High‐resolution manometric characteristics help differentiate types of distal esophageal obstruction in patients with peristalsis

Background High‐resolution manometry (HRM) can identify obstructive motor features at the esophagogastric junction and abnormalities in esophageal bolus transit. We sought to determine if HRM patterns can differentiate functional from organic mechanical lower esophageal sphincter (LES) obstruction. Methods Segmental characteristics of peristalsis were examined using HRM in symptomatic subjects with elevated postdeglutitive residual pressure gradients across the LES (≥5 mmHg). Sixteen consecutive patients with non‐achalasic mechanical fixed obstruction were compared with 13 patients with elevated pressure gradients yet no mechanical obstruction and 14 asymptomatic controls. Pressure volumes were determined in mmHg cm s for peristaltic segments defined on HRM Clouse plots using an on‐screen pressure volume measurement tool. Key Results Residual pressure gradients were similarly elevated in both patient groups. A visually conspicuous and distinctive shift in the proportionate pressure strengths of the second and third peristaltic segments was apparent across groups. Whereas the ratios of peak pressures and pressure volumes between second and third segments approached 1 in controls (0.92, 0.98), pressures shifted to the second segment in mechanical obstruction (peak pressure ratio: 1.2 ± 0.4; pressure volume ratio: 1.8 ± 0.9) and to the third segment in functional obstruction (peak ratio: 0.7 ± 0.2; volume ratio: 0.5 ± 0.2; P < 0.02 for any comparison of either group with controls). A threshold volume ratio of 1.0 correctly segregated 93% of obstruction (P < 0.0001); visual pattern inspection was equally effective. Conclusions & Inferences When elevated residual pressure gradients are present in non‐achalasic patients, topographic characteristics of peristalsis can differentiate fixed mechanical obstruction from functional obstruction.     

Reproducibility of esophageal high‐resolution manometry

Background Esophageal high‐resolution manometry (HRM) is a novel method for esophageal function testing that has prompted the development of new parameters for quantitative analysis of esophageal function. Until now, the reproducibility of these parameters has not been investigated. Methods Twenty healthy volunteers underwent HRM on two separate days. Standard HRM parameters were measured. In addition, in conventional (virtual) line tracings, lower esophageal sphincter (LES) resting pressure, relaxation pressure, and relative relaxation pressure were measured. Firstly, for each variable, the mean percentage of covariation (100 × SD/mean: %COV) was derived as a measure of inter‐ and intra‐individual variation. Secondly, Kendall’s coefficients of concordance (W values) were calculated. Thirdly, Bland–Altman plots were used to express concordance graphically. Key Results Statistically significant concordance values were found for upper esophageal sphincter (UES) pressure (W = 0.90, P = 0.02), transition zone length (W = 0.92, P = 0.01), LES length (W = 0.81, P = 0.04), LES pressure (W = 0.75, P = 0.05), LES relaxation pressure (W = 0.75, P = 0.03), relative LES relaxation pressure (W = 0.78, P = 0.05), gastric pressure (W = 0.81, P = 0.04), and contraction amplitude 5 cm above the LES (W = 0.86, P = 0.03). In conventional setting, only LES resting pressure (W = 0.835, P = 0.03) proved significant. In HRM tracings, concordance values for contraction wave parameters, and in conventional line tracings, LES relaxation pressure and relative relaxation pressure did not reach levels of statistical significance. Conclusions & Inferences Esophageal HRM yields reproducible results. Parameters that represent anatomic structures show better reproducibility than contraction wave parameters. The reproducibility of LES resting and relaxation pressure assessed with HRM is better than with conventional manometry and further supports the clinical use of HRM.     

