus Transport After Peroral Endoscopic Myotomy in Type III Achalasia

Background/AimsThe effect of peroral endoscopic myotomy (POEM) on esophageal body movement in achalasia is poorly understood. This study aims to evaluate morphological changes in esophageal body movement after POEM in type III achalasia by analyzing intraluminal ultrasound (US) images in comparison to type I and II achalasia.MethodsIntraluminal US images and impedance values of the distal esophagus from 47 achalasia patients who underwent POEM or pneumatic dilatation (PD) (30 patients in the POEM group and 17 patients in the PD group) with pre- and post-procedural high-resolution impedance manometry and intraluminal US examinations were analyzed. The muscle thickness (MT), muscle cross-sectional area, lumen cross-sectional area (LCSA), contractility and distensibility indices, swallow-to-distension interval, and distension duration during each bolus transport were analyzed.ResultsThe MT increased and LCSA decreased significantly (P < 0.001), but the contractility index was not improved after POEM or PD in type I achalasia. Baseline MT increased and LCSA decreased significantly after POEM and PD in type II achalasia (P < 0.001). In contrast, MT and the swallow-to-distension interval decreased and the distension LCSA/duration and contractility index increased after POEM in type III achalasia (P < 0.001). In contrast to type I and II achalasia, in type III achalasia, these effects were unique to the POEM group.ConclusionsPOEM decreased the esophageal LCSA by decreasing intrabolus pressure without improving contractility in type I and II achalasia. In contrast, POEM increased esophageal body distension and contractility and improved the inhibitory process during bolus transport in type III achalasia.

Anatomic and Manometric Abnormalities of the Upper and Lower Esophageal Sphincters in Patients With Reflux Disease

Laryngopharyngeal reflux (LPR) may cause inflammation of the laryngeal and pharyngeal mucosa. Gastroesophageal reflux disease (GERD) involves retrograde flow of gastric content into the esophagus below the upper esophageal sphincter (UES). The goal of this study was to investigate the esophageal anatomical and manometric variations of the esophagus in patients with LPR and/or GERD. Adult voice center patients who underwent diagnostic workup for reflux complaints with 24-hour multichannel intraluminal pH-impedance testing and esophageal manometry were included in this retrospective study. Subjects were classified as having LPR (>10 proximal reflux events), LPR + GERD (>10 proximal reflux events plus >73 distal reflux events) or were assigned to a control group (≤10 proximal events and ≤73 distal reflux events) based on pH study results. Anatomic and manometric parameters were evaluated between groups. There were 169 cases (65 male, 104 female) included in this study. The average age was 50.50 ± 17.29. Subjects in the LPR group had significantly higher UES relaxation pressures and greater UES length compared with the control group. Lower esophageal sphincter relaxation pressure was significantly higher in the control group compared with the LPR group or the GERD + LPR group. Subjects in the GERD + LPR group had a significantly shorter intra-abdominal portion of the lower esophageal sphincter compared with the LPR only group and the control group. Intrabolus pressure was significantly lower in both the LPR group and the LPR + GERD group compared with the control group. Distal wave amplitude was significantly lower in the LPR + GERD group compared to both the LPR group and the control group. The percentage of swallows with incomplete clearance was significantly greater in the LPR + GERD group than both the control group and the LPR group. The LPR group had significantly fewer swallows with incomplete clearance than the control group. Anatomic and manometric abnormalities are present in subjects with LPR with or without GERD and may contribute to the pathogenesis of reflux disease. Further research is needed to confirm or refute these findings.

Pharyngo-Esophageal Modulatory Swallow Responses to Bolus Volume and Viscosity Across Time.

