Physiology of the esophageal pressure transition zone: separate contraction waves above and below

Esophageal body adaptation to Nissen fundoplication: Increased esophagogastric outflow resistance yields delayed and sustained peristaltic contractions without increased amplitude

BACKGROUND

Improvement in lower esophageal sphincter (LES) competency after laparoscopic Nissen fundoplication (LNF) is well established, yet esophageal body physiology data are limited. We aimed to describe the impact of LNF on whole esophagus physiology using standard and novel manometric characteristics.

METHODS

A cohort of patients with an intact fundoplication without herniation and no postoperative dysphagia were selected and underwent esophageal manometry at one-year after surgery. Pre- and post-operative manometry files were reanalyzed using standard and novel manometric characteristics and compared.

KEY RESULTS

A total of 95 patients were included in this study. At 16.1 (8.7) months LNF increased LES overall and abdominal length and resting pressure (p < 0.0001). Outflow resistance (IRP) increased [5.8 (3-11) to 11.1 (9-15), p < 0.0001] with a 95th percentile of 20 mmHg in this cohort of dysphagia-free patients. Distal contractile integral (DCI) also increased [1177.0 (667-2139) to 1321.1 (783-2895), p = 0.002], yet contractile amplitude was unchanged (p = 0.158). There were direct correlations between pre- and post-operative DCI [R: 0.727 (0.62-0.81), p < 0.0001] and postoperative DCI and postoperative IRP [R: 0.347 (0.16-0.51), p = 0.0006]. Contractile front velocity [3.5 (3-4) to 3.2 (3-4), p = 0.0013] was slower, while distal latency [6.7 (6-8) to 7.4 (7-9), p < 0.0001], the interval from swallow onset to proximal smooth muscle initiation [4.0 (4-5) to 4.4 (4-5), p = 0.0002], and the interval from swallow onset to point when the peristaltic wave meets the LES [9.4 (8-10) to 10.3 (9-12), p < 0.0001] were longer. Esophageal length [21.9 (19-24) to 23.2 (21-25), p < 0.0001] and transition zone (TZ) length [2.2 (1-3) to 2.5 (1-4), p = 0.004] were longer. Bolus clearance was inversely correlated with TZ length (p = 0.0002) and time from swallow onset to proximal smooth muscle initiation (p < 0.0001). Bolus clearance and UES characteristics were unchanged (p > 0.05).

CONCLUSIONS & INFERENCES

Increased outflow resistance after LNF required an increased DCI. However, this increased contractile vigor was achieved through sustained, not stronger, peristaltic contractions. Increased esophageal length was associated with increased TZ and delayed initiation of smooth muscle contractions.

Development of Test Programs for the Biorelevant Characterization of Esophageal-Applied Dosage Forms

In the local treatment of the esophageal mucosa, the retention time of the different dosage forms, such as tablets, films or liquids, is of high relevance for the effective treatment of diseases. Unfortunately, there are only few in vitro models describing the esophageal route of administration. To predict the behaviour of an esophageal-applied dosage form, it is necessary to simulate the site of application in a biorelevant way. The aim of this work was to develop two test setups for an esophageal peristalsis model which was described in a previous study. Different parameters such as flow rate, peristalsis, angle of inclination or mucous membrane were varied or introduced into the model. A stimulated and unstimulated modus were developed and tested with two different dosage forms. The time until the dosage form was cleared from the in vitro model was shorter with the stimulated than with the unstimulated modus. Also, esophageal-applied films had a prolonged transit time compared to a viscous syrup. The modification of the simulated esophageal surface made it possible to estimate the retention time of the dosage forms. It could be demonstrated that the residence time of a dosage form depends on different parameters affecting each other.

The Modified Barium Swallow Study and Esophageal Screening: A Survey of Clinical Practice Patterns

PURPOSE

Modified barium swallow study (MBSS) is a videofluoroscopic evaluation of oropharyngeal swallowing. Views of esophageal bolus flow during MBSS are permitted under speech-language pathology practice guidelines. However, controversy exists over its implementation. Poor consensus and limited practice guidance may lead to clinical practice variations. Aims of the investigation were to (a) describe current practice patterns of speech-language pathologist visualizing bolus flow through the esophagus during the MBSS, (b) understand areas of variation when incorporating esophageal visualization during the MBSS, and (c) determine clinicians' willingness to modify MBSS procedures to include esophageal imaging.

METHOD

A web-based survey (Qualtrics XM) consisting of 26 questions was distributed via web posting and e-mail to members of the American Speech-Language-Hearing Association Special Interest Group 13 and Dysphagia Café. The survey was open for 3 months. Descriptive and associative statistics were completed. Field-testing was performed prior to dissemination of the survey to address content validity.

RESULTS

A total of 321 individuals participated; 265 responses were used for analysis. Ninety-three percent of respondents viewed the esophagus during the MBSS. Twelve percent followed to the proximal esophagus, 15% to the mid esophagus, 66% to the lower esophagus, and 6% to varied levels. Variability was also reported in contrast type, volume administered, and nomenclature used. Interestingly, few people (3.61%) disagreed that esophageal visualization should be performed during MBSS.

CONCLUSIONS

Speech-language pathology respondents in this study visualize contrast flow through the esophagus and are enthusiastic about expanding the standard MBSS. However, results of the survey demonstrate a lack of uniformity in assessment practices. Unfortunately, this may impact the diagnostic accuracy and clinical utility when adding esophageal visualization to the MBSS. This study highlights the need for a standardized protocol and identifies current barriers and controversies that may prevent expanding the MBSS to more comprehensively evaluate individuals with dysphagia.

Normative values of intra-bolus pressure and esophageal compliance based on 4D high-resolution impedance manometry

BACKGROUND

This study aimed to quantify normative values of phase-specific intra-bolus pressure (IBP) and esophageal distensibility using 4D analysis of high-resolution-impedance manometry (HRIM).

METHODS

HRIM studies of supine swallows from 34 normal controls were analyzed with respect to the four phases of bolus transit: (1) accommodation, (2) compartmentalization, (3) peristalsis/esophageal emptying, and (4) ampullary emptying. Phase-specific IBP, bolus volume, and distensibility index (DI) in the esophageal body and esophagogastric junction (EGJ) during phases 1-3 were extracted.

RESULTS

The median (5-95th/IQR) IBP values were as follows: phase 1: 4.0 (-2.0-10.4/1.9-5.8) mmHg, phase 2: 5.7 (0.2-14.1/3.6-8.9) mmHg, and phase 3: 11.2 (2.9-19.4/7.7-15.1) mmHg. The median bolus volume calculated by integrating impedance planimetry cross-sectional areas was 4.1 ml during the compartmentalization phase. The EGJ-DI at max EGJ diameter during phase 2 and 3 was 2.8 (1.1-9.5/1.8-3.7) mm² /mmHg and 6.0 (3.2-20.3/5.1-7.8) mm² /mmHg, respectively. The phase 3 EGJ-DI values (6.0 (3.2-20.3/5.1-7.8) mm² /mmHg) were similar to those calculated using functional lumen imaging probe (FLIP) at the 60 ml volume on the same subjects (5.8 [3.5-7.2/5.0-6.4] mm² /mmHg).

CONCLUSIONS AND INFERENCES

4D-HRIM provides a standardized methodology to track the nadir impedance and provide measurements of IBP during maximal distention across phases 1-3 of bolus transit. Median IBP and delta IBP were different across the phases, supporting the need to define IBP by phase. Additionally, the EGJ-DI calculated during phase 3 was similar to the 60-ml EGJ-DI from FLIP in the same subjects suggesting that 4D-HRIM can quantify EGJ opening during primary peristalsis.

A Comparative Assessment of the Diagnosis of Swallowing Impairment and Gastroesophageal Reflux in Canines and Humans

Swallowing impairment is a highly prevalent and clinically significant problem affecting people and dogs. There are myriad causes of swallowing impairment of which gastroesophageal reflux is the most common in both species. Similarities in anatomy and physiology between humans and canines results in analogous swallowing disorders including cricopharyngeus muscle achalasia, esophageal achalasia, hiatal herniation, and gastroesophageal reflux with secondary esophagitis and esophageal dysmotility. Accordingly, the diagnostic approach to human and canine patients with swallowing impairment is similar. Diagnostic procedures such as swallowing fluoroscopy, high-resolution manometry, pH/impedance monitoring, and endolumenal functional luminal imaging probe can be performed in both species; however, nasofacial conformation, increased esophageal length, and the difficulty of completing several of these procedures in awake dogs are inherent challenges that need to be considered. Human patients can convey their symptoms and respond to verbal cues, whereas veterinarians must rely on clinical histories narrated by pet owners followed by comprehensive physical examination and observation of the animal eating different food consistencies and drinking water. Dogs may also be unwilling to drink or eat in the hospital setting and may be resistant to physical restraint during diagnostic procedures. Despite the species differences and diagnostic challenges, dogs are a natural animal model for many oropharyngeal and esophageal disorders affecting people, which presents a tremendous opportunity for shared learnings. This manuscript reviews the comparative aspects of esophageal anatomy and physiology between humans and canines, summarizes the diagnostic assessment of swallowing impairment in both species, and discusses future considerations for collaborative medicine and translational research.