High‐resolution esophageal pressure topography is superior to conventional sleeve manometry for the detection of transient lower esophageal sphincter relaxations associated with a reflux event

Background Transient lower esophageal sphincter relaxations (TLESRs) are the main mechanism underlying gastro‐esophageal reflux and are detected during manometric studies using well defined criteria. Recently, high‐resolution esophageal pressure topography (HREPT) has been introduced and is now considered as the new standard to study esophageal and lower esophageal sphincter (LES) function. In this study we performed a head‐to‐head comparison between HREPT and conventional sleeve manometry for the detection of TLESRs. Methods A setup with two synchronized MMS‐solar systems was used. A solid state HREPT catheter, a water‐perfused sleeve catheter, and a multi intraluminal impedance pH (MII‐pH) catheter were introduced in 10 healthy volunteers (M6F4, age 19–56). Subjects were studied 0.5 h before and 3 h after ingestion of a standardized meal. Tracings were blinded and analyzed by the three authors according to the TLESR criteria. Key Results In the HREPT mode 156 TLESRs were scored, vs 143 during sleeve manometry (P = 0.10). Hundred and twenty‐three TLESRs were scored by both techniques. Of all TLESRs (177), 138 were associated with reflux (78%). High‐resolution esophageal pressure topography detected significantly more TLESRs associated with a reflux event (132 vs 119, P = 0.015) resulting in a sensitivity for detection of TLESRs with reflux of 96% compared to 86% respectively. Analysis of the discordant TLESRs associated with reflux showed that TLESRs were missed by sleeve manometry due to low basal LES pressure (N = 5), unstable pharyngeal signal (N = 4), and residual sleeve pressure >2 mmHg (N = 10). Conclusions & Inferences The HREPT is superior to sleeve manometry for the detection of TLESRs associated with reflux. However, rigid HREPT criteria are awaited.     

Localizing the contractile deceleration point (CDP) in patients with abnormal esophageal pressure topography

Background The contractile deceleration point (CDP) is an important landmark for interpreting esophageal pressure topography (EPT) plots. Previous analysis in normal subjects confirmed that the CDP could be localized using an algorithm that found the time during peristalsis at which a maximal length of the distal esophagus was contracting concurrently (tML method). This study aimed to test the tML method for localizing CDP in patients with abnormal motility. Methods High‐resolution manometry studies of 75 patients with normal and disordered peristalsis were analyzed. Two experts, JEP and YX, used the original tangent‐intersection method to score CDP coordinates for the first two swallows of each study. Alternative computerized algorithms tested against the expert were: (i) the tML method, (ii & iii) the intercept between the leading edge of the 30‐mmHg isobaric contour and a line 2.0 cm (or 10% of esophageal length) proximal to the esophagogastric junction (EGJ) at rest, or (iv) the ‘tML‐3 cm’ method, which added the stipulation that the CDP be within 3 cm of the EGJ. Key Results All tested algorithms were highly correlated with the expert. However, the tMl‐3 cm method was better in the sense that it eliminated outliers (>1 s discrepancy with the expert) that occurred with the other methods usually attributable to weak distal peristalsis. Conclusions & Inferences Optimal automated CDP localization was achieved in both normal and a spectrum of abnormal motility using the tML method with the added stipulation that the CDP be restricted to within the distal 3 cm of the EGJ at rest.     

Measuring EGJ opening patterns using high resolution intraluminal impedance

The aim of this study was to adapt impedance methodology to study esophagogastric junction (EGJ) sphincter opening and compare opening patterns of the EGJ during deglutitive LES relaxation (dLESR) and transient LES relaxation (tLESR). We studied eight healthy subjects with a novel 12-lumen combined impedance/manometry catheter, the main element of which was a 6 cm sleeve sensor with six side hole sensors and six impedance rings spaced at 1 cm increments along its length. Subjects underwent an air infusion protocol after standard assessment and data tracings and isocontour plots were analysed to assess opening characteristics of the EGJ during dLESRs and tLESRs. Our results revealed that during dLESR the opening pattern was top to bottom, occurred in 0-2.7 s and in 29 of 35 (83%) cases the leading edge of the bolus was liquid. Opening during tLESR began between -7.8 and +8.6 s relative to the onset of nadir LES relaxation. The opening pattern during tLESR was bottom to top, occurred in 0-7.7 s, and in 22 of 29 (76%) the leading edge was liquid. These results support that impedance monitoring can be adapted to identify sphincter opening, to distinguish sphincter opening from sphincter relaxation, and to determine luminal contents during the opening period.     