Objectives/HypothesisModulation of the pharyngeal swallow to bolus volume and viscosity is important for safe swallowing and is commonly studied using high‐resolution pharyngeal manometry (HRPM). Use of unidirectional pressure sensor technology may, however, introduce variability in swallow measures and a fixed bolus administration protocol may induce time and order effects. We aimed to overcome these limitations and to investigate the effect of time by repeating randomized measurements using circumferential pressure sensor technology.Study DesignSub‐set analysis of data from the placebo arm of a randomized, repeated measures trial.MethodsHRPM with impedance was recorded using a solid‐state catheter with 36 circumferential pressure sensors and 18 impedance segments straddling from hypopharynx to stomach. Testing included triplicates of 5, 10, and 20 ml thin liquid and 10 ml thick liquid boluses, the order of the thin liquid boluses was randomized. The swallow challenges were repeated approximately 10 minutes after finishing the baseline measurement.ResultsWe included 19 healthy adults (10/9 male/female; age 24.5 ± 4.1 year). Intrabolus pressure, all upper esophageal sphincter (UES) opening and relaxation metrics, and flow timing metrics increased with larger volumes. A thicker viscosity decreased UES relaxation time, UES basal pressure, and flow timing metrics, whereas UES opening extent increased. Pre‐swallow UES basal pressure and post‐swallow UES contractile integral decreased over time.ConclusionUsing circumferential pressure sensor technology, the effects of volume and viscosity were largely consistent with previous reports. UES contractile pressures reduced over time. The growing body of literature offers a benchmark for recognizing aberrant pharyngo‐esophageal motor responses.Level of Evidence3 Laryngoscope, 132:1817–1824, 2022

Cricopharyngeal peroral endoscopic myotomy improves oropharyngeal dysphagia in patients with Parkinson's disease.

Background and study aims Oropharyngeal dysphagia (OPD) is prevalent in patients with Parkinson’s disease (PD). Upper esophageal sphincter (UES) dysfunction is an important pathophysiological factor for OPD in PD. The cricopharyngeus (CP) is the main component of UES. We assessed the preliminary efficacy of cricopharyngeal peroral endoscopic myotomy (C-POEM) as a treatment for dysphagia due to UES dysfunction in PD. Patients and methods Consecutive dysphagic PD patients with UES dysfunction underwent C-POEM. Swallow metrics derived using high-resolution pharyngeal impedance manometry (HRPIM) including raised UES integrated relaxation pressure (IRP), raised hypopharyngeal intrabolus pressure (IBP), reduced UES opening caliber and relaxation time defined UES dysfunction. Sydney Swallow Questionnaire (SSQ) and Swallowing Quality of Life Questionnaire (SWAL-QOL) at before and 1 month after C-POEM measured symptomatic improvement in swallow function. HRPIM was repeated at 1-month follow-up. Results C-POEM was performed without complications in all (n = 8) patients. At 1 month, there was an improvement in both the mean SSQ (from 621.5 to 341.8, mean difference –277.3, 95 %CI [–497.8, –56.7], P = 0.02) and SWAL-QOL (from 54.9 to 68.3, mean difference 9.1, 95 %CI [0.7, 17.5], P = 0.037) scores. Repeat HRPIM confirmed a decrease in both the mean UES IRP (13.7 mm Hg to 3.6 mm Hg, mean difference –10.1 mm Hg, 95 %CI [–16.3, –3.9], P = 0.007) and the mean hypopharyngeal IBP (23.5 mm Hg to 10.4 mm Hg, mean difference –11.3 mm Hg, 95 %CI [–17.2, –5.4], P = 0.003). Conclusions In dysphagic PD patients with UES dysfunction, C-POEM is feasible and enhances UES relaxation and reduces sphincteric resistance to flow during the swallow, thereby improving dysphagia symptoms.

Pitfalls in the Interpretation of Chicago Classification for Esophageal Motility Disorders.

High-resolution manometry permitted the creation of the Chicago classification, that is the categorization for esophageal motility disorders most currently used. Despite its wide acceptance, there are few pitfalls for the correct interpretation of the tests. This technique review illustrates some difficult cases that may lead to misinterpretation of the results. Difficult cases are analyzed, such as the distinction of: (1) esophagogastric junction morphology and lower esophageal sphincter excursion, (2) intrabolus pressure pattern or common cavity, (3) hypercontractile esophagus (jackhammer) and achalasia type III, (4) absent contractility and severe ineffective esophageal motility or achalasia type I, and (5) simultaneous distal esophageal spasm and ineffective esophageal motility.

The Impact of Magnetic Sphincter Augmentation (MSA) on Esophagogastric Junction (EGJ) and Esophageal Body Physiology and Manometric Characteristics.