Four-dimensional impedance manometry derived from esophageal high-resolution impedance-manometry studies: a novel analysis paradigm

BACKGROUND

This study aimed to introduce a novel analysis paradigm, referred to as 4-dimensional (4D) manometry based on biophysical analysis; 4D manometry enables the visualization of luminal geometry of the esophagus and esophagogastric junction (EGJ) using high-resolution-impedance-manometry (HRIM) data.

METHODS

HRIM studies from two asymptomatic controls and one type-I achalasia patient were analyzed. Concomitant fluoroscopy images from one control subject were used to validate the calculated temporal-spatial luminal radius and time-history of intraluminal bolus volume and movement. EGJ analysis computed diameter threshold for emptying, emptying time, flow rate, and distensibility index (DI), which were compared with bolus flow time (BFT) analysis.

RESULTS

For normal control, calculated volumes for 5 ml swallows were 4.1 ml-6.7 ml; for 30 ml swallows 21.3 ml-21.8 ml. With type-I achalasia, >4 ml of intraesophageal bolus residual was present both pre- and post-swallow. The four phases of bolus transit were clearly illustrated on the time-history of bolus movement, correlating well with the fluoroscopic images. In the control subjects, the EGJ diameter threshold for emptying was 8 mm for 5 ml swallows and 10 mm for 30 ml swallows; emptying time was 1.2-2.2 s for 5 ml swallows (BFT was 0.3-3 s) and 3.25-3.75 s for 30 ml swallows; DI was 2.4-3.4 mm²/mmHg for 5 ml swallows and 4.2-4.6 mm²/mmHg for 30 ml swallows.

CONCLUSIONS

The 4D manometry system facilitates a comprehensive characterization of dynamic esophageal bolus transit with concurrent luminal morphology and pressure from conventional HRIM measurements. Calculations of flow rate and wall distensibility provide novel measures of EGJ functionality.

Gastroesophageal Reflux Disease in the Neonatal Intensive Care Unit Neonate: Controversies, Current Understanding, and Future Directions

Gastroesophageal reflux (GER) is considered physiologic and is a normal process; whereas, when aerodigestive consequences are associated, it is often interpreted as GER disease (GERD). However, the distinction between them remains a challenge in infants in the NICU. Reflux-type of symptoms are heterogeneous, and often managed with changes in diet, feeding methods, and acid-suppressive therapy; all these empiric therapies lack objectivity; hence, practice variation is universal. We clarify the current controversies, explain the potential role of GERD in causing symptoms and complications, and highlight current advances. The evidence basis for the diagnostic strategies is discussed.

Characterization and mechanism of the esophago-esophageal contractile reflex of the striated muscle esophagus

An esophago-esophageal contractile reflex (EECR) of the cervical esophagus has been identified in humans. The aim of this study was to characterize and determine the mechanisms of the EECR. Cats (n = 35) were decerebrated, electrodes were placed on pharynx and cervical esophagus, and esophageal motility was recorded using manometry. All areas of esophagus were distended to locate and quantify the EECR. The effects of esophageal perfusion of NaCl or HCl, vagus nerve or pharyngoesophageal nerve (PEN) transection, or hexamethonium administration (5 mg/kg iv) were determined. We found that distension of the esophagus at all locations activated EECR rostral to stimulus only. EECR response was greatest when the esophagus 2.5-11.5 cm from cricopharyngeus (CP) was distended. HCl perfusion activated repetitively an EECR-like response of the proximal esophagus only within 2 min, and after ~20 min EECR was inhibited. Transection of PEN blocked or inhibited EECR 1-7 cm from CP, and vagotomy blocked EECR at all locations. Hexamethonium blocked EECR at 13 and 16 cm from CP but sensitized its activation at 1-7 cm from CP. EECR of the entire esophagus exists, which is directed in the orad direction only. EECR of striated muscle esophagus is mediated by vagus nerve and PEN and inhibited by mechanoreceptors of smooth muscle esophagus. EECR of smooth muscle esophagus is mediated by enteric nervous system and vagus nerve. Activation of EECR of the striated muscle esophagus is initially sensitized by HCl exposure, which may have a role in prevention of supraesophageal reflux.NEW & NOTEWORTHY An esophago-esophageal contractile reflex (EECR) exists, which is directed in the orad direction only. EECR of the proximal esophagus can appear similar to and be mistaken for secondary peristalsis. The EECR of the striated muscle is mediated by the vagus nerve and pharyngoesophageal nerve and inhibited by mechanoreceptor input from the smooth muscle esophagus. HCl perfusion initially sensitizes activation of the EECR of the striated muscle esophagus, which may participate in prevention of supraesophageal reflux.

Utility of Esophageal High-Resolution Manometry in Clinical Practice: First, Do HRM

Esophageal high-resolution manometry (HRM) has advanced the understanding of esophageal motor function and the ability to diagnose and manage disorders of esophageal motility. In this review, we describe the indications for and the technical performance of HRM. The Chicago classification of esophageal motor function, now in its third iteration, streamlines and standardizes the nomenclature and basic interpretation of HRM data depicted as Clouse topographic plots. In clinical practice, HRM is an important diagnostic test for patients with dysphagia as well as patients with suspected gastroesophageal reflux disease (GERD), particularly in those patients with a suboptimal symptomatic response to antisecretory therapy. HRM can support diagnoses such as achalasia, as well as provide evidence for behavioral disorders such as rumination syndrome or supragastric belching with the assistance of postprandial HRM with impedance. Further, the GERD classification of motor function introduces a three-part hierarchical evaluation of esophageal motor function in GERD, highlighting the value of assessment of esophageal contractile reserve through provocative maneuvers during HRM such as multiple rapid swallows.

Roles of High-resolution Manometry in Predicting Incomplete Bolus Transit in Patients With Dysphagia

BACKGROUND

High-resolution manometry (HRM) is used to assess esophageal motility diseases. Abnormalities in a number of HRM parameters have been reported in patients with dysphagia. However, it is unclear whether some of abnormal HRM parameters are predictive of dysphagia. The aim of this retrospective study was to investigate the roles of HRM parameters in predicting incomplete bolus clearance (IBC) in patients with dysphagia using high-resolution impedance manometry.

METHODS

A total of 644 wet swallows were reviewed and analyzed in 63 patients with symptoms of dysphagia or reflux who underwent a clinical high-resolution impedance manometry test. IBC was defined based on impedance measurement. The relationship of each of abnormal HRM parameters with IBC was analyzed and their roles in predicting IBC were determined.

RESULTS

Patients with symptoms of both dysphagia and reflux showed the highest IBC rate, and patients with symptoms of reflux had the lowest IBC rate. The IBC was more prevalent in the distal esophagus. Premature contractions and peristalsis with large breaks were associated with a higher IBC rate in the proximal esophagus (P<0.05); large breaks, ineffective peristalsis, and abnormalities of the esophageal gastric junction functions were associate with higher IBC rates in the distal esophagus (P<0.05). Abnormalities in a number of motility parameters were able to predict IBC with high specificities and/or high sensitivity, such as pan esophageal pressurization, ineffective peristalsis, and large breaks. Abnormal integrative relaxation pressure of the lower esophageal sphincter with concurrent pan esophageal pressurization, ineffective peristalsis, or large breaks is predictive of IBC with nearly 100% of specificity.

CONCLUSIONS

Abnormalities in a number of HRM parameters are not only useful in diagnosing esophageal motility diseases, but also valuable in predicting IBC during swallowing.

Does Chicago Classification address Symptom Correlation with High-resolution Esophageal Manometry?

Aim:

To assess the correlation of symptoms with findings on esophageal high-resolution manometry (HRM) in Indian patients.

Materials and methods:

Prospective data collection of all patients undergoing esophageal manometry was done at two centers in India—Indore and Chennai—over a period of 18 months. Symptom profile of the study group was divided into four: Motor dysphagia, noncardiac chest pain (NCCP), gastroesophageal reflux (GER), and esophageal belchers. The symptoms were correlated with manometric findings.

