Gastro-esophageal reflux disease confined to the sphincter

Magnetic sphincter augmentation: paradigm change or just another device in the surgeon's toolbox?

The common denominator for virtually all episodes of gastroesophageal reflux in health and disease is the loss of the barrier that confines the distal esophagus to the stomach. Factors important in maintaining the function of the barrier are its pressure, length and position. In early reflux disease, overeating, gastric distention and delayed gastric emptying led to a transient loss of the barrier. A permanent loss of the barrier occurs from inflammatory injury to the muscle allowing free flow of gastric juice into the esophageal body. Corrective therapy requires augmentation or restoration of the barrier referred to more commonly as the lower esophageal sphincter.

In healthy volunteers, immunohistochemistry supports squamous to columnar metaplasia as mechanism of expansion of cardia, aggravated by central obesity

INTRODUCTION

Recently, we showed that the length of cardiac mucosa in healthy volunteers correlated with age and obesity. We have now examined the immunohistological characteristics of this expanded cardia to determine whether it may be due to columnar metaplasia of the distal oesophagus.

METHODS

We used the squamocolumnar junction (SCJ), antral and body biopsies from the 52 Helicobacter pylori-negative healthy volunteers who had participated in our earlier physiological study and did not have hiatus hernia, transsphincteric acid reflux, Barrett's oesophagus or intestinal metaplasia (IM) at cardia. The densities of inflammatory cells and reactive atypia were scored at squamous, cardiac and oxyntocardiac mucosa of SCJ, antrum and body. Slides were stained for caudal type homeobox 2 (CDX-2), villin, trefoil factor family 3 (TFF-3) and liver-intestine (LI)-cadherin, mucin MUC1, Muc-2 and Muc-5ac. In addition, biopsies from 15 Barrett's patients with/without IM were stained and scored as comparison. Immunohistological characteristics were correlated with parameters of obesity and high-resolution pH metry recording.

RESULTS

Cardiac mucosa had a similar intensity of inflammatory infiltrate to non-IM Barrett's and greater than any of the other upper GI mucosae. The immunostaining pattern of cardiac mucosa most closely resembled non-IM Barrett's showing only slightly weaker CDX-2 immunostaining. In distal oesophageal squamous mucosa, expression of markers of columnar differentiation (TFF-3 and LI-cadherin) was apparent and these correlated with central obesity (correlation coefficient (CC)=0.604, p=0.001 and CC=0.462, p=0.002, respectively). In addition, expression of TFF-3 in distal oesophageal squamous mucosa correlated with proximal extension of gastric acidity within the region of the lower oesophageal sphincter (CC=-0.538, p=0.001).

CONCLUSIONS

These findings are consistent with expansion of cardia in healthy volunteers occurring by squamo columnar metaplasia of distal oesophagus and aggravated by central obesity. This metaplastic origin of expanded cardia may be relevant to the substantial proportion of cardia adenocarcinomas unattributable to H. pylori or transsphincteric acid reflux.

Role of the lower esophageal sphincter on acid exposure revisited with high-resolution manometry

BACKGROUND

The objective of this study was to investigate the role of lower esophageal sphincter (LES) length and pressure on acid exposure with high-resolution manometry (HRM).

STUDY DESIGN

After Institutional Review Board approval, a retrospective review of a prospectively maintained database identified patients who had undergone HRM and 24-hour pH studies. Abdominal LES length (AL) ≤1 cm and overall LES length ≤2 cm were considered inadequate. A new parameter called lower esophageal sphincter pressure integral (LESPI) was analyzed in this study. Distal esophageal acid exposure was analyzed in relation to LES parameters.

RESULTS

One hundred eight patients (inadequate AL, n = 54; inadequate overall LES length, n = 54) satisfied study criteria. Patients with inadequate AL had considerably lower LESPI and LES pressure. They also had more severe acid exposure and higher DeMeester score. However, inadequate overall LES length was not associated with abnormal acid exposure. Patients with a positive pH study had considerably lower LESPI than patients with a negative pH study. Inadequate AL and low LESPI (<400 mmHg/s/cm) had a synergistic effect on acid reflux. Multivariate logistic regression analysis identified inadequate AL, low LESPI, and male sex as predictors of a positive pH study.

CONCLUSIONS

Using HRM, inadequate AL (≤1cm) and low LESPI (<400 mmHg/s/cm) are associated with gastroesophageal reflux disease and appear to have a synergistic effect on the severity of distal esophageal acid exposure. LESPI, which is a function of both sphincter length and pressure, appears to be the most sensitive HRM parameter for distal esophageal acid exposure.

The dilated distal esophagus: a new entity that is the pathologic basis of early gastroesophageal reflux disease

Present management algorithms for patients with gastroesophageal reflux disease (GERD) limit endoscopy to patients with advanced disease. When endoscopy is performed, biopsy is limited to patients who have a visible columnar-lined esophagus. Biopsy is not recommended for patients whose endoscopy is normal. This algorithm results in the failure to evaluate patients with early stages of GERD at a pathologic level. We report 714 patients with normal endoscopic findings irrespective of symptoms who had adequate biopsies taken from the squamocolumnar junction and the area 1-cm distal to this from mucosa that had rugal folds. Concurrent biopsies were also taken from the gastric body and/or antrum. All patients had a gap between their esophageal squamous epithelium and gastric oxyntic mucosa in the junctional region composed of oxyntocardiac ± cardiac ± intestinal epithelia. A total of 643 (90.1%) patients had no significant pathology in the gastric antrum and/or body, indicating that the squamooxyntic gap was an isolated abnormality in this region in all but 71 (9.9%) patients. The gap contained only oxyntocardiac epithelium in 71 (9.9%) patients, cardiac mucosa without intestinal metaplasia in 482 (67.5%) patients, and intestinal metaplasia in 161 (22.6%) patients. The pathologic interpretation of biopsies taken from the gastroesophageal junction is confusing and has significant interobserver variation. This results from lack of agreement as to whether these biopsies originate in the proximal stomach ("gastric cardia") or in the esophagus. We provide evidence that the presence of oxyntocardiac ± cardiac ± intestinal epithelia in biopsies from patients who are endoscopically normal is diagnostic of a dilated GERD-damaged distal esophagus. The dilated distal esophagus is the pathologic manifestation of destruction of the abdominal segment of the lower esophageal sphincter. Its presence is the pathologic basis of early GERD, which is missed if patients who are endoscopically normal are not biopsied, as is the present recommendation. Its recognition allows for accurate and evidence-based interpretation of biopsies from this region and removes the present confusion and permits the development of a reproducible pathologic diagnostic method.

The histologic squamo-oxyntic gap: an accurate and reproducible diagnostic marker of gastroesophageal reflux disease

The present definition of gastroesophageal reflux disease (GERD) is based on clinical criteria that are difficult to reproduce accurately. This study provides a method to develop a histologic definition of GERD based on biopsies obtained from the affected esophagus. Pathology reports from 1655 patients who had upper gastrointestinal endoscopy and biopsy according to a systematic protocol were reviewed. Biopsies were obtained from the esophagus, around the gastroesophageal junction and the stomach: proximal, body, and antrum. Patients who had oxyntocardiac±cardiac±intestinal epithelia between the squamous epithelium proximally and the proximal limit of gastric oxyntic mucosa distally were defined as having a squamo-oxyntic gap. The length of the squamo-oxyntic gap varied from less than 1 cm in 1399 (84.5%) patients to greater than 5 cm in 80 (4.8%) of the patients. Only oxyntocardiac epithelium was seen in 190 (11.5%) of the patients, oxyntocardiac and cardiac epithelia in 898 (54.3%), and intestinal metaplasia in addition to the other 2 epithelial types in 567 (34.2%). The prevalence of intestinal metaplasia was directly proportional to length of the squamo-oxyntic gap, being 24.3% (340/1399) when the length was <1 cm, and 83.5% (147/176) with length 1 to 5 cm. All patients with a length more than 5 cm had intestinal metaplasia. The distribution of the 3 epithelia was constant irrespective of the length of the squamocolumnar gap; intestinal metaplasia, when present, was seen maximally in the proximal region of the gap, cardiac epithelium intermediate and oxyntocardiac epithelium in the most distal segment of the gap. The squamo-oxyntic gap started in a dilated region distal to the end of the tubular esophagus and distal to the proximal limit of the rugal folds and extended into the tubular esophagus. Distal gastric biopsies showed no evidence of significant inflammation, intestinal metaplasia or Helicobacter pylori infection in 1543 (93.2%) of the patients, indicating that the squamo-oxyntic gap was largely independent of gastric pathology. We provide evidence that the squamo-oxyntic gap is equivalent to the columnar-lined esophagus. Its presence is a specific and sensitive indicator of reflux and can be used as a cellular criterion to define GERD. The length of the squamo-oxyntic gap provides an accurate assessment of the severity of chronic GERD. The distal limit of the squamo-oxyntic gap, which is the junction between oxyntocardiac and gastric oxyntic epithelium is the true gastroesophageal junction. The presence of intestinal metaplasia within the squamo-oxyntic gap is the most accurate risk indicator for esophageal adenocarcinoma and defines Barrett esophagus.

The impact of gastric distension on the lower esophageal sphincter and its exposure to acid gastric juice

BACKGROUND AND AIMS

The lower esophageal sphincter (LES) in patients with gastroesophageal reflux disease often has a low resting pressure and a short abdominal length. The mechanism by which this occurs is unknown. We hypothesize that gastric distension causes progressive effacement of the abdominal portion of the LES, exposing it to acid injury resulting in mucosal and sphincter damage. Our aim was to assess in normal subjects the effect of gastric distension on the LES length and pressure and its exposure to acid gastric juice.

METHODS

Eleven asymptomatic volunteers had their LES length and pressure measured before and during gastric distension. The location of the pH step-up point (shift from gastric pH to a pH >4) was also measured before and after distension.

RESULTS

Progressive gastric distension with air resulted in progressive shortening of LES (R = 0.89, P < 0.0001). After infusion of 750 cc of air there was a significant reduction in the median LES length from 4 to 2.6 cm (P = 0.001). This change occurred in the abdominal length of the LES (2.6-1.4 cm [P = 0.001]) and not in the thoracic length. At rest the pH step-up point was 0.5 cm above the lower border of the LES and with distension moved a median of 1 cm cephalad within the LES. Simultaneously with the loss of length there was a reduction in LES pressure (27.4-23.4 mm Hg, P = 0.02).

CONCLUSIONS

Gastric distension causes progressive shortening of the abdominal length of the LES and a reduction in its pressure. The process exposes the effaced mucosa and sphincter to acid gastric juice.

Where are you and how do we find you? The dilemma of identifying Barrett's epithelium before adenocarcinoma of the esophagus

The incidence of esophageal adenocarcinoma in white males has been increasing steadily over the past decade. However, attempts to identify the precursor lesion, intestinal metaplasia of the esophagus, or early in-situ cancers have been dismal, with no increase in the diagnosis of early cancers over 9 years of follow-up, as noted in the study by Cooper et al. Important predictors of survival,such as a previous diagnosis of gastroesophageal reflux disease, endoscopy, and the diagnosis of intestinal metaplasia, continue to represent a minority of patients who present with esophageal adenocarcinoma. A discussion on the possible pathophysiology, and reasons for the poor diagnostic yields in spite of performing more endoscopies, are presented. It may be that most patients are relatively asymptomatic, or have very distal, endoscopically imperceptible intestinal metaplasia. Over time, factors that encourage localized, distal esophageal reflux may be the insidious culprit that leads to intestinal metaplasia.

Microvasive gastric stapler: the device, technique, and preclinical results

Antireflux surgery was initiated in 1950 with the Allison repair, improved in the 1970s with the introduction of the partial and complete fundoplication, and performed laparoscopically in the 1990s. Today the challenge is to perform the procedure endoscopically. The physiology of the gastroesophageal barrier and the causes and consequences of its failure are discussed. The experimental development of an intraluminal transgastric valvuloplasty is discussed, and comments are made about the future role of endoscopic repairs.