To evaluate the impact of MSA on lower esophageal sphincter (LES) and esophageal body using high resolution impedance manometry. MSA is an effective treatment in patients with gastroesophageal reflux disease, but there is limited data on its impact on esophageal functional physiology. Patients who underwent MSA were approached 1-year after surgery for objective foregut testing consists of upper endoscopy, esophagram, high resolution impedance manometry, and esophageal pH-monitoring. Postoperative data were then compared to the preoperative measurements. A total of 100 patients were included in this study. At a mean follow up of 14.9(10.1) months, 72% had normalization of esophageal acid exposure. MSA resulted in an increase in mean LES resting pressure [29.3(12.9) vs 25(12.3), P < 0.001]. This was also true for LES overall length [2.9(0.6) vs 2.6(0.6), P = 0.02] and intra-abdominal length [1.2(0.7) vs 0.8(0.8), P < 0.001]. Outflow resistance at the EGJ increased after MSA as demonstrated by elevation in intrabolus pressure (19.6 vs 13.5 mmHg, P < 0.001) and integrated relaxation pressure (13.5 vs 7.2, P < 0.001). MSA was also associated with an increase in distal esophageal body contraction amplitude [103.8(45.4) vs 94.1(39.1), P = 0.015] and distal contractile integral [2647.1(2064.4) vs 2099.7(1656.1), P < 0.001]. The percent peristalsis and incomplete bolus clearance remained unchanged ( P = 0.47 and 0.08, respectively). MSA results in improvement in the LES manometric characteristics. Although the device results in an increased outflow resistance at the EGJ, the compensatory increase in the force of esophageal contraction will result in unaltered esophageal peristaltic progression and bolus clearance.

Transient hypopharyngeal intrabolus pressurization patterns: Clinically relevant or normal variant?

In oropharyngeal dysphagia, impaired pharyngoesophageal junction (PEJ) opening is reflected by an elevated hypopharyngeal intrabolus pressure (IBP), quantifiable using pharyngeal high-resolution manometry with impedance (P-HRM-I). Transient intrabolus pressurization (TP) phenomena are not sustained and last for only a brief period. We hypothesized that TP patterns reflect impaired coordination between timing of hypopharyngeal bolus arrival and PEJ relaxation. A retrospective audit was conducted of P-HRM-I datasets; 93 asymptomatic Controls and 214Patients with differing etiological/clinical backgrounds were included. TP patterns were examined during 10ml liquid swallows. TP was defined by a simultaneous, non-sustained, pressurization wave spanning from the velo-/meso-pharynx to PEJ. The coordination between deglutitive pharyngeal bolus distension and PEJ relaxation timing was assessed using timing variables; (i) Distention-Contraction Latency (DCL, s) and (ii) PEJ Relaxation Time (RT, s). Resultant flow resistance was quantified (IBP, mmHg). TP swallows were observed in 87 (28%) cases. DCL was not significantly different in relation to TP, while PEJ relaxation time was shorter, and IBP was higher during TP swallows. In Patients RT-DCL time difference correlated with IBP (r -0.368, p<0.01). Bolus distension and PEJ relaxation were miss-timed during TP swallows, impeding bolus flow and leading to a brief period of pressurization of the pharyngeal chamber by muscular propulsive forces. While TP swallows were identified in both Controls and Patients, increased IBPs were most apparent for Patient swallows indicating that the extent of IBP increase may differentiate pathological TP swallows.

The upper esophageal sphincter in the high-resolution manometry era.

The evaluation of the upper esophageal sphincter (UES) has been neglected during routine manometric tests for decades, mostly due to the limitations of the conventional manometry which were eventually overcome by high-resolution manometry (HRM). This study reviewed the current knowledge of the manometric evaluation of the UES in health and disease in the HRM era. We found that HRM allowed more precise measurements, in addition to the parameters as compared to conventional manometry, but most of them still need confirmation of the clinical significance. The parameters used to evaluate the UES were extension, basal pressure, residual pressure, relaxation duration, relaxation time to nadir, recovery time, intrabolus pressure, and deglutitive sphincter resistance. UES may be affected by different diseases: achalasia (UES is hypertonic with impaired relaxation), gastroesophageal reflux disease (UES is short and hypotonic), globus (UES ranges from normal to impaired relaxation to hypertonic), neurologic diseases (stroke and Parkinson - UES is hypotonic in early-stage to impaired relaxation in end-stage disease), and Zenker's diverticulum (UES has impaired relaxation). This review shows that UES dysfunction is part of several disease processes and that the study of the UES is possible and valuable with the aid of HRM.