Results:

Of the study group (154), 35.71% patients had a normal study, while major and minor peristaltic disorders were noted in 31.16 and 33.76% respectively. In patients with symptoms of dysphagia, achalasia cardia was the commonest cause (45.1%), followed by ineffective esophageal motility (IEM) (22.53%) and normal study (19.71%). In patients with NCCP, normal peristalsis (50%) and ineffective motility (31.25%) formed the major diagnosis. Of the 56 patients with GER symptoms, 26 (46.4%) had normal manometry. An equal number had ineffective motility. Of the 11 esophageal belchers, 7 (63.6%) of these had a normal study and 3 had major motility disorder. Dysphagia was the only symptom to have a high likelihood ratio and positive predictive value to pick up major motility disorder.

Conclusion:

Dysphagia correlates with high chance to pick up a major peristaltic abnormality in motor dysphagia. The role of manometry in other symptoms in Indian setting needs to be ascertained by larger studies.

Clinical significance:

The present study highlights lack of symptom correlation with manometry findings in Indian patients.

How to cite this article: Jain M, Srinivas M, Bawane P, Venkataraman J. Does Chicago Classification address Symptom Correlation with High-resolution Esophageal Manometry? Euroasian J Hepato-Gastroenterol 2017;7(2):122-125.

A continuum mechanics-based musculo-mechanical model for esophageal transport

In this work, we extend our previous esophageal transport model using an immersed boundary (IB) method with discrete fiber-based structural model, to one using a continuum mechanics-based model that is approximated based on finite elements (IB-FE). To deal with the leakage of flow when the Lagrangian mesh becomes coarser than the fluid mesh, we employ adaptive interaction quadrature points to deal with Lagrangian-Eulerian interaction equations based on a previous work (Griffith and Luo [1]). In particular, we introduce a new anisotropic adaptive interaction quadrature rule. The new rule permits us to vary the interaction quadrature points not only at each time-step and element but also at different orientations per element. This helps to avoid the leakage issue without sacrificing the computational efficiency and accuracy in dealing with the interaction equations. For the material model, we extend our previous fiber-based model to a continuum-based model. We present formulations for general fiber-reinforced material models in the IB-FE framework. The new material model can handle non-linear elasticity and fiber-matrix interactions, and thus permits us to consider more realistic material behavior of biological tissues. To validate our method, we first study a case in which a three-dimensional short tube is dilated. Results on the pressure-displacement relationship and the stress distribution matches very well with those obtained from the implicit FE method. We remark that in our IB-FE case, the three-dimensional tube undergoes a very large deformation and the Lagrangian mesh-size becomes about 6 times of Eulerian mesh-size in the circumferential orientation. To validate the performance of the method in handling fiber-matrix material models, we perform a second study on dilating a long fiber-reinforced tube. Errors are small when we compare numerical solutions with analytical solutions. The technique is then applied to the problem of esophageal transport. We use two fiber-reinforced models for the esophageal tissue: a bi-linear model and an exponential model. We present three cases on esophageal transport that differ in the material model and the muscle fiber architecture. The overall transport features are consistent with those observed from the previous model. We remark that the continuum-based model can handle more realistic and complicated material behavior. This is demonstrated in our third case where a spatially varying fiber architecture is included based on experimental study. We find that this unique muscle fiber architecture could generate a so-called pressure transition zone, which is a luminal pressure pattern that is of clinical interest. This suggests an important role of muscle fiber architecture in esophageal transport.

Could the peristaltic transition zone be caused by non-uniform esophageal muscle fiber architecture? A simulation study

BACKGROUND

Based on a fully coupled computational model of esophageal transport, we analyzed how varied esophageal muscle fiber architecture and/or dual contraction waves (CWs) affect bolus transport. Specifically, we studied the luminal pressure profile in those cases to better understand possible origins of the peristaltic transition zone.

METHODS

Two groups of studies were conducted using a computational model. The first studied esophageal transport with circumferential-longitudinal fiber architecture, helical fiber architecture and various combinations of the two. In the second group, cases with dual CWs and varied muscle fiber architecture were simulated. Overall transport characteristics were examined and the space-time profiles of luminal pressure were plotted and compared.

KEY RESULTS

Helical muscle fiber architecture featured reduced circumferential wall stress, greater esophageal distensibility, and greater axial shortening. Non-uniform fiber architecture featured a peristaltic pressure trough between two high-pressure segments. The distal pressure segment showed greater amplitude than the proximal segment, consistent with experimental data. Dual CWs also featured a pressure trough between two high-pressure segments. However, the minimum pressure in the region of overlap was much lower, and the amplitudes of the two high-pressure segments were similar.

CONCLUSIONS & INFERENCES

The efficacy of esophageal transport is greatly affected by muscle fiber architecture. The peristaltic transition zone may be attributable to non-uniform architecture of muscle fibers along the length of the esophagus and/or dual CWs. The difference in amplitude between the proximal and distal pressure segments may be attributable to non-uniform muscle fiber architecture.

Functional disorders of swallowing

Swallowing involves complex coordination of the neuromuscular anatomy and physiology of the oropharynx and esophagus, controlled by the enteric and central nervous systems. Dysphagia is classified as either oropharyngeal or esophageal and results from mechanical or structural disturbances. Videofluoroscopy, fiberoptic endoscopic evaluation of swallowing, barium swallow, manometry, and endoscopy are common modalities utilized in diagnosis, but none is as important as a patient's history. Functional dysphagia is a diagnosis of exclusion and is based on Rome criteria. Its mechanism is unknown but potentially related to visceral hypersensitivity, inappropriate pain perception, or unidentified contraction abnormalities. Its management is mainly supportive; however, there is literature to suggest, but not confirm, benefit with the use of antidepressants. Continued understanding of functional dysphagia and other functional esophageal disorders, including globus sensation, will require further investigation into diagnostic algorithms and finding treatment methods.

The Esophagiome: concept, status, and future perspectives

The term "Esophagiome" is meant to imply a holistic, multiscale treatment of esophageal function from cellular and muscle physiology to the mechanical responses that transport and mix fluid contents. The development and application of multiscale mathematical models of esophageal function are central to the Esophagiome concept. These model elements underlie the development of a "virtual esophagus" modeling framework to characterize and analyze function and disease by quantitatively contrasting normal and pathophysiological function. Functional models incorporate anatomical details with sensory-motor properties and functional responses, especially related to biomechanical functions, such as bolus transport and gastrointestinal fluid mixing. This brief review provides insight into Esophagiome research. Future advanced models can provide predictive evaluations of the therapeutic consequences of surgical and endoscopic treatments and will aim to facilitate clinical diagnostics and treatment.

Motility characteristics in the transition zone in Gastroesophageal Reflux Disease (GORD) patients

Background

Defects in distal oesophageal peristalsis was thought to be an indication of incomplete bolus transit (BT). However, the role of transition zone (TZ) defects in the BT in gastroesophageal reflux disease (GORD) patients needs clarification. The aim of this study was to assess the TZ defects in GORD patients and to explore the relationship between TZ defects and BT.

Methods

One hundred and two patients with reflux symptoms and 20 healthy adults were included in the study. All subjects underwent upper gastrointestinal endoscopy, high resolution impedance manometry (HRiM) and 24-h ambulatory multichannel impedance-pH (MII-pH) monitoring. Patients were subgrouped into reflux oesophagitis (RE), non-erosive reflux disease (NERD), hypersensitive oesophagus (HO) and functional heartburn (FH) classified following MII-pH monitoring. Oesophageal pressure topography was analysed to define TZ defects by spatial or temporal TZ measurements exceeding 2 cm or 1 s, weak and fragmented swallows were excluded, and the association between TZ and BT was investigated.

Results

Following liquid swallows, there were no significant differences in TZ delay time and TZ length between groups (RE: 1.75 s (1.32–2.17) and 2.50 cm (2.40–3.20); NERD: 1.60 s (1.10–2.00) and 2.20 cm (2.10–2.65); HO: 1.60 s (1.30–1.80) and 2.70 cm (2.30–3.00); FH: 1.55 s (1.20–2.17) and 3.10 cm (2.25–5.00); Healthy volunteers: 1.50 s (1.20–1.90) and 2.30 cm (2.10–3.00). However, individuals with TZ defects had lower complete BT rates compared with those without TZ defects (p < 0.001). There were also significantly more incomplete BT in patients with RE, HO and FH than in healthy controls (p < 0.05).

Conclusions

In GORD patients, TZ defects correlated with proximal bolus retention in the corresponding area independent of distal weak peristalsis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0525-1) contains supplementary material, which is available to authorized users.

