High-resolution Esophageal Impedance Manometry Research Articles

Esophago-gastric junction findings on high resolution impedance manometry in children with esophageal atresia.

Using high resolution impedance manometry (HRIM), this study characterized the esophago-gastric junction (EGJ) dynamics in children with esophageal atresia (EA). Esophageal HRIM was performed in patients with EA aged less than 18 years. Objective motility patterns were analyzed, and EGJ data reported. Controls were pediatric patients without EA undergoing investigations for consideration of fundoplication surgery. Seventy-five patients (M:F = 43:32, median age 1 year 3 months [3 months-17 years 4 months]) completed 133 HRIM studies. The majority (64/75, 85.3%) had EA with distal tracheo-esophageal fistula. Compared with controls, liquid swallows were poorer in patients with EA, as evident by significant differences in distension pressure emptying and bolus flow time (BFT). The integrated relaxation pressure for thin liquid swallows was significantly different between EA types, as well as when comparing patients with EA with and without previous esophageal dilatations. The BFT for solid swallows was significantly different when compared with EA types. We have utilized HRIM in patients with EA to demonstrate abnormalities in their long-term EGJ function. These abnormalities correlate with poorer esophageal compliance and reduced esophageal peristalsis across the EGJ. Understanding the EGJ function in patients with EA will allow us to tailor long-term management to specific patients.

Pediatric retrograde cricopharyngeal dysfunction diagnosed by high-resolutionimpedance manometry.

The inability to burp, known as retrograde cricopharyngeal dysfunction (R-CPD), was initially described in adults. The proposed clinical diagnostic criteria for R-CPD include belching inability, abdominal bloating and discomfort/nausea, postprandial chest pain, and involuntary noises. Botulinum toxin injection to the cricopharyngeal muscle has been reported to be beneficial. High-resolution esophageal impedance-manometry (HRIM) features in adolescent patients with R-CPD have not been described yet. The aim of our study was to describe the clinical and HRIM findings of pediatric patients with R-CPD. Clinical and manometric features of five pediatric patients diagnosed with R-CPD were reviewed. HRIM study protocol was modified to include the consumption of carbonated drink to provoke symptoms and distinctive manometric features. We report five female patients aged 15-20 years who presented with an inability to burp and involuntary throat sounds. HRIM revealed normal upper esophageal sphincter (UES) relaxation during swallowing, but abnormal UES relaxation with concurrent high esophageal impedance reflecting air entrapment and secondary peristalsis following the carbonated drink challenge. Four patients exhibited esophageal motility disorder. All patients reported improvement or resolution of symptoms after botulinum toxin injection to the cricopharyngeus muscle. Adolescents with an inability to burp, reflux-like symptoms, bloating, and involuntary throat noises should be assessed for R-CPD by pediatric gastroenterologists with HRIM. The relatively recent recognition of this novel condition is the likely reason for its under- and misdiagnosis in children.

Bolus transit of upper esophageal sphincter on high-resolution impedance manometry study correlate with the laryngopharyngeal reflux symptoms

Laryngopharyngeal reflux symptom is a troublesome upper esophageal problem, and reflux symptom index (RSI) is commonly applied for the assessment of clinical severity. We investigated the relationship between the upper esophageal sphincter impedance integral (UESII) and RSI scores in this study. Totally 158 subjects with high-resolution esophageal impedance manometry (HRIM) with RSI questionnaire assessment were recruited. There are 57 (36.08%), 74 (46.84%), 21 (13.29%), and 6 (3.79%) patients were categorized as normal, ineffective esophageal motility disorder, absent contractility, and achalasia by HRIM examination, respectively. Subjects with RSI > 13 were noted to have lower UESII than others with RSI ≦ 13 (7363.14 ± 1085.58 vs. 11,833.75 ± 918.77 Ω s cm; P < 0.005). The ROC analysis yielded a UESII cutoff of < 2900 Ω s cm for the best prediction of subjects with RSI > 13 (P = 0.002). Both female gender and UESII cutoff of < 2900 Ω s cm were significant predictors of RSI > 13 in logistic regression analysis (OR = 3.84 and 2.83; P = 0.001 and 0.01; respectively). Lower UESII on HRIM study, indicating poor bolus transit of UES during saline swallows, is significantly associated with prominent laryngopharyngeal reflux symptoms scored by RSI score.

Pressure-impedance analysis: Assist the diagnosis and classification of ineffective esophageal motility disorder.