Esophagogastric junction outflow obstruction.

In the Chicago Classification version 4.0 (CCv4), esophagogastric junction outflow obstruction (EGJOO) is manometrically defined as an elevated median integrated relaxation pressure (IRP) and elevated intrabolus pressure (IBP) during supine wet swallows, and persistently elevated median IRP in the upright position. A clinically relevant conclusive diagnosis of EGJOO requires a manometric diagnosis of EGJOO and associated symptoms such as dysphagia and/or chest pain with at least one of the following supportive investigations (pharmacologic provocation, timed barium esophagogram, and/or endoflip). The Chicago Classification is intended for diagnosis of primary esophageal motor disorders, and thus history and endoscopic evaluation are important to exclude conditions (eg, previous surgery, strictures, or masses) that can secondarily generate the EGJOO pattern on HRM. While a manometric finding of EGJOO is often made and can be an early sign of achalasia, more often it is a manometric finding without clinical implications. The proposed changes in CC4.0 have attempted to make the diagnosis more specific, in order to reduce the number of clinically irrelevant diagnoses and avoid confusion by patients and physicians alike.

Altered swallowing biomechanics in people with moderate-severe obstructive sleep apnea.

Dysphagia is a common but under-recognized complication of obstructive sleep apnea (OSA). However, the mechanisms remain poorly described. Accordingly, the aim of this study was to assess swallowing symptoms and use high-resolution pharyngeal manometry to quantify swallowing biomechanics in patients with moderate-severe OSA. Nineteen adults (4 female; mean (range) age, 46 ± 26-68 years) with moderate-severe OSA underwent high-resolution pharyngeal manometry testing with 5-, 10-, and 20-mL volumes of thin and extremely thick liquids. Data were compared with 19 age- and sex-matched healthy controls (mean (range) age, 46 ± 27-68 years). Symptomatic dysphagia was assessed using the Sydney Swallow Questionnaire. Swallow metrics were analyzed using the online application swallowgateway.com. General linear mixed model analysis was performed to investigate potential differences between people with moderate-severe OSA and controls. Data presented are means [95% confidence intervals]. Twenty-six percent (5 of 19) of the OSA group but none of the controls reported symptomatic dysphagia (Sydney Swallow Questionnaire > 234). Compared with healthy controls, the OSA group had increased upper esophageal sphincter relaxation pressure (-2 [-1] vs 2 [1] mm Hg, F = 32.1, P < .0001), reduced upper esophageal sphincter opening (6 vs 5 mS, F = 23.6, P < .0001), and increased hypopharyngeal intrabolus pressure (2 [1] vs 7 [1] mm Hg, F = 19.0, P < .05). Additionally, upper pharyngeal pressures were higher, particularly at the velopharynx (88 [12] vs 144 [12] mm Hg⋅cm⋅s, F = 69.6, P < .0001). High-resolution pharyngeal manometry identified altered swallowing biomechanics in people with moderate-severe OSA, which is consistent with a subclinical presentation. Potential contributing mechanisms include upper esophageal sphincter dysfunction with associated upstream changes of increased hypopharyngeal distension pressure and velopharyngeal contractility. Schar MS, Omari TI, Woods CM, etal. Altered swallowing biomechanics in people with moderate-severe obstructive sleep apnea. J Clin Sleep Med. 2021;17(9):1793-1803.

Reference high-resolution manometry values after magnetic sphincter augmentation.

BackgroundMagnetic sphincter augmentation (MSA) is an innovative antireflux procedure that can improve lower esophageal sphincter (LES) competency and reduce symptoms of gastroesophageal reflux disease (GERD). Some patients report postoperative dysphagia. To date, no studies have described reference high‐resolution manometry (HRM) values after MSA implantation.MethodsHigh‐resolution manometry was performed in patients free of dysphagia after MSA with or without concurrent crura repair. Reference values for all parameters of the Chicago Classification were defined as those between the 5th and 95th percentiles. The contribution of concurrent crura repair to LES competency and to reference values was also analyzed.Key ResultsEighty‐four patients met the study inclusion criteria. The upper limit of normality for integrated relaxation pressure (IRP) and intrabolus pressure (IBP) was 20.2 mmHg and 30.3 mmHg, respectively. Both variables were higher after MSA compared to normative Chicago Classification v3.0 values. The Distal Contractile Integral upper limit was in the range of normality. Patients undergoing crura repair had a significantly higher IRP (p = 0.0378) and lower GERDQ‐A scores (p = 0.0374) and Reflux Symptom Index (p = 0.0030) compared to those who underwent MSA device implantation alone.Conclusion & InferencesThis study provides HRM reference values for patients undergoing successful MSA implantation. Crural repair appears to be a key component of LES augmentation and is associated with improved clinical outcomes.

