Relationship between rate of change in acid exposure along the esophagus and length of Barrett's epithelium

The prevalence of Barrett 's esophagus in Iranian patients with gastrointestinal symptoms: a systematic review and meta-analysis

BACKGROUND

Barrett's esophagus (BE) is a premalignant columnar metaplasia of the esophagus that predisposes victims to esophageal adenocarcinoma (EAC). Depending on differences in the study population and risk factors, the prevalence of BE may vary, from 0.4 to 20% globally. The current study aimed to systematically review and analyse the prevalence of BE in in patients with gastrointestinal symptoms in Iran. Furthermore, gastrointestinal malignancies are among the most common tumours in Iran, making this study even more significant.

METHODS

A systematic search was carried out in PubMed, Web of Science, Scopus, and EMBASE as well as some domestic databases including SID, Magiran, IranDoc, IranMedex from inception to the end of 2023. We included all cross-sectional studies which reported the prevalence of BE and calculated pooled prevalence.

RESULTS

The results of the analysis, including 9 studies in a total of 4978 cases (213 Barret diagnoses), revealed that by the results of these studies, the prevalence of Barret's esophagus is 4.4% [I2 = 94.9% [92.2%; 96.6%]/p-value < 0.0001]. Subgroup analysis, divided by region and year, revealed significant differences between groups.

CONCLUSIONS

The epidemiology of BE in Iran is not completely identified. This is the first systematic review and meta-analysis evaluating the prevalence and of BE in Iran. Due to the importance of BE in progressing to esophageal adenocarcinoma, much importance should be given to its timely diagnosis. It is strongly recommended to conduct more comprehensive studies including more patients in this field.

Association between hiatal hernia and Barrett's esophagus: an updated meta-analysis with trial sequential analysis

BACKGROUND

Barrett's esophagus (BE) is a precursor of esophageal adenocarcinoma. It is critical to recognize the risk factors associated with BE.

OBJECTIVES

The present meta-analysis aims to systematically estimate the association of hiatal hernia with the risk of BE.

DESIGN

A meta-analysis with trial sequential analysis.

DATA SOURCES AND METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched. The pooled odds ratios (ORs) and adjusted ORs (aORs) with their 95% confidence intervals (CIs) were calculated for the combined estimation of unadjusted data and data adjusted for confounders, respectively. Heterogeneity was quantified using the Cochrane Q test and I² statistics. Subgroup, meta-regression, and leave-one-out sensitivity analyses were employed to explore the sources of heterogeneity.

RESULTS

Forty-seven studies with 131,517 participants were included. Based on the unadjusted data from 47 studies, hiatal hernia was significantly associated with an increased risk of any length BE (OR = 3.91, 95% CI = 3.31-4.62, p < 0.001). The heterogeneity was significant (I² = 77%; p < 0.001) and the definition of controls (p = 0.014) might be a potential contributor to heterogeneity. Based on the adjusted data from 14 studies, this positive association remained (aOR = 3.26, 95% CI = 2.44-4.35, p < 0.001). The heterogeneity was also significant (I² = 65%; p < 0.001). Meta-analysis of seven studies demonstrated that hiatal hernia was significantly associated with an increased risk of long-segment BE (LSBE) (OR = 10.01, 95% CI = 4.16-24.06, p < 0.001). The heterogeneity was significant (I² = 78%; p < 0.001). Meta-analysis of seven studies also demonstrated that hiatal hernia was significantly associated with an increased risk of short-segment BE (OR = 2.76, 95% CI = 2.05-3.71, p < 0.001). The heterogeneity was not significant (I² = 30%; p = 0.201).

CONCLUSION

Hiatal hernia should be a significant risk factor for BE, especially LSBE.

REGISTRATION

PROSPERO registration number CRD42022367376.

Esophageal Hypocontractile Disorders and Hiatal Hernia Size Are Predictors for Long Segment Barrett's Esophagus

Background/Aims

Presently, there is paucity of information about clinical predictors, especially esophageal motor abnormalities, for long segment Barrett's esophagus (LSBE) as compared with short segment Barrett's esophagus (SSBE). The aims of this study are to compare the frequency of esophageal function abnormalities between patients with LSBE and those with SSBE and to determine their clinical predictors.