We elucidated the clinical significance of distal contractile integral-to-esophageal impedance integral (EII) ratio (DCIIR) in ineffective esophageal motility (IEM) adult patients. We recruited 101 patients with IEM (48.38±1.58years) and 42 matched healthy volunteers (44.28±1.85years) in this case-control study. All subjects underwent esophageal high-resolution impedance manometry from October 2014 to May 2018. The diagnosis of IEM was based on the Chicago Classification version 3.0. The EII, EII ratio, and DCIIR were analyzed by matlab software. The EII, EII ratio, and DCIIR calculated at an impedance threshold of 1500Ω (EII1500, EII ratio1500, and DCIIR1500, respectively) were significantly lower in the IEM group than in healthy controls (P<0.0001, <0.0001, and <0.0001, respectively). Receiver operating characteristic analysis showed that DCIIR1500<0.008mmHg/Ω, EII1500>71000Ω.s.cm, and EII ratio1500 >0.43 were all predictive of IEM. Only DCIIR1500<0.008mmHg/Ω remained significant in diagnosing IEM in the multivariate logistic regression analysis (odds ratio=72.13, P<0.001). The DCIIR1500 is negatively correlated with Eckardt score and the Reflux Disease Questionnaire (correlation coefficient=-0.2844 and -0.3136; P=0.0006 and 0.0002, respectively). Receiver operating characteristic analysis further showed that a DCIIR1500 cut-off of 0.002mmHg/Ω achieved the best differentiation between the IEM-alternans and IEM-persistens subtypes among IEM patients (P<0.001). The novel pressure-impedance parameter of high-resolution impedance manometry, DCIIR1500, may assist in the diagnosis and classification of IEM and correlated with clinical symptoms.

Role of esophageal manometry in children with refractory gastroesophageal reflux symptoms.

We investigated the prevalence of psychiatric referral, frequency of repeat upper gastrointestinal (UGI) contrast studies, and esophagogastroduodenoscopy (EGD) in children with ineffective esophageal motility (IEM) before the confirmation of esophageal dysmotility. A total of 19 children (nine boys, 10 girls; mean age, 13.80±5.10years) with symptoms of refractory gastroesophageal reflux (GER) who underwent high-resolution esophageal impedance manometry (HRIM) were enrolled in this retrospective analysis. Refractory GER symptoms were defined as persistent symptoms even under acid-suppression therapy for 8weeks in this study. Clinical data including age, gender, time from symptom onset to diagnosis, and number of UGI contrast studies and EGD before diagnosis were obtained. HRM parameters and the prevalence of psychiatric referral were also analyzed. There are 14 children (73.68%) diagnosed with IEM by HRIM, and another 5 children (26.32%) diagnosed as GER disease (GERD) by EGD. A significant proportion of IEM children were misdiagnosed with psychological problems compared with the GERD children (78.57% vs 20.00%, P=0.04). Three IEM children (21.43%) received antipsychotic and antidepressant agents before diagnosis of IEM, and all of them discontinued these medications after diagnosis. IEM children underwent a greater number of UGI contrast studies (1.07±0.92 vs 0.20±0.45; P=0.02) and EGD (2.36±2.50 vs 0.60±0.55; P=0.03) before HRM than GERD children. Esophageal manometry for the diagnosis of IEM should be considered in children with GER symptoms refractory to acid-suppression therapy for 8weeks to avoid repeat UGI contrast studies, EGD, and psychological therapy.

A study of dysphagia symptoms and esophageal body function in children undergoing anti-reflux surgery.

The role of high-resolution esophageal impedance manometry (HRIM) for establishing risk for dysphagia after anti-reflux surgery is unclear. We conducted a prospective study of children with primary gastroesophageal reflux (GER) disease, for whom symptoms of dysphagia were determined pre-operatively and then post-operatively and we examined for features that may predict post-operative dysphagia. Thirteen children (aged 6.8-15.5 years) undergoing work-up prior to 360o Nissen fundoplication were included in the study. A dysphagia score assessed symptoms at pre-operative study and post-operatively (mean 1.4 years). A HRIM procedure recorded 5-ml liquid, 5-ml viscous and 2-cm solid boluses. We assessed esophageal motility, esophago-gastric junction (EGJ) morphology, EGJ contractility and pressure-flow variables indicative of bolus distension pressures and bolus clearance pressures. A composite pressure-flow index score was also derived. Pre-operative pressure-flow index was positively correlated with post-operative dysphagia score (viscous bolus r = 0.771, p < 0.005). Of three variables that comprise the pressure-flow index, the ramp pressure measured during bolus clearance was the main driver of the effect seen (viscous bolus r = 0.819, p < 0.005). In order to mitigate symptoms in relation to anti-reflux surgery, dysphagia symptoms and esophageal function need to be pre-operatively assessed. In patients with normal motility, an elevated pressure-flow index may predict post-operative dysphagia.