The Spatial Predilection for Early Esophageal Squamous Cell Neoplasia: A "Hot Zone" for Endoscopic Screening and Surveillance

Early esophageal squamous cell neoplasias (ESCNs) are easily missed with conventional white-light endoscopy. This study aimed to assess whether early ESCNs have a spatial predilection and the patterns of recurrence after endoscopic treatment. We analyzed the circumferential and longitudinal location of early ESCNs, as well as their correlations with exposure to carcinogens in a cohort of 162 subjects with 248 early ESCNs; 219 of which were identified by screening and 29 by surveillance endoscopy. The circumferential location was identified using a clock-face orientation, and the longitudinal location was identified according to the distance from the incisor. The most common circumferential and longitudinal distributions of the early ESCNs were found in the 6 to 9 o'clock quadrant (38.5%) and at 26 to 30 cm from the incisor (41.3%), respectively. A total of 163 lesions (75%) were located in the lower hemisphere arc, and 149 (68.4%) were located at 26 to 35 cm from the incisor. One hundred eleven (51%) early ESCNs were centered within the "hot zone" (i.e., lower hemisphere arc of the esophagus at 26 to 35 cm from the incisor), which comprised 20% of the esophageal area. Exposure to alcohol, betel nut, or cigarette was risk factors for the development of early ESCNs in the lower hemisphere. After complete endoscopic treatment, the mean annual incidence of metachronous tumors was 10%. In addition, 43% of the metachronous recurrent neoplasias developed within the "hot zone." Cox regression analysis revealed that the index tumor within the hot zone (hazard ratio [HR]: 3.19; 95% confidence interval [CI]: 1.17-8.68; P = 0.02) and the presence of numerous Lugol-voiding lesions in the esophageal background mucosa were independent predictors for metachronous recurrence (HR: 4.61; 95% CI: 1.36-15.56; P = 0.01). We identified a hot zone that may be used to enhance the detection of early ESCNs during endoscopic screening and surveillance, especially in areas that lack resources and have a high prevalence of ESCNs.

Esophageal testing: What we have so far

Gastroesophageal reflux disease (GERD) is a common disorder of the gastrointestinal tract. In the last few decades, new technologies have evolved and have been applied to the functional study of the esophagus, allowing for the improvement of our knowledge of the pathophysiology of GERD. High-resolution manometry (HRM) permits greater understanding of the function of the esophagogastric junction and the risks associated with hiatal hernia. Moreover, HRM has been found to be more reproducible and sensitive than conventional water-perfused manometry to detect the presence of transient lower esophageal sphincter relaxation. Esophageal 24-h pH-metry with or without combined impedance is usually performed in patients with negative endoscopy and reflux symptoms who have a poor response to anti-reflux medical therapy to assess esophageal acid exposure and symptom-reflux correlations. In particular, esophageal 24-h impedance and pH monitoring can detect acid and non-acid reflux events. EndoFLIP is a recent technique poorly applied in clinical practice, although it provides a large amount of information about the esophagogastric junction. In the coming years, laryngopharyngeal symptoms could be evaluated with up and coming non-invasive or minimally invasive techniques, such as pepsin detection in saliva or pharyngeal pH-metry. Future studies are required of these techniques to evaluate their diagnostic accuracy and usefulness, although the available data are promising.

Upper gastrointestinal motility: prenatal development and problems in infancy

Deglutition, or swallowing, refers to the process of propulsion of a food bolus from the mouth into the stomach and involves the highly coordinated interplay of swallowing and breathing. At 34 weeks gestational age most neonates are capable of successful oral feeding if born at this time; however, the maturation of respiration is still in progress at this stage. Infants can experience congenital and developmental pharyngeal and/or gastrointestinal motility disorders, which might manifest clinically as gastro-oesophageal reflux (GER) symptoms, feeding difficulties and/or refusal, choking episodes and airway changes secondary to micro or overt aspiration. These problems might lead to impaired nutritional intake and failure to thrive. These gastrointestinal motility disorders are mostly classified according to the phase of swallowing in which they occur, that is, the oral preparatory, oral, pharyngeal and oesophageal phases. GER is a common phenomenon in infancy and is referred to as GERD when it causes troublesome complications. GER is predominantly caused by transient relaxation of the lower oesophageal sphincter. In oesophageal atresia, oesophageal motility disorders develop in almost all patients after surgery; however, a congenital origin of disordered motility has also been proposed. This Review highlights the prenatal development of upper gastrointestinal motility and describes the most common motility disorders that occur in early infancy.

The four phases of esophageal bolus transit defined by high-resolution impedance manometry and fluoroscopy

We aimed to model esophageal bolus transit based on esophageal pressure topography (EPT) landmarks, concurrent intrabolus pressure (IBP), and esophageal diameter as defined with fluoroscopy. Ten healthy subjects were studied with high-resolution impedance manometry and videofluoroscopy. Data from four 5-ml barium swallows (2 upright, 2 supine) in each subject were analyzed. EPT landmarks were utilized to divide bolus transit into four phases: phase I, upper esophageal sphincter (UES) opening; phase II, UES closure to the transition zone (TZ); phase III, TZ to contractile deceleration point (CDP); and phase IV, CDP to completion of bolus emptying. IBP and esophageal diameter were analyzed to define functional differences among phases. IBP exhibited distinct changes during the four phases of bolus transit. Phase I was associated with filling via passive dilatation of the esophagus and IBP reflective of intrathoracic pressure. Phase II was associated with auxotonic relaxation and compartmentalization of the bolus distal to the TZ. During phase III, IBP exhibited a slow increase with loss of volume related to peristalsis (auxotonic contraction) and passive dilatation in the distal esophagus. Phase IV was associated with the highest IBP and exhibited isometric contraction during periods of nonemptying and auxotonic contraction during emptying. IBP may be used as a marker of esophageal wall state during the four phases of esophageal bolus transit. Thus abnormalities in IBP may identify subtypes of esophageal disease attributable to abnormal distensibility or neuromuscular dysfunction.

Utilizing intrabolus pressure and esophagogastric junction pressure to predict transit in patients with Dysphagia

Background/Aims

High-resolution manometry (HRM), with a greatly increased number of recording sites and decreased spacing between sites, allows evaluation of the dynamic simultaneous relationship between intrabolus pressure (IBP) and esophagogastric junction (EGJ) relaxation pressure. We hypothesized that bolus transit may occur when IBP overcomes integrated relaxation pressure (IRP) and analyzed the relationships between peristalsis pattern and the discrepancy between IBP and IRP in patients with dysphagia.

Methods

Twenty-two dysphagia patients with normal EGJ relaxation were examined with a 36-channel HRM assembly. Each of the 10 examinations was performed with 20 and 30 mmHg pressure topography isobaric contours, and findings were categorized based on the Chicago classification. We analyzed the relationships between peristalsis pattern and the discrepancy between IBP and IRP.

Results

Twenty-two patients were classified by the Chicago classification: 1 patient with normal EGJ relaxation and normal peristalsis, 8 patients with intermittent hypotensive peristalsis and 13 patients with frequent hypotensive peristalsis. A total of 220 individual swallows were analyzed. There were no statistically significant relationships between peristalsis pattern and the discrepancy between IBP and IRP on the 20 or 30 mmHg isobaric contours.

Conclusions

Peristalsis pattern was not associated with bolus transit in patients with dysphagia. However, further controlled studies are needed to evaluate the relationship between bolus transit and peristalsis pattern using HRM with impedance.

Transition zone defect associated with the response to proton pump inhibitor treatment in patients with globus sensation

BACKGROUND AND AIM

Few data describing short-term proton pump inhibitor (PPI) treatment in patients with globus sensation exist. The aim of this study was to evaluate the use of high-resolution manometry (HRM) for predicting the response to PPI treatment in patients with globus sensation.

METHOD

A total of 41 patients with globus sensation were treated with PPIs for 4 weeks and were classified as positive and negative responders. HRM topographical plots were analyzed for relevant manometric parameters. In addition, clinical and HRM data of 20 patients with typical gastroesophageal reflux disease (GERD) not presenting globus symptom were analyzed.

RESULTS

Of the 41 patients, 19 (46%) were clinically diagnosed with GERD. The proportion of patients with favorable symptomatic improvement was higher in patients with GERD than in those without reflux (P=0.046). Positive and negative responders to PPI treatment did not differ in upper esophageal sphincter and proximal esophageal contraction. In globus patients with GERD, the temporal and spatial dimension of the transitional zone were greater among negative responders than among PPI-positive responders (P=0.010 and P=0.011). Regarding GERD patients without globus, there was no significant difference in transition zone defect according to PPI responsiveness. By receiver operating characteristic curve analysis, 2.1 cm and 1.1 s were found to be the spatial and temporal transitional zone dimensions that best differentiated positive and negative responders.

