American Gastroenterological Association technical review on the clinical use of esophageal manometry

Nasopharyngeal airway assistance improves esophageal intubation rates of high-resolution esophageal manometry catheters

BACKGROUND

High-resolution esophageal manometry (HREM) is the gold standard test for esophageal motility disorders. Nasopharyngeal airway-assisted insertion of the HREM catheter is a suggested salvage technique for failure from the inability to pass the catheter through the upper esophageal sphincter (UES). It has not been demonstrated that the nasopharyngeal airway improves procedural success rate.

METHODS

Patients undergoing HREM between March 2019 and March 2023 were evaluated. Chart review was conducted for patient factors and procedural success rates before and after use of nasopharyngeal airway. Patients from March 2019 to May 2021 did not have nasopharyngeal airway available and were compared to patients from May 2021 to March 2023 who had the nasopharyngeal airway available.

KEY RESULTS

In total, 523 HREM studies were conducted; 234 occurred prior to nasopharyngeal airway availability, and 289 occurred with nasopharyngeal airway availability. There was no difference in HREM catheter UES intubation rates between periods when a nasopharyngeal airway attempt was considered procedural failure (85% vs. 85%, p = 0.9). Nasopharyngeal airway use after UES intubation failure lead to improved UES intubation rates (94% vs. 85%, p < 0.01). Thirty-six patients that failed HREM catheter UES intubation had the procedure reattempted with a nasopharyngeal airway, 30 (83%) of which were successful. The nasopharyngeal airway assisted catheter UES intubation for failures attributed to nasal pain and hypersensitivity, gagging, coughing, and pharyngeal coiling.

CONCLUSIONS & INFERENCES

Utilization of the nasopharyngeal airway increased rates of UES intubation. When HREM catheter placement through the UES fails, placement of a nasopharyngeal airway can be trialed to overcome patient procedural intolerance.

Atypical presentations and pitfalls of achalasia

Achalasia is a rare disease with significant diagnostic delay and association with false diagnoses and unnecessary interventions. It remains unclear, whether atypical presentations, misinterpreted symptoms or inconclusive diagnostics are the cause. The aim of this study was the characterization of typical and atypical features of achalasia and their impact on delays, misinterpretations or false diagnoses. A retrospective analysis of prospective database over a period of 30 years was performed. Data about symptoms, delays and false diagnoses were obtained and correlated with manometric, endoscopic and radiologic findings. Totally, 300 patients with achalasia were included. Typical symptoms (dysphagia, regurgitation, weight loss and retrosternal pain) were present in 98.7%, 88%, 58.4% and 52.4%. The mean diagnostic delay was 4.7 years. Atypical symptoms were found in 61.7% and led to a delay of 6 months. Atypical gastrointestinal symptoms were common (43%), mostly 'heartburn' (16.3%), 'vomiting' (15.3%) or belching (7.7%). A single false diagnosis occurred in 26%, multiple in 16%. Major gastrointestinal misdiagnoses were GERD in 16.7% and eosinophilic esophagitis in 4%. Other false diagnosis affected ENT-, psychiatric, neurologic, cardiologic or thyroid diseases. Pitfalls were the description of 'heartburn' or 'nausea'. Tertiary contractions at barium swallows, hiatal hernias and 'reflux-like' changes at endoscopy or eosinophils in the biopsies were misleading. Atypical symptoms are common in achalasia, but they are not the sole source for diagnostic delays. Misleading descriptions of typical symptoms or misinterpretation of diagnostic studies contribute to false diagnoses and delays.

Associations Between Patterns of Esophageal Dysmotility and Extra-Intestinal Features in Patients With Systemic Sclerosis

OBJECTIVE

The gastrointestinal tract is commonly involved in patients with systemic sclerosis (SSc) with varied manifestations. As our understanding of SSc gastrointestinal disease pathogenesis and risk stratification is limited, we sought to investigate whether patterns of esophageal dysfunction associate with specific clinical phenotypes in SSc.

METHODS

Patients enrolled in the Johns Hopkins Scleroderma Center Research Registry who completed high-resolution esophageal manometry (HREM) studies as part of their clinical care between 2011 and 2020 were identified. Associations between esophageal abnormalities on HREM (absent contractility [AC], ineffective esophageal motility [IEM], hypotensive lower esophageal sphincter [hypoLES]) and patient demographic information, clinical characteristics, and autoantibody profiles were examined.

RESULTS

Ninety-five patients with SSc had HREM data. Sixty-five patients (68.4%) had AC (37 patients with only AC, 28 patients with AC and a hypoLES), 9 patients (9.5%) had IEM, and 11 patients (11.6%) had normal studies. AC was significantly associated with diffuse cutaneous disease (38.5% versus 10.0%; P < 0.01), more severe Raynaud's phenomenon, including digital pits, ulcers, or gangrene (56.9% versus 30.0%; P = 0.02), and reduced median diffusing capacity of lung for carbon monoxide (50.6% versus 72.2%; P = 0.03). AC was observed in most of the patients who died (13 of 14; P = 0.06). These findings were not seen in patients with IEM.

CONCLUSION

Among patients with SSc, AC is associated with a significantly more severe clinical phenotype. IEM may associate with a milder phenotype. Further studies are needed to evaluate AC, IEM, and their clinical impact relative to the timing of other end-organ complications in SSc.

The burden of gastroesophageal reflux disease on the cost of managing chronic diseases in Australia. The need for a new diagnostic and management paradigm

INTRODUCTION

Chronic disease poses a major problem for the Australian healthcare system as the leading cost-burden and cause of death. Gastroesophageal reflux disease (GORD) typifies the problems with a growing prevalence and cost. We hypothesise that a scintigraphic test could optimise the diagnosis, especially in problematic extraoesophageal disease.

MATERIALS AND METHODS

Data was collected from 2 groups of patients. Patients undergoing fundoplication for severe GORD (n = 30) and those with atypical symptoms (n = 30) were studied by scintigraphy and 24-hour oesophageal pH, impedance and manometry.

RESULTS

Mean age of cohort was 55.8 years with 40 females and 20 males. Body mass index was a mean of 28.3. DeMeester score was normal in 12/60 with atypical symptoms and abnormal in the rest. Good correlation was shown between scintigraphy and impedance, manometry and distal pH readings. Pulmonary aspiration was shown in 25/60 (15 with atypical symptoms) and LPR in 20/30. Several impedance, manometric and scintigraphic finding were good predictors of lung aspiration of refluxate.

CONCLUSION

Scintigraphy provides a good tool for screening patients with typical and atypical symptoms of GORD. It is well correlated with the standard methods for the diagnosis and provides visual evidence of LPR and lung aspiration.

Pressure and length of the lower esophageal sphincter as predictive indicators of therapeutic efficacy of baclofen for refractory gastroesophageal reflux-induced chronic cough

BACKGROUND

Therapeutic efficacy of baclofen is suboptimal in the treatment of refractory gastroesophageal reflux-induced chronic cough (GERC). The purpose of the study is to identify its therapeutic predictors in a prospective clinical study.