Diagnosis and Treatment of Rumination Syndrome

Rumination syndrome is a functional gastrointestinal disorder characterized by effortless postprandial regurgitation. The disorder appears uncommon, although only limited epidemiologic data are available. Awareness of the characteristic symptoms is essential for recognizing the disorder, and thus avoiding the long delay in diagnosis, that many patients experience. Although objective testing by postprandial esophageal high-resolution impedance manometry is available in select referral centers, a clinical diagnosis can be made in most patients. The main therapy for rumination syndrome is behavioral modification with postprandial diaphragmatic breathing. This clinical practice update reviews the pathophysiology, diagnosis, and treatment of rumination syndrome. Best Practice Advice 1: Clinicians strongly should consider rumination syndrome in patients who report consistent postprandial regurgitation. Such patients often are labeled as having refractory gastroesophageal reflux or vomiting. Best Practice Advice 2: Presence of nocturnal regurgitation, dysphagia, nausea, or symptoms occurring in the absence of meals does not exclude rumination syndrome, but makes the presence of it less likely. Best Practice Advice 3: Clinicians should diagnose rumination syndrome primarily on the basis of Rome IV criteria after an appropriate medical work-up. Best Practice Advice 4: Diaphragmatic breathing with or without biofeedback is the first-line therapy in all cases of rumination syndrome. Best Practice Advice 5: Instructions for effective diaphragmatic breathing can be given by speech therapists, psychologists, gastroenterologists, and other health practitioners familiar with the technique. Best Practice Advice 6: Objective testing for rumination syndrome with postprandial high-resolution esophageal impedance manometry can be used to support the diagnosis, but expertise and lack of standardized protocols are current limitations. Best Practice Advice 7: Baclofen, at a dose of 10 mg 3 times daily, is a reasonable next step in refractory patients.

Su1060 - Baseline Impedance on High-Resolution Esophageal Impedance-Manometry is Associated with Non-Elective Hospitalization after Lung Transplantation

Su1060 - Baseline Impedance on High-Resolution Esophageal Impedance-Manometry is Associated with Non-Elective Hospitalization after Lung Transplantation

Esophageal high-resolution impedance manometry alterations in asymptomatic patients with systemic sclerosis: prevalence, associations with disease features, and prognostic value.

This study aims to investigate pre-clinical esophageal involvement in systemic sclerosis (SSc) by high-resolution impedance manometry (HRiM), its associations with disease features including lung involvement, and its predictivity of esophageal symptoms overtime. Charts of 45 asymptomatic (no heartburn/regurgitation/dysphagia) SSc patients (96% females; mean age 46years) with at least one follow-up (FU) visit and complete clinical, serological, functional, and radiological assessment, including high-resolution computed tomography (HRCT) of the chest and lung function tests, that had undergone esophageal HRiM were retrospectively evaluated. Esophagogastric junction-contractile integral (EGJ-CI) and esophageal body motility, as evaluated by mean distal contractile integral (DCI), were assessed. SSc patients had a normal esophageal motility in 7/45 cases, a defective EGJ-CI in 28, an ineffective esophageal motility (IEM) in 17, and aperistalsis in 12. Defective EGJ-CI was associated with IEM/aperistalsis in 20 cases, while 9 patients had isolated IEM. Defective EGJ-CI and/or IEM/aperistalsis were associated with a diffusing lung capacity for CO < 80% of predicted value (all p < 0.05), while defective EGJ-CI was also associated with interstitial lung disease on HRCT (p = 0.03). Prevalence of any HRiM abnormality was higher in anti-centromere antibody negative patients (all p < 0.05). IEM/aperistalsis independently increased the risk of esophageal symptoms by 2.3-fold (95% CI 1.1-5.7) and was associated with their higher cumulative incidence with respect to patients with other HRiM patterns at FU (χ2 = 4.63; p = 0.03). SSc patients asymptomatic for esophageal involvement can have HRiM abnormalities in up to 84% of cases. A baseline-impaired motility is a risk factor for symptomatic esophageal disease.