Methods

This was a multicenter cohort study that included all patients with a diagnosis of BE who underwent high-resolution esophageal manometry. Motility disorders were categorized as hypercontractile disorders or hypocontractile disorders and their frequency was compared between patients with LSBE and those with SSBE. Multivariable logistic regression modeling was used to calculate the odds of being diagnosed with LSBE relative to SSBE for demographics, comorbidities, medication use, endoscopic findings, and the type of motility disorders.

Results

A total of 148 patients with BE were identified, of which 89 (60.1%) had SSBE and 59 (39.9%) LSBE. Patients with LSBE had a significantly larger hiatal hernia and higher likelihood of erosive esophagitis than patients with SSBE (P = 0.002). Patients with LSBE had a significantly lower mean LES resting pressure, distal contractile integral, distal latency, and significantly higher failed swallows and hypocontractile motility disorders than those with SSBE (P < 0.05). Hiatal hernia and hypocontractile motility disorder increased the odds of LSBE by 38.0% and 242.0%, as opposed to SSBE.

Conclusions

The presence of a hypocontractile motility disorder increased the risk for LSBE. Furthermore, the risk for LSBE was directly associated with the length of the hiatal hernia.

Esophageal Function Abnormalities in Patients With Barrett's Esophagus

Various esophageal functional abnormalities have been described in patients with Barrett's esophagus (BE). A significantly higher esophageal acid exposure especially in the supine position has been documented in BE, as compared with the other gastroesophageal reflux disease phenotypes. In addition, weakly acidic reflux and duodenogastroesophageal reflux are more common in BE patients. The presence of Barrett's mucosa reduces esophageal mucosal impedance, occasionally to a level that prevents detection of reflux episodes. Reduced amplitude contractions and lower esophageal sphincter basal pressure are more common in BE patients as compared with the other gastroesophageal reflux disease groups. Ineffective esophageal motility is the most commonly defined motor disorder in BE. Reduced chemoreceptor and mechanoreceptor sensitivity to acid and balloon distention, respectively, have been suggested to explain lack or significantly less reports of reflux-related symptoms by BE patients.

Influence of metabolic syndrome on upper gastrointestinal disease

A recent increase in the rate of obesity as a result of insufficient physical exercise and excess food consumption has been seen in both developed and developing countries throughout the world. Additionally, the recent increased number of obese individuals with lifestyle-related diseases associated with abnormalities in glucose metabolism, dyslipidemia, and hypertension, defined as metabolic syndrome (MS), has been problematic. Although MS has been highlighted as a risk factor for ischemic heart disease and arteriosclerotic diseases, it was also recently shown to be associated with digestive system disorders, including upper gastrointestinal diseases. Unlike high body weight and high body mass index, abdominal obesity with visceral fat accumulation is implicated in the onset of various digestive system diseases because excessive visceral fat accumulation may cause an increase in intra-abdominal pressure, inducing the release of various bioactive substances, known as adipocytokines, including tumor necrosis factor-α, interleukin-6, resistin, leptin, and adiponectin. This review article focuses on upper gastrointestinal disorders and their association with MS, including obesity, visceral fat accumulation, and the major upper gastrointestinal diseases.

The relationship between length of Barrett's oesophagus mucosa and body mass index

BACKGROUND

Length of Barrett's oesophagus (BE) is a risk factor for oesophageal cancer. The underlying mechanisms that determine BE length are nor fully known.

AIM

To determine if there is a correlation between obesity and length of BE.

METHODS

Using a population-based study, 381 patients diagnosed with Barrett's oesophagus between 1999 and 2013 were included. Body mass index (BMI) at the time of BE diagnosis was calculated. Upper endoscopy reports were reviewed to obtain the length of BE. Spearman's correlation coefficient was performed to assess the strength of the relationship between Barrett's length and BMI. A multivariate logistic regression analysis was conducted to further examine the association between BMI and length of BE.

RESULTS

The adjusted odds ratio for each five-point increase in BMI was 1.5 (95% CI 1.24-1.81, P < 0.001). The mean BMI was significantly higher in patients with long segment BE as compared to patients with short segment BE (32.7 vs. 30.3, P = 0.001). There was also a positive trend in long segment BE as patients entered into higher BMI categories (Z = 4.25, P < 0.001). There was a significant correlation between BMI and length of BE (r = 0.25, P < 0.0001).