Kinetics of transient hiatus hernia during transient lower esophageal sphincter relaxations and swallows in healthy subjects

Background Proximal displacement of the gastro‐esophageal junction (GEJ) is present in hiatus hernia but also occurs transiently during transient lower esophageal sphincter relaxations (TLESRs) and swallows. Using a novel magnetic‐based technique we have performed detailed examination of the GEJ movement during TLESRs and swallows in healthy subjects. Methods In 12 subjects, a magnet was endoscopically clipped to the GEJ and combined assembly of Hall‐Effect locator probe and 36 channel high‐resolution manometer passed nasally. After a test meal the subjects were studied for 90 min. Key Results The median amplitude of proximal movement of GEJ during TLESRs was 4.3 cm (1.6–8.8 cm) and this was substantially greater than during swallowing at 1.2 cm (0.4–2.7 cm), P = 0.002. With both TLESRs and swallows proximal GEJ movement coincided with lower esophageal sphincter (LES) relaxation and return to its original position occurred 4 s after return of LES tone. Kinetic modeling of the movement of the GEJ during TLESRs indicated two return phases with the initial return phase having the greater velocity (0.9 cm s^?1) and being strongly correlated with amplitude of proximal movement (r = 0.8, P < 0.001). Conclusions & Inferences The marked proximal GEJ migration during TLESRs represents very severe herniation of the GEJ. The rapid initial return of the GEJ following TLESRs when the crural diaphragm is relaxed and its correlation with amplitude suggest it is due to elastic recoil of the phreno‐esophageal ligament. The marked stretching of the phreno‐esophageal ligament during TLESRs may contribute to its weakening and development of established hiatus hernia.     

Identifying hiatal hernia with impedance planimetry during esophageal distension testing

Introduction

Functional luminal imaging probe (FLIP) Panometry evaluates the esophageal response to distension involving biomechanics and motility. We have observed that hiatus hernia (HH) is evident during FLIP studies as a separation between the crural diaphragm (CD) and lower esophageal sphincter (LES) like what is seen with high-resolution manometry (HRM). The aim of this study was to compare FLIP findings to endoscopy and HRM in the detection of HH.

Methods

A total of 100 consecutive patients that completed FLIP during sedated endoscopy and HRM were included. LES-CD separation was assessed on FLIP and HRM with the presence of HH defined as LES-CD ≥1 cm. The agreement was evaluated using the kappa (κ) statistic.

Results

Hiatal hernia was detected in 32% of patients on HRM and 44% of patients on FLIP with a substantial agreement between studies (84% agreement; κ = 0.667). On FLIP, a ‘new’ HH (i.e. HH not observed on HRM) occurred in 14 patients and an “enlarged” HH (i.e., LES-CD ≥2 cm larger than on HRM) occurred in 11 patients. Among patients that also completed, timed barium esophagogram (TBE), delayed esophageal emptying on TBE was more common in patients with new or enlarged HH on FLIP than those without: 7/11 (64%) versus 2/12 (17%); p = 0.017.

Conclusion

FLIP can detect HH with a substantial agreement with HRM, though esophageal distension with FLIP testing appeared to elicit and/or enlarge a HH in an additional 25% of patients. Although this unique response to esophageal distension may represent a mechanism of dysphagia or susceptibility to reflux, additional study is needed to clarify its significance.     

Multiple rapid swallow responses segregate achalasia subtypes on high‐resolution manometry

Background Multiple rapid swallows (MRS) inhibit esophageal peristalsis and lower esophageal sphincter (LES) tone; a rebound excitatory response then results in an exaggerated peristaltic sequence. Multiple rapid swallows responses are dependent on intact inhibitory and excitatory neural function and could vary by subtype in achalasia spectrum disorders. Methods Consecutive subjects with incomplete LES relaxation on high‐resolution manometry (HRM) (Sierra Scientific, Los Angeles, CA, USA) in the absence of mechanical obstruction were prospectively identified. Achalasia spectrum disorders were classified and HRM plots reviewed according to Chicago criteria. Esophageal peristaltic performance and LES function were assessed after 10 wet swallows and MRS (five 2 mL water swallows 2–3 s apart). Findings were compared with 18 healthy controls (28.5 ± 0.6 years, 44% women). Key Results A total of 46 subjects (57.1 ± 2.1 years, 52.2% women) met inclusion criteria. There was complete failure of peristalsis with MRS in all subjects with achalasia subtypes 1 and 2. In contrast, 80% of achalasia subtype 3 and incomplete LES relaxation (EGJ outflow obstruction) with preserved esophageal body peristalsis had a contractile response to MRS (P < 0.001 compared with subtypes 1 and 2); controls demonstrated 94.4% peristalsis. Percent decrease in LES residual pressure during MRS (compared to wet swallows) segregated achalasia subtypes; those with aperistalsis (subtypes 1 and 2) had a lesser decline (22.6%) compared to those with retained esophageal body peristalsis (40.5%) and controls (51.3%, P < 0.001 across groups). Conclusions & Inferences Multiple rapid swallow responses segregate achalasia spectrum disorders into two patterns differentiated by presence or absence of esophageal body contraction response to wet swallows. These findings support subtyping of achalasia, with pathophysiologic implications.     