Assessment of Esophageal High-Resolution Impedance Manometry in Patients with Nonobstructive Dysphagia.

Background High-resolution impedance manometry (HRIM) can calculate the bolus motion parameters and the ratio of complete esophageal transit besides the conventional esophageal dynamic parameters; therefore, we could better manage the patients with nonobstructive dysphagia (NOD) clinically. Aim To analyze the HRIM parameter results of NOD patients and evaluate the characteristics of their esophageal motility and transit function. Methods In total, 58 NOD patients were assessed and the clinical diagnoses were determined. HRIM was performed, and both conventional high-resolution manometry and esophageal transit parameters were analyzed. Results In 58 NOD patients, 28 patients had achalasia, 3 esophagogastric junction outflow obstruction, and 20 nonspecific esophageal motility disorders, and 7 were normal. Impedance results demonstrated that all the patients with achalasia exhibited incomplete esophageal transit (ICET), three patients with esophagogastric junction outflow obstruction showed ICET, and the average bolus transit time (BTT) was 6.6 ± 1.2 sec. In 20 nonspecific esophageal motility disorders, 13 patients with gastroenterologly reflux disease (GERD) presented ineffective esophageal motility and fragmented peristalsis, and 65.0% swallows had exhibited ICET. However, 49.1% swallows of 7 nonspecific esophageal motility disorder patients with non-GERD had exhibited ICET. The average BTT in 13 GERD patients was longer than that in the non-GERD patients (8.1 ± 1.1 sec versus 5.5 ± 0.3 sec, P < 0.05). And in the seven patients with normal esophagus function, 3.5% swallows showed ICET and BTT was 5.6 ± 0.3 sec. Conclusion Achalasia was the most common esophageal dysmotility in NOD patients, followed by nonspecific esophageal motility disorders. The clinical diagnoses of NOD were mostly achalasia and GERD. Impedance assessments showed that all achalasia cases exhibited ICET, and other esophageal motility abnormalities that represented ICET were associated with contraction break and ineffective swallow. Compared to non-GERD patients, BTT was significantly prolonged in patients with GERD.

Normative values and factors affecting water-perfused esophageal high-resolution impedance manometry for a Chinese population.

Combined esophageal high-resolution impedance manometry (HRIM) measures multiple pressures and bolus transit simultaneously, facilitating detailed assessment of esophageal motility. Currently, normative values for water-perfused HRIM systems for Chinese populations are lacking. Healthy volunteers were enrolled for comprehensive anthropometric measures, blood biochemistry tests, and an HRIM study using 22 water-perfused pressure sensors and 12 impedance channels. Ten 5-mL liquid swallows of saline at 30-second intervals were conducted. The following parameters were calculated: distal contractile integral (DCI), distal latency (DL), lower esophageal sphincter (LES) basal pressure, 4-second integrated relaxation pressure (IRP-4s), and complete bolus transit percentage. Normal values were established based on the 5th and 95th percentiles. All 66 participants (34 male, 32 female, aged 21-64years) completed the study and tolerated the HRIM procedure well. The upper normal limit (95th percentile) of IRP-4second was 20mmHg. The 5th-95th percentile range for DCI, DL, and complete bolus transit was 99-2186mmHg●s●cm, 6.2-11.3second, and 50%-100%, respectively. Age was negatively correlated with DL. Females had significantly higher upper limits for IRP-4s and median DCI than males. Multivariate analyses confirmed that IRP-4s was higher in females, and that higher body mass index and waist circumference were associated with reduced DL and better bolus transit, respectively. We established normative values for the water-perfused HRIM system for a Chinese population. Gender and anthropometric factors may affect various major HRIM parameters and should be taken into account when interpreting HRIM results in clinical practice.

Transmitted cardiovascular pulsations on high resolution esophageal impedance manometry, and their significance in dysphagia.