CONCLUSION

The study demonstrated a correlation between BMI and the length of Barrett's oesophagus mucosa. Thus, increased BMI is associated with longer segment of Barrett's oesophagus.

The dose of omeprazole required to achieve adequate intraesophageal acid suppression in patients with gastroesophageal junction specialized intestinal metaplasia and Barrett's esophagus

BACKGROUND

The mainstay of medical therapy for Barrett's esophagus is normalization of esophageal acid exposure with proton pump inhibitors (PPIs). However, the optimal dose and whether once daily or twice daily is required for acid suppression is unknown.

AIM

The purpose of this study was to assess whether adequate intra-esophageal acid suppression could be achieved with once daily versus twice daily omeprazole in patients with gastroesophageal specialized intestinal metaplasia (GEJSIM), short-segment (SSBE) and long-segment Barrett's esophagus (LSBE).

METHODS

Patients with GEJSIM and Barrett's esophagus underwent upper endoscopy with 48-h wireless pH capsule while on once daily 20 mg omeprazole for at least 1 week. If intra-esophageal acid was not adequately controlled, defined as pH value <4 for greater than 4.2 % of the time during the second 24-h period, omeprazole was increased to twice daily for 1 week and upper endoscopy with wireless pH capsule was repeated.

RESULTS

A total of 36 patients completed the study (10 patients had GEJSIM, 16 patients had SSBE, and 10 patients had LSBE). Normalization of intraesophageal pH was achieved in 28 patients (78 %) with once daily PPI and eight patients required twice daily PPI. There was no significant difference between the three groups in the proportion of patients requiring high dose PPI (GEJSIM 10 %, SSBE 25 %, LSBE 30 %, p = 0.526).

CONCLUSIONS

The majority of patients with Barrett's esophagus were controlled with once daily low dose PPI and only a minority required twice daily dosing, regardless of the length of Barrett's mucosa.

Characterization of bacterial biota in the distal esophagus of Japanese patients with reflux esophagitis and Barrett's esophagus

BACKGROUND

The distal esophagus harbors a complex bacterial population. We hypothesized that a better understanding of bacterial communities in the esophagus would facilitate understanding of the role of bacteria in esophageal disease. Here, we investigated bacterial composition in the distal esophagus in subjects with a normal esophagus, reflux esophagitis, and Barrett's esophagus.

METHODS

Two biopsy specimens were obtained from the distal esophagus at 1 cm above the gastroesophageal junction under endoscopic examination in 18 patients (6 each with normal esophagus, reflux esophagitis, and Barrett's esophagus) and used for histological examination and DNA extraction. Fragments of 16S rDNA genes were amplified by PCR using general bacterial primers, and bacterial populations were examined. A third biopsy specimen was taken from the patients with Barrett's esophagus to histologically confirm the replacement of squamous epithelium with columnar epithelium in the distal esophagus.

RESULTS

Endoscopic diagnoses of normal esophagus, esophagitis, and Barrett's esophagus were confirmed by histological findings. The total amount of bacterial DNA detected did not significantly differ among groups (p > 0.1). On average, each of the 18 subjects yielded about 350 clones, of which 40 were randomly picked and sequenced. Analysis of 147 16S rDNA sequences from 240 clones of 6 subjects with normal esophagus yielded four phyla, Proteobacteria (49%), Firmicutes (40%), Bacteroidetes (8%), and Actinobacteria (3%). Similar analysis of 139 16S rDNA sequences from 240 clones of 6 patients with reflux esophagitis yielded 6 phyla, Proteobacteria (43%), Firmicutes (33%), Bacteroidetes (10%), Fusobacteria (10%), Actinobacteria (2%), and TM7 (2%). while that of 138 16S rDNA sequences from 240 clones of 6 cases of Barrett's esophagus yielded 5 phyla, Firmicutes (55%), Proteobacteria (20%), Bacteroidetes (14%), Fusobacteria (9%), and Actinobacteria (2%). Thus, microbial communities differed among patients with a normal esophagus, reflux esophagitis and Barrett's esophagus.

CONCLUSIONS

Esophageal bacterial composition differs under conditions of normal esophagus, reflux esophagitis, and Barrett's esophagus. Diverse bacterial communities may be associated with esophageal disease.