Ambulatory high-resolution manometry, lower esophageal sphincter lift and transient lower esophageal sphincter relaxation

Background Lower esophageal sphincter (LES) lift seen on high‐resolution manometry (HRM) is a possible surrogate marker of the longitudinal muscle contraction of the esophagus. Recent studies suggest that longitudinal muscle contraction of the esophagus induces LES relaxation. Aim Our goal was to determine: (i) the feasibility of prolonged ambulatory HRM and (ii) to detect LES lift with LES relaxation using ambulatory HRM color isobaric contour plots. Methods In vitro validation studies were performed to determine the accuracy of HRM technique in detecting axial movement of the LES. Eight healthy normal volunteers were studied using a custom designed HRM catheter and a 16 channel data recorder, in the ambulatory setting of subject’s home environment. Color HRM plots were analyzed to determine the LES lift during swallow‐induced LES relaxation as well as during complete and incomplete transient LES relaxations (TLESR). Key Results Satisfactory recordings were obtained for 16 h in all subjects. LES lift was small (2 mm) in association with swallow‐induced LES relaxation. LES lift could not be measured during complete TLESR as the LES is not identified on the HRM color isobaric contour plot once it is fully relaxed. On the other hand, LES lift, mean 8.4 ± 0.6 mm, range: 4–18 mm was seen with incomplete TLESRs (n = 80). Conclusions & Inferences Our study demonstrates the feasibility of prolonged ambulatory HRM recordings. Similar to a complete TLESR, longitudinal muscle contraction of the distal esophagus occurs during incomplete TLESRs, which can be detected by the HRM. Using prolonged ambulatory HRM, future studies may investigate the temporal correlation between abnormal longitudinal muscle contraction and esophageal symptoms.     

Does body position modify the results of oesophageal high resolution manometry?

Background Oesophageal motility classification using high resolution manometry (HRM) has been established in the supine position. Nevertheless, examination in the sitting position is more physiological. Our aim was to determine if body position modifies oesophago‐gastric junction (OGJ) morphology and oesophageal motility. Methods A total of 100 patients (47 males, mean age 51 years) were included in this study. The oesophageal HRM protocol included examination in supine and sitting positions. Recordings were reviewed by two different operators. Amplitude, duration, velocity, Distal Contractile Integral (DCI) and Pressurization Front Velocity of oesophageal waves induced by swallowing were recorded. Key Results The lower oesophageal sphincter resting pressure was not significantly changed by body position. The sitting position modified the OGJ classification in 12 patients. The inter‐observer agreement to classify OGJ was moderate (kappa = 0.54 and 0.46, in the supine and sitting positions respectively) while it was good to diagnose motility disorders (kappa = 0.72 and 0.83). The percentage of normal waves was lower in the sitting position in comparison with the supine position (56%vs 67%, P < 0.01). The DCI was also lower in the sitting position (1125 mmHg.s.cm vs 1639, P < 0.01) as well as the amplitude of oesophageal waves. Finally the diagnosis was concordant in both positions in 72 patients. Conclusions & Inferences Body position can affect OGJ morphology and oesophageal motility assessment by HRM in some patients. Normal values in the sitting position should thus be determined. Inter‐observer variation for the proposed classification of OGJ morphology must also be taken into account.     

