Oesophageal high-resolution manometry: moving from research into clinical practice

Manometry measures pressure within the oesophageal lumen and sphincters, and provides an assessment of the neuromuscular activity that dictates function in health and disease. It is performed to investigate the cause of functional dysphagia, unexplained "non-cardiac" chest pain, and in the pre-operative work-up of patients referred for anti-reflux surgery. Manometric techniques have improved in a step-wise fashion from a single pressure channel to the development of high-resolution manometry (HRM) with up to 36 pressure sensors. At the same time, advances in computer processing allow pressure data to be presented in real time as a compact, visually intuitive "spatiotemporal plot" of oesophageal pressure activity. HRM recordings reveal the complex functional anatomy of the oesophagus and its sphincters. Spatiotemporal plots provide objective measurements of the forces that move food and fluid from the pharynx to the stomach and determine the risk of reflux events. The introduction of commercially available HRM has been followed by rapid uptake of the technique. This review examines the current evidence that supports the move of HRM from the research setting into clinical practice. It is assessed whether a detailed description of pressure activity identifies clinically relevant oesophageal dysfunction that is missed by conventional investigation, increasing diagnostic yield and accuracy. The need for a new classification system for oesophageal motor activity based on HRM recordings is discussed. Looking ahead the potential of this technology to guide more effective medical and surgical treatment of oesophageal disease is considered because, ultimately, it is this that will define the success of HRM in clinical practice.

Mechanisms of acid, weakly acidic and gas reflux after anti-reflux surgery

BACKGROUND

Whereas it is well documented that fundoplication reduces acid reflux, the effects of the procedure on non-acid and gas reflux and the mechanisms through which this is achieved have not been fully elucidated.

METHODS

In 14 patients, reflux was measured with impedance-pH monitoring during a postprandial 90 min stationary recording period before and 3 months after fundoplication. Concomitantly, the occurrence of transient lower oesophageal sphincter relaxations (TLOSRs) and morphology of the oesophagogastric junction were studied with high-resolution manometry. This was followed by 24 h ambulatory impedance-pH monitoring.

RESULTS

Before fundoplication, two separate high-pressure zones (hernia profile) were detected during 24.9% of total time, during which there was a large increase in reflux rate. After fundoplication, the hernia profile did not occur. Fundoplication decreased the number of TLOSRs (from 10.5 (SEM 1.2) to 4.5 (0.7), p<0.01) and also the percentage of TLOSRs associated with acidic or weakly acidic reflux (from 72.7% to 4.1%, p<0.01). Nadir pressure during TLOSRs increased after surgery (from 0 (0-0) to 1.0 (1-2) kPa, p<0.05). In the ambulatory study, there was a large decrease in prevalence of both acid (-96%, from 47.0 (5.9) to 1.8 (0.5), p<0.01) and weakly acidic reflux (-92%, from 25.0 (9.7) to 2.3 (0.9), p<0.01). The decrease in gas reflux was less pronounced (-53%, from 24.2 (4.9) to 11.3 (3.0), p<0.01).

CONCLUSIONS

Fundoplication greatly reduces both acid and weakly acidic liquid reflux; gas reflux is reduced to a lesser extent. Three mechanisms play a role: (1) abolition of the double high-pressure zone profile (hiatal hernia); (2) reduced incidence of TLOSRs; and (3) decreased percentage of TLOSRs associated with reflux.

Effects of age on the gastroesophageal junction, esophageal motility, and reflux disease

BACKGROUND & AIMS

The prevalence of complicated gastroesophageal reflux disease (GERD) increases with age; however, the mechanism by which this occurs is uncertain. This study assessed (1) whether physiologic degradation of the gastroesophageal junction and esophageal motility occurs with aging, and (2) whether these effects are associated with increased esophageal acid exposure and reflux symptoms in the elderly.

METHODS

Retrospective study of 1307 patients referred for investigations of reflux symptoms (median age, 49 years; range, 15-92 years) was conducted. Manometry assessed LES pressure, LES length, and esophageal peristalsis. Ambulatory pH studies assessed esophageal acid exposure (% time pH <4) during a period of 24 hours; reflux symptoms were assessed by validated questionnaire.

RESULTS

On multivariate regression, esophageal acid exposure was associated independently with decreasing LES pressure (P < .0001) and abdominal LES length (P < .0004). Dysmotility exacerbated reflux in the recumbent position (P < .004). Acid exposure increased with age (P < .0001), a 1.1%/24 hours (95% confidence interval, 0.4%-1.4%) increase in acid exposure every decade (more pronounced in the recumbent position). The age-related increase in acid exposure was associated independently with decreasing abdominal LES length (P < .001) and increasing dysmotility (P < 0.01). Reflux symptoms increased with acid exposure (P < .001); however, at any given level of exposure, symptom severity was less in the elderly (P < .006).

CONCLUSIONS

Age was associated with an increase in esophageal acid exposure; however, the severity of reflux symptoms reduced with age. These changes were associated with progressive decrease in abdominal LES length and esophageal motility. Increasing GERD severity in the elderly is related to degradation of the gastroesophageal junction and impaired esophageal clearance.

Influence of radiofrequency energy delivery at the gastroesophageal junction (the Stretta procedure) on symptoms, acid exposure, and esophageal sensitivity to acid perfusion in gastroesophagal reflux disease

Several studies have demonstrated that radiofrequency energy delivery at the gastroesophageal junction (the Stretta procedure) induces symptom relief in gastroesophageal reflux disease (GERD), although improvement of acid exposure on pH monitoring was usually limited. A role for decreased esophageal sensitivity has been suggested. Our aim was to evaluate the influence of Stretta on symptoms, acid exposure, and sensitivity to esophageal acid perfusion in GERD. Thirteen patients with established proton pump inhibitor (PPI)-dependent GERD (three males; mean age, 51+/-10 years) participated in the study. Before and 6 months after the procedure symptom score, pH monitoring and Bernstein acid perfusion test were performed. The latter was done by infusing HCl (pH 0.1) at a rate of 6 ml/min 15 cm proximal to the gastroesophageal junction for a maximum of 30 min or until the patients experienced heartburn. Results were compared by Student's t-test. Stretta procedure time was 51+/-4 min and no complications occurred. After 6 months, the symptom score was significantly improved (12.5+/-2.0 to 7.5+/-2.1; P<0.05), seven patients no longer needed daily PPI, and acid exposure was significantly decreased (11.6%+/-1.6% to 8.5%+/-1.8% of time pH<4; P<0.05). The time needed to induce heartburn during acid perfusion decreased from 9.5+/-2.3 to 18.1+/-3.4 min (P=0.01), and five patients became insensitive to 30-min acid perfusion, versus none at baseline (P=0.04). In conclusion, the Stretta procedure induces subjective improvement of GERD symptoms and decreases esophageal acid exposure. In addition, esophageal acid sensitivity is decreased 6 months after the Stretta procedure. The mechanism underlying this finding and its relevance to symptom control require further studies.

The prevalence of Helicobacter pylori infection and the status of gastric acid secretion in patients with gastroesophageal junction adenocarcinoma in Japan

We have previously reported that H. pylori infection prevents reflux esophagitis (RE) and Barrett's esophagus (BE) by decreasing gastric acid secretion. Gastroesophageal (GE) junction adenocarcinoma, including Barrett's adenocarcinoma, has been thought to be a complication of gastroesophageal reflux disease. However, the relationship between H. pylori infection, gastric acid secretion and GE junction adenocarcinoma had not yet been investigated in Japan. We demonstrated that the status of gastric acid secretion was higher in patients with GE junction adenocarcinoma than in patients with early gastric cancer (EGC), and that the level was the same in patients with RE and those with BE. We also found that the prevalence of H. pylori infection in patients with GE junction adenocarcinoma was significantly lower than that in patients with EGC, although not as low as that in patients with RE and BE, suggesting that preservation of gastric acid secretion may be important for the development of GE junction adenocarcinoma in Japanese people, regardless of the presence of H. pylori infection.

[Comparison of the results of surgical treatment of patients suffering from gastroesophageal reflux disease with unanatomical and anatomical dysfunction of gastroesophageal junction]

The evolution of surgery of no neoplastic diseases of the gastroesophageal junction, particularly gastroesophageal reflux disease (GERD), is an unquestionable factor for further analysis of indications for treatment and treatment results. Full-symptomatic GERD with coexisting sliding hiatal hernia is an indication for surgical treatment for a long time. The question is when to operate functional disorders of the esophagus and lower esophageal sphincter (LES) and what the results of the treatment are. Aim of study was to analyze results of surgical treatment of patients with GERD on the background of functional disorders and patients with sliding and mixed hiatal hernia.

MATERIAL AND METHODS

This study retrospectively analyzed the data of 49 patients operated in Department of General, Oncological and Thoracic Surgery. Patients were divided into two groups. First group: patients with symptomatic GERD with confirmed 24 hour pH monitoring night-time and after-meal acid refluxes--23 subjects. Second group: patients with symptomatic GERD with type I and III hiatal hernia proven by gastroscopy, radiological tests and intraoperative examinations--26 subjects. There was no sign of decreased esophageal propulsive function among examined patients. For surgical intervention from the first group were qualified patients after ineffective conservative management. All patients underwent Nissen procedure--laparoscopy, hernioplasty and floppy fundoplication, and agreed on follow-up evaluation after 3, and some after 6 and 12 months which included case history, gastroscopy and 24 hour pH monitoring.