Characteristics of gastro-esophageal reflux episodes in Barrett's esophagus, erosive esophagitis and healthy volunteers

BACKGROUND

Gastro-esophageal reflux is considered a major culprit in the pathogenesis of Barrett's esophagus (BE). Still, there is controversy on the role of weakly acidic and weakly alkaline reflux in BE. To compare characteristics of reflux episodes patients with BE, erosive esophagitis (EE), and healthy volunteers (HV).

METHODS

One hundred consecutive patients with BE (75 short-segment BE, 25 long-segment BE), 50 with EE and 48 HV underwent multichannel intraluminal impedance-pH off-therapy. We quantified esophageal acid exposure, characteristics, and proximal extension of reflux episodes.

KEY RESULTS

Total and acid reflux episodes gradually increased from HV [28 (17.5-43) and 18 (8-31)] to EE [73.5 (54-96) and 52 (39-68)], short-segment BE (SSBE) [83 (73.2-131) and 65 (43.3-95)] and long-segment BE (LSBE) [105 (102-187) and 77 (75-107)]. Weakly acidic reflux episodes were significantly higher (P < 0.05) in LSBE [36 (27.5-50.5)] and SSBE [34 (18.5-41)] compared to EE [21.5 (15-37)] and HV [19 (14-25)]. No differences in terms of proportion of acid, weakly acidic and weakly alkaline reflux were found [HV (49%-49%-2%) vs EE (68%-32%-1%) vs SSBE (65%-34%-1%) vs LSBE (69%-30%-1%); P = ns]. In LSBE, a higher percentage of reflux episodes (P < 0.05) reached the proximal esophagus (59%) compared with SSBE (43%).

CONCLUSIONS & INFERENCES

 Barrett esophagus patients have more severe reflux as shown by the number of acid and weakly acidic reflux episodes, re-reflux episodes and proximal migration. Given that PPI change only the pH of the refluxate, the role of weakly acidic reflux in Barrett's patients on acid suppressive therapy warrants further investigation.

Cellular mechanisms of Barrett's esophagus development

Barrett's esophagus (BE) is a metaplastic premalignant disorder in which the normal stratified squamous epithelium of the lower esophagus is replaced by a columnar lined epithelium with intestinal differentiation. BE generally occurs in the context of chronic gastroesophageal reflux disease and it is the primary risk factor for the development of esophageal adenocarcinoma, with a conversion rate of 0.5% to 1% per annum. The dramatic increase of esophageal adenocarcinoma incidence in the western world over the last two decades justifies the strong interest in BE and its development with the aim to improve preventative and therapeutic clinical strategies.

Barrett's esophagus in Japanese patients: its prevalence, form, and elongation

BACKGROUND

Barrett's esophagus is a well-known acquired condition resulting from gastroesophageal reflux disease (GERD). However, it is still unknown whether Barrett's esophagus develops gradually over time in patients with GERD. To address this issue, we investigated the change in the prevalence and length of short-segment Barrett's esophagus (SSBE) over time.

METHODS

From January 2005 to March 2007, we enrolled 5338 patients who received upper gastrointestinal endoscopy. Prevalence and length of endoscopically identified SSBE were evaluated within groups divided on the basis of 10-year age intervals. The factors possibly influencing SSBE length such as symptoms, antacid use, and endoscopic findings were also evaluated. Additionally, the length change in 236 patients with histologically confirmed Barrett's esophagus was evaluated over a 2-year follow-up.

RESULTS

Of the 5338 enrolled patients, 1997 had SSBE. The prevalence of endoscopically identified SSBE was significantly higher and its length was significantly longer in elderly patients. Multiple regression analysis showed that age, presence of reflux esophagitis, reflux symptoms, and hiatal hernia were positively correlated with SSBE length. Analysis of the 2-year follow-up study of histologically confirmed SSBE revealed significant extension of Barrett's length in 28.0% of 236 patients. Presence of reflux symptoms and hiatal hernia were identified as positive predictors and proton pump inhibitor administration as a negative predictor of SSBE elongation.

CONCLUSIONS

Positive predictors for the extension of SSBE were presence of hiatal hernia and reflux symptoms, but not age.