AIMTo investigate the behavior of pulsatile pressure zones (PPZ’s) as noted on high resolution esophageal impedance manometry (HREIM), and determine their association with dysphagia.METHODSRetrospective, single center case control design screening HREIM studies for cases (dysphagia) and controls (no dysphagia). Thoracic radiology studies were reviewed further in cases for (thoracic cardiovascular) thoracic cardiovascular (TCV) structures in esophageal proximity to compare with HREIM findings. Manometric data was collected for number, location, axial length, PPZ pressure and esophageal clearance function (impedance).RESULTSAmong 317 screened patients, 56% cases and 64% controls had PPZ’s. Fifty cases had an available thoracic radiology comparison. The distribution of PPZ’s in these 50 cases and 59 controls was similar (average 1.4 PPZ/patient). Controls (mean 31.2 ± SD 12 years) were a significantly younger population than cases (mean 67.3 ± SD 14.9 years) with P < 0.0001. The upright posture PPZ pressure was higher in controls (15.7 ± 10.0 mmHg) than cases (10.8 ± 9.7 mmHg). Although statistically significant (P = 0.005), it was a weak predictor using logistic regression and ROC model (AUC = 0.65). Three dysphagia patients had partial compression from external TCV on radiology (1 aberrant subclavian artery, 2 dilated left atrium). The posture (supine vs upright) with more prominent PPZ’s impaired bolus clearance in 9 additional cases by > 20%.CONCLUSIONTransmitted TCV pulsations observed in HREIM bear no significant impact on swallowing. However, in older adults with dysphagia, evidence of impaired bolus clearance on impedance should be evaluated for external TCV compression. These associations have never been explored previously in literature, and are novel.

Effects of Age on Esophageal Motility: Use of High-resolution Esophageal Impedance Manometry.

Background/AimsDisturbances of esophageal motility have been reported to be more frequent the aged population. However, the physiology of disturbances in esophageal motility during aging is unclear. The aim of this study was to evaluate the effects of age on esophageal motility using high-resolution esophageal impedance manometry (HRIM).MethodsEsophageal motor function of 268 subjects were measured using HRIM in 3 age groups, < 40 years (Group A, n = 32), 40–65 years (Group B, n = 185), and > 65 years (Group C, n = 62). Lower esophageal sphincter (LES) and upper esophageal sphincter (UES) pressures, integrated relaxation pressure, distal contractile integral, contractile front velocity, distal latency, and pressures and duration of contraction on 4 positions along the esophagus, and complete bolus transit were measured.ResultsBasal UES pressure was lower in Group C (P < 0.001) but there was no significant difference in the LES pressure among groups. Contractile duration on position 3 (10 cm from proximal LES high pressure zone) was longer in Group C (P = 0.001), and the contractile amplitude on position 4 (5 cm from proximal LES high pressure zone) was lower in Group C (P = 0.005). Distal contractile integral was lower in Group C (P = 0.037). Contractile front velocity (P = 0.015) and the onset velocity (P = 0.040) was lower in Group C. There was no significant difference in impedance values.ConclusionsThe decrease of UES pressure, distal esophageal motility, and peristaltic velocity might be related with esophageal symptoms in the aged population.

Rumination

Rumination syndrome is one of the functional gastroduodenal disorders. Effortless and repetitive regurgitation of recently ingested food from the stomach to the oral cavity followed by rechewing and reswallowing or spitting are the characteristic clinical features. This disorder is believed to be uncommon, but many patients with this disorder are overlooked by their physicians. Rumination might be caused by a reversal of the gastric contents through the esophagogastric junction, which is initiated by an increase in intragastric pressure. The characteristic symptoms are sufficient for the diagnosis of rumination syndrome. Postprandial high resolution esophageal impedance manometry can detect gastric pressurization exceeding 30 mmHg associated with the return of ingested material into the proximal esophagus, which is a pathognomonic finding of rumination syndrome. An extensive explanation of the condition and the underlying mechanism is the first step of the treatment of rumination syndrome. Behavioral therapy through diaphragmatic breathing is the mainstay of treatment. Further studies on the long term effects of biofeedback therapy as well as a proper strategy for refractory rumination syndrome are needed.

Baseline Impedance Measured During High-Resolution Esophageal Impedance Manometry Reliably Discriminates GERD Patients

Baseline Impedance Measured During High-Resolution Esophageal Impedance Manometry Reliably Discriminates GERD Patients

Impaired bolus clearance in asymptomatic older adults during high-resolution impedance manometry.