Chicago Classification Update (v4.0): Technical review on diagnostic criteria for distal esophageal spasm.

Distal esophageal spasm (DES) is defined as a manometric pattern of at least 20% of premature contractions in a context of normal esophago-gastric junction relaxation in a patient with dysphagia or non-cardiac chest pain. The definition of premature contraction requires the measurement of the distal latency and identification of the contractile deceleration point (CDP). The CDP can be difficult to localize, and alternative methods are proposed. Further, it is important to differentiate contractile activity and intrabolus pressure. Multiple rapid swallows are a useful adjunctive test to perform during high-resolution manometry to search for a lack of inhibition that is encountered in DES. The clinical relevance of the DES-manometric pattern was raised as it can be secondary to treatment with opioids or observed in patients referred for esophageal manometry before antireflux surgery in absence of dysphagia and non-cardiac chest pain. Further idiopathic DES is rare, and one can argue that when encountered, it could be part of type III achalasia spectrum. Medical treatment of DES can be challenging. Recently, endoscopic treatments with botulinum toxin and peroral endoscopic myotomy have been evaluated, with conflicting results while rigorously controlled studies are lacking. Future research is required to determine the role of contractile vigor and lower esophageal sphincter hypercontractility in the occurrence of symptoms in patients with DES. The role of impedance-combined high-resolution manometry also needs to be evaluated.

Diagnosis of congenital esophageal stenosis in adults and treatment with peroral endoscopic myotomy.

BackgroundCongenital esophageal stenosis (CES) in adults is a rare disorder that can present as achalasia, particularly in the distal esophagus. We describe the salient features of CES in adults and identify the feasibility and short-term outcomes of peroral endoscopic myotomy (POEM) for CES.MethodsIn this retrospective, single-center case series, we included 6 patients with a “misdiagnosis” of achalasia established elsewhere, ultimately diagnosed with CES and referred to our institution for POEM. Symptom improvement (clinical success rate), defined as an Eckardt Symptom Score (ESS) of <3 at 2-month follow up was assessed.ResultsSix patients (median age: 40 [range: 18-58] years; 4 males) were included. A long-standing history of dysphagia, ring-shaped stenosis on endoscopic examination, “lopsided hourglass” sign on barium esophagogram, and high-resolution manometry findings indicated by a compartmentalized intrabolus pressure pattern with distinction between the stenotic area and the lower esophageal sphincter were the salient features identified. POEM could not be completed in the first 2 cases due to technical challenges. All subsequent 4 patients who underwent successful POEM, exhibited improved ESS of ≤3 (clinical success rate 100%) at 2 months post-POEM.ConclusionsAlong with identification of salient features on several diagnostic modalities, a differential diagnosis of CES in adults must be considered in patients presenting with long-standing history of dysphagia arising from childhood and persisting into adulthood. Although favorable short-term outcomes of POEM were achieved, further evaluation is still warranted, and an inexperienced operator should not attempt POEM on CES patients due to its technical difficulties.

Study of etiology and esophageal motility characteristics of esophagogastric junction outlet obstruction patients