RESULTS

Operative management resulted in withdrawal of suffered subjective symptoms and remission of lesions in lower part of esophagus. 10% of the patients had LES motor activity dysfunction not qualified for surgical consultation. There was no case of recurrence of hiatal hernia.

CONCLUSIONS

Patients suffering from LES functional disorders and type I and III hiatal hernia can be effectively treated with surgical management.

[The analysis of hiatal hernia occurrence in connection with GERD]

Hiatal hernia seems to be one of the significant clinical problems. The criteria of its diagnosis, occurrence and possible influence on esophageal reflux disease are still controversial. The aim of this paper is to research the incidence of hiatal hernia based on endoscopic criteria of its diagnosis and its influence on other esophageal diseases.

MATERIAL AND METHODS

More than 729 patients, to whom endoscopy was made, were examined. The accepted endoscopic features of hiatal hernia and other lesions which could be related to it and other characteristic features of esophageal reflux disease were searched.

RESULTS

On the basis of accepted diagnostic criteria the hiatal hernia was diagnosed in 44.16% of men and in 42.77% of women. There were no difference in hiatal hernia occurrence in relation to age, gender and weight. The endoscopic features of esophageal reflux disease were found in 36.14% of women and 61.47% of men. The statistically significant incidence was observed in patients with hernia 55.99% women and 74.51% men and without hernia respectively in 22.81% and 51.16%. Similar differences took place in specific types of gastroesophageal disease, especially endoscopic features characteristic for Barrett's esophagus were observed nine times more frequently in men with hernia. Types with erosions were observed twice as much in patients with hernia of both sex. Esophagus mucosae cloudiness was observed three times more frequently in women with hernia and 50% more frequently in women.

CONCLUSIONS

All the data suggests there is a significant coincidence between hiatal hernia and esophageal reflux disease.

High-resolution manometry of the EGJ: an analysis of crural diaphragm function in GERD

AIM

High-resolution manometry (HRM) provides a spatially enhanced, dynamic representation of the esophagogastric junction (EGJ) high-pressure zone making it possible to isolate the crural diaphragm (CD) contraction from expiratory lower esophageal sphincter (LES) pressure. This study compared CD function of subjects with and without gastroesophageal reflux disease (GERD).

METHODS

A total of 75 asymptomatic controls and 156 GERD patients (EGD or pH monitoring positive) underwent HRM. The EGJ axial pressure profile was analyzed over five respiratory cycles to quantify the position and contractile vigor of the CD relative to the LES. Correlations between EGJ HRM attributes and GERD status were examined.

RESULTS

GERD patients had significantly greater CD-LES separation compared with either controls or EGD-/pH- patients. GERD patients also had significantly less inspiratory augmentation of EGJ pressure (EGD-/pH+, 11.5 +/- 1.9 mmHg; EGD+, 10.0 +/- 1.2 mmHg) compared with controls (16.9 +/- 1 mmHg) or EGD-/pH- patients (16.7 +/- 0.2 mmHg). Using a logistic regression model that simultaneously examined expiratory LES pressure, LES-CD separation, and inspiratory EGJ augmentation while controlling for age and BMI, only inspiratory augmentation had a significant independent association with GERD.

CONCLUSIONS

HRM characterization of EGJ morphology correlates with the objective demonstration of GERD. Although both LES pressure and LES-CD separation are associated with GERD, the strongest association and the only independent predictor of GERD as a categorical outcome in a logistic regression analysis was impaired CD function as indicated by reduced inspiratory augmentation of EGJ pressure.

Ösophageale Schluckstörungen

Eine ösophageale Schluckstörung oder Dysphagie kann durch eine mechanische Obstruktion, entzündliche Läsionen oder funktionell durch eine Motilitässtörung bedingt sein. Bei Dysphagie muss stets mit entsprechender Diagnostik, insbesondere der Endoskopie, das Vorliegen eines Malignoms ausgeschlossen werden. Diese Übersicht fasst die häufigsten Ursachen einer funktionell oder entzündlich bedingten Dysphagie zusammen. Symptomatik, Diagnostik und Therapie von Motilitätsstörungen des Ösophagus wie Achalasie und diffuse Ösophagusspasmen, der Refluxkrankheit als Folge einer Funktionsstörung vorwiegend des unteren Ösophagussphinkters sowie der eosinophilen Ösophagitis werden dargestellt.

Computation of flow through the oesophagogastric junction

Whilst methods exist to indirectly measure the effects of increased flow or gastro-oesophageal refluxing, they cannot quantitatively measure the amount of acid travelling back up into the oesophagus during reflux, nor can they indicate the flow rate through the oesophago-gastric junction (OGJ). Since OGJ dysfunction affects flow it seems most appropriate to describe the geometry of the OGJ and its effect on the flow.

A device known as the functional lumen imaging probe (FLIP) has been shown to reliably measure the geometry of and pressure changes in the OGJ. FLIP cannot directly measure flow but the data gathered from the probe can be used to model flow through the junction by using computational flow dynamics (CFD). CFD uses a set of equations known as the Navier-Stokes equations to predict flow patterns and is a technique widely used in engineering. These equations are complex and require appropriate assumptions to provide simplifications before useful data can be obtained. With the assumption that the cross-sectional areas obtained via FLIP are circular, the radii of these circles can be obtained. A cubic interpolation scheme can then be applied to give a high-resolution geometry for the OGJ.

In the case of modelling a reflux scenario, it can be seen that at the narrowest section a jet of fluid squirts into the oesophagus at a higher velocity than the fluid surrounding it. This jet has a maximum velocity of almost 2 ms^-1 that occurs where the OGJ is at its narrowest. This simple prediction of acid ‘squirting’ into the oesophagus illustrates how the use of numerical methods can be used to develop a better understanding of the OGJ. This initial work using CFD shows some considerable promise for the future.

Anatomy of reflux: a growing health problem affecting structures of the head and neck

Gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) are sibling diseases that are a modern-day plague. Millions of Americans suffer from their sequelae, ranging from subtle annoyances to life-threatening illnesses such as asthma, sleep apnea, and cancer. Indeed, the recognized prevalence of GERD alone has increased threefold throughout the 1990s. Knowledge of the precise etiologies for GERD and LPR is becoming essential for proper treatment. This review focuses on the anatomical, physiological, neurobiological, and cellular aspects of these diseases. By definition, gastroesophageal reflux (GER) is the passage of gastric contents into the esophagus; when excessive and damaging to the esophageal mucosa, GERD results. Reflux that advances to the laryngopharynx and, subsequently, to other regions of the head and neck such as the larynx, oral cavity, nasopharynx, nasal cavity, paranasal sinuses, and even middle ear results in LPR. While GERD has long been identified as a source of esophageal disease, LPR has only recently been implicated in causing head and neck problems. Recent research has identified four anatomical/physiological "barriers" that serve as guardians to prevent the cranial incursion of reflux: the gastroesophageal junction, esophageal motor function and acid clearance, the upper esophageal sphincter, and pharyngeal and laryngeal mucosal resistance. Sequential failure of all four barriers is necessary to produce LPR. While it has become apparent that GER must precede both GERD and LPR, the head and neck distribution of the latter clearly separates these diseases as distinct entities warranting specialized focus and treatment.

Optical properties of adenocarcinoma and squamous cell carcinoma of the gastroesophageal junction

Photodynamic therapy (PDT) is an alternative to radical surgical resection for T1a or nonresectable carcinomas of the gastroesophageal junction. Besides the concentration of the photosensitizer, the light distribution in tissue is responsible for tumor destruction. For this reason, knowledge about the behavior of light in healthy and dysplastic tissue is of great interest for careful irradiation scheduling. The aim of this study is to determine the optical parameters (OP) of healthy and carcinomatous tissue of the gastroesophageal junction in vitro to provide reproducible parameters for optimal dosimetry when applying PDT. A total of 36 tissue samples [adenocarcinoma tissue (n=21), squamous cell tissue (n=15)] are obtained from patients with carcinomas of the gastroesophageal junction. The optical parameters are measured in 10-nm steps using new integrating sphere spectrometers in the PDT-relevant wavelength range of 300 to 1140 nm and evaluated by inverse Monte-Carlo simulation. Additional examinations are done in healthy tissue from the surgical safety margin. In the wavelength range of frequently applied photosensitizers at 330, 630, and 650 nm, the absorption coefficient in tumor tissue (adenocarcinoma 1.22, 0.16, and 0.15 mm(-1); squamous cell carcinoma 1.48, 0.13, and 0.11 mm(-1)) is significantly lower than in healthy tissue (stomach 3.34, 0.26, and 0.20 mm(-1); esophagus 2.47, 0.21, and 0.18 mm(-1)). The scattering coefficient of all tissues decreases continuously with increasing wavelength (adenocarcinoma 22.8, 12.99, and 12.52 mm(-1); squamous cell carcinoma 19.44, 9.35, and 8.98 mm(-1); stomach 20.55, 13.96, and 13.94 mm(-1); esophagus 20.34, 12.56, and 12.22 mm(-1). All tissues show an anisotropy factor between 0.80 and 0.94 over the entire spectrum. The maximum optical penetration depth for all tissues is achieved in the range of 800 to 1100 nm. At the wavelength range of 330, 630, and 650 nm, the optical penetration depth is significantly higher in carcinoma tissue (adenocarcinoma 0.27, 1.54, and 1.66 mm; squamous cell carcinoma 0.23, 1.71, and 1.84 mm) than in healthy tissue (stomach 0.16, 1.10, and 1.26 mm; esophagus 0.17, 1.47, and 1.65 mm; p<0.05). Above 1000 nm, a higher absorption coefficient of tumor tissue results in a lower optical penetration depth than in healthy tissue (p<0.05). The higher absorption and scattering of the tumor tissue in the wavelength range of available photosensitizer is associated with a low optical penetration depth. This necessitates higher energy doses and long application times or repeated applications to effectively treat large tumor volumes. Photosensitizers optimized for larger wavelength range need to be developed to increase the efficacy of PDT.