Dysphagia becomes more common in old age. We performed high-resolution impedance manometry (HRIM) in asymptomatic healthy adults (including an older cohort >80years) to assess HRIM findings in relation to bolus clearance. Esophageal HRIM was performed in a sitting posture in 45 healthy volunteers (n=30 young control, mean age 37±11years and n=15 older subjects aged 85±4years) using a 3.2-mm solid-state catheter (Solar GI system; MMS, Enschede, The Netherlands) with 25 pressure (1-cm spacing) and 12 impedance segments (2-cm intervals). Five swallows each of 5- and 10-mL liquid and viscous bolus were performed and analyzed using esophageal pressure topography metrics and Chicago classification criteria as well as pressure-flow parameters. Bolus transit was determined using standard impedance criteria. A p-value <0.05 was considered significant. Impaired bolus clearance occurred more frequently in asymptomatic older subjects compared with young controls (YC) during liquid (40 vs 18%, χ2 =4.935; p<0.05) and viscous (60 vs 17%; χ2 =39.08; p<0.001) swallowing. Longer peristaltic breaks (p<0.05) and more rapid peristalsis (L: p<0.004, V: p=0.003) occurred in the older cohort, with reduced impedance-based clearance for both bolus consistencies (L: p<0.05, V: p<0.001). Decreased peristaltic vigor (distal contractile integral <450mmHg/s/cm) was associated with reduced liquid clearance in both age groups (p<0.001) and of viscous swallows in the older group (p<0.001). Impedance ratio, a marker of bolus retention, was increased in older subjects during liquid (p=0.002) and viscous (p<0.001) swallowing. Impaired liquid and viscous bolus clearance, esophageal pressure topography, and pressure-flow changes were seen in asymptomatic older subjects.

Esophageal Manometry Among Patients With Dysphagia Referred To Kurdistan Center For Gastroenterology And Hepatology

Background and Objectives:Dysphagia is a common problem in patients with primary motor disorders of the esophagus. Esophageal manom- etry is the gold standard for diagnosis of these disorders. Introduction of high resolution manometry represented a significant improvement in data recording and diagnostic yield. The objective of the study was to assess the findings of esophageal high resolution impedance manometry in patients presenting with dysphagia in Sulaimani governorate. Patients and Methods:This study extended from September, 2012 to December, 2013 and included 120 patients with dysphagia who were referred for manometry in Kurdistan Center for Gastroenterology and Hepatology (KCGH) in Sulaimani city. All patients underwent upper endoscopy to exclude mechanical and inflammatory causes of dysphagia then the high resolution impedance manometry was used with liquid and viscous swallows. Results:The mean age of the study population was 43 years. The female to male ratio was 1.5:1. The mean duration of dysphagia was 2 years. The most common esophageal motility abnormality was achalasia (N=44, 36.7%) followed by hypertensive LES (N=31, 25.8%), ineffective esophageal motility (N=9, 7.5%), hypotensive LES (N=5, 4.2%) and diffuse esophageal spasm (N=3, 2.5%). The high resolution impedance manometry was normal in 28 patients (23.3%). Of the 44 patients with achalasia, 15 patients (34%) had vigorous achalasia. Using Chica- go classification, the most common type of achalasia was type II (N=26, 59%) followed by type I (N=13, 29.6%) and then type III (N=5, 11.4%). Conclusions:Esophageal high resolution impedance manometry has an acceptable diagnostic yield in patients with dysphagia.The most common finding is achalasia. Further studies are recommended.

Tu1149 Anxiety and Impedance During Contraction in the Proximal Esophagus Are Significantly Associated With Bolus Perception in Healthy Control Individuals. Results of a Multicenter Study Using High Resolution Esophageal Impedance Manometry

Tu1149 Anxiety and Impedance During Contraction in the Proximal Esophagus Are Significantly Associated With Bolus Perception in Healthy Control Individuals. Results of a Multicenter Study Using High Resolution Esophageal Impedance Manometry

Clinical Significance of Pulsatile High Pressure Zones on High Resolution Esophageal Manometry in Dysphagia Patients