To analyze the causes of the esophagogastric junction outlet obstruction (EGJOO) patients, to discuss the differences of the clinical manifestation and esophageal motility characteristics between the anatomic EGJOO (A-EGJOO) and functional EGJOO (F-EGJOO) subgroups, and to search the diagnostic values of the specific metrics for differentiating the subgroups of EGJOO patients. For the current retrospective study, all the patients who underwent the esophageal high resonance manometry test were retrospectively analyzed from Jan 2012 to Oct 2018 in Peking University Third Hospital. The EGJOO patients were enrolled in the following research. The clinical characteristics, such as symptoms and causes of the patients were studied. Then the patients were divided into two subgroups as A-EGJOO subgroup and F-EGJOO subgroup. The clinical symptoms and the main manometry metrics were compared between these two subgroups. The significant different metrics between the two groups were selected to draw receiver operating characteristic (ROC) curves and the diagnostic values were analyzed in differentiating the A-EGJOO and F-EGJOO subgroups. The most common symptom of EGJOO was chest pain or chest discomfort (30.63%), then the dysphagia (29.73%), and acid regurgitation/heartburn (27.03%). Non-erosive reflux disease (36.04%) was the most popular cause for EGJOO, then the reflux esophagitis (17.12%). Besides the intra-EGJOO and extra-EGJOO lesions, the connective tissue disease (6.31%) and central nervous diseases (2.70%) were found to be the etiology of EGJOO. The causes of the rest 19 EGJOO were unknown. A-EGJOO patients presented significantly higher intra bolus pressure (IBP) than that of F-EGJOO [6.80 (5.20, 9.20) mmHg vs. 5.10 (3.10, 7.60) mmHg, P=0.016]. The area under curve of IBP was 0.637. When IBP≥5.15 mmHg, the sensitivity was 78.60% and specificity 50.70% to differentiate A- or F-EGJOO. Chest pain or chest discomfort was the most common symptom in EGJOO patients. Besides the intraluminal structural disorders, the extra-luminal causes were found in EGJOO patients. A-EGJOO presented higher IBP than that of F-EGJOO patients. The cutoff value of IBP to differentiate A-EGJOO from EGJOO was 5.15 mmHg with sensitivity 78.06% and specificity 50.70%. However for the low area under curve, the diagnostic value of IBP was limited.

Measurement of outflow resistance imposed by magnetic sphincter augmentation: defining normal values and clinical implication

IntroductionNo manometric criteria have been defined to select patients for magnetic sphincter augmentation (MSA). The first step to establish such criteria is to measure the outflow resistance at esophagogastric junction (EGJ) imposed by MSA. This resistance needs to be overcome by the esophageal contraction in order for the esophagus to empty and to avoid postoperative dysphagia. This study was designed to measure the outflow resistance caused by MSA in patients free of postoperative dysphagia.MethodsRecords of the patients who underwent MSA in our institution were reviewed. A group of MSA patients with excellent functional outcome, who were free of clinically significant postoperative dysphagia, were selected. These patients then underwent high-resolution impedance manometry (HRIM) at a target date of 1 year after surgery. The outflow resistance was measured by the esophageal intrabolus pressure (iBP) recorded 2 cm proximal to the lower esophageal sphincter (LES).ResultsThe study population consisted of 43 patients. HRIM was performed at mean of 20.4 (10.4) months after surgery. The mean (SD) amplitude of the iBP was 13.5 (4.3) before surgery and increased to 19.1 (5.6) after MSA (p < 0.0001). Patients with a smaller size LINX device (≤ 14 beads) had a similar iBP when compared to those with a larger device (> 15 beads) [19.7 (4.5) vs. 18.4 (5.9), p = 0.35]. There was a significant correlation between the iBP and % incomplete bolus clearance [Spearman R: 0.44 (95% CI 0.15–0.66), p = 0.0032]. The 95th percentile value for iBP after MSA was 30.4 mmHg.ConclusionThe EGJ outflow resistance measured by iBP is increased after MSA. The upper limit of normal for iBP is 30 mmHg in this cohort of patients who were free of dysphagia after MSA. This degree of resistance needs to be overcome by distal esophageal contraction and will likely be requisite to prevent persistent postoperative dysphagia.

S0430 The Effect of Hiatal Hernia on High-Resolution Esophageal Pressure Topography Measures in Patients With Esophagogastric Junction Outflow Obstruction