Evaluation of esophageal motor function in clinical practice

Esophageal motor function is highly coordinated between central and enteric nervous systems and the esophageal musculature, which consists of proximal skeletal and distal smooth muscle in three functional regions, the upper and lower esophageal sphincters, and the esophageal body. While upper endoscopy is useful in evaluating for structural disorders of the esophagus, barium esophagography, radionuclide transit studies, and esophageal intraluminal impedance evaluate esophageal transit and partially assess motor function. However, esophageal manometry is the test of choice for the evaluation of esophageal motor function. In recent years, high‐resolution manometry (HRM) has streamlined the process of acquisition and display of esophageal pressure data, while uncovering hitherto unrecognized esophageal physiologic mechanisms and pathophysiologic patterns. New algorithms have been devised for analysis and reporting of esophageal pressure topography from HRM. The clinical value of HRM extends to the pediatric population, and complements preoperative evaluation prior to foregut surgery. Provocative maneuvers during HRM may add to the assessment of esophageal motor function. The addition of impedance to HRM provides bolus transit data, but impact on clinical management remains unclear. Emerging techniques such as 3‐D HRM and impedance planimetry show promise in the assessment of esophageal sphincter function and esophageal biomechanics.     

What is new in Chicago Classification version 4.0?

Since publication of Chicago Classification version 3.0 in 2015, the clinical and research applications of high‐resolution manometry (HRM) have expanded. In order to update the Chicago Classification, an International HRM Working Group consisting of 52 diverse experts worked for two years and utilized formally validated methodologies. Compared with the prior iteration, there are four key modifications in Chicago Classification version 4.0 (CCv4.0). First, further manometric and non‐manometric evaluation is required to arrive at a conclusive, actionable diagnosis of esophagogastric junction (EGJ) outflow obstruction (EGJOO). Second, EGJOO, distal esophageal spasm, and hypercontractile esophagus are three manometric patterns that must be accompanied by obstructive esophageal symptoms of dysphagia and/or non‐cardiac chest pain to be considered clinically relevant. Third, the standardized manometric protocol should ideally include supine and upright positions as well as additional manometric maneuvers such as the multiple rapid swallows and rapid drink challenge. Solid test swallows, postprandial testing, and pharmacologic provocation can also be considered for particular conditions. Finally, the definition of ineffective esophageal motility is more stringent and now encompasses fragmented peristalsis. Hence, CCv4.0 no longer distinguishes between major versus minor motility disorders but simply separates disorders of EGJ outflow from disorders of peristalsis.     

Swallow induces a peristaltic wave of distension that marches in front of the peristaltic wave of contraction

Background Current understanding is that swallow induces simultaneous inhibition of the entire esophagus followed by a sequential wave of contraction (peristalsis). We observed a pattern of luminal distension preceding contraction which suggested that inhibition may also traverses in a peristaltic fashion. Our aim is to determine the relationship between contraction and luminal distension during bolus transport. Methods Eight subjects using two solid‐state pressure and two ultrasound (US) transducers were studied. Synchronous pressure and US images were obtained with wet swallows and after edrophonium and atropine. Luminal cross‐sectional area (CSA) at 2 cm and 12 cm above the lower esophageal sphincter (LES) were recorded. Relationship between pressure and CSA at each site, propagation velocity of peak pressure and peak distension waves were determined. Fluoroscopy coupled with manometry was also performed in five normal subjects. Key Results Esophageal distension precedes contraction wave at both‐recorded sites. During distension, esophageal pressure remains constant while luminal CSA increases significantly. The onset and the peak of distension wave traverses in a peristaltic fashion between both sites. A tight coupling exists between the peak distension and peak contraction waves with similar velocities (3.7 cm s^?1 and 3.6 cm s^?1) of propagation. The degree of distension is greater at 2 cm compared to 12 cm. Atropine and edrophonium reduced and increased the contraction pressure respectively, without affecting the distension wave. Fluoroscopic study confirmed that the wave of distension traverses the esophagus in a peristaltic fashion. Conclusions & Inferences Distension and contraction waves are tightly coupled to each other and both traverse in a peristaltic fashion.     