Introduction: Pulsatile high pressure zones (HPZ’s) are commonly seen in high resolution esophageal impedance manometry (HREIM) studies secondary to external association with thoracic cardiovascular structures (TCVS) and transmitted pulsations. The clinical significance of these findings is unclear in patients with dysphagia in terms of external CVS compression on esophagus. Methods: Retrospective review of 241 patients undergoing HREIM for dysphagia due to causes other than achalasia, stricture, esophageal dysmotility, mechanical obstruction, pharyngeal or esophageal pouch. The HRIM protocol included multiple 5 ml Gatorade swallows in both supine and upright swallows. Patients were identified based on findings of consistent pulsatile HPZ from either position with an average pressure of > 5mmHg. Further chart review was done for comparative radiology studies for TCV structures in anatomical esophageal proximity. Fifty patients with available radiology images (CT/MR chest, esophagogram) were identified. Manometric data were collected regarding number, location, width, pressure of HPZs from both postures. Esophageal clearance function identified by impedance was analyzed. Radiological imaging was reviewed to correlate with HREIM findings. Results: Among 241 patients (90F; 46M, Age 24-89 yrs), 136 (56.4%) were noted to have HPZ’s in either posture. Fifty of these 136 patients had at least one radiology comparison. A total of 70 HPZs were found in these 50 patients. Majority (39/70) of the HPZs were observed in both upright and supine postures, and 10 in upright, 16 in supine only. Only 3/50 patients had evidence of partial obstruction from TCVS compression on radiology (1 from aberrant subclavian artery with dysphagia lusoria, 2 from dilated left atrium). In the patient with dysphagia lusoria, bolus clearance was 10% in supine swallows and 90% upright swallows. In one of the patients with enlarged left atrium, bolus clearance was 80% in supine swallows and 10% in upright posture. No impedance data was available for the third patient. Pressure across HPZ in these 3 patients was from 25 to 35 mmHg. There was no radiological evidence of obstruction caused by TCVS in remaining 47/50 patients. Cross pressure of the HPZs ranged from 0-35mmHg (mean 9.96 mmHg). Impaired bolus clearance observed in 9/47 patients. Posture affected bolus clearance in these patients by >20% when HPZ became more prominent (supine vs upright). Conclusion: Pulsatile HPZ’s due to transmitted pulsations from TCV structures are frequently observed in HREIM; however, there was minimum clinical significance in most of the patients with dysphagia.

Tu1976 The 4 Phases of Swallowing: a Functional Model Based on Esophageal Pressure Topography Landmarks

OBJECTIVES: Noncardiac chest pain (NCCP) is defined as recurrent chest pain which does not originate from cardiac cause. Gastroesophageal reflux disease (GERD) is themost common cause of NCCP. However, there are patients presenting NCCP whose symptom is not related with GERD. This study aims to evaluate novel mechanism of non-GERD-related NCCP using high-resolution impedance manometry (HRIM) and 24-hour multichannel intraluminal impedance-pH (MII-pH) testing. PATIENTS AND METHODS: This retrospective study was conducted at Samsung Medical Center between June 2011 and December 2012. A total of 77 NCCP patients and 14 healthy volunteers (control group) were included. The subjects underwent upper endoscopy, esophageal HRIM and 24-hr MII-pH testing. According to the presence of erosive esophagitis and/or pathologic acid exposure, patients were divided into GERD-related group and non-GERD-related group. We measured mean esophageal baseline intraluminal impedances and investigated esophageal motility disorders and/or peristaltic abnormalities. The mean baseline intraluminal impedance was measured at distal and proximal esophagus, 3 cm and 17 cm above the lower esophageal sphincter. The esophageal motility disorders and peristaltic abnormalities were determined by Chicago classification. RESULTS: Among 77 NCCP patients, 16 (11.7%) were included in GERD-related group and 61 (88.3%) were included in non-GERD-related group. The distal mean baseline intraluminal impedance did not differ between NCCP patients and control group. However, the proximal mean baseline intraluminal impedance was lower in NCCP patients than in control group (2463±631 vs. 3739±486 V, P<0.001). In subgroup analysis, the distal mean baseline intraluminal impedance was lower only in GERD-related group than in non-GERD-related NCCP group (1924±802 vs. 2666±804 V, P<0.001) and control group (1924±802 vs. 3739±486 V, P=0.02). There was no difference in distal mean baseline intraluminal impedance between non-GERD-related group and control group. On the contrary, the proximal mean baseline intraluminal impedance was lower both in GERD-related (2391±711 vs. 3739±486V, P<0.001) and non-GERD-related group (2482±614 vs. 3739±486V, P<0.001) than in control group. The proximal mean baseline intraluminal impedance did not differ between GERD-related and non-GERD-related group. There was no difference in esophageal motility disorders, peristaltic abnormalities or impaired bolus transit among these groups. CONCLUSIONS: The proximal esophageal mucosal integrity impairment may play a causative role in patients with non-GERD-related NCCP. The proximal mucosal integrity seems to be impaired by another mechanism rather than esophageal hypomotility and impaired bolus transit.