CONCLUSION

In patients with GERD-related globus, there were larger transition zone defect in the negative responders compared with the PPI-positive responders.

Effect of mosapride combined with esomeprazole improves esophageal peristaltic function in patients with gastroesophageal reflux disease: a study using high resolution manometry

BACKGROUND

Whether addition of prokinetics to proton pump inhibitors improves esophageal peristalsis and symptoms in patients with gastroesophageal reflux disease (GERD) remains unknown.

AIM

We evaluated the effect of mosapride, a 5-HT4 agonist, and PPI cotherapy in patients with GERD on esophageal motility using high-resolution manometry (HRM).

METHOD

This study was designed as a double-blind, randomized, placebo-controlled trial. Patients with GERD were allocated to a group either taking 40 mg esomeprazole plus 30 mg mosapride or taking esomeprazole plus placebo. Symptom assessment and the HRM study were conducted before drug treatment and after 4 weeks.

RESULTS

Of 50 patients enrolled, 24 in the mosapride group (49 years old, 15 males) and 19 in the placebo group (43 years old, nine males) completed the study. Approximately 79 % of the patients had normal peristaltic function. Treatment response was not different between the two groups (79 vs. 68 %). Mosapride cotherapy tended to yield better response in patients with dyspepsia than those without dyspepsia (92 vs. 67 %). Lower esophageal sphincter pressure didn't change in both groups. Intrabolus pressure decreased in the mosapride group (3.4 ± 3.5 mmHg to 1.4 ± 4.1 mmHg, P < 0.05). Distal esophageal amplitude increased in the mosapride group and not in the placebo group (81 ± 34 to 89 ± 29 mmHg vs. 82 ± 32 to 83 ± 31 mmHg).

CONCLUSION

Adding mosapride on esomeprazole improved esophageal contractability and lowered intrabolus pressure in patients with GERD. Mosapride and esomeprazole cotherapy tended to yield better response in patients with concomitant dyspepsia.

Slow esophageal propagation velocity: association with dysphagia for solids

BACKGROUND

Spastic disorders of the esophagus, associated with rapid esophageal propagation velocity, are classically associated with dysphagia and/or chest pain. The aim of this study was to characterize patients with slow esophageal propagation velocity (SPV) on high-resolution esophageal manometry (HRM).

METHODS

A review of patients undergoing HRM was conducted during 1-year study period. Patients with achalasia, aperistalsis, and diffuse esophageal spasm were excluded. Patients with contractile front velocity (CFV) ≤ 2.3 cm s(-1) were defined as having SPV, whereas normal propagation velocity (NPV) was defined as ≥ 2.6 cm s(-1). A composite isobaric contour of all swallows for each patient was generated to determine composite distal contraction latency (cDL).

KEY RESULTS

A total of 650 HRMs were reviewed and 552 met inclusion criteria. 173 patients had SPV and 339 had NPV. There was a greater female predominance in the SPV group compared with NPV (75.7%vs 66.4%, P = 0.03). Patients in the SPV group reported more dysphagia for solids (66.3%vs 53.3%; P = 0.004) and nausea (68.6%vs 59.0%; P = 0.04) than NPV group. Dysphagia for solids was the only symptom significantly associated with SPV group (OR = 2.21, CI = 1.21-4.02; P = .01). There was a negative correlation between CFV and cDL, r = -0.494, P < 0.001.

CONCLUSIONS & INFERENCES

Patients with SPV have a higher prevalence of dysphagia for solids and nausea when compared with NPV. Dysphagia for solids was the only symptom significantly associated with SPV group. Thus, abnormal esophageal propagation velocity (both slow and rapid) is associated with dysphagia.

Prevalence of human papillomavirus (HPV) in oesophageal squamous cell carcinoma in relation to anatomical site of the tumour

BACKGROUND

The prevalence and role of human papillomavirus (HPV) in the aetiology of oesophageal squamous cell carcinoma is uncertain. Based on the presence of HPV in the oral cavity and its causal association with squamous cell carcinoma of the oropharynx, we hypothesised that HPV is more strongly associated with proximal than distal oesophageal squamous cell carcinoma.

METHODS

A population-based study comparing HPV infection in relation to tumour site in patients diagnosed with oesophageal squamous cell carcinomas in the Stockholm County in 1999-2006. Multiplex polymerase chain reaction genotyping (PCR) with Luminex was conducted on pre-treatment endoscopic biopsies to identify type specify HPV. Carcinogenic activity of HPV was assessed by p16(INK4a) expression. Multivariable logistic regression was used to calculate odds ratios and 95% confidence intervals.

RESULTS

Among 204 patients, 20 (10%) had tumours harbouring HPV DNA, almost all (90%) of HPV high-risk type, mainly HPV16. Tumours containing HPV were not overrepresented in the upper compared to the middle or lower third of the oesophagus (odds ratio 0.6, 95% confidence interval 0.2-1.9). P16(INK4a) expression was similarly common (24% and 16%) in the HPV-positive and HPV-negative groups.

CONCLUSION

This study found a limited presence of HPV in oesophageal squamous cell carcinoma of uncertain oncogenic relevance and did not demonstrate that HPV was more strongly associated with proximal than distal tumours.

Esophageal motor dysfunction plays a key role in GERD with globus sensation--analysis of factors promoting resistance to PPI therapy

OBJECTIVE

Patients with gastroesophageal reflux disease (GERD) also have various extra-esophageal symptoms. Laryngopharyngeal reflux disease (LPRD) is a subtype of GERD associated with globus sensation, but proton pump inhibitor (PPI) therapy achieves disappointing results. This study investigated esophageal motility in GERD patients with globus sensation who were resistant to PPI therapy.

DESIGN

The subjects were 350 patients with globus sensation. All patients underwent both laryngoscopy and upper gastrointestinal endoscopy to exclude organic disease. After 4 weeks of treatment with rabeprazole sodium (20 mg daily), the patients were divided into PPI-responsive and PPI-resistant groups. Then we investigated esophageal motility in the PPI-resistant group by a multichannel intraluminal impedance and manometry study.

RESULTS

A total of 119 patients (55.6%) were resistant to PPI therapy, among whom 57 patients (47.9%) had abnormal esophageal motility. They included 36 patients (66.4%) with ineffective esophageal motility, 9 patients (14.4%) with achalasia, 6 patients (9.6%) with diffuse esophageal spasm, 5 patients (8%) with nutcracker esophagus, and 1 patient (1.6%) with hypertensive lower esophageal sphincter. There were significant differences of upper esophageal sphincter pressure and esophageal body peristalsis between the patients with PPI-resistant LPRD and healthy controls matched for age and sex.

CONCLUSION

Among patients with PPI-resistant LPRD, 47.9% had abnormal esophageal motility.

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

BACKGROUND

Esophageal peristalsis consists of a chain of contracting striated and smooth muscle segments on high resolution manometry (HRM). We compared smooth muscle contraction segments in symptomatic subjects with reflux disease to healthy controls.

METHODS

High resolution manometry Clouse plots were analyzed in 110 subjects with reflux disease (50 ± 1.4 years, 51.5% women) and 15 controls (27 ± 2.1 years, 60.0% women). Using the 30 mmHg isobaric contour tool, sequences were designated fragmented if either smooth muscle contraction segment was absent or if the two smooth muscle segments were separated by a pressure trough, and failed if both smooth muscle contraction segments were absent. The discriminative value of contraction segment analysis was assessed.

KEY RESULTS

A total of 1115 swallows were analyzed (reflux group: 965, controls: 150). Reflux subjects had lower peak and averaged contraction amplitudes compared with controls (P < 0.0001 for all comparisons). Fragmented sequences followed 18.4% wet swallows in the reflux group, compared with 7.5% in controls (P < 0.0001), and were seen more frequently than failed sequences (7.9% and 2.5%, respectively). Using a threshold of 30% in individual subjects, a composite of failed and/or fragmented sequences was effective in segregating reflux subjects from control subjects (P = 0.04).

CONCLUSIONS & INFERENCES

Evaluation of smooth muscle contraction segments adds value to HRM analysis. Specifically, fragmented smooth muscle contraction segments may be a marker of esophageal hypomotility.

Relationship between esophageal contraction patterns and clearance of swallowed liquid and solid boluses in healthy controls and patients with dysphagia

BACKGROUND

Non-obstructive dysphagia patients prove to be a difficult category for clinical management. Esophageal high-resolution manometry (HRM) is a novel method, used to analyze dysphagia. However, it is not yet clear how findings on HRM relate to bolus transport through the esophagus.

METHODS

Twenty healthy volunteers and 20 patients with dysphagia underwent HRM and videofluoroscopy in a supine position. Each subject swallowed five liquid and five solid barium boluses. Esophageal contraction parameters and bolus transport were evaluated with HRM and concurrent videofluoroscopy.