INTRODUCTION: High resolution esophageal pressure topography (HREPT) is used to diagnose esophagogastric junction outflow obstruction (EGJOO), a motility disorder with impairment of lower esophageal sphincter (LES) opening defined by an elevated integrated relaxation pressure (IRP) with preserved peristalsis. Many of these patients also have concomitant hiatal hernia (HH) that may independently affect LES relaxation pressures. This study aimed to evaluate the effect of HH on the diagnosis of EGJOO by comparing manometric outcomes at a single US tertiary care academic medical center. METHODS: This retrospective, observational, cohort study identified patients who had undergone HREPT between January 2017 and March 2018. Patients diagnosed with EGJOO were eligible for inclusion and further evaluated for HH via manometry. Those with obstructive dysphagia, pseudo-achalasia, or other neuromuscular disorders affecting esophageal motility were excluded. LES integrated relaxation pressures (IRP), basal pressure (BP), distal contractile integral (DCI), intrabolus pressure (IBP), and incomplete bolus transit (IBT) were collected. Student’s t- tests were used to compare groups and Chi-square analysis was used for independent variables. RESULTS: A total of 90 total patients were identified (n = 54 EGJOO without HH, n = 36 EGJOO with HH). In general, baseline characteristics were similar between groups with no significant differences in gender or age. Comparing patients with only EGJOO to those with both EGJOO and HH, there was a statistically significant difference in basal LES pressures (50.9 mmHg vs. 42.2 mmHg, P = 0.029) but no difference in IRP (22.5 mmHg vs. 20.3 mmHg, P = 0.173) between groups. Additionally there were no intergroup differences in DCI, IBP, or IBT. CONCLUSION: EGJOO is a heterogenous manometric diagnosis with many patients also experiencing anatomic defects including HH. Our study reports among the largest real-world comparisons of these groups. The observed higher basal LES pressures in patients with only EGJOO compared to those with both EGJOO and HH suggests a possible anatomic effect on LES pressures. However, this difference does not have affect other manometric measures including IRP which is currently the principal measure of outflow obstruction. Further work exploring the anatomic and physiologic components of LES pressure is needed to understand the development of EGJOO and guide therapeutic interventions.Table 1.: Outcomes

Effect of Bridge Position Swallow on Esophageal Motility in Healthy Individuals Using High-Resolution Manometry

Recently, there has been clinical interest in the effect of different body positions on esophageal motility. This study aimed to identify the effect of three different body positions on esophageal motility using high-resolution manometry. Thirteen healthy adults swallowed 5 mL of water in the upright, supine, and bridge positions. For the bridge position, each subject raised their waist against gravity, placed a cushion under their back, and bent their knees. The proximal contractile integral (PCI) and distal contractile integral (DCI), integrated relaxation pressure (IRP), distal latency (DL), peristaltic breaks (PBs), intrabolus pressure (IBP), and expiratory and inspiratory esophagoesophageal junction (EGJ) pressure were measured. In the bridge position, PCI, DCI, IRP, and expiratory and inspiratory EGJ pressure were significantly higher than those in the upright position (bridge PCI vs. upright PCI [p = 0.001], bridge DCI vs. upright DCI [p < 0.001], bridge IRP vs. upright IRP [p = 0.018], bridge EGJ pressure vs. upright EGJ pressure [expiratory: p = 0.001] [inspiratory: p < 0.001]). PBs were significantly shorter and DL was significantly longer in the bridge position compared to upright (bridge PBs vs. upright PBs [p = 0.001], bridge DL vs. upright DL [p = 0.001]). IBP was significantly higher in the bridge position compared to supine (bridge IBP vs. supine IBP [p = 0.01]). These results demonstrated changes in esophageal motility according to changes in position while swallowing, where esophageal contractions became stronger against gravity. Further study is required to examine the effectiveness of swallowing in the bridge position.

RoSE: A Robotic Soft Esophagus for Endoprosthetic Stent Testing.

Soft robotic systems are well suited for developing devices for biomedical applications. A bio-mimicking robotic soft esophagus (RoSE) is developed as an in vitro testing device of endoprosthetic stents for dysphagia management. Endoprosthetic stent placement is an immediate and cost-effective therapy for dysphagia caused by malignant esophageal strictures from esophageal cancer. However, later stage complications, such as stent migration, could weaken the swallow efficacy in the esophagus. The stent radial force (RF) on the esophageal wall is pivotal in avoiding stent migration. Due to limited randomized controlled trials in patients, the stent design and stenting guidelines are still unconstructive. To address the knowledge deficit, we have investigated the capabilities of the RoSE by implanting two stents (stent A and B) of different radial stiffness characteristics, to measure the stent RF and its effect on the stent migration. Also, endoscopic manometry on the RoSE under peristalsis has been performed to study the impact of stenting and stent dysfunctionality on the intrabolus pressure signatures (IBPSs) in the RoSE, and further its effects on the swallowing efficacy. Each implanted stent in the RoSE underwent a set of experiments with various test variables (peristalsis velocity and wavelength, and bolus concentrations). In this study, the conducted tests are representative of the application of RoSE to perform a wide-ranging assessment of the stent behavior. The usability of RoSE has been discussed by comparing the results of stent A and B, for various combinations of the test variables mentioned earlier. The results have demonstrated that the stiffer stent B has a higher RF, whereas stent A maintained its RF at a low profile due to its lesser stiffness. The results have also implicated that a high RF is necessary to minimize the stent migration under prolonged peristaltic contractions in the RoSE. For the manometry experiments, stent A slightly increased the IBPS, but the stiffer stent B significantly decreased the IBPS, especially for the higher concentration boluses. It was found that if a stiffer stent buckles, it can reduce the swallow efficacy and cause recurrent dysphagia. Therefore, RoSE is an innovative soft robotic platform that is capable of testing various endoprosthetic stents, thereby offering a solution to many existing clinical challenges in the area of stent testing.