Botulinum toxin injection in dysphagia syndromes with preserved esophageal peristalsis and incomplete lower esophageal sphincter relaxation

Background Botulinum toxin injection into the lower esophageal sphincter (LES) treats dysphagia syndromes with preserved peristalsis and incomplete LES relaxation (LESR). We evaluated clinical and esophageal motor characteristics predicting response, and compared duration of efficacy to similarly treated achalasia patients. Methods Thirty‐six subjects (59 ± 2.2 years, 19F/17M) with incomplete LESR on high resolution manometry (HRM) treated with botulinum toxin injection were identified. Individual and composite symptom indices were calculated, and HRM characteristics extracted. Symptom resolution for 6 months was a primary outcome measure, and repeat botulinum toxin injection, dysphagia recurrence or employment of alternate therapeutic approaches were secondary outcome measures. Duration of response was compared using Kaplan‐Meier survival curves to a historical cohort of similarly treated achalasia subjects. Key Results Response lasted a mean of 12.8 ± 2.3 months. Symptom relief for >6 months was seen in 58.3%; short (<6 months) response was associated with younger age, higher chest pain index, and esophageal body spastic features (P ≤ 0.04). On multivariate logistic regression, chest pain, younger age and contraction amplitudes >180 mmHg independently predicted <6 months relief (P < 0.05 for each). On survival analysis, relief with a single injection extended to 1 year in 54.8% and 1.5 years in 49.8%, statistically equivalent to that reported by 42 similarly treated achalasia subjects (59 ± 3.2 years, 24F/18M). Symptom relief was more prolonged compared to achalasia when repeat injections were performed on demand (P = 0.003). Conclusions & Inferences Botulinum toxin injections can provide lasting symptom relief in dysphagia syndromes with incomplete LESR. Prominent perceptive symptoms and non‐specific spastic features may predict shorter relief.     

Mechanisms of gastric and supragastric belching: a study using concurrent high‐resolution manometry and impedance monitoring

Background Esophageal impedance monitoring has made it possible to distinguish two types of belches, designated gastric and supragastric. We aimed to compare the esophageal pressure characteristics during supragastric belches and gastric belches using combined high‐resolution manometry and impedance monitoring. Methods We included 10 patients with severe and frequent belching. Combined high‐resolution manometry and impedance monitoring was performed. Key Results Whereas gastric belching was relatively rare in all patients (median incidence 2 per 90‐min period), nine of the 10 patients exhibited excessive supragastric belching (36 in 90 min). Supragastric belches were characterized by: (i) movement of the diaphragm in aboral direction and increased esophagogastric junction (EGJ) pressure, (ii) decrease in esophageal pressure, (iii) upper esophageal sphincter (UES) relaxation, (iv) antegrade airflow into the esophagus, and (v) increase in esophageal and gastric pressure leading to expulsion of air out of the esophagus in retrograde direction. In contrast, gastric belches were characterized by: (i) decreased or unchanged EGJ pressure, which was significantly lower than during supragastric belches, (ii) absence of decreased esophageal pressure preceding entrance of air into the esophagus (iii) retrograde airflow into the esophagus, (iv) common cavity phenomenon, and (v) upper esophageal sphincter relaxation after the onset of the retrograde airflow. Conclusions & Inferences In gastric belching UES relaxation is a late event, allowing efflux of air that entered the esophagus from the stomach. In most patients with supragastric belching air is brought into the esophagus by movement of the diaphragm in aboral direction, creation of negative esophageal pressure, and UES relaxation.     

Effect of proximal gastric volume on hiatal hernia

Background Spatial separation of the diaphragm and the lower esophageal sphincter (LES) occurs frequently and intermittently in patients with a sliding hiatus hernia and favors gastro‐esophageal reflux. This can be studied with high‐resolution manometry. Although fundic accommodation is associated with a lower basal LES pressure, its effect on esophagogastric junction configuration and hiatal hernia is unknown. Therefore, the aim of this study was to investigate the relationship between proximal gastric volume, the presence of a hiatal hernia profile and acid reflux. Methods Twenty gastro‐esophageal reflux disease (GERD) patients were studied and compared to 20 healthy controls. High‐resolution manometry and pH recording were performed for 1 h before and 2 h following meal ingestion (500 mL per 300 kcal). Volume of the proximal stomach was assessed with three‐dimensional ultrasonography before and every 15 min after meal ingestion. Key Results During fasting, the hernia profile [2 separate high‐pressure zones (HPZs) at manometry] was present for 31.9 ± 4.9 min h^?1 (53.2%) in GERD patients, and 8.7 ± 3.3 min h^?1 (14.5%) in controls (P < 0.001). In GERD patients, the presence of hernia profile decreased during the first postprandial hour to 15.9 ± 4.2 min h^?1, 26.5%, P < 0.01 whilst this phenomenon was not observed in controls. The rate of transition between the two profiles was 5.7 ± 1.1 per hour in GERD patients and 2.5 ± 1.0 per hour in controls (P < 0.001). The pre and postprandial acid reflux rate in GERD patients during the hernia profile (6.4 ± 1.1 per hour and 18.4 ± 4.3 per hour respectively) was significantly higher than during reduced hernia (2.1 ± 0.6 per hour; P < 0.05 and 3.8 ± 0.9 per hour; P < 0.05). A similar difference was found in controls. Furthermore, an inverse correlation was found between fundic volume and the time the hernia profile was present (r = ?0.45; P < 0.05) in GERD patients, but not in controls. Conclusions & Inferences (i) In GERD patients a postprandial increase in proximal gastric volume is accompanied by a decrease in hernia prevalence, which can be explained by a reduction of the intra‐thoracic part of the stomach. (ii) A temporal hernia profile also occurs in healthy subjects. (iii) During the hernia profile, acid reflux is more prevalent, especially after meal ingestion.     