KEY RESULTS

Stasis of liquid and solid barium boluses occurred in patients and in healthy volunteers in 64% and 41% and in 84% and 82% of the swallows, respectively. Overall, 70% of the liquid and 72% of the solid bolus swallows were followed by a peristaltic contraction, the difference not being statistically significant. Statistically significant associations were found for transition zone length of liquid and solid boluses, and for DCI and distal contraction amplitudes for liquid stasis. No correlation was found between the degree of stasis and other manometric parameters.

CONCLUSIONS & INFERENCES

Stasis of both liquid and solid boluses occurs frequently in patients and in controls and can be regarded as physiological. Motility patterns can predict the effectiveness of bolus transit and level of stasis to some degree but the relationship between esophageal motility and transit is complex and far from perfect. Esophageal manometry is therefore currently deemed unfit to be used for the prediction of bolus transit, and should rather be used for the identification of treatable esophageal motility disorders.

Anatomy and physiology of the esophageal body

The primary role of the esophagus is to propel swallowed food or fluid into the stomach and to prevent or clear gastroesophageal reflux. This function is achieved by an organized pattern that involves a sensory pathway, neural reflexes, and a motor response that includes esophageal tone, peristalsis, and shortening. The motor function of the esophagus is controlled by highly complex voluntary and involuntary mechanisms. There are three different functional areas in the esophagus: the upper esophageal sphincter, the esophageal body, and the LES. This article focused on anatomy and physiology of the esophageal body.

In vitro effect of bethanechol and suberyldicholine on regions of guinea pig esophagus

BACKGROUND

Tissue engineering and regenerative medicine is envisaged as the future option for esophageal replacement; however, engineering of a functional esophagus is impeded by the limited understanding of the anatomical complexity of this dynamic muscular organ. The aim of this study was to characterize the function of native esophageal tissue and determine differences in functional response to stimulation between anatomical sites.

MATERIALS AND METHODS

The in-vitro response of guinea pig esophageal preparations, from various anatomical sites, to muscle agonists was investigated. Esophageal strips were exposed to bethanechol, an agonist of muscarinic receptors located on smooth muscle, and suberyldicholine, an agonist of nicotinic receptors located on striated muscle, within a Schuler organ bath, to determine the contractile response on the various segments of the esophagus.

RESULTS

The esophagus responded in a reliable and consistent manner to agonist stimulation. Bethanechol dose response curves were constructed with doses of 10 to 300 μM. The average maximal contractions to bethanechol exposure were 4.51, 4.80, 5.55, and 9.15 mN for upper, upper middle, lower middle, and lower esophageal segments, respectively. Responses to singular stimulation with 30 μM suberyldicholine in the presence of tetrodotoxin (100 μM) gave average contractions of 1.07, 0.84, 2.60, and 3.02 mN for upper, upper middle, lower middle, and lower esophageal segments, respectively. Bethanechol and suberyldicholine-induced responses were greater in the lower esophagus in comparison to the upper esophageal segments.

CONCLUSION

These findings pave the way for the use of an in-vitro bethanechol and suberyldicholine-induced contraction model for future assessment of engineered esophageal tissue.

Chicago classification criteria of esophageal motility disorders defined in high resolution esophageal pressure topography

BACKGROUND

The Chicago Classification of esophageal motility was developed to facilitate the interpretation of clinical high resolution esophageal pressure topography (EPT) studies, concurrent with the widespread adoption of this technology into clinical practice. The Chicago Classification has been an evolutionary process, molded first by published evidence pertinent to the clinical interpretation of high resolution manometry (HRM) studies and secondarily by group experience when suitable evidence is lacking.

PURPOSE

This publication summarizes the state of our knowledge as of the most recent meeting of the International High Resolution Manometry Working Group in Ascona, Switzerland in April 2011. The prior iteration of the Chicago Classification was updated through a process of literature analysis and discussion. The major changes in this document from the prior iteration are largely attributable to research studies published since the prior iteration, in many cases research conducted in response to prior deliberations of the International High Resolution Manometry Working Group. The classification now includes criteria for subtyping achalasia, EGJ outflow obstruction, motility disorders not observed in normal subjects (Distal esophageal spasm, Hypercontractile esophagus, and Absent peristalsis), and statistically defined peristaltic abnormalities (Weak peristalsis, Frequent failed peristalsis, Rapid contractions with normal latency, and Hypertensive peristalsis). The Chicago Classification is an algorithmic scheme for diagnosis of esophageal motility disorders from clinical EPT studies. Moving forward, we anticipate continuing this process with increased emphasis placed on natural history studies and outcome data based on the classification.

Automated calculation of the distal contractile integral in esophageal pressure topography with a region-growing algorithm

BACKGROUND

The distal contractile integral (DCI) is an index of contractile vigor in high-resolution esophageal pressure topography (EPT) calculated as the product of amplitude, duration, and span of the distal esophageal contraction. The aim of this study was to develop an automated algorithm calculating DCI.

METHODS

The DCI was calculated conventionally using ManoView™ (Given Imaging, Los Angeles, CA, USA) software in EPT studies from 72 controls and 20 patients and compared to the calculation using a MATLAB™ (Version 7.9.0, R2009b; The MathWorks Inc., Natick, MA, USA) 'region-growing' algorithm. This algorithm first established the spatial limits of the distal contraction (the proximal pressure trough to either the distal pressure trough or to the superior margin of the lower esophageal sphincter at rest). Pixel-by-pixel horizontal line segments were then analyzed within this span starting at the pressure maximum and extending outward from that point. The limits of 'region-growing' were defined either by the spatial DCI limits or by encountering a pressure <20 mmHg. The DCI was then calculated as the total units of mmHg s cm greater than 20 mmHg within this domain.

KEY RESULTS

Excellent correlation existed between the two methods (r = 0.98, P < 0.001). The DCI values obtained with the conventional calculation were slightly but significantly greater than with the region-growing algorithm. Differences were attributed to the inclusion of vascular pressures in the conventional calculation or to differences in localization of the distal limit of the DCI.

CONCLUSIONS & INFERENCES

The proposed region-growing algorithm provides an automated method to calculate DCI that limits inclusion of vascular pressure artifacts and minimizes the need for user input in data analysis.

Factors influencing lower esophageal sphincter relaxation after deglutition

AIM

To study the relationship between upper esophageal sphincter (UES) relaxation, peristaltic pressure and lower esophageal sphincter (LES) relaxation following deglutition in non-dysphagic subjects.

METHODS

Ten non-dysphagic adult subjects had a high-resolution manometry probe passed transnasally and positioned to cover the UES, the esophageal body and the LES. Ten water swallows in each subject were analyzed for time lag between UES relaxation and LES relaxation, LES pressure at time of UES relaxation, duration of LES relaxation, the distance between the transition level (TL) and the LES, time in seconds that the peristaltic wave was before (negative value) or after the TL when the LES became relaxed, and the maximal peristaltic pressure in the body of the esophagus.

RESULTS

Relaxation of the LES occurred on average 3.5 s after the bolus had passed the UES and in most cases when the peristaltic wave front had reached the TL. The LES remained relaxed until the peristaltic wave faded away above the LES.

CONCLUSION

LES relaxation seemed to be caused by the peristaltic wave pushing the bolus from behind against the LES gate.

Apple sauce improves detection of esophageal motor dysfunction during high-resolution manometry evaluation of dysphagia

BACKGROUND

Esophageal manometry utilizes water swallows to evaluate esophageal motor abnormalities in patients with dysphagia, chest pain, or reflux symptoms. Although manometry is the gold standard for evaluation of these symptoms, patients with dysphagia often have normal results in manometry studies.

AIM

The objective of this work was to test the hypothesis that challenging the esophagus with viscous apple sauce boluses uncovers motor abnormalities in patients with dysphagia not seen when using water swallows.

METHODS

High-resolution esophageal manometry was performed using ten water swallows followed by ten apple sauce swallows in consecutive subjects presenting with dysphagia. Subjects with grossly abnormal water swallow evaluations were excluded. Each swallow was categorized as normal, hypotensive (distal isobaric contour plots of < 30 mmHg over >5 cm), or simultaneous (distal esophageal velocity ≥ 8.0 cm/s). Ineffective esophageal motility (IEM) was defined as ≥ 30% hypotensive swallows, and pressurization was defined as ≥ 20% simultaneous pressure waves.