Transient lower esophageal sphincter relaxations and reflux: mechanistic analysis using concurrent fluoroscopy and high-resolution manometry

BACKGROUND & AIMS

The aim of this study was to perform a detailed analysis of the mechanics leading to esophagogastric junction (EGJ) opening during transient lower esophageal sphincter relaxations (tLESRs) using high-resolution manometry coupled with simultaneous fluoroscopy.

METHODS

Six subjects without hiatus hernia had endoclips placed at the squamocolumnar junction and 10 cm proximal. A 36-channel solid-state manometric assembly was placed spanning from stomach to pharynx, and subjects were studied for 2 hours after a high-fat meal. An esophageal pH electrode also was placed and fluoroscopy was initiated at the onset of a tLESR. Axial clip movement was measured during replay of the videotaped fluoroscopy and was correlated with manometric data.

RESULTS

Ninety-three tLESRs were recorded, 62 tLESRs of which had good fluoroscopic visualization. Seventy-eight tLESRs had manometric evidence of flow and the majority had evidence of a common cavity (88%), but few were detected by the pH electrode. Esophageal shortening and crural diaphragm inhibition always preceded EGJ opening and common cavity. A positive pressure gradient between the stomach and the EGJ lumen of 7.1 mm Hg (interquartile range, 4.1-9.1 mm Hg) preceded the EGJ opening.

CONCLUSIONS

Key events leading to the EGJ opening during tLESRs were LES relaxation, crural diaphragm inhibition, esophageal shortening, and a positive pressure gradient between the stomach and the EGJ lumen. The manometric signature of opening was pressure equalization within the EGJ, but this only occasionally was associated with pH evidence of reflux. Future investigations will need to analyze how this delicately balanced anatomic-physiologic system is perturbed in subjects with reflux disease.

Surgical management of esophagogastric junction tumors

Surgical resection with lymphadenectomy is the mainstay of treatment for all resectable esophagogastric junction tumors, prior to systemic generalization of the disease. This makes accurate pre-treatment staging and classification of the tumors most demanding. A well-established and internationally accepted classification for adenocarcinomas of the esophagogastric junction (AEG) helps to choose the appropriate surgical approach and to make results from different institutions comparable. Distal esophageal adenocarcinomas (AEGI) are distinguished from true cardia carcinomas (AEG II) and subcardiac gastric cancers (AEG III). Substantial advancements in this surgical field during the preceding decades have clearly revealed that individualization of the surgical strategy is the key to successfully approaching these entities. In this review we discuss the surgical management of esophagogastric junction tumors with a tailored surgical strategy.

[Pandrial gastroesophageal reflux in healthy preterm infants]

The neutralization of gastric content during feeding and in the immediate postpandrial period, has determined that until recently time these periods were excluded in the studies of the gastroesophageal reflux disease (GERD) that were made with pH-metría. The aim of this study was to characterize the events of reflux during feeding with pH and impedance,and later to compare them with which it happens in fasting periods.

MATERIAL AND METHOD

We recording pH and Impedance in 21 preterms neonates without associated pathology, except the prematurity, during 8 periods of feeding-fasting (1 hour of feeding and 2 hours of rest), replacing the nasogastric tube by a catheter of feeding + impedance, previous informed consent.

RESULTS

The average of reflux during the meals per hour was of 3.36 h +/- 1.23 h, whereas in fasting periods was 1.02 h was of 2.65 h +/- (p = 0.068). The number of acid reflux per hour during the fasting was higher [1, 05 (0.34-1.23) h] than in feeding periods [0, 20 (0-1.12) h] (p = 0,044). The number of weakly acid reflux per hour was significantly higher in feeding periods [2, 71 (2.03-3.30) h] than in fasting periods [1, 35 (1.13-1.97) h] (p = 0, 05). The acid exposure during the meals was of 2, 35% whereas in fasting periods was of 7, 23%.

CONCLUSION

The incorporation of the Impedance within the battery of tests for the diagnosis of the gastroesophageal reflux in the pediatric population, at the moment allows us to know the pattern behavior of esophagus during the meals: feeding periods were associated with a greater number of reflux per hour, most of which weakly acidic; the acid exposure was significantly greater during fasting periods.

Gastric carditis: Is it a histological response to high concentrations of luminal nitric oxide?

During the last decade, inflammation (carditis) and intestinal metaplasia localized to immediately below the human gastro-oesophageal junction have received much attention in relation to the rising incidence of cancer at this site. Since these histological findings are frequently observed even among those who are H pylori-negative, the causative factors for such histologic events at the human gastro-oesophageal junction remain obscure. A series of recent studies have demonstrated that a high level of salivary nitrite is sustained over several hours after the ingestion of a high nitrate meal, and that the nitrite in swallowed saliva is rapidly converted to nitric oxide by an acid catalyzed chemical reaction at the gastro-oesophageal junction. Eventually, a substantial amount of nitric oxide diffuses from the lumen into the adjacent tissue. Therefore, the human gastro-oesophageal junction is likely to be a region of high nitrosative stress. Considering the life-time exposure of the gastro-oesophageal junction to cytotoxic levels of nitric oxide, this may account for the high prevalence of inflammation, intestinal metaplasia, and subsequent development of neoplasia at this site. Although gastric acid, pepsin, and bile acid have been intensively investigated as a cause of adenocarcinoma at the gastro-oesophageal junction and the distal esophagus, nitric oxide and the related nitrosative stress should also be examined.

[Barrier function of esophagogastric junction in patients with gastroesophageal reflux disease]

OBJECTIVE

To investigate the barrier function of esophagogastric junction (EGJ) in the patients with gastroesophageal reflux diseases (GERD).

METHODS

Ninety-six GERD patients and 18 healthy subjects (HSs) underwent esophageal manometry. Forty-two of the 96 patients were with reflux esophagitis (RE) and were divided into 2 subgroups according to the LA typing: 31 subgroup of LA-A or B (n = 31), and subgroup of LA-C or D (n = 11). Fifty-four of the 96 patients suffered from non-erosive reflux disease (NERD) and were divided into 2 subgroups based on 24 h esophageal pH monitoring: 31 patients with normal acid exposure (pH < 14.72 according to DeMeester scoring) and 23 with excessive acid exposure (pH > 14.72). The EGJ functions, including lower esophageal sphincter pressure (LESP), crura of diaphragm pressure (CDP), esophagogastric junction pressure (EGJP, sum of LESP and CDP), and post-lower esophageal sphincter relaxation pressure (post-LESRP), and the contractive pressure of esophageal body, including proximal esophageal contractive pressure (PECP) and distal esophageal contractive pressure (DECP), were measured.

RESULTS

The levels of LESP, CDP, EGJP, and post-LESRP of the RE patients were (8 +/- 3), (13 +/- 7), (20 +/- 9), and (31 +/- 13) mm Hg respectively, all significantly lower than those of the NERD patients [(9 +/- 3), (18 +/- 6), (28 +/- 8), and (39 +/- 15) mm Hg, all P < 0.05]. The levels of LESP and post-LESRP of the NERD patients were significantly lower than those of the HSs [(32 +/- 7) and (50 +/- 15) mm Hg, both P < 0.05], however, the levels of CDP and EGJP of the NERD patients were both not significantly different from those of the HSs [(16 +/- 6) and (32 +/- 7) mm Hg, both P > 0.05]. The PECP and DECP of the RE and NERD patients were all significantly lower than those of the HSs (all P < 0.05), however, there were not significant differences in DECP and PECP between the RE and NERD patients (both P > 0.05). Among the NERD patients there were not significant differences in the PECP and DECP between the LA-A and B subgroup and RE LA-C and D subgroup, and among the NERD patients there were not significant differences in PECP and DECP between the subgroups with and without excessive esophageal acid exposure (all P > 0.05).

CONCLUSION

The EGF anti-reflux function of the GERD patients is impaired. The function of crura of diaphragm of the NERD patients is almost normal, however, that of the RE patients is impaired. NERD and RE have different path physiological basis.