METHODS

138 patients with suspected refractory GERC were treated with baclofen. Before the therapy, all the patients underwent esophageal manometry and multichannel intraluminal impedance-pH monitoring to establish the diagnosis. After the efficacy of baclofen was evaluated, a stepwise logistic regression analysis was performed to identify the therapeutic predictors of baclofen and to establish a regression prediction model.

RESULTS

The overall response rate of baclofen treatment was 52.2% (72/138). The lower esophageal sphincter pressure (LESP) (odds ratio (OR) = 0.592, P = 0.000) and lower esophageal sphincter length (LESL) (OR = 0.144, P = 0.008) were independent predictors of baclofen efficacy. The optimal cut-off point to predict baclofen efficacy for LESP was 11.00 mmHg, with a sensitivity of 83.7% and specificity of 79.1% while that for LESL was 2.35 cm, with a sensitivity of 81.6% and specificity of 72.1%. The highest predictive specificity (90.7%) was achieved when both LESP and LESL were jointly used.

CONCLUSIONS

LESP and LESL may be used to screen the patients with refractory GERC suitable for baclofen therapy and help improve the therapeutic precision.

CLINICAL TRIAL REGISTRATION

ChiCTR- ONC-13003123.

Evaluation of the Esophagogastric Junction on High Resolution Manometry

The esophagogastric junction (EGJ) is a complex barrier between the thoracic and abdominal luminal gut compartments, comprised primarily of the lower esophageal sphincter (LES) and crural diaphragm. Although closed at rest, the EGJ relaxes to allow antegrade bolus transit and retrograde venting of air. Abnormal relaxation is the hallmark of achalasia spectrum disorders, while increased frequency of transient lower esophageal sphincter relaxations and/or EGJ disruption are seen in gastroesophageal reflux disease. High resolution manometry (HRM) is the modern day gold standard for assessment of EGJ morphology and function, with better performance characteristics compared with endoscopy and barium esophagography. Conventional LES metrics defining EGJ function include resting LES pressure as well as postswallow residual pressures. Newer HRM-based metrics include EGJ contractile integral, which measures static barrier function at rest, and EGJ morphology, which characterizes the relationship between LES and crural diaphragm. Provocative maneuvers assess dynamic EGJ function during physiological or pharmacologic stress. The most useful of these maneuvers, the rapid drink challenge, assesses for latent obstruction, while multiple rapid swallows evaluate adequacy of deglutitive inhibition. Amyl nitrate and cholecystokinin administration can segregate motor from structural obstruction. Newer provocative tests (straight leg raise maneuver, abdominal compression) and novel diagnostic tools (functional lumen imaging probe) complement HRM evaluation of the EGJ. Although current HRM metrics and maneuvers show promise in identifying clinically relevant EGJ abnormalities, future investigations evaluating management outcomes will improve segregation of normal from abnormal EGJ morphology and function.

The 100 most cited manuscripts in esophageal motility disorders: a bibliometric analysis

BACKGROUND

The use of bibliometrics can help us identify the most impactful articles on a topic or scientific discipline and their influence on clinical practice. We aimed to identify the 100 most cited articles covering esophageal motility disorders and examine their key characteristics.

METHODS

The Web of Science database was utilized to perform the search, using predefined search terms. The returned dataset was filtered to include full manuscripts written in the English language. After screening, we identified the 100 most cited articles and analyzed them for title, year of publication, names of authors, institution, country of the first author, number of citations and citation rate.

RESULTS

The initial search returned 29,521 results. The top 100 articles received a total of 20,688 citations. The most cited paper was by Inoue et al. (665 citations) who first described peroral endoscopic myotomy (POEM) for treating achalasia. The article with the highest citation rate was the third version of the Chicago Classification system, written by Kahrilas and colleagues. Gastroenterology published most papers on the list (n=32) and accrued the highest number of citations (6,675 citations). Peter Kahrilas was the most cited author (3,650 citations) and, along with Joel Richter, authored the highest number of manuscripts (n=14). Most articles were produced in the USA (n=66) between the years 1991 and 2000 (n=32).

CONCLUSIONS

By analyzing the most influential articles, this work is a reference on the articles that shaped our understanding of esophageal motility disorders, thus serving as a guide for future research.

Outcomes of pneumatic dilation in achalasia: Extended follow-up of more than 25 years with a focus on manometric subtypes

BACKGROUND AND AIM

Pneumatic dilation (PD) is the most popular nonsurgical treatment for achalasia. This study investigated predicting factors, including manometric subtypes for symptom recurrence in the long term, in patients with achalasia treated with a single PD.

METHODS

Between 1983 and 2013, a total of 107 patients were treated initially with a single PD and included in this longitudinal cohort study. Outcomes were correlated with demographics, symptoms (Eckardt score), and esophagographic and manometric features. Manometric tracings were retrospectively classified according to the three subtypes of the Chicago classification.

RESULTS

Ninety-one (85%) patients were successfully treated after the first PD. The median follow-up was 13.8 years (interquartile range 7-20). During follow-up, 54% of the patients experienced a clinical relapse. The overall cumulative success rates at 2, 5, 10, 15, 20, and 25 years were 64%, 53%, 49%, 42%, 36%, and 36%, respectively. Age < 40 years, lower esophageal sphincter pressure > 15 mmHg, a cardia width < 5 mm, and an esophageal barium column height > 1 cm 4 to 12 weeks post-dilation significantly correlated with symptom recurrence, whereas achalasia subtypes did not significantly correlate with the treatment results.

CONCLUSION

Pneumatic dilation in achalasia is an effective therapy in the short term, but its effect wanes in the very long term. Young age at presentation, a high lower esophageal sphincter pressure, a narrow cardia, and an esophageal barium column of > 1 cm after PD are predictive factors for the need of repeated treatment.

Esophageal hiatal hernia: risk, diagnosis and management

Esophageal hiatal hernia involves abnormal abdominal entry into thoracic cavity. It is classified based on orientation between esophageal junction and diaphragm. Sliding hiatal hernia (Type-I) comprises the most frequent category, emanating from right crus of diaphragm. Type-II esophageal hernia engages both left and right muscular crura. Type-III and IV additionally include the left crus. Age and increased body mass index are key risk factors, and congenital skeletal aberrations trigger pathogenesis through intestinal malrotations. Familiar manifestations include gastric reflux, nausea, bloating, chest and epigastric discomfort, pharyngeal and esophageal expulsion and dysphagia. Weight loss and colorectal bleeding are severe symptoms. Areas covered: This review summarizes updated evidence of pathophysiology, risk factors, diagnosis and management of hiatal hernias. Laparoscopy and oesophagectomy procedures have been discussed as surgical procedures. Expert commentary: Endoscopy identifies untreatable gastric reflux; radiology is better for pre-operative assessments; manometry measures esophageal peristalsis, and CT scanning detects gastric volvulus and associated organ ruptures. Gastric reflux disease is mitigated using antacids and proton pump and histamine-2-receptor blockers. Severe abdominal penetration into chest cavity demands surgical approaches. Hence, esophagectomy has chances of post-operative morbidity, while minimally invasive laparoscopy entails fewer postoperative difficulties and better visualization of hernia and related vascular damages.

A Procedure for the Automatic Analysis of High-Resolution Manometry Data to Support the Clinical Diagnosis of Esophageal Motility Disorders

OBJECTIVE

Degenerative phenomena may affect esophageal motility as a relevant social-health problem. The diagnosis of such disorders is usually performed by the analysis of data from high-resolution manometry (HRM). Inter- and intraobserver variability frequently affects the diagnosis, with potential interpretative and thus therapeutic errors, with unnecessary or worse treatments. This may be avoided with automatic procedures that minimize human intervention in data processing.

METHODS

In order to support the traditional diagnostic process, an automatic procedure was defined considering a specific physiomechanical model that is able to objectively interpret data from HRM. A training set (N = 226) of healthy volunteers and pathological subjects was collected in order to define the model parameters distributions of the different groups of subjects, providing a preliminary database. A statistical algorithm was defined for an objective identification of the patient's healthy or pathological condition by comparing patient parameters with the database.

RESULTS

A collection of HRMs including subjects of the training set has been built. Statistical relationships between parameters and pathologies have been established leading to a preliminary database. An automatic diagnosis procedure has been developed to compare model parameters of a specific patient with the database. The procedure was able to match the correct diagnosis up to 86% of the analyzed subjects.

CONCLUSION

The success rate of the automatic procedure addresses the suitability of the developed algorithms to provide a valid support to the clinicians for the diagnostic activity.

SIGNIFICANCE

The objectivity of developed tools increases the reliability of data interpretation and, consequently, patient acceptance.

A physiological model for the investigation of esophageal motility in healthy and pathologic conditions

Recent technological advances in esophageal manometry allowed the definition of new classification methods for the diagnosis of disorders of esophageal motility and the implementation of innovative computational tools for the autonomic, reliable and unbiased detection of different disorders. Computational models can be developed aiming to interpret the mechanical behavior and functionality of the gastrointestinal tract and to summarize the results from clinical measurements, as high-resolution manometry pressure plots, into model parameters. A physiological model was here developed to interpret data from esophageal high-resolution manometry. Such model accounts for parameters related to specific physiological properties of the biological structures involved in the peristaltic mechanism. The identification of model parameters was performed by minimizing the discrepancy between clinical data from high-resolution manometry and model results. Clinical data were collected from both healthy volunteers ( n = 35) and patients with different motor disorders, such as achalasia patterns 1 ( n = 13), 2 ( n = 20) and 3 ( n = 5), distal esophageal spasm ( n = 69), esophago-gastric junction outflow obstruction ( n = 25), nutcracker esophagus ( n = 11) and normal motility ( n = 42). The physiological model that was formulated in this work can properly explain high-resolution manometry data, as confirmed by the evaluation of the coefficient of determination R² = 0.83 - 0.96. The study finally led to identify the statistical distributions of model parameters for each healthy or pathologic conditions considered, addressing the applicability of the achieved results for the implementation of autonomic diagnosis procedures to support the medical staff during the traditional diagnostic process.

Achalasia: new perspectives on an old disease

Achalasia is defined by esophageal outflow obstruction from abnormal relaxation of the lower esophageal sphincter (LES) due to deranged inhibitory control. In genetically predisposed individuals, an autoimmune response to an unknown inciting agent, perhaps a viral infection, results in inflammation and sometimes loss of myenteric plexus ganglia and neurons. The net result is varying degrees of inhibitory dysfunction, at times associated with imbalanced and exaggerated excitatory function, with manometrically distinct achalasia phenotypes on high resolution manometry. There is new evidence in the current issue of this Journal suggesting that type 1 achalasia, with esophageal outflow obstruction and absent esophageal body contractility, is an end-stage phenotype from progression of type 2 achalasia, which is characterized by panesophageal compartmentalization of pressure in the untreated patient, and partial recovery of peristalsis after treatment. Esophageal outflow obstruction with premature peristalsis (type 3 achalasia) or intact peristalsis may result from plexitis in the myenteric plexus but can also be encountered in other settings including chronic opioid medication usage and structural processes at the esophagogastric junction and distally. In most instances when idiopathic esophageal outflow obstruction is confirmed, some form of pharmacologic manipulation or disruption of the LES provides durable symptom relief. This review will focus on current understanding of pathophysiology, diagnosis, and principles of management of achalasia in light of emerging literature on the topic.

Automated impedance manometry analysis as a method to assess esophageal function

BACKGROUND

Diagnostic evaluation of non-achalasia esophageal dysphagia remains challenging because of a lack of a clear relationship between symptoms, esophageal contraction patterns, and esophageal bolus flow. This study evaluates a novel approach to pressure-impedance analysis called automated impedance manometry (AIM) analysis in relation to bolus characteristics, Chicago classification metrics, bolus perception, and dysphagia.

METHODS

AIM analysis was performed on esophageal high resolution manometry-impedance recordings from 12 healthy controls and 15 patients with dysphagia. In each subject, 10 liquid, 10 semisolid, and 10 solid swallows were analyzed using AIMplot software.

KEY RESULTS

This study demonstrated that (i) esophageal pressure-flow parameters differ with bolus type (liquid, semisolid, and solids), (ii) impedance at peak pressure parameter can discriminate normal from dysphagic subjects with high accuracy on a cut-off threshold at 2400 Ohms (kappa 0.77, sensitivity 0.83, and specificity 0.93), and (iii) nadir impedance and impedance at peak pressure highly correlate with perception of esophageal bolus flow (r = -0.65, p = 0.02; r = -0.70, p = 0.01 resp).

CONCLUSIONS & INFERENCES

This study presents novel esophageal pressure-flow variables in control subjects and in a cohort of patients with dysphagia. These variables are altered in relation to bolus consistency and can discriminate between subjects with and without symptoms of dysphagia. For the first time, we present high resolution esophageal pressure-flow variables that accurately link in with patient perception of esophageal bolus hold up.

Clinical applications of gastrointestinal manometry in children

Manometry is a noninvasive diagnostic tool for identifying motility dysfunction of the gastrointestinal tract. Despite the great technical advances in monitoring motility, performance of the study in pediatric patients has several limitations that should be considered during the procedure and interpretation of the test results. This article reviews the clinical applications of conventional esophageal and anorectal manometries in children by describing a technique for performing the test. This review will develop the uniformity required for the methods of performance, the parameters for measurement, and interpretation of test results that could be applied in pediatric clinical practice.

Recorded lower esophageal pressures as a function of electronic sleeve placement and location of gastric pressure measurement in patients with hiatal hernia

Background/Aims

In high-resolution manometry lower esophageal sphincter pressure (LESP) is measured relative to intragastric pressure, however Gastric Marker™ (GM) location used to determine resting LESP is not well established with hiatal hernia (HH). We test the hypothesis that measured resting LESP varies with HH based on GM location.

Methods

Subjects with HH ≥ 2 cm were included. The eSleeve™ was adjusted to span only the LES, excluding the crural diaphragm (CD). Resting LESP was determined by placing the GM below and above the CD (in the position yielding the highest resting LESP). Resting pressure across the lower esophageal sphincter (LES) to CD and pressure in the HH relative to subdiaphragmatic intragastric pressure were also measured.

Results

HH ≥ 2 cm was present in 98 patients (mean length 2.7 cm). LESP decreased when GM was moved from below the CD into the HH: respiratory minimum LESP 7.5 ± 1.1 to 3.6 ± 0.9 mmHg; P < 0.001, mean LESP 17.7 ± 1.3 to 13.7 ± 1.1 mmHg; P < 0.001. When the eSleeve encompassed the LES and CD, the respiratory minimum pressure was 12.2 ± 0.9 mmHg and mean pressure was 23.9 ± 1.0 mmHg pressure (P < 0.001 for both). Pressure in the hernia pouch was greater than intragastric pressure: respiratory minimum 3.0 ± 0.7 mmHg and mean 9.0 ± 0.8 mmHg (P < 0.001 for both). pH studies showed a trend toward an association between abnormal distal esophagus acid exposure and lower resting LESP.

Conclusions

GM placement in the HH produces lower resting LESPs. This may provide a more physiologic representation of LESP in HH.

Anorectal functional abnormalities in Egyptian children with chronic functional constipation

BACKGROUND AND STUDY AIMS

Chronic functional constipation represents 95% of the cases of paediatric constipation. Epidemiologic data, pathophysiology and anorectal functional abnormalities vary greatly among different reports across different populations. The aim of this study was to evaluate these data in Egyptian children with chronic functional constipation.

PATIENTS AND METHODS

This study included 150 children with chronic functional constipation (101 males, 49 females; mean age 6 ± 3.1 years); a control group of 50 age- and sex-matched healthy children were enrolled for standardisation of the manometry technique. A structured symptom questionnaire and clinical examination including digital rectal examination in addition to anorectal manometry were done for all included children. Defaecation dynamics were assessed in all children 5 years or older using anorectal manometry with integrated electromyogram of the external anal sphincter and the puborectalis muscle.

RESULTS

The maximal tolerable volume was significantly higher in the constipated children than in the control group (p=0.03). No significant differences existed between constipated and control children regarding other anorectal manometric parameters. Abnormal defaecation dynamics were detected in 35 out of 95 tested patients (36.8%).

CONCLUSION

Increased maximal tolerable volume is the most striking manometric feature in Egyptian children with chronic functional constipation. Abnormal defaecation dynamics were detected in about one-third of the tested patients. Standardisation of the measurement techniques and obtaining normal ranges for anorectal manometric parameters for each laboratory are recommended.

Surgical treatment for nonspecific esophageal motility disorders

PURPOSE

Nonspecific esophageal motility disorder (NEMD) is a vague category that includes patients with poorly defined contraction abnormalities observed during esophageal manometry. This study investigated the therapeutic effects of the video-assisted thoracoscopic surgery (VATS) approach using long myotomy and fundopexy for NEMD.

METHODS

The VATS approach using myotomy and fundopexy was performed for 4 patients of NEMD between 2005 and 2008. A total of 4 patients with NEMD that underwent treatment at our institution were analyzed retrospectively.

RESULTS

The patients included 2 males and 2 females with a median age of 48 years (range 21-74 years). The median duration of NEMD symptoms was 58 months (range 4-108 months). Dysphagia was a primary symptom in all patients. Chest pain was a primary symptom in 3 of 4 patients (75 %). Treatment with medication was attempted before the operation. The median operative time was 344.5 min (range 210-476 min). The median time before starting oral feeding was 2.5 days (range 2-22 days). All patients achieved a significant improvement of their previous condition.

CONCLUSIONS

The VATS approach using myotomy and fundopexy for NEMD is a good treatment in cases resistant to medication and balloon dilation.

Diagnostic utility of the oesophageal balloon distension test in the evaluation of oesophageal chest pain

BACKGROUND

Oesophageal balloon distension test (EBDT) has been advocated for the evaluation of functional oesophageal noncardiac chest pain (NCCP), but its diagnostic utility remains unclear.

AIM

To prospectively assess the diagnostic yield of EBDT in clinical practice and compare its yield with standard oesophageal tests.

METHODS

Over a period of 6 years, patients with chest pain and negative cardiac work-up underwent sequential testing with endoscopy/biopsy, oesophageal manometry, 24 h pH study and EBDT to elucidate an oesophageal source for their symptoms. Patients with a definite abnormality, for example, erosive oesophagitis on oesophagogastroduodenoscopy (EGD) were designated as having positive test and excluded from further work up.

RESULTS

Of 348 (m/f = 105/243) suspected NCCP patients, 16 (5%) were excluded; 332 (95%) underwent oesophageal testing. Among these, 48 (14%) had macro/microscopic oesophagitis on endoscopy, 7 (2%) had achalasia and 96 (28%) had excessive acid reflux (pH study). The remaining 181 (52%) patients underwent EBDT; 128 (37%) had oesophageal hypersensitivity. Chest pain was reproduced in 97/128 (75%) subjects. There were no adverse effects.

CONCLUSIONS

Oesophageal testing can reveal an oesophageal source for chest pain in 86% of NCCP subjects. The majority (42%) of patients had gastro-oesophageal reflux disease (GERD). Oesophageal balloon distension test identified hypersensitivity in over one-third of subjects. The oesophageal balloon distension test provides useful diagnostic information and should be performed routinely in patients with NCCP after excluding GERD.

Evaluation of the esophagogastric junction using high resolution manometry and esophageal pressure topography

BACKGROUND

The assessment of the esophagogastric junction (EGJ) is the most challenging aspect of clinical esophageal manometry. Although conventional manometric systems can be optimized toward interrogating specific aspects of the EGJ, they are too limited in recording channels and/or fidelity for a comprehensive assessment. The technological advantages inherent in high resolution manometry (HRM) with esophageal pressure topography (EPT) analysis substantially change this equation providing a technology sufficiently robust to dynamically record the contractile activity within the EGJ with both good fidelity and good spatial resolution.

PURPOSE

This review is an update on our understanding of the application of HRM and EPT to the analysis of EGJ function. With respect to sphincter relaxation, the integrated relaxation pressure (IRP) has proven to be a robust metric in differentiating intact from impaired EGJ relaxation. In the process, it revealed that impaired EGJ relaxation could occur not only in the setting of achalasia but also with other causes of EGJ outflow obstruction including hiatus hernia. The morphological description of the EGJ by EPT has also revealed not only a spectrum of abnormality ranging from an intact sphincter to overt herniation, but also the surprise finding of spontaneous conversion among sphincter configurations, emphasizing its dynamic nature. With respect to barrier function, preliminary data have refocused on the crural diaphragm as a key-differentiating feature between preserved and compromised function. Finally, although the accomplishments summarized above are substantial, much work remains to fully exploit the potential of EPT in the clinical characterization of the EGJ.

Recent advances in noncardiac chest pain in Korea

Gastroesophageal reflux disease (GERD) is the most common cause of noncardiac chest pain (NCCP) and is present in up to 60% of patients with NCCP in Western countries. In Korea, after a reasonable cardiac evaluation, GERD is reported to underlie 41% of NCCP cases. Typical reflux symptoms are frequent in Korean patients suffering from NCCP. Therefore, a careful history of the predominant symptoms, including heartburn and acid regurgitation, is relatively indicative of the GERD diagnosis in Korea. In Korea, in contrast to Western countries, patients aged 40 years and over who have been diagnosed with NCCP but who are without alarming features should undergo endoscopy to exclude gastric cancer or peptic ulcers because of the higher prevalence of peptic ulcer disease and gastric cancers in the region. In a primary care setting, in the absence of any alarming symptoms, a symptomatic response to a trial of a proton pump inhibitor (PPI) is sufficient for the presumptive diagnosis of GERD. In addition, the optimal duration of a PPI test may be at least 2 weeks, as GERD symptoms tend to be less frequent or atypical in Korean patients than in patients from Western countries. In patients diagnosed with GERD-related NCCP, long-term therapy (more than 2 months) with double the standard dose of a PPI is required to alleviate symptoms. Esophageal dysmotility is relatively uncommon, and pain modulators seem to offer significant improvement of chest pain control in non-GERD-related NCCP. Most traditionally available tricyclics or heterocyclics have many undesirable effects. Therefore, newer drugs with fewer side effects (for example, the serotonin - norepinephrine reuptake inhibitors) may be needed.

THE BIOMECHANICAL BEHAVIOR OF SPHINCTERS: HOW THE THEORY AND THE PRACTICE MISMATCH

Monitoring sphincter activity presents remarkable methodological and conceptual problems. The particular shape, structure and function of the sphincters require an accurate analysis of the objectives of diagnostic procedures and the physical concepts applied. Researchers have developed practical solutions to the description of the sphincter activity not always rigorous on a theoretical basis, and the measurement results are difficult to evaluate and compare, in the event that the contour conditions of the assumed descriptive model are not well defined. A practical solution is to "create" a constant curvature radius chamber by introducing a cylinder within the sphincter and measuring the pressure, linearly proportional to the tangential force strength of the wall. This paper analyzes the coherence between the theoretical basis and the practical solutions of the different methods of sphincter monitoring, to clarify some controversial aspects, highlight the limitations and to suggest possible alternative solutions.

Is the schatzki ring a unique esophageal entity?

AIM: To study, whether the association of Schatzki rings with other esophageal disorders support one of the theories about its etiology.

METHODS: From 1987 until 2007, all patients with newly diagnosed symptomatic Schatzki rings (SRs) were prospectively registered and followed. All of them underwent structured interviews with regards to clinical symptoms, as well as endoscopic and/or radiographic examinations. Endoscopic and radiographic studies determined the presence of an SR and additional morphological abnormalities.

RESULTS: One hundred and sixty-seven patients (125 male, 42 female) with a mean age of 57.1 ± 14.6 years were studied. All patients complained of intermittent dysphagia for solid food and 113 (79.6%) patients had a history of food impaction. Patients experienced symptoms for a mean of 4.7 ± 5.2 years before diagnosis. Only in 23.4% of the 64 patients who had endoscopic and/or radiological examinations before their first presentation to our clinic, was the SR previously diagnosed. At presentation, the mean ring diameter was 13.9 ± 4.97 mm. One hundred and sixty-two (97%) patients showed a sliding hiatal hernia. Erosive reflux esophagitis was found in 47 (28.1%) patients. Twenty-six (15.6%) of 167 patients showed single or multiple esophageal webs; five (3.0%) patients exhibited eosinophilic esophagitis; and four (2.4%) had esophageal diverticula. Four (7%) of 57 patients undergoing esophageal manometry had non-specific esophageal motility disorders.

CONCLUSION: Schatzki rings are frequently associated with additional esophageal disorders, which support the assumption of a multifactorial etiology. Despite typical symptoms, SRs might be overlooked.

Weak peristalsis in esophageal pressure topography: classification and association with Dysphagia

OBJECTIVES

Esophageal manometry is frequently used to assess for weak peristalsis. Although commonly used clinically, there are currently no validated metrics of weak peristalsis in high-resolution esophageal pressure topography (EPT). This study aimed to develop a classification of weak peristalsis in EPT based on a comparative analysis of control subjects and patients with unexplained non-obstructive dysphagia.

METHODS

High-resolution esophageal pressure topography (high-resolution impedance manometry) studies were carried out in 16 control subjects to verify EPT features associated with incomplete bolus transit (IBT). The technique of superimposing EPT plots in a computer simulation was used to derive normal limits of peristaltic integrity in EPT in another 75 control subjects. The occurrence of critical EPT defects was then compared between control subjects and 113 patients with non-obstructive dysphagia identified from a large clinical series.

RESULTS

IBT occurred with failed peristalsis or with breaks in the 20 mm Hg isobaric contour occurring at the proximal or distal pressure troughs in EPT plots. The normal range for isobaric contour breaks was 0-20% for large (>5 cm) and 0-30% for small (2-5 cm) breaks, with both occurring significantly more frequently in dysphagic patients. Failed peristalsis was not more frequent in dysphagic patients.

CONCLUSIONS

A classification of weak peristalsis adapted to EPT is proposed based on the occurrence of breaks in the 20 mm Hg isobaric contour wherein weak peristalsis with large breaks is defined by those occurring with >20% of swallows and weak peristalsis with small breaks defined by those occurring with >30% of swallows.

Pathological bolus exposure plays a significant role in eliciting non-cardiac chest pain

BACKGROUND AND AIM

Pathological bolus exposure is defined in the present study as cases in which all reflux percentage times are above 1.4% of the total reflux number, as revealed by impedance-pH monitoring. The role of pathological bolus exposure in the pathogenesis of non-cardiac chest pain (NCCP) is poorly known. We aimed to classify and characterize NCCP using combined impedance-pH monitoring.

METHODS

Seventy-five consecutive patients with NCCP were prospectively enrolled from January 2006 to October 2008. All the patients underwent upper endoscopy, esophageal manometry, and 24-h multichannel intraluminal impedance (MII)-pH metering.

RESULTS

Sixteen patients (21.3%) had esophageal erosion upon endoscopy. Upon esophageal manometry, 37 patients (49.3%) had esophageal dysmotility. When the patients were classified based on MII-pH metering, 16 (21.3%) showed pathological acid exposure, and 40 (53.3%) showed pathological bolus exposure. The DeMeester score of patients with pathological acid exposure was higher than that of patients with pathological bolus exposure (P = 0.002). There was no significant difference in age, sex, typical esophageal symptoms, presence of esophageal erosion, esophageal dysmotility, improvement with proton pump inhibitor medication, symptom index ≥ 50%, percentage of time clearance pH below 4 ≥ 4%, and all reflux time ≥ 1.4% in the fasting period between the two groups. When the patients were divided into gastroesophageal reflux disease (GERD)-related NCCP and non-GERD-related NCCP groups based on MII-pH metering and upper endoscopy, there was no difference between the two groups.

CONCLUSIONS

Combined impedance-pH monitoring improves the detection and characterization of NCCP. This study suggests that pathological bolus exposure plays a major role in eliciting NCCP.

Clinical distinct features of noncardiac chest pain in young patients

Background/Aims

Noncardiac chest pain (NCCP) is a very common disorder world-wide and gastroesophageal reflux disease (GERD) is known to be the most common cause. The prevalence of NCCP may tend to decrease with increasing age. However, there is little report about young aged NCCP. The aim of this study was to examine the prevalence of GERD and to evaluate the efficacy of proton pump inhibitor (PPI) test in the young NCCP patients.

Methods

Thirty patients with at least weekly NCCP less than 40 years were enrolled. The baseline symptoms were assessed using a daily symptom diary for 14 days. Esophago-gastro-duodenoscopy (EGD) and 24 hr esophageal pH monitoring were performed for the diagnosis of GERD and esophageal manometry was done. Then, patients were tried with lansoprazole 30 mg twice daily for 14 days, considering positive if a symptom score improved ≥ 50% compared to the baseline.

Results

Nine (30%) of the patients were diagnosed with GERD at EGD and/or 24 hr esophageal pH monitoring, also, 3 (10%) were diagnosed with GERD-associated esophageal motility disorder and 3 (10%) were non GERD-associated. Concerning PPI test, GERD-related NCCP had a higher positive PPI test (n = 8, 89%) than non GERD-related NCCP (n = 5, 24%) (p = 0.002).

Conclusions

In young patients with NCCP, a prevalence of GERD diagnosed using EGD and/or 24 hr esophageal pH monitoring was 30%. PPI test was very predictable on diagnosis of GERD-related NCCP, thus, PPI test in young NCCP patients may assist to the physician's clinical judgment of NCCP.

High-resolution esophageal manometry: using technical advances for clinical advantages

BACKGROUND

High-resolution manometry (HRM) is a new technique to investigate the motor function of the esophagus. It differs from conventional manometry in recording pressures by solid state microtransducers at 12 points around the circumference at every centimeter of esophageal length, and displaying the data in pseudo-three-dimensional format using a topographic plot, where esophageal pressures within a given range are represented by different colors.

RATIONALE

The large amount of data and the capacity to analyze and display it intuitively has afforded many new insights into esophageal dysfunction. Among these insights are the ability to distinguish three different subtypes of achalasia and predict their response to therapy, better understanding of the relationship between the lower esophageal sphincter (LES) and the crural diaphragm, the development of novel quantitative parameters to understand the nature of the dysfunction in non-specific esophageal motor disorders, and the elucidation of a newly described motility disorder characterized by failure of peristalsis at the transitional zone between the upper skeletal muscle and the more distal smooth muscle portion of the esophagus. It is also ideally suited to analysis of the effect of prokinetic medications. The method is quicker and less uncomfortable for patients and the analysis is visually appealing and intuitively comprehensible.

CONCLUSION

Despite these potential advantages, there are currently no data to demonstrate a clinical advantage in treatment. The results of such studies will be crucial to the acceptance of this novel technology.

Functional esophagogastric junction obstruction with intact peristalsis: a heterogeneous syndrome sometimes akin to achalasia

BACKGROUND

Some patients with suspected achalasia are found on manometry to have preserved peristalsis, thereby excluding that diagnosis. This study evaluated a series of such patients with functional esophagogastric junction (EGJ) obstruction.

METHODS

Among 1,000 consecutive high-resolution manometry studies, 16 patients had functional EGJ obstruction characterized by impaired EGJ relaxation and intact peristalsis. Eight patients with post-fundoplication dysphagia and similarly impaired EGJ relaxation were studied as a comparator group with mechanical obstruction. Intrabolus pressure (IBP) was measured 1 cm proximal to the EGJ. Sixty-eight normal controls were used to define normal IBP. Patients' clinical features were evaluated.

RESULTS

Functional EGJ obstruction patients presented with dysphagia (96%) and/or chest pain (42%). IBP was significantly elevated in idiopathic and post-fundoplication dysphagia patients versus controls. Among the idiopathic EGJ obstruction group treated with pneumatic dilation, BoTox(TM), or Heller myotomy, only the three treated with Heller myotomy responded well. Among the post-fundoplication dysphagia patients, three of four responded well to redo operations.

CONCLUSION

Functional EGJ obstruction is characterized by pressure topography metrics demonstrating EGJ outflow obstruction of magnitude comparable to that seen with post-fundoplication dysphagia. Affected patients experience dysphagia and/or chest pain. In some cases, functional EGJ obstruction may represent an incomplete achalasia syndrome.

High-resolution manometry in clinical practice: utilizing pressure topography to classify oesophageal motility abnormalities

High-resolution manometry capable of pressure monitoring from the pharynx to the stomach together with pressure topography plotting represents an unquestionable evolution in oesophageal manometry. However, with this advanced technology come challenges and one of those is devising the optimal scheme to apply high-resolution oesophageal pressure topography (HROPT) to the clinical evaluation of patients. The first iteration of the Chicago classification was based on a systematic analysis of motility patterns in 75 control subjects and 400 consecutive patients. This review summarizes the analysis process as it has evolved. Individual swallows are analysed in a stepwise fashion for the morphology of the oesophagogastric junction (OGJ), the extent of OGJ relaxation, the propagation velocity of peristalsis, the vigour of the peristaltic contraction, and abnormalities of intrabolus pressure utilizing metrics that have now been customized to HROPT. These results are then synthesized into a comprehensive diagnosis that, although based on conventional manometry criteria, is also customized to HROPT measures. The resultant classification objectifies the identification of three unique subtypes of achalasia. Additionally, it provides enhanced detail in the description of distal oesophageal spasm, nutcracker oesophagus subtypes, and OGJ obstruction. It is our expectation that modification of this classification scheme will continue to occur and this should further clarify the utility of pressure topography plotting in assessing oesophageal motility disorders.

Utility of non-endoscopic investigations in the practical management of oesophageal disorders

The current available methods for diagnosis of GORD are symptom questionnaires, catheter and wireless pH-metry, impedance-pH monitoring and Bilitec(@). Osophageal pH monitoring allows both quantitative analysis of acid reflux and assessment of reflux-symptom association. Impedance-pH monitoring detects all types of reflux (acid and non-acid) and allows assessment of proximal extent of reflux, a relevant parameter for understanding symptoms perception and extraoesophageal symptoms. Bilitec provides a quantitative assessment of duodeno-gastro-oesophageal reflux. Oesophageal motor abnormalities have been associated with GORD symptoms as well as chest pain and dysphagia. High-resolution manometry contributed to re-classify oesphageal motor disorders. However, barium swallows are still essential for evaluation of oesophageal anatomy and combined oesophageal manometry-impedance can assess oesophageal motility and bolus transit simultaneously in a non-radiological way. Still in experimental phase, high-frequency ultrasound allows monitoring of the oesophageal wall thickness and exaggerated longitudinal muscle contraction that might be associated to chest pain and dysphagia. This chapter provides a critical evaluation of the clinical application of these techniques.

Endoscopic CO2 laser cricopharyngeal myotomy

OBJECTIVES

Over the past 10 years, endoscopic cricopharyngeal myotomy laser surgery has been proposed as an alternative to transcervical cricopharyngeal myotomy. We will describe the technique and review the literature so that it may gain credence as a viable option for the treatment of cricopharyngeal achalasia.

METHODS

A literature review of endoscopic and transcervical cricopharyngeal myotomy will be performed. The technical aspects of endoscopic cricopharyngeal myotomy will be presented and accompanied by intraoperative photographs, illustrations, and an online video demonstration.

RESULTS

Endoscopic cricopharyngeal myotomy is a well-tolerated procedure with low morbidity and good outcomes. It can be performed by surgeons who are comfortable with transoral laryngopharyngeal laser surgery.

CONCLUSIONS

Endoscopic cricopharyngeal myotomy is a viable alternative to classic transcervical cricopharyngeal myotomy with equivalent outcomes and comparable if not less morbidity.

Manometric study of lower esophageal sphincter in children with primary acid gastroesophageal reflux and acid gastroesophageal reflux secondary to food allergy

PURPOSE

The comparison of values of selected lower esophageal sphincter (LES) manometric parameters measured in children suspected of gastroesophageal reflux disease (GERD) (preliminary study) and in children with primary acid GER and acid GER secondary to cow's milk allergy and/or other food (CMA/FA) in relation to the duration of the disease (prospective study).

MATERIAL AND METHODS

A 24-hour esophageal pH monitoring was performed on 264 children of both sexes suspected of GERD (mean age x=20.78+/-17.23 months). Pathological acid gastroesophageal reflux (GER) was diagnosed and divided into primary and secondary reflux in 138 children (52.3%). 76 patients (28.8%) (x=25.2+/-27.28 months) with primary GER made up Group 1. Group 2 consisted of 62 patients (23.5%) (x=21.53+/-17.79 months) with GER secondary to CMA/FA. 32 patients (12.1%) (x=23.7+/-12.63 months) with CMA/FA symptoms made up Group 3 (reference group). Prospective assessment of LES manometric parameters, i.e. resting LES pressure and LES length, was performed on 138 children with GER. Manometric parameters, resting LES pressure and LES length, measured at the preliminary study (0) and control studies (after 1, 2 and 8 years), were prospectively assessed in 138 children. The assessment resulted from clinical observation and/or conservative treatment.

RESULTS

The mean value of resting LES pressure (mm Hg) before treatment was x=11.75+/-3.98 in Group 1, x=11.05+/-3.31 in Group 2, and x=14.17+/-3.86 in Group 3 (reference group). After 2 years of clinical observation, the mean value of resting LES pressure accounted for x=13.71+/-3.88 in Group 1, x=13.01+/-2.94 in Group 2, and x=17.92+/-3.36 in Group 3. The mean LES length (cm) before treatment accounted for x=1.68+/-0.72 in Group 1, x=1.78+/-0.70 in Group 2, and x=2.0+/-0.86 in Group 3. After 2 years of clinical observation, the mean LES length was x=2.80+/-0.40 in Group 1, x=2.76+/-0.40 in Group 2, and x=2.97+/-0.48 in Group 3. 12 children with persistent GERD (Group 1) and 8 children with persistent GERD and food allergy (Group 2) underwent manometric evaluation of LES after 8 years. No statistical differentiation of the mean values of resting LES pressure and LES length were shown in examined children of Groups 1 and 2 during prospective studies.

CONCLUSIONS

Manometric studies of LES assessing only resting LES pressure and its length in the examined children with acid GER do not clearly differentiate GER into primary and secondary refluxes to food allergy.

Evaluation and management of neonatal dysphagia: impact of pharyngoesophageal motility studies and multidisciplinary feeding strategy

BACKGROUND AND OBJECTIVES

Abnormal swallowing (dysphagia) among neonates is commonly evaluated using the videofluoroscopic swallow study (VSS). Radiological findings considered high risk for administration of oral feeding include nasopharyngeal reflux, laryngeal penetration, aspiration, or pooling. Our aims were to determine pharyngoesophageal motility correlates in neonates with dysphagia and the impact of multidisciplinary feeding strategy.

METHODS

Twenty dysphagic neonates (mean gestation +/- standard deviation [SD] = 30.9 +/- 4.9 weeks; median 31.1 weeks; range = 23.7-38.6 weeks) with abnormal VSS results were evaluated at 49.9 +/- 16.5 weeks (median 41.36 weeks) postmenstrual age. The subjects underwent a swallow-integrated pharyngoesophageal motility assessment of basal and adaptive swallowing reflexes using a micromanometry catheter and pneumohydraulic water perfusion system. Based on observations during the motility study, multidisciplinary feeding strategies were applied and included postural adaptation, sensory modification, hunger manipulation, and operant conditioning methods. To discriminate pharyngoesophageal manometry correlates between oral feeders and tube feeders, data were stratified based on the primary feeding method at discharge, oral feeding versus tube feeding.

RESULTS

At discharge, 15 of 20 dysphagic neonates achieved oral feeding success, and the rest required chronic tube feeding. Pharyngoesophageal manometry correlates were significantly different (P < 0.05) between the primary oral feeders versus the chronic tube feeders for swallow frequency, swallow propagation, presence of adaptive peristaltic reflexes, oral feeding challenge test results, and upper esophageal sphincter tone. VSS results or disease characteristics had little effect on the feeding outcomes (P = NS).

CONCLUSIONS

Swallow-integrated esophageal motility studies permit prolonged evaluation of swallowing reflexes and responses to stimuli under controlled conditions at cribside. The dysfunctional neuromotor mechanisms may be responsible for neonatal dysphagia or its consequences. Manometry may be a better predictor than VSS in identifying patients who are likely to succeed in vigorous intervention programs.

A descriptive investigation of dysphagia in adults with intellectual disabilities

BACKGROUND

Dysphagia has rarely been investigated in adults with intellectual disabilities (ID) despite being a serious condition affecting health and quality of life.

METHOD

This study collected information about 101 adults with ID, living in community settings, referred for an assessment of their eating and drinking. Ninety-nine people were classified as having dysphagia from clinical and videofluoroscopic assessments. This information was used to give an indication of the prevalence of dysphagia in adults with ID and identify the co-occurrence of physiological and anatomical indicators and associated negative health conditions.

RESULTS

Details of the characteristics and conditions associated with dysphagia are provided. These include cerebral palsy, increased physical disability and cognitive impairment. A tentative indication of the current prevalence of dysphagia was found (8.15%).

CONCLUSION

Findings indicate that dysphagia is a significant issue for people with ID warranting further investigation. Practice implications detailed include increasing awareness of 'at risk' groups, changes in dysphagia with ageing, medication use and illness, and how findings can inform assessment and training.

High-resolution manometry and impedance-pH/manometry: valuable tools in clinical and investigational esophagology

Both high-resolution manometry (HRM) and impedance-pH/manometry monitoring have established themselves as research tools and both are now emerging in the clinical arena. Solid-state HRM capable of simultaneously monitoring the entire pressure profile from the pharynx to the stomach along with pressure topography plotting represents an evolution in esophageal manometry. Two strengths of HRM with pressure topography plots compared with conventional manometric recordings are (1) accurately delineating and tracking the movement of functionally defined contractile elements of the esophagus and its sphincters, and (2) easily distinguishing between luminal pressurization attributable to spastic contractions and that resultant from a trapped bolus in a dysfunctional esophagus. Making these distinctions objectifies the identification of achalasia, distal esophageal spasm, functional obstruction, and subtypes thereof. Ambulatory intraluminal impedance pH monitoring has opened our eyes to the trafficking of much more than acid reflux through the esophageal lumen. It is clear that acid reflux as identified by a conventional pH electrode represents only a subset of reflux events with many more reflux episodes being composed of less acidic and gaseous mixtures. This has prompted many investigations into the genesis of refractory reflux symptoms. However, with both technologies, the challenge has been to make sense of the vastly expanded datasets. At the very least, HRM is a major technological tweak on conventional manometry, and impedance pH monitoring yields information above and beyond that gained from conventional pH monitoring studies. Ultimately, however, both technologies will be strengthened as outcome studies evaluating their utilization become available.

Ineffective oesophageal motility: Manometric subsets exhibit different symptom profiles

AIM: To compare the demographic and clinical features of different manometric subsets of ineffective oesophageal motility (IOM; defined as ≥ 30% wet swallows with distal contractile amplitude < 30 mmHg), and to determine whether the prevalence of gastro-oesophageal reflux differs between IOM subsets.

METHODS: Clinical characteristics of manometric subsets were determined in 100 IOM patients (73 female, median age 58 years) and compared to those of 100 age-and gender-matched patient controls with oesophageal symptoms, but normal manometry. Supine oesophageal manometry was performed with an eight-channel DentSleeve water-perfused catheter, and an ambulatory pH study assessed gastro-oesophageal reflux.

RESULTS: Patients in the IOM subset featuring a majority of low-amplitude simultaneous contractions (LASC) experienced less heartburn (prevalence 26%), but more dysphagia (57%) than those in the IOM subset featuring low-amplitude propagated contractions (LAP; heartburn 70%, dysphagia 24%; both P≤ 0.01). LASC patients also experienced less heartburn and more dysphagia than patient controls (heartburn 68%, dysphagia 11%; both P < 0.001). The prevalence of heartburn and dysphagia in IOM patients featuring a majority of non-transmitted sequences (NT) was 54% (P = 0.04 vs LASC) and 36% (P < 0.01 vs controls), respectively. No differences in age and gender distribution, chest pain prevalence, acid exposure time (AET) and symptom/reflux association existed between IOM subsets, or between subsets and controls.

CONCLUSION: IOM patients with LASC exhibit a different symptom profile to those with LAP, but do not differ in gastro-oesophageal reflux prevalence. These findings raise the possibility of different pathophysiological mechanisms in IOM subsets, which warrants further investigation.

Esophageal motility disorders in terms of pressure topography: the Chicago Classification

Two recent advances have revolutionized the performance of clinical esophageal manometry; the introduction of practical high resolution manometry (HRM) systems and the development of sophisticated algorithms to display the expanded manometric dataset as pressure topography plots. We utilized a large clinical experience of 400 consecutive patients and 75 control subjects to develop a systematic approach to analyzing esophageal motility using HRM and pressure topography plots. The resultant classification scheme has been named as the Chicago Classification of esophageal motility. Two strengths of pressure topography plots compared with conventional manometric recordings were the ability to (1) delineate the spatial limits, vigor, and integrity of individual contractile segments along the esophagus and (2) to distinguish between loci of compartmentalized intraesophageal pressurization and rapidly propagated contractions. Making these distinctions objectified the identification of distal esophageal spasm, vigorous achalasia, functional obstruction, and nutcracker esophagus subtypes. Applying these distinctions made the diagnosis of spastic disorders quite rare: spasm in 1.5% of patients, vigorous achalasia in 1.5%, and a newly defined entity, spastic nutcracker, in 1.5%. Ultimately, further clinical experience will be the judge, but it is our expectation that pressure topography analysis of HRM data, along with its well-defined functional implications, will prove valuable in the clinical management of esophageal motility disorders.

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.

Dorsal motor nucleus of the vagus: a site for evoking simultaneous changes in crural diaphragm activity, lower esophageal sphincter pressure, and fundus tone

The sphincter mechanism at the esophagogastric junction includes smooth muscle of the lower esophagus and skeletal muscle of the crural diaphragm (CD). Smooth muscle is known to be under the control of the dorsal motor nucleus of the vagus (DMV), while central nervous system (CNS) control of the CD is unknown. The main purposes of our study were to determine the CNS site that controls the CD and whether simultaneous changes in lower esophageal sphincter (LES) pressure and CD activity occur when this site is activated. Experiments were performed on anesthetized male ferrets whose LES pressure, CD activity, and fundus tone were monitored. To activate DMV neurons, L-glutamate was microinjected unilaterally into the DMV at three areas: intermediate, rostral, and caudal. Stimulation of the intermediate DMV decreased CD activity (-4.8 +/- 0.1 bursts/min and -0.3 +/- 0.01 mV) and LES pressure (-13.2 +/- 2.0 mmHg; n = 9). Stimulation of this brain site also produced an increase in fundus tone. Stimulation of the rostral DMV elicited increases in the activity of all three target organs (n = 5). Stimulation of the caudal DMV had no effect on the CD but did decrease both LES pressure and fundus tone (n = 5). All changes in LES pressure, fundus tone, and some DMV-induced changes in CD activity (i.e., bursts/min) were prevented by ipsilateral vagotomy. Our data indicate that simultaneous changes in activity of esophagogastric sphincters and fundus tone occur from rostral and intermediate areas of the DMV and that these changes are largely mediated by efferent vagus nerves.

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

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

Non-achalasic motor disorders of the oesophagus

Motor abnormalities of the oesophagus are characterised by a chronic impairment of the neuromuscular structures that co-ordinate oesophageal function. The best-defined entity is achalasia, which is discussed in a separate chapter. Other motor disorders with clinical relevance include diffuse oesophageal spasm, oesophageal dysmotility associated with scleroderma, and ineffective oesophageal motility. These non-achalasic motor disorders have variable prevalence but they could be associated with invalidating symptoms such as dysphagia, chest pain and gastro-oesophageal reflux disease. New oesophageal diagnostic techniques, including high-resolution manometry, high-frequency intraluminal ultrasound and intraluminal impedance, allow (1) better definition of peristalsis and sphincter function, (2) assessment of changes in oesophageal wall thickness, and (3) evaluation of pressure gradients within the oesophagus and across the sphincters that can produce normal or abnormal patterns of bolus transport. This chapter discusses recent advances in physiology, pathophysiology, diagnosis and treatment of non-achalasic oesophageal motor disorders.