RESULTS

Data from 41 subjects was evaluated. Overall, 96.3% of water swallows were normal, 2.9% hypotensive, and 0.7% simultaneous. Only 70.3% of viscous swallows were normal; 16.7% were hypotensive and 13.0% were simultaneous (P < 0.001 all groups). Seven (17.1%) met criteria for IEM, and pressurization with viscous swallows was observed for nine (22.0%). Fourteen subjects (34.1%) had abnormal results from viscous studies. The presence of any abnormal water swallows was predictive of abnormal viscous swallows (OR = 9.00, CI = 2.15-80.0), although the presence of hypotensive or simultaneous water swallows was not associated with IEM (OR = 0.63, CI = 0.16-2.17) or pressurization (OR = 7.00, CI = 0.90-315.4) with viscous apple sauce.

CONCLUSIONS

Apple sauce challenge increased identification of classifiable motor disorders in patients with dysphagia and may be preferred to alternative bolus materials.

Effects of anti-hypertensive drugs on esophageal body contraction

AIM: To clarify the effects of anti-hypertensive drugs on esophageal contraction and determine their possible relationship with gastro-esophageal reflux disease.

METHODS: Thirteen healthy male volunteers were enrolled. Esophageal body peristaltic contractions and lower esophageal sphincter (LES) pressure were measured using high resolution manometry. All subjects were randomly examined on four separate occasions following administrations of nifedipine, losartan, and atenolol, as well as without any drug administration.

RESULTS: Peristaltic contractions by the esophageal body were separated into three segments by two troughs. The peak peristaltic pressures in the mid and lower segments of the esophageal body under atenolol administration were significantly higher than those without medication in a supine position. On the other hand, peristaltic pressures under nifedipine administration were lower than those observed without drug administration. Losartan did not change esophageal body peristalsis. Atenolol elevated LES pressure and slowed peristaltic wave transition, while the effects of nifedipine were the opposite.

CONCLUSION: Among the anti-hypertensive drugs tested, atenolol enhanced esophageal motor activity, which was in contrast to nifedipine.

Pediatric esophageal high-resolution manometry: utility of a standardized protocol and size-adjusted pressure topography parameters

OBJECTIVES

Esophageal high-resolution manometry (EHRM) has evolved rapidly from a research tool to a routine investigation in adult clinical practice. This study proposes and evaluates a standardized EHRM protocol for use in pediatric clinical practice.

METHODS

Thirty pediatric patients underwent unsedated EHRM. Indications for EHRM were dysphagia, feeding difficulty, or pre-fundoplication assessment. Two 20-channel customized water-perfused silicone catheters, with an outside diameter of 3.8 mm (MuiScientific, Ontario, CA), were used. The catheters had one distal gastric channel, five channels 0.5 cm apart for the e-sleeve, and 14 proximal channels either 1 cm (for children <5 years) or 2 cm apart (for children >5 years). Single wet swallows, multiple rapid swallows (MRS), and solid swallows were systematically studied.

RESULTS

The median age was 10 years (range 6 months-15 years). The esophageal motor findings were normal peristalsis (n=15), peristaltic dysfunction (n=12), achalasia (n=3), and spasm on consumption of solid food (n=2). The distal contractile integral adjusted for esophageal length (DCIa) of patients with peristaltic dysfunction was significantly lower than that of patients without peristaltic dysfunction (P<0.001). On MRS, aperistalsis with lack of esophagogastric junction (EGJ) relaxation was observed in patients with achalasia, and aperistalsis with complete EGJ relaxation was observed in patients with severe peristaltic dysfunction. On consumption of solid food, esophageal spasm associated with bolus impaction was observed in two patients.

CONCLUSIONS

This study provides objective information with regard to topography pressure parameters in esophageal motility disorders of childhood while using a standardized EHRM protocol. The new DCIa variable may be useful for the assessment of patients with peristaltic dysfunction.

Histologic and manometric studies on the esophagus following endoscopic sclerotherapy

OBJECTIVE

The aim of this work was to study the histologic and manometric changes in the distal esophagus beyond 2 years following endoscopic sclerotherapy (EST) and/or surgical intervention, and to try to understand the etiological factors associated with these changes.

PATIENTS AND INTERVENTIONS

Forty patients, with an average age of 61.5 years, were studied for 2-12 years following sclerotherapy and/or surgical intervention. The causes of liver disease were alcoholic cirrhosis (78.6%), primary biliary cirrhosis (14.3%), and chronic aggressive hepatitis (7.1%). A predominant number of cases (65%) had a mesocaval interposition shunt due to the failure of EST, 32.5% EST alone, and 2.5% esophageal devascularization. All patients had esophageal manometry following mucosal biopsies taken in duplicate endoscopically from three levels of the distal esophagus.

RESULTS

In the EST and shunt groups, 88.5% had manometric abnormalities, esophagitis, and chronic inflammatory changes. In the EST group, all but two patients had manometric abnormalities and chronic inflammatory changes. Analysis of the patient groups on the basis of the number of EST sessions and the amount of sclerosant injected showed that both histologic changes and dysmotility were more profound in those treated over five times with EST. The differences were significant.

CONCLUSION

It appears that EST causes persistent manometric abnormalities and chronic inflammatory changes in the distal esophagus, the severity of which seems to vary directly with the frequency of sclerotherapy and not amount of sclerosant injected.

Globus: are we any nearer to understanding it?

Globus is a common functional symptom without a clearly accepted etiology. Upper esophageal sphincter (UES) hypertension and gastroesophageal reflux have been proposed but not confirmed. Kwiatek et al. report a detailed study in globus patients using high-resolution manometry (HRM). The study showed greater respiratory augmentation of UES pressure compared with control groups among two-thirds of globus patients. Further prospective studies are needed to confirm these findings and to establish whether they are of etiologic significance.

New technologies in the gastrointestinal clinic and research: Impedance and high-resolution manometry

The last five years have been an exciting time in the study of esophageal motor disorders due to the recent advances in esophageal function testing. New technologies have emerged, such as intraluminal impedance, while conventional techniques, such as manometry, have enjoyed many improvements due to advances in transducer technology, computerization and graphic data presentation. While these techniques provide more detailed information regarding esophageal function, our understanding of whether they can improve our ability to diagnose and treat patients more effectively is evolving. These techniques are also excellent research tools and they have added substantially to our understanding of esophageal motor function in dysphagia. This review describes the potential benefits that these new technologies may have over conventional techniques for the evaluation of dysphagia.

Esophageal motility testing: impedance-based transit measurement and high-resolution manometry

Esophageal function tests are widely used, not only to obtain insight into esophageal physiology and pathophysiology in a research setting, but also to diagnose esophageal motor disorders in patients with symptoms such as dysphagia and chest pain. While esophageal function testing has long been considered almost synonymous with manometry, recently new techniques such as impedance measurement and high-resolution manometry have emerged. With impedance monitoring the transit of a bolus through the esophagus can be studied without the use of ionizing radiation. High-resolution manometry offers a highly detailed and comprehensive view of esophageal pressure patterns. Multichannel high resolution manometry with color plotting facilitates positioning of the catheter and interpretation of the tracings. In this article the development, clinical usefulness, and indications of these new tests are discussed.

Characteristics of the esophageal low-pressure zone in healthy volunteers and patients with esophageal symptoms: assessment by high-resolution manometry

BACKGROUND

Esophageal motility studies in humans have documented a low-pressure zone (LPZ) in the area of transition from striated to smooth muscle. While preliminary studies indicate that a bolus might be retained in this area, the clinical relevance of the LPZ remains unclear.

AIM

To investigate a possible relationship between esophageal symptoms and the size of the esophageal LPZ.

METHODS

We reviewed high-resolution manometry (HRM) data from patients with esophageal symptoms (dysphagia, chest pain, and heartburn/regurgitation) and asymptomatic volunteers. The proximal border of the LPZ was defined as the point where the amplitude of the proximal contraction wave declined below 30 mmHg, and the distal border as the point where the distal contraction wave first increased above 30 mmHg.

RESULTS

The average (+/- standard error of mean [SEM]) length of the LPZ in 44 asymptomatic individuals was 5.4 +/- 0.6 cm and did not differ (P= 0.222) from the LPZ in 64 patients with dysphagia (6.8 +/- 0.4 cm), 34 patients with chest pain (6.4 +/- 0.6 cm), and 42 patients with gastroesophageal reflux disease (GERD) symptoms (7.0 +/- 0.6 cm). These results did not change when the length of the LPZ was corrected for total esophageal length. The time width of the LPZ in asymptomatic individuals (1.6 +/- 0.2 s) was shorter than in patients with dysphagia and GERD symptoms (dysphagia 2.4 +/- 0.2 s, GERD symptoms 2.8 +/- 0.3 s).

CONCLUSION

A time delay between the proximal and distal esophageal contraction waves might be a meaningful variable in GERD and dysphagia.