Pressure abnormalities in patients with Zenker's diverticulum using pharyngeal high-resolution manometry.

ObjectivesZenker's diverticulum is associated with reduced cricopharyngeal compliance and abnormal intrabolus pressure. However, it is unclear how the pharynx compensates for these deficits. Developments in manometric technology have improved our ability to capture pharyngeal pressure events. This study aims to describe the pharyngeal‐upper esophageal sphincter (UES) pressure profile during swallowing in patients with Zenker's diverticulum.MethodsHigh‐resolution manometry was performed on 11 patients with symptomatic Zenker's diverticulum and 11 age‐ and sex‐matched healthy controls during 10 mL liquid swallowing tasks. Pharyngeal and UES pressure magnitudes, durations, and integrals were compared between patients and controls using independent t tests. Other manometric parameters, including residual UES pressure at the time of maximum tongue base pressure and pharyngeal‐UES pressure gradient, were also evaluated. A case example using three‐dimensional high‐resolution manometry is presented.ResultsCompared with healthy controls, patients with Zenker's diverticulum exhibited pressure abnormalities in the UES region. While baseline and pre‐opening maximum pressures were not different, residual pressures were elevated (P = .001). Pharyngeal‐UES pressure gradients did not differ between the two groups.ConclusionThis study used high‐resolution manometry to characterize pharyngeal pressure dynamics in patients with Zenker's diverticulum. The changes occurring at the cricopharyngeus appear to result in persistent UES pressurization during UES opening, rather than high tonic resting pressure. Pharyngeal‐UES pressure gradients, critical to bolus passage, were also preserved in this patient population.Level of Evidence3b.

High-resolution manometry features of paraesophageal hernia.

Paraesophageal hernias (PEH) can be associated with obstructive symptoms, but high-resolution manometry (HRM) characteristics have not been described in detail. HRM studies of confirmed PEH patients (n=60, 66.3±1.5years, 76.7% F), axial hernias (n=125, 56.1±1.1years, 58.4% F), and healthy controls (n=20, 27.9±0.7years, 45% F) were analyzed. Axial hernias (type 1) were compared to PEH subtyped as isolated PEH (type 2), PEH with axial hernia (type 3), PEH with herniated abdominal organs (type 4), and unknown. Distal contractile integral (DCI), esophageal length, lower esophageal sphincter pressures (LESP), EGJ contractile integral (EGJ-CI), and integrated relaxation pressure (IRP) were extracted. Intra-luminal pressures were measured proximal (intrabolus pressure, IBP) and distal (intragastric pressure, IGP) to EGJ. Univariate and multivariate analyses were performed to characterize esophageal and EGJ motor physiology in PEH. PEH patients had LESP and EGJ-CI similar to controls; axial hernia patients had lower LESP. While IRP was within normal limits, PEH had elevated IBP and IGP, and shorter esophageal length compared to axial hernia and normal controls (P≤.0001 across groups). Short esophageal length was consistent across PEH subtypes (P=.06). On multivariate regression analysis, IBP remained an independent predictor of PEH (P<.0001). Within PEH subtypes, gastric pressure was higher when axial HH was also present, in contrast to isolated PEH (P=.03); other metrics did not differ. Luminal pressure increase both upstream and downstream of the EGJ on HRM likely represents obstructive phenomena in PEH, identification of which may support suspicion of PEH.