Functional morphology of anal sphincter complex unveiled by high definition anal manometery and three dimensional ultrasound imaging

Background Anal sphincter complex consists of anatomically overlapping internal anal sphincter (IAS), external anal sphincter (EAS) and puborectalis muscle (PRM). We determined the functional morphology of anal sphincter muscles using high definition anal manometery (HDAM), three dimensional (3D)‐ultrasound (US) and Magnetic resonance (MR) imaging. Methods We studied 15 nulliparous women. High definition anal manometery probe equipped with 256 pressure transducers was used to measure the anal canal pressures at rest and squeeze. Lengths of IAS, PRM, and EAS were determined from the 3D‐US images and superimposed on the HDAM plots. Movements of anorectal angle with squeeze were determined from the dynamic MR images. Key Results High definition anal manometery plots reveal that anal canal pressures are highly asymmetric in the axial and circumferential direction. Anal canal length determined by the 3D‐US images is slightly smaller than that measured by HDAM. The EAS (1.9 ± 0.5 cm long) and PRM (1.7 ± 0.4 cm long) surround distal and proximal parts of the anal canal, respectively. With voluntary contraction, anal canal pressures increase in the proximal (PRM) and distal (EAS zone) parts of anal canal. Posterior peak pressure in the anal canal moves cranially in relation to the anterior peak pressure, with squeeze. Similar to the movement of peak posterior pressure, MR images show cranial movement of anorectal angle with squeeze. Conclusions & Inferences Our study proves that the PRM is responsible for the closure of the cranial part of anal canal. HDAM, in addition to measuring constrictor function can also record the elevator function of levator ani/pelvic floor muscles.     

Optimizing the swallow protocol of clinical high‐resolution esophageal manometry studies

Background The Chicago Classification (CC) of Esophageal Motility Disorders is based on 10 water swallows performed in the supine position. The aim of the study was to assess whether upright and provocative swallows (PS) provided important information beyond that obtained from the standard supine manometric protocol. Methods Two independent investigators reviewed high‐resolution manometry (HRM) studies of 148 patients with both supine and upright liquid swallows and additional studies from patients with PS (increased volume, viscosity, and a marshmallow) for a resultant change in CC diagnoses. Significant diagnostic changes were defined as a change from normal or borderline motor function to abnormal motor function, esophagogastric junction (EGJ) outflow obstruction, or achalasia. Discordant diagnoses were reviewed and the Kappa test was used to evaluate the agreement between diagnoses in the different protocols. Key Results The overall agreement in diagnosis between the five supine swallows and the five upright swallows was good (k = 0.583). Changing to the upright position elicited a significant diagnostic change in 10.1% (15/148) of cases. The PS suggested an alternative diagnosis from the supine position in 14 of 75 studies (18.7%); 11 of these changed to EGJ obstruction during viscous or solid bolus challenges. Conclusions & Inferences Changing position in HRM elicited a significant change in diagnosis in about 10% of studies, whereas provocative bolus challenges with viscous liquid and marshmallows increased the detection of EGJ outflow obstruction. Performing manometric evaluations in both positions with PS may increase the yield of standard HRM technique.