Physiology of the oesophageal transition zone in the presence of chronic bolus retention: studies using concurrent high resolution manometry and digital fluoroscopy

Distinct contraction waves (CWs) exist above and below the transition zone (TZ) between the striated and smooth muscle oesophagus. We hypothesize that bolus transport is impaired in patients with abnormal spatio-temporal coordination and/or contractile pressure in the TZ. Concurrent high resolution manometry and digital fluoroscopy were performed in healthy subjects and patients with reflux oesophagitis; a condition associated with ineffective oesophageal contractility and clearance. A detailed analysis of space-time variations in bolus movement, intra-bolus and intra-luminal pressure was performed on 17 normal studies and nine studies in oesophagitis patients with impaired bolus transit using an interactive computer based system. Compared with normal controls, oesophagitis patients had greater spatial separation between the upper and lower CW tails [median 5.2 cm (range 4.4-5.6) vs 3.1 cm (2.2-3.7)], the average relative pressure within the TZ region (TZ strength) was lower [30.8 mmHg (28.3-36.5) vs 45.8 mmHg (36.1-55.7), P < 0.001], and the risk of bolus retention was higher (90%vs 12%; P < 0.01). The presence of bolus retention was associated with a wider spatial separation of the upper and lower CWs (>3 cm, the upper limit of normal; P < 0.002), independent of the presence of oesophagitis. We conclude that bolus retention in the TZ is associated with excessively wide spatial separation between the upper and lower CWs and lower TZ muscle squeeze. These findings provide a physio-mechanical basis for the occurrence of bolus retention at the level of the aortic arch, and may underlie impaired clearance with reflux oesophagitis.

Diagnostic evaluation of dysphagia

Taking a careful history is vital for the evaluation of dysphagia. The history will yield the likely underlying pathophysiologic process and anatomic site of the problem in most patients, and is crucial for determining whether subsequently detected radiographic or endoscopic 'anomalies' are relevant or incidental. Although the symptoms of pharyngeal dysphagia can be multiple and varied, the typical features of neurogenic pharyngeal dysphagia are highly specific, and can accurately distinguish pharyngeal from esophageal disorders. The history will also dictate whether the next diagnostic procedure should be endoscopy, a barium swallow or esophageal manometry. In some difficult cases, all three diagnostic techniques may need to be performed to establish an accurate diagnosis. Stroke is the most common cause of pharyngeal dysphagia. A videoradiographic swallow study is vital in such cases to determine the extent and timing of aspiration and the severity and mechanics of dysfunction as a prelude to therapy.

Influence of bolus consistency and position on esophageal high-resolution manometry findings

BACKGROUND

Conventional esophageal manometry evaluating liquid swallows in the recumbent position measures pressure changes at a limited number of sites and does not assess motility during solid swallows in the physiologic upright position.

AIM

To evaluate esophageal motility abnormalities during water and bread swallows in the upright and recumbent positions using high-resolution manometry (HRM).

METHODS

Thirty-two-channel HRM testing was performed using water (10 ml each) and bread swallows in the upright and recumbent positions. The swallows were considered normal if the distal peristaltic segment >30 mmHg was >5 cm, ineffective if the 30-mmHg pressure band was <5 cm, and simultaneous if the onset velocity of the 30 mmHg pressure band was >8 cm/s. Abnormal esophageal manometry was defined as the presence of > or =30% ineffective and/or > or =20% simultaneous contractions.

RESULTS

The data from 96 patients (48 F; mean age 51 years, range 17-79) evaluated for dysphagia (56%), chest pain (22%), and gastroesophageal reflux disease (GERD) symptoms (22%) were reviewed. During recumbent water swallows, patients with dysphagia, chest pain, and GERD had a similar prevalence of motility abnormalities. During upright bread swallows, motility abnormalities were more frequent (p = 0.01) in patients with chest pain (71%) and GERD (67%) compared to patients with dysphagia (37%).

CONCLUSIONS

Evaluating bread swallows in the upright position reveals differences in motility abnormalities overlooked by liquid swallows alone.

Oesophageal tone and sensation in the transition zone between proximal striated and distal smooth muscle oesophagus

Previous studies have shown that the proximal striated muscle oesophagus is less compliant and more sensitive than the distal smooth muscle oesophagus. Conventional and high resolution manometry described a transition zone between striated and smooth muscle oesophagus. We aimed to evaluate oesophageal tone and sensitivity at the transition zone of oesophagus in healthy volunteers. In 18 subjects (seven men, mean age: 28 years) an oesophageal barostat study was performed. Tone and sensitivity were assessed using stepwise isobaric distensions with the balloon located at transition zone and at distal oesophagus in random order. To study the effect induced on transition zone by a previous distension at the distal oesophagus and vice versa, identical protocol was repeated after 7 days with inverted order. Initial distension of a region is referred to as 'naïf' distension and distension of a region following the distension of the other segment as 'primed' distension. Assessment of three oesophageal symptoms (chest pain, heartburn and 'other') was obtained at the end of every distension step. Compliance was significantly higher in the transition zone than in the distal oesophagus (1.47 +/- 0.14 vs 1.09 +/- 0.09 mL mmHg(-1), P = 0.03) after 'naif' distensions. This difference was not observed during 'primed' distensions. Higher sensitivity at transition zone level was found in 11/18 (61%) subjects compared to 6/18 (33%, P < 0.05) at smooth muscle oesophagus. Chest pain and 'other' symptom were more often induced by distention of the transition zone, whereas heartburn was equally triggered by distension of either region. The transition zone is more complaint and more sensitive than smooth muscle oesophagus.

High-resolution manometry

Recently, high-resolution oesophageal manometry was added to the armamentarium of researchers and gastroenterologists. Current studies suggest that the yield of high-resolution oesophageal manometry is higher than that of conventional pull-through manometry and is at least comparable to that of sleeve sensor manometry. Probably the most important advantage of solid-state high-resolution manometry is that it makes oesophageal manometry faster and easier to perform. Topographic plotting of high-resolution manometry signals facilitates their interpretation. It is concluded that high-resolution manometry is a promising technique for the evaluation of oesophageal motor function. Further studies will have to determine whether high-resolution manometry is superior to conventional manometry in the diagnostic work-up of patients with oesophageal symptoms.

Segmental characteristics of oesophageal peristalsis in paediatric patients

High-resolution manometry (HRM) in adults identifies a sequential chain of pressure segments that together form normal oesophageal peristalsis. HRM was performed in 40 neonates, infants/toddlers and children (age 1 day-14 years) to see if a similar segmental pattern could be identified in paediatric subjects. A chain of three pressure segments was found with inter-segmental troughs at 27.4 +/- 1.1%, 62.6 +/- 1.3% and 94.9 +/- 0.8% oesophageal length. The first and second pressure troughs were similarly distributed along the oesophagus across age groups; the third was 7.6-8.9% oesophageal length further from the lower oesophageal sphincter in neonates (P < 0.05 compared with other age groups). There were no significant differences in trough locations between subjects with or without oesophageal disease, controlling for age. Consistent presence of all three segments was less common in neonates, primarily because of fewer swallows demonstrating the first (proximal) and third (distal) segments compared with children. HRM in paediatric patients demonstrates, from neonates to children, the distinctive chain of pressure events that also characterizes oesophageal peristalsis in adults. The segmental character to oesophageal peristalsis should be taken into consideration in manometric investigation of all age groups - for example, in testing pharmacological responses and evaluating clearance mechanisms.

Esophagopharyngeal reflux

Objective

Laryngopharyngeal reflux (LPR) is the disorder caused by the regurgitation of gastric contents into the laryngopharynx. Many persons diagnosed with LPR who fail medical therapy regurgitate contents from the proximal esophagus into the laryngopharynx (esophagopharyngeal reflux or EPR) on cinefluoroscopy.

Study Design

Retrospective review.

Subjects and Methods

The charts of consecutive adult patients with findings of EPR on cinefluoroscopy were reviewed.

Results

Twenty patients met the diagnostic criteria for EPR (mean age, 50 years of age; 60% female). Most common symptoms were cough (40%), dysphagia (35%), dysphonia (25%), and chronic throat clearing (25%). Eighty-five percent had a prior diagnosis of acid reflux disease (LPR or GER) and were unsuccessfully treated with proton pump inhibitors and/or anti-reflux surgery; 15% had fluoroscopic oropharyngeal abnormalities; all patients had fluoroscopic esophageal abnormalities.

Conclusion

EPR is characterized by regurgitation of proximal esophageal contents into the laryngopharynx. The symptoms are similar to LPR. EPR appears to be caused by a disorder of volume clearance and esophageal dysmotility not acid and peptic injury.