Acid reflux immediately above the squamocolumnar junction and in the distal esophagus: simultaneous pH monitoring using the wireless capsule pH system

OBJECTIVES

The pattern of reflux in the most distal esophagus of asymptomatic individuals is largely unknown. Using a wireless technique we compared the degree and the pattern of acid reflux just above the squamocolumnar junction (SCJ) with that measured at the conventional level for pH monitoring.

METHODS

Fifty-three asymptomatic volunteers underwent endoscopy with transoral placement of two pH recording capsules, one immediately above and one 6 cm above the SCJ. Ambulatory pH monitoring was performed during 48 h.

RESULTS

Three subjects were excluded as the distal capsule was inadvertently placed with the pH electrode below the SCJ. The median percent time with pH < 4 and the median number of reflux episodes were significantly higher immediately above the SCJ compared with that found more proximally (1.6%vs 0.9% and 67 vs 26, p < 0.0001). Of all acid reflux events, 69% were isolated episodes immediately above the SCJ. Only 26% of reflux episodes detected at the SCJ extended to the more proximal pH electrode. Reflux events occurring just above the SCJ were more acidic. The number of reflux events with a minimum pH below 2 or 3 was significantly higher at the SCJ compared with that recorded by the upper capsule (16% and 44%vs 6% and 34%, p < 0.0001).

CONCLUSIONS

Conventional pH monitoring substantially underestimates the degree of acid exposure in the most distal esophagus. In healthy subjects, acid exposure immediately above the SCJ was considerably higher and was characterized by shorter reflux episodes that had a lower minimum pH compared with that measured at the traditional level for pH monitoring.

Thal-Hatafuku oesophagogastroplasty: an effective option in the palliation of non-chagasic megaesophagus

The palliation of patients with megaesophagus secondary to achalasia of the cardia presents significant challenges to the surgeon. Experience with palliation of megaesophagus secondary to Chagas' disease suggests that options other than cardiomyotomy or oesophagectomy can result in satisfactory outcomes. A small series of patients with non-chagasic megaesophagus who were treated with a gastroesophagoplasty procedure is discussed.

Symptom and function heterogenicity among patients with distal esophageal spasm: studies using combined impedance-manometry

BACKGROUND

Combined multichannel intraluminal impedance and esophageal manometry (MII-EM) is a clinically available tool that assesses the functional defect of various manometric abnormalities. The aim of our study was to evaluate esophageal bolus transit in patients with manometrically defined distal esophageal spasm (DES).

METHODS

Patients referred for esophageal function testing underwent combined MII-EM studies including 10 liquid and 10 viscous swallows. Individual swallows were classified using previously published manometric and impedance criteria. DES is traditionally defined as > or =20% simultaneous contractions in the distal esophagus. Diagnosis of esophageal transit abnormalities was defined by the presence of > or =30% incomplete liquid or > or =40% incomplete viscous swallows.

RESULTS

Data from 71 patients (43 female, mean age 57 yr, range 16-85) with a manometric diagnosis of DES were analyzed. During liquid swallows, patients with chest pain had higher (p < 0.05) distal esophageal amplitudes (202.3 +/- 34.5 mmHg) and a higher (p < 0.05) percentage of swallows with complete bolus transit (89%+/- 3%) compared to patients presenting with dysphagia (amplitude 117.8 +/- 8.7 mmHg; percentage of complete transit 69%+/- 5%) and patients with reflux symptoms (amplitude 116.4 +/- 12.7 mmHg; percentage of complete transit 74%+/- 5%). Fifty-one percent of the DES patients had a normal bolus transit for liquid and viscous, 24% abnormal bolus transit for one substance, and 25% abnormal bolus transit for liquid and viscous.

CONCLUSION

Pressure and bolus transit information in patients with manometrically defined DES points toward heterogenicity of this group of patients. Outcomes data are warranted to evaluate whether stratifying DES patients based on pressure and bolus transit information may improve the clinical approach.

Abnormal gastroesophageal flap valve is highly associated with gastroesophageal reflux disease among subjects undergoing routine endoscopy in Taiwan

OBJECTIVE

Gastroesophageal flap valve (GEFV) grade predicts severe gastroesophageal reflux disease in Caucasians, but its role in other populations is unclear. This study evaluated the significance of endoscopic grading of the GEFV in Taiwanese subjects.

METHODS

Five hundred and six consecutive patients undergoing routine check-ups at the National Taiwan University Hospital were enrolled. Symptoms of upper gastrointestinal disease and endoscopic severity of esophageal mucosal injury were correlated to GEFV grades according to the Hill classification.

RESULTS

The frequency of abnormal valves (Hill grades III or IV) was 27.3%. Of these, 42.7% had erosive esophagitis (EE). The majority of patients with EE were classified as Los Angeles grades A and B (79.7 and 16.9%, respectively). The prevalence of EE, hiatal hernia and, to a lesser degree, non-erosive reflux disease, increased with altered GEFV. Patients with abnormal valves were younger and more likely to be male, overweight, and to have atypical and extraesophageal symptoms.

CONCLUSIONS

Taiwanese patients with abnormal GEFVs share similar characteristics and risk factors with the patients who have EE. Endoscopic grading of the GEFV is highly associated with GERD, and in particular EE, in subjects undergoing routine endoscopy.

Effects of partial (Belsey Mark IV) and complete (Nissen) fundoplication on proximal gastric function and esophagogastric junction dynamics

OBJECTIVES

This study aimed to assess the effects of Belsey Mark IV 270 degrees (partial) and Nissen 360 degrees (complete) fundoplication on proximal stomach function, transient lower esophageal sphincter relaxation (TLESR) elicitation and the esophagogastric junction (EGJ) pressure profile during TLESR to further elucidate the mechanism of action of fundoplication.

METHODS

Ten patients after partial and 10 patients after complete fundoplication were studied. High-resolution EGJ manometry and pH recording were performed for 1 h at baseline and 2 h following meal ingestion (500 mL/300 kcal). Three dimensional (3D) ultrasonographic images of the stomach were acquired every 15 min after meal ingestion. From the 3D ultrasonographic images, proximal gastric volumes were computed.

RESULTS

Postprandial proximal to complete gastric volume distribution ratios were larger among patients after partial (0.42 +/- 0.028) compared with patients after complete fundoplication (0.37 +/- 0.035; p < 0.05). Partial fundoplication patients had a markedly greater postprandial rate of TLESR (1.7 +/- 0.3/h) than patients after complete fundoplication (0.8 +/- 0.2/h; p < 0.05). The axial EGJ pressure profile was minimally affected by partial fundoplication but instead markedly changed after complete fundoplication.

CONCLUSIONS

Patients after partial fundoplication exhibit a larger meal-induced increase in proximal stomach volume, a higher TLESR rate, and a minimally affected axial EGJ pressure profile compared to patients after complete fundoplication.

Obesity: a challenge to esophagogastric junction integrity

BACKGROUND & AIMS

The aim of the current study was to analyze the relationship between obesity and the morphology of the esophagogastric junction (EGJ) pressure segment using high-resolution manometry.

METHODS

Two hundred eighty-five patients (108 men, aged 18-87) were studied. A solid-state manometric assembly with 36 circumferential sensors spaced 1 cm apart was placed transnasally, and simultaneous intra-esophageal and intragastric pressures were measured over 6-8 respiratory cycles. Separation of the lower esophageal sphincter (LES) and crural diaphragm was quantified by measuring the distance between the two EGJ elements during inspiration. The association between anthropometric variables and pressure values were examined using univariate and multivariate analysis.

RESULTS

There was a significant correlation of body mass index (BMI) and waist circumference (WC) with intragastric pressure (inspiration, BMI [r = 0.57], WC [r = 0.62] P < .0001; expiration, BMI [r = 0.58], WC [r = 0.64], P < .0001) and gastroesophageal pressure gradient (GEPG) (inspiration, BMI [r = 0.37], WC [r = 0.43], P < .0001; expiration, BMI [r = 0.24], WC [r = 0.26], P < .0001). Multivariate analysis adjusting for age, gender, and patient type did not alter the direction or magnitude of this relationship. In addition, obesity was associated with separation of the EGJ pressure components (BMI, r = 0.17, P < .005; WC, r = 0.21, P < .001).

CONCLUSIONS

Obese subjects are more likely to have EGJ disruption (leading to hiatal hernia) and an augmented GEPG providing a perfect scenario for reflux to occur. Whether or not weight loss can reverse these abnormalities is unknown.

The Effect of Esophageal and Gastric Distension on the Crural Diaphragm

BACKGROUND

The mechanism of prevention of gastric reflux into the esophagus is not exactly known. The lower esophagus has a barrier function provided by the lower esophageal sphincter. We investigated the hypothesis that the crural diaphragm shares in the barrier function not only mechanically but also actively through a crural-esophageal-gastric reflex action.

METHODS

The study was performed during repair of abdominal ventral and incisional hernias in 20 subjects (11 men, 9 women; age 38.6+/-4.8 years). The electromyographic response of the crural diaphragm to individual balloon distension of esophagus and stomach was recorded by means of a needle electrode inserted into the crural diaphragm and connected to an electromyographic apparatus. The recordings were repeated after separate crural, esophageal, and gastric anesthetization.