Barrett's esophagus and severe reflux esophagitis share common pathophysiological characteristics among Chinese in Taiwan

OBJECTIVE

The pathophysiological data on Barrett's esophagus are scant in Asia, so the purpose of this study was to compare and analyze the pathophysiological characteristics of Barrett's esophagus and reflux esophagitis among Chinese in Taiwan.

PATIENTS AND METHODS

From November 2001 to January 2003, fifteen patients with Barrett's esophagus were consecutively enrolled as the Barrett's esophagus group. Fourteen patients with Los Angeles grade A/B esophagitis (mild esophagitis group) and fourteen patients with LA grade C/D esophagitis (severe esophagitis group) who were matched in age and gender with the Barrett's esophagus group were enrolled. The data of esophageal manometry and ambulatory 24-hour pH monitoring were collected.

RESULTS

We found that the Barrett's esophagus group had significantly weaker lower esophageal sphincter (LES) pressure and distal esophageal body contractions (p<0.05) than the mild esophagitis group. Both the Barrett's esophagus group and severe esophagitis group had significantly higher esophageal acid reflux scores and frequency (p<0.05-0.01) compared to the mild esophagitis group. However, data on esophageal manometry and 24-hour pH monitoring in the Barrett's esophagus and severe esophagitis groups did not significantly differ.

CONCLUSION

We concluded that Barrett's esophagus had significantly stronger acid reflux, lower LES pressure, and weaker distal esophageal peristalsis compared to mild esophagitis. Barrett's esophagus and severe reflux esophagitis share common pathophysiological characteristics among Chinese in Taiwan.

Prevalence and topography of intestinal metaplasia in columnar lined esophagus

OBJECTIVES

Barrett's mucosa is considered as a mosaic of three epithelial types but little is known about the topography of intestinal metaplasia in columnar lined esophagus. The aims of the study were to determine the prevalence of intestinal metaplasia within long and short segments of columnar lined esophagus and to analyze the distribution of the intestinal metaplasia within long segments of Barrett's esophagus.

PATIENTS AND METHODS

The study was performed on the initial endoscopy carried out among 112 patients enrolled in an endoscopic surveillance program. Seventy-two patients with columnar mucosa extending more than 3 cm into the esophagus (group I) and 40 patients with a short segment of columnar mucosa (group II) had multiple biopsies according to a standardized protocol. 1163 biopsies were analyzed on the whole: 949 biopsies in group I and 214 biopsies in group II.

RESULTS

Intestinal metaplasia was identified among 650 (68.5%) and 50 (23.4%) biopsies in groups I and II respectively (P<10-7). The proportion of biopsies with foci of intestinal metaplasia increased significantly with the length of the columnar mucosa. The diagnosis of Barrett's esophagus was confirmed in 100% of the patients in group I and in 45% of the patients in group II. In long segments of Barrett's esophagus, intestinal metaplasia was more frequently observed in the 2 upper thirds of the columnar mucosa that in the lower third (P<10-7). Detailed mapping of the distribution of epithelial types within the columnar lined esophagus identified three patterns of distribution of intestinal metaplasia within long segments of Barrett's esophagus: unifocal, multifocal and diffuse, in 5%, 56% and 39% of the patients respectively. Dysplasia was present in 15% of patients with long segments of Barrett's esophagus and 11% of patients with short segments (NS).

CONCLUSION

The distribution of intestinal metaplasia within columnar lined esophagus is heterogeneous and three distinct patterns can be identified: unifocal, multifocal and diffuse. Considering the risk of sampling error, the current recommendations concerning the biopsy protocols are mandatory until the validation of new techniques such as chromoendoscopy or magnifying endoscopy.

Predictors for squamous re-epithelialization of Barrett's esophagus after endoscopic biopsy

BACKGROUND AND AIM

Acid suppressive therapy has been reported to regress Barrett's esophagus. However, it is still controversial as to whether all Barrett's esophagus patients respond to this therapy. The factors that might facilitate newly developed squamous re-epithelialization after biopsy excision of Barrett's mucosa were evaluated to identity individuals who may favorably respond to the regression therapy.

METHODS

Two hundred and forty-seven biopsy sites from 185 patients with Barrett's esophagus were examined by endoscopy to investigate possible squamous re-epithelialization of Barrett's mucosa after endoscopic biopsy. Before endoscopic examination, all