RESULTS

The crural diaphragm exhibited basal motor unit action potentials, which decreased on esophageal distension (P<0.001) after a mean latency of 17.3+/-2.8 SD ms. The crural diaphragm response to esophageal distension did not occur after the crural diaphragm or esophagus was anesthetized. Gastric distension effected an increase of crural diaphragm electromyographic activity with a mean latency of 18.4+/-4.6 ms; this effect could not be achieved after the crural diaphragm or stomach was anesthetized.

CONCLUSIONS

The crural diaphragm has a resting tone that relaxes after esophageal distension and contracts after gastric distension. This sphincter-like action of the crural diaphragm appears to be a reflex and is mediated through the esophagocrural inhibitory and gastrocrural excitatory reflexes. The crural diaphragm seems to share actively in the gastroesophageal competence mechanism.

A novel antireflux device based on magnets

BACKGROUND

The problem of eliminating gastroesophageal reflux (GER) with simple, effective and devoid of unpleasant side effects procedures is still unresolved. We tried to settle this problem with a magnetic device that should be applied to the distal end of the esophagus.

MATERIALS AND METHODS

Two plastoferrite magnets of 2 x 4 x 0.5cm(1) were applied, on the opposite sides of a flaccid polyethylene tube mimicking the physical characteristics of the terminal esophagus. The two magnets attracting themselves compressed the tube, creating an artificial high-pressure zone that divided the tube in two segments. Both segments of the tube were connected to pressure transducers and a polygraph and one of them was connected to a hydraulic pump. The pressure was progressively increased in this segment up to a value sufficient to detach the magnets with consequent flowing of the water in the other segment of the tube.

RESULTS

The progressive increase of the pressure in a segment of the tube detached the magnets allowing a free flow into the other segment when the pressure reached an average value of 9.75+/-1.05 mmHg (mean+/-SD).

CONCLUSIONS

A couple of magnets clamping a tube with the characteristics of the distal esophagus is able to prevent the passage of liquid with a pressure value near to that of a normal lower esophageal sphincter. This magnetic device could be useful to maintain closed a sphincter unable to prevent gastroesophageal reflux.

Laparoscopic Nissen fundoplication decreases gastroesophageal junction distensibility in patients with gastroesophageal reflux disease

Laparoscopic Nissen fundoplication (LNF) is the surgical treatment of choice for gastroesophageal reflux disease (GERD). Post-LNF complications, such as gas bloat syndrome, inability to belch and vomit, and dysphagia, remain too common and prevent LNF from being more highly recommended. It remains controversial as to whether preoperative assessment can predict the development of post-LNF complications. Some authors have shown a correlation between pre-LNF manometry characteristics and post-LNF dysphagia, and others have not. We hypothesize that many post-LNF complications are caused by a decrease in the distensibility of the GEJ and that standard manometry is at best an indirect measure of this. The aim of this study is to directly measure the effect of LNF on gastroesophageal junction (GEJ) distensibility (GEJD). The lower esophageal sphincter (LES) of 15 patients undergoing LNF was characterized using standard manometry. The GEJD before and after a standardized LNF was measured using a specialized catheter, containing an infinitely compliant bag, placed within the LES. GEJD was measured, as dV/dP over volumes 5 to 25 mL distended at a rate of 20 mL/min. Mean dP +/- standard error of the mean for each volume was calculated, and distensibility curves were generated and compared. Measurements were also taken after abolishing LES tone by mid-esophageal balloon distension. Patient symptoms were recorded before and after surgery. Statistical analysis was performed by two-way repeated-measures analysis of variance, paired t test, and the Tukey test. Laparoscopic Nissen fundoplication led to a statistically significant increase in Delta pressure over each volume tested and therefore a significant decrease in the distensibility of the GEJ. Abolition of LES tone had no statistical effect on GEJD after fundoplication. There were no complications, and none of the patients developed the symptom of dysphagia postoperatively. These are the first direct measurements to show that LNF significantly reduces the distensibility of the GEJ. We hypothesize that the magnitude of this reduction may be the vital variable in the development of post-LNF complications and specifically post-LNF dysphagia. The intraoperative measurement of LES distensibility may provide a means for avoiding this feared and other post-LNF complications in the future.

Pathophysiology of gastroesophageal reflux disease

From a pathophysiologic viewpoint, GERD results from the excessive reflux of gastric contents into the distal esophagus. Under normal conditions, this is prevented as a function of the antireflux barrier at the EGJ, the integrity of which is dependent on the delicate interplay of a host of anatomic and physiologic factors, including the integrity of the LES, TLESR, and anatomic degradation of the EGJ inclusive of but not limited to hiatus hernia. Considerable investigative focus is aimed at describing the subtle aberrations of the EGJ that may contribute to the root causes of GERD. The net result is an increased number of reflux events, an increasing diversity of potential mechanisms of reflux, and a diminished ability of the stomach to selectively vent gas, as opposed to gas and gastric juice, during TLESR. Once reflux occurs, the duration of resultant esophageal acid exposure is determined by the effectiveness of esophageal acid clearance, the dominant determinants of which are peristalsis, salivation, and, again, the anatomic integrity of the EGJ. Approximately half of patients who have GERD have abnormal acid clearance and the major contributor to this is hiatus hernia. Abnormalities of acid clearance probably are the major determining factor influencing which patients who have GERD are most prone to developing esophagitis as opposed to symptomatic GERD. In summary, GERD is a multifactorial process involving physiologic and anatomic abnormalities. These abnormalities exhibit a complicated interplay that degrades the ability of the EGJ to contain gastric juice within the stomach and to clear the esophagus of gastric juice effectively once reflux has occurred.

Residence of liquids in the infra-junctional portion of the proximal stomach in patients with gastroesophageal reflux disease

Patients with gastroesophageal reflux disease may have disturbances of gastric motility, which could play a role in the pathophysiology of the disease. Recent studies have suggested that the gastric region just below the gastroesophageal junction may have a distinct physiological behavior. We determined whether patients with gastroesophageal reflux disease have abnormal residence of food in the infra-junctional portion of the stomach after ingesting a liquid nutrient meal. Fasted adult patients with reflux disease (N = 11) and healthy volunteers (N = 10) ingested a liquid meal (320 ml; 437 kcal) labeled with 99m technetium-phytate and their total gastric emptying half-time and regional emptying from the stomach infra-junctional region were determined. In 8 patients, episodes of postprandial acidic reflux to the esophagus were measured for 2 h using pH monitoring. There were no differences between reflux patients and controls regarding total gastric emptying time (median: 68 min; range: 39-123 min vs 65 min and 60-99 min, respectively; P > 0.50). Food residence in the infra-junctional area was similar for patients and controls: 23% (range: 20-30) vs 27% (range: 19-30%; P = 0.28) and emptying from this area paralleled total gastric emptying (Rs = 0.79; P = 0.04). There was no correlation between residence of food in the infra-junctional area and episodes of gastroesophageal reflux (Rs = 0.06; P = 0.88). We conclude that it is unlikely that regional motor disturbances involving the infra-junctional region of the stomach play a relevant role in the pathogenesis of acidic gastroesophageal reflux.

Assessment of the esophageal pressure in gastroesophageal reflux disease by the local regression

Gastroesophageal reflux disease (GERD) is one of the most prevalent gastrointestinal diseases. It is characterized by excessive reflux of gastric content (acid, pepsin, etc.) into the esophagus causing symptoms (heartburn, acid regurgitation, etc.) and mucosal inflammation and injuries. GERD occurs when the lower esophageal sphincter (LES) has a low resting pressure and stomach contents leak back, or reflux, into the esophagus. Therefore, the accurate measurement of the LES pressure is of great importance for the diagnosis of GERD. The LES pressure signal, involving severe respiratory contamination and motion artifacts, demands specific capabilities not provided by conventional data analysis methods. Recently, local regression has proved to be a very attractive technique to the nonparametric regression in statistics. In this contribution we apply the ideas of local regression to develop strategies for selecting smoothing parameters of local linear squares estimators, and present its application on the extraction of the LES pressure in GERD. The results from both extensive simulations and real data demonstrate the ability of local regression to characterize the LES pressure, which is consistent with the clinical observation.

Restoration of normal distensive characteristics of the esophagogastric junction after fundoplication

OBJECTIVE

To study the mechanical characteristics of the esophagogastric junction (EGJ) of postfundoplication patients and compare them with previously reported data on normal subjects and GERD patients.

METHODS

Eight normal subjects, 9 GERD patients, and 8 fundoplication patients were studied with concurrent manometry, fluoroscopy, and stepwise controlled barostat distention of the EGJ. The minimal barostat pressure required to open the EGJ during the interswallow period was determined. Thereafter, barium swallows were imaged in 5-mm Hg increments of intrabag pressure. EGJ diameter and length were measured at each pressure during deglutitive relaxation.

RESULTS

EGJ opening diameter during deglutitive relaxation was on average 0.5 cm greater in GERD patients compared with normal subjects and fundoplication patients (P < 0.05). EGJ opening pressure and opening diameter were comparable between normal subjects and fundoplication patients; however, the EGJ length was 32% longer in fundoplication patients.

CONCLUSIONS

Fundoplication restores distensibility of the EGJ to a level similar to normal subjects. Since trans-EGJ flow is related to EGJ length and EGJ diameter, these findings suggest that retrograde flow through the EGJ would be decreased by both a reduction in diameter and an increase in length of the EGJ.

Unraveling the mystery of the gastroesophageal junction: a pathologist's perspective

The gastroesophageal junction (GEJ), which is defined as the point where the distal esophagus joins the proximal stomach (cardia), is a short anatomic area that is commonly exposed to the injurious effects of GERD and/or Helicobacter pylori infection. These disorders often lead to inflammation and intestinal metaplasia (IM) of this anatomic region. The true gastric cardia is an extremely short segment (<0.4 mm) of mucosa that is typically composed of pure mucous glands, or mixed mucous/oxyntic glands that are histologically indistinguishable from metaplastic mucinous columnar epithelium of the distal esophagus. In patients with GERD, whether physiologic or pathologic, the length of cardia-type epithelium increases and extends proximally above the level of the anatomic GEJ into the distal esophagus. Columnar metaplasia of the distal esophagus represents a squamous to columnar metaplastic reaction that develops from an esophageal stem cell and may pass through an intermediate phase characterized by the presence of a type of epithelium that possesses a mixture of squamous and columnar features, termed multilayered epithelium. In contrast, IM of the gastric cardia represents a columnar to columnar cell metaplastic reaction that develops from a gastric stem cell located in the deep foveolar compartment of the gastric mucosa. Intestinal metaplasia, particularly the incomplete type, is widely believed to represent the precursor lesion upon which dysplasia and cancer arises. The frequency of IM is probably greater in metaplastic columnar epithelium in the esophagus secondary to GERD, than in cases of true gastric carditis secondary to H. pylori, and may be a reason why there is a higher risk of carcinoma in the former compared to the latter. A variety of clinical, endoscopic, histologic, and histochemical methods can be used to distinguish GERD-induced columnar metaplasia of the distal esophagus from H. pylori-induced inflammation of true gastric cardia, and these are outlined in this review, but further controlled studies are needed to critically evaluate these techniques. Further prospective trials are needed to adequately evaluate the different etiologic and pathogenetic mechanisms and, most importantly, the risk of malignancy in these two conditions.

On the pathogenesis of gastroesophageal reflux: The concept of gastroesophageal dyssynergia

OBJECTIVES

The cause of lower esophageal sphincter incompetence in gastroesophageal reflux disease is not clearly understood. We investigated the hypothesis that the esophagogastric junction incompetence results from failure of the gastric distention to produce the lower esophageal sphincter and crural diaphragm contraction caused by a disordered reflex action.

METHODS

The study was performed in 19 subjects (mean age, 42.6 +/- 7.2 years; 11 men and 8 women) who had reflux esophagitis and hiatus hernia and were scheduled for a fundoplication operation. Eight control volunteers (mean age, 41.8 +/- 6.9; 5 men and 3 women) who had huge supraumbilical ventral hernia but no reflux esophagitis or hiatus hernia were studied during operative hernia repair. The electromyographic activity and pressure response of the lower esophageal sphincter and crural diaphragm to separate esophageal and gastric distention were recorded.

RESULTS

In the control subjects (volunteers) esophageal distention caused diminished electromyographic activity of the crural diaphragm and lower esophageal sphincter with decreased esophagogastric junction pressure, whereas gastric distention increased the electromyographic activity of the crural diaphragm and lower esophageal sphincter with increased esophagogastric junction pressure. In the patients the crural diaphragm and lower esophageal sphincter showed diminished resting electromyographic activity, with either no response or a paradoxical response to esophageal or gastric distention.

CONCLUSION

The current study has demonstrated that the lower esophageal sphincter and crural diaphragm in patients with gastroesophageal reflux disease exhibited a diminished resting electric activity and either did not respond or reacted paradoxically to esophageal and gastric distention, constituting what we call esophagosphincteric and gastroesophageal paradox or dyssynergia. The cause of lower esophageal sphincter and crural diaphragm dysfunction is not known; a neurogenic cause was proposed. Further studies are required to investigate this point.

Impaired bolus transit across the esophagogastric junction in postfundoplication dysphagia

OBJECTIVES

This study assessed the effect of fundoplication on liquid and solid bolus transit across the esophagogastric junction (EGJ) in relation to EGJ dynamics and dysphagia.

METHODS

Twelve patients with gastro-esophageal reflux disease (GERD) were studied before and after fundoplication. Concurrent high-resolution EGJ manometry and fluoroscopy were performed whilst swallowing liquid barium and a solid bolus. The EGJ transit time, EGJ opening duration, transit efficacy, and EGJ relaxation were measured. During the test symptoms of dysphagia were scored using a visual analog scale.

RESULTS

The minimal opening aperture at fluoroscopy was located at the manometric EGJ in all subjects. Fundoplication markedly reduced the EGJ opening diameter from 1.0 +/- 0.1 to 0.6 +/- 0.1 cm (p < 0.01) and rendered deglutative EGJ relaxation incomplete. After fundoplication, a higher intrabolus pressure was found (p < 0.05) associated with a reduced axial bolus length (p < 0.001). EGJ transit time increased from 6.9 +/- 0.9 to 9.8 +/- 1.0 s for liquids (p < 0.01) and from 2.8 +/- 0.5 to 5.8 +/- 0.8 s (p < 0.01) for solids after fundoplication. No relation between EGJ transit and dysphagia scores was observed before fundoplication. In contrast, EGJ transit time significantly correlated with dysphagia scores both during liquid (r = 0.84; p < 0.01) and solid (r = 0.69; p < 0.05) bolus transit following fundoplication.

CONCLUSIONS

Fundoplication patients exhibit a restricted hiatal opening and an incomplete deglutative EGJ relaxation. To facilitate EGJ transit despite these altered EGJ dynamics a higher intrabolus pressure is created by augmented bolus compression. Fundoplication increases EGJ transit time, the degree of which is associated with postoperative dysphagia.

The place of gastro-jejuno-duodenal interposition following limited esophageal resection

OBJECTIVE

Although stomach is the best choice for reconstruction after esophagectomy from the viewpoint of safety and ease, an intrathoracic stomach, nevertheless, is a poor long-term substitute. This anatomical configuration abolishes normal antireflux mechanisms and places the acid-excreting stomach subject to biliary reflux, moreover, in an adjacent position to the esophagus within the negative-pressure environment of the thorax.

METHODS

Between 1995 and 2002, 27 patients with high-grade neoplasia-as early Barrett's carcinoma-or non-dilatable peptic stricture underwent limited surgical resection of the distal esophagus and esophagogastric junction. In 11 of these cases, the reconstruction was performed with gastro-jejuno-duodenal interposition. The long-term functional results of this specially adapted form of interposition reconstruction have been evaluated. The postoperative follow-up period ranged between 24 and 95 months (mean 68 months). Nine patients (9/11=81.8%) have agreed to undergo endoscopy, radiographic contrast-swallow examination, and 24-h ambulatory esophageal pH and bilirubin monitoring.

RESULTS

Three out of nine patients (3/9=33%) demonstrated abnormal levels of esophageal acid exposure during the 24-h study period, whilst none had any evidence of bilirubin exposure in the esophageal remnant. Endoscopy revealed that three patients had reflux esophagitis in the remnant esophagus: Los Angeles A=2, C=1. No stomal or jejunal ulceration at the gastro-jejunal anastomosis could be observed. Histopathologic assessment of the squamous epithelial biopsies demonstrated microscopic evidence of inflammation: minor in two cases, moderate in one and major in one case; however, none of them had evidence of columnar metaplasia in the esophageal remnant at a median of 68 months after surgery. The majority of the patients have been doing well since the operation: 8/9 (88%)=Visick I-II.

CONCLUSIONS

Gastro-jejuno-duodenal interposition represents an adequate 'second-best' method of choice if technical difficulties emerge with jejunal or colon interposition following limited resection of the esophagus performed due to early Barett's carcinoma or non-dilatable peptic stricture.

Attaining and Maintaining Isometric and Isokinetic Goals of the Shaker Exercise

Previous studies have shown that the Shaker Exercise is effective in restoring oral intake in patients with deglutitive failure due to upper esophageal sphincter (UES) dysfunction. Our aim was to determine (1) exerciser compliance among healthy older adults, (2) number of days required to attain the isometric (IM) and isokinetic (IK) exercise goals, (3) rate and reason for dropout of exercisers, and (4) complaints associated with performance of the exercise. Twenty-six nondysphagic older adults were enrolled from an independent-living community (66-93 yr) to perform the Shaker Exercise. Each participant completed a questionnaire on exercise performance and its associated difficulties three times a day for six weeks. Four randomly chosen nondysphagic participants underwent pre- and postexercise videofluoroscopic swallow studies for biomechanical measurements. Maximum anterior hyoid and laryngeal excursions, as well as maximum anteroposterior UES opening increased (p<0.05) following exercise. Duration to attain Shaker Exercise performance goals varied among participants. IK was more easily attained than IM. Only 50% and 70% of those enrolled initially were able to complete the exercise duration and attain its IK and IM goals, respectively. However, those who stayed in the program attained the IK and IM goals (100% and 74%, respectively). Most dropouts occurred in the first two weeks of exercise. Performance of the exercise was associated with mild muscle discomfort that resolved spontaneously after a couple of weeks. We concluded that although the Shaker Exercise can be performed independently, a structured and gradually progressive program is needed to attain the exercise goals completely.

Transient failure of opening of the lower oesophageal sphincter on upright oesophagrams: radiographic and clinical findings

The purpose of our study was to determine the frequency, radiographic features, and clinical importance of transient failure of opening of the lower oesophageal sphincter (LOS) on upright double-contrast views of the oesophagus. A computerized search of radiology records identified 16 patients who had transient failure of opening of the LOS on upright views from biphasic oesophagrams or upper gastrointestinal tract examinations using high-density barium but normal opening of the LOS on prone views using low-density barium. The radiographic findings were reviewed and correlated with the clinical and manometric findings. In all cases, barium studies revealed tapered, beaklike narrowing of the distal oesophagus on upright double-contrast views, with a normal-appearing distal oesophagus, normal opening of the LOS, and intact peristalsis on prone single-contrast views. Only seven patients (44%) had dysphagia. Five of these patients had clinical follow-up, and the dysphagia improved or resolved without specific treatment for LOS dysfunction in four. The remaining patient had persistent dysphagia, but this individual had polymyositis as the likely cause for his dysphagia. Manometry revealed incomplete relaxation of the LOS in two patients and normal relaxation in one. Our experience suggests that failure of opening of the LOS may be observed as a transient finding of little clinical importance on upright double-contrast views of the oesophagus using high-density barium, with normal opening of the LOS on prone single-contrast views using low-density barium. It is important to be aware of this finding, so that it is not mistaken for achalasia or other abnormalities of the distal oesophagus.

Inflammation induced changes in arachidonic acid metabolism in cat LES circular muscle

Myogenic lower esophageal sphincter (LES) tone is maintained by arachidonic acid metabolites, such as PGF(2alpha) and thromboxane A(2)/B(2). Experimental esophagitis in cat reduces LES in vivo pressure and in vitro tone. Because IL-1beta may mediate esophagitis-associated reduction in ACh release in esophagus, we examined whether IL-1beta may also play a role in esophagitis-induced reduction of LES tone. A cat model of experimental esophagitis was obtained by repeated esophageal perfusion with HCl (Biancani P, Barwick K, Selling J, and McCallum R. Gastreonterology 87: 8-16, 1984 and Sohn UD, Harnett KM, Cao W, Rich H, Kim N, Behar J, and Biancani P. J Pharmacol Exp Ther 283: 1293-1304, 1997.). LES circular muscle strips were examined in muscle chambers as previously described (Biancani P, Billett G, Hillemeier C, Nissenshon M, Rhim BY, Sweczack S, and Behar J. Gastroenterology 103: 1199-1206, 1992). Levels of inflammatory mediators were measured. IL-1beta levels were higher in esophagitis than in normal LES. IL-1beta reduced normal LES tone, and the reduction was reversed by catalase, suggesting a role of H(2)O(2). This was confirmed by IL-1beta-induced production of H(2)O(2) in normal LES and elevated H(2)O(2) levels in esophagitis. H(2)O(2) by itself is sufficient to explain the changes that occur in the muscle, reducing its ability to contract. H(2)O(2) increased PGE(2) in normal LES, and PGE(2) levels were elevated in esophagitis LES, whereas PGF(2alpha) levels were unchanged. H(2)O(2) also increased levels of 8-isoprostanes, stable prostaglandin-like compounds formed by free radical-induced peroxidation of arachidonic acid, and 8-isoprostane levels were elevated in esophagitis. The PGF(2alpha) analog 8-iso-PGF(2alpha) caused little contraction of LES strips but reduced PGF(2alpha) binding and contraction of normal LES. In esophagitis, PGF(2alpha) binding and contraction were reduced in LES, suggesting that isoprostanes may contribute to reduction in tone in esophagitis. The data suggest that, in esophagitis, IL-1beta causes production of H(2)O(2). H(2)O(2) increases PGE(2), which relaxes the LES, and 8-iso-F(2alpha), which blocks PGF(2alpha)-mediated contraction.

Management of malignant stricture of the esophagogastric junction with a newly designed self-expanding metal stent with an antireflux mechanism

BACKGROUND AND STUDY AIMS

When stents are placed across the esophagogastric junction for palliative treatment of malignant strictures, they may lead to esophagogastric reflux. The aim of this study was to compare the effectiveness of a newly designed antireflux stent with that of a standard open stent and a currently available antireflux stent (Dostent) in preventing gastroesophageal reflux symptoms in patients with inoperable cancer at the esophagogastric junction.

PATIENTS AND METHODS

Thirty-six consecutive patients with cancer at the esophagogastric junction were randomly assigned to undergo placement of a newly designed antireflux stent (n = 12), a Dostent (n = 12), or a standard open stent (n = 12). Technical and clinical success, dysphagia score, reflux symptoms, complications and ambulatory 24-h esophageal pH monitoring were assessed.

RESULTS

The technical success rates were 100 %. After 1 week, dysphagia had improved in all patient groups ( P < 0.05), but the degree of improvement did not differ between the three groups. The DeMeester score was significantly lower in the group with the newly designed antireflux stent than in the other groups. The fraction of the total recording time during which esophageal pH was below 4 was 3.14 +/- 5.78 % using the newly designed antireflux stent, in comparison with 29.25 +/- 15.41 % in the Dostent group and 15.01 +/- 11.72 % in the standard open stent group ( P < 0.001). Fewer reflux episodes occurred with the newly designed antireflux stent than with the Dostent or standard open stent. There were no complications with any of the three stents.

CONCLUSIONS

The newly designed antireflux stent is effective in relieving dysphagia caused by malignant cancer at the esophagogastric junction. The newly designed antireflux stent is significantly more effective in preventing gastroesophageal reflux than currently available antireflux stents.

Motor and sensory function of the esophagus: revelations through ultrasound imaging

Catheter based high frequency intraluminal ultrasound (HFIUS) imaging is a powerful tool to study esophageal sensory and motor function and dysfunction in vivo in humans. It has provided a number of important insights into the longitudinal muscle function of the esophagus. Based on the ultrasound images and intraluminal pressure recordings, it is clear that there is synchrony in the timing as well as the amplitude of contraction between the circular and the longitudinal muscle layers of the esophagus in normal subjects. On the other hand, in patients with spastic disorders of the esophagus, there is an asynchrony of contraction related to the timing and amplitude of contraction of the two muscle layers during peristalsis. Achalasia, diffuse esophageal spasm, and nutcracker esophagus (spastic motor disorders of the esophagus) are associated with hypertrophy of the circular as well as longitudinal muscle layers. A sustained contraction of the longitudinal muscle of the esophagus is temporally related to chest pain and heartburn and may very well be the cause of symptoms. Longitudinal muscle function of the esophagus can be studied in vivo in humans using dynamic ultrasound imaging. Longitudinal muscle dysfunction appears to be important in the motor and sensory disorders of the esophagus.

Manometric characteristics of the gastroesophageal junction after anterior versus posterior partial fundoplication

How best to surgically treat GERD is an unresolved issue. To increase our insights into the fundoplication procedures, functional consequences for the gastroesophageal junction of an anterior or a posterior partial fundoplication were studied by manometry. Patients were randomly selected from a larger study in a randomised comparison between posterior and anterior partial fundoplications. The manometric studies were done 12 months after respective procedures in 24 patients. The motor characteristics of the esophagus and lower esophageal sphincter (LES) function were determined by use of sleeve catheter manometry. The manometric characteristics of the esophageal body were similar in the study groups except for the ramp pressure. This was significantly higher in patients with posterior partial fundoplications. The posterior group had significantly longer total length (P < 0.02) as well as longer intra-abdominal portions (P = 0.07) of the LES while the basal tone, albeit numerically higher, did not reach statistical significance. Water-swallow induced LES relaxations reached lower nadir values in the anterior group (1.7 vs 2.7 mmHg). Gas distension triggered few transient LES relaxations in both study groups while common cavities were more frequently observed in those having an anterior partial wrap (P < 0.01). A posterior partial fundoplication is followed by manometric characteristics suggesting a well functioning antireflux barrier with some obstruction to bolus passage as well as restricted venting of air from the stomach. The manometric mechanisms behind the inferior reflux control achieved by a Watson type of anterior partial wrap has now been further elucidated.

Mechanisms of gastroesophageal reflux in critically ill mechanically ventilated patients

BACKGROUND & AIMS

Gastroesophageal reflux is a major problem in mechanically ventilated patients and may lead to pulmonary aspiration and erosive esophagitis. Transient lower esophageal sphincter relaxations are the most common mechanism underlying reflux in nonventilated patients. The mechanisms that underlie reflux in critically ill ventilated patients have not been studied. The aim of this study was to determine the mechanisms underlying gastroesophageal reflux in mechanically ventilated patients in the intensive care unit.

METHODS

In 15 mechanically ventilated intensive care unit patients, esophageal motility, pH, and intraluminal impedance (11/15 patients) were recorded for 1 hour before and 5 hours during continuous nasogastric feeding.

RESULTS

Basal lower esophageal sphincter pressure was uniformly low (2.2 +/- 0.4 mmHg). The median (interquartile range) acid exposure (pH <4) was 39.4% (0%-100%) fasting and 32% (7.5%-94.2%) fed. Acid reflux occurred in 10 patients, but slow drifts in esophageal pH were also an important contributor to acid exposure. If esophageal pH decreased to pH <4, it tended to remain so for prolonged periods. A total of 46 acid reflux events were identified. Most (55%) occurred because of absent lower esophageal sphincter pressure alone; 45% occurred during straining or coughing.

CONCLUSIONS

Gastroesophageal reflux in mechanically ventilated patients is predominantly due to very low or absent lower esophageal sphincter pressure, often with a superimposed cough or strain. These data suggest that measures that increase basal LES pressure may be useful to prevent reflux in ventilated patients.

Relevance of volume and proximal extent of reflux in gastro-oesophageal reflux disease

In patients with gastro-oesophageal reflux disease (GORD), oesophageal and extraoesophageal symptoms are traditionally attributed to increased contact time between the mucosa and refluxates. However, the volume of reflux may be important by increasing the total amount of highly concentrated damaging substances, either by prolonging distal mucosal exposure or by expanding to more proximal areas. To date, it has not been possible to accurately measure the volume of gastro-oesophageal reflux. Determination of the volume of reflux will help to better understand the pathophysiology of GORD and to evaluate the efficacy of antireflux treatments.

Non-acid gastroesophageal reflux: documenting its relationship to symptoms using multichannel intraluminal impedance (MII)

Multichannel intraluminal impedance (MII) is a new technique for evaluating esophageal function and gastroesophageal reflux. This technique depends on changes in resistance to alternating current between two metal electrodes produced by the presence of liquid or gas bolus inside the esophageal lumen. Combined multichannel intraluminal impedance and manometry (MII-EM) provides simultaneous information on intraluminal pressure changes and bolus movement whereas combined multichannel intraluminal impedance and pH (MII-pH) allows detection of gastroesophageal reflux (GER) episodes irrespective of their pH values (i.e. acid and non-acid reflux). Combined MII-pH testing presents a new paradigm for reflux testing. In MII-pH studies reflux events are no longer primarily detected by pH. Refluxate presence, distribution and clearing is primarily detected by MII and simply characterized as acid or non-acid based on pH change and as liquid, gas or mixed based on MII. MII determines refluxate clearance time while pH measures acid clearance time. MII-pH shows promise to become an important clinical tool, particularly to assess GER in the postprandial period and in patients with persistent symptoms on acid suppression therapy.

[Barrett's esophagus]

INTRODUCTION

It is widely accepted that long segments of Barrett's esophagus are caused by end-stage gastroesophageal reflux disease (GERD), but little is known about the correlation of severity of GERD and extent of metaplasia.

METHODS

Twenty normal volunteers and 142 patients with different extent of intestinal metaplasia (39 with intestinal metaplasia limited to the esophagogastric junction, 48 with short segments of Barrett's esophagus, and 55 with long segments) underwent manometry and combined pH-bilirubin monitoring.

RESULTS

The extent of intestinal metaplasia correlated to the exposition of gastric and duodenal juice in the esophagus and inversely with a competent lower esophageal sphincter.

CONCLUSIONS

The extent of intestinal metaplasia is related to the severity of GERD.

Long-term effect of fundoplication on motility of the oesophagus and oesophagogastric junction

BACKGROUND

This study assessed the long-term effect of Nissen fundoplication on oesophageal and oesophagogastric junction (OGJ) motility.

METHODS

Symptoms were scored and oesophageal manometry performed in 34 consecutive patients with chronic gastro-oesophageal reflux disease, before, 3 months after and 2 years after surgery.

RESULTS

Distal peristaltic amplitude increased from a median of 57 (95 per cent confidence interval (c.i.) 18 to 107) mmHg to 86 (95 per cent c.i. 54 to 208) mmHg (P < 0.001) at 3 months and 92 (45 to 210) mmHg (P < 0.001) at 2 years. In four patients the amplitude increased to more than 180 mmHg and three of these patients reported odynophagia. After surgery, a linear relationship was observed between the peristaltic amplitude and nadir OGJ relaxation pressure at 3 months (r(s) = 0.68, P < 0.001) and 2 years (r(s) = 0.64, P < 0.001). A significant correlation was also found between amplitude and both basal OGJ pressure and intrabolus pressure at 3 months (r(s) = 0.58, P < 0.001 and r(s) = 0.63, P < 0.001 respectively) and 2 years (r(s) = 0.71, P < 0.001 and r(s) = 0.49, P = 0.024). There was a relationship between peristaltic amplitude and the odynophagia score at 2 years (r(s) = 0.60, P = 0.017).

CONCLUSION

Within 3 months of fundoplication the amplitude of oesophageal peristalsis increased substantially, leading to a nutcracker oesophagus and odynophagia in a subgroup of patients. These phenomena did not appear to progress with time.

Regional Differences in the Manifestation of Gastrointestinal Motor Disorders in Type 1 Diabetic Patients with Autonomic Neuropathy

OBJECTIVE

The aim of this work was to establish the prevalence and severity of different gastrointestinal symptoms and their relationships to esophageal, gastric and recto-anal motor disturbances by manometry in patients with Type 1 diabetes mellitus and autonomic neuropathy.

PATIENTS AND METHODS

Sixteen patients (mean age: 53.4 +/- 14.9 years) with long standing type 1 diabetes mellitus (mean diabetes duration: 22.1 +/- 14.7 years) and autonomic neuropathy (mean Ewing score: 5.73 +/- 2.34) were investigated. The gastrointestinal symptom scores were established by using the Talley dyspepsia questionnaire. The motor function of the digestive tract was tested in the esophagus, in the stomach, and in the ano-rectum by perfusion manometry.

RESULTS

Manometric evaluation of the esophagus did not reveal significant abnormalities in the region of the upper sphincter in patients with diabetes mellitus. In contrast, diabetic patients had decreased peristaltic wave amplitude, prolonged duration, decreased wave propagation velocity, and increased number of simultaneous contractions in the esophageal body, and decreased lower esophageal sphincter pressures with prolonged relaxation compared to the age- and sex-matched controls. Symptom analysis showed correlations between reflux symptoms and LES relaxation times, and between dysphagia scores and esophageal body peristaltic wave duration, propagation velocity and the rate of simultaneous contractions. In the gastric antrum, frequent, and often severe, fasting motility disorders were observed, which had no correlation with dyspeptic symptoms. In the ano-rectal region the diabetic patients had a lower squeezing-resting pressure difference, and impaired fecal expulsive function. Motility disorders were simultaneously present at multiple parts of the gastrointestinal tract in 13/16 cases.

CONCLUSIONS

In patients with type 1 diabetes mellitus and autonomic neuropathy gastrointestinal motility disorders were observed frequently, and in most of the cases simultaneously. While esophageal and ano-rectal symptoms correlated better with the manometric abnormalities, the lack of correlation between the impaired fasting gastric motility and dyspeptic symptoms shows that, on the basis of the clinical symptom analysis, the prevalence of such motor disorders could be underestimated. The early recognition of gastrointestinal motility disorders may be important for the better long-term management of patients with type 1 diabetes mellitus.

[The relationship between lower esophageal sphincter motility and function with gastroesophageal reflux disease]

SUBJECTIVE

To evaluate the motor pattern and function of lower esophageal sphincter (LES) and esophageal acidification episodes before and after intragastric load in the patients with gastroesophageal reflux disease (GERD) and in controls, and identify the relationship between transient LES relaxations (TLESR), and low LES pressure and acid reflux episodes.

METHODS

All of them undergone a pH/manometric monitoring during fasting and for 3 h after meal.

RESULTS

68 episodes of acid reflux were detected totally, and 43% (29/68) occurred during transient LES relaxation, 31% (21/68) occurred after down drifts (<1 mmHg/s) in basal LES pressure or in persisting low basal LES pressure. There were more patients with acid reflux episodes compared TLESR in patients with GERD than in volunteers (P <0.05). More acid reflux episodes in patients with GERD than in controls (P <0.001). But ingestion of the meal induced a significant increase in the TLESR frequency during the first and second postprandial hours.

CONCLUSIONS

The pathophysiology of gastroesophageal reflux disease is multifactorial. It is established that impaired lower esophageal sphincter function play an important role in GERD. Transient LES relaxation could probably be considered one of the pathophysiologic mechanisms of gastroesophageal reflux, but it is not a necessary prerequisite for the acidification events. Some reflux episodes result from low resting LES pressure rather than from transient LES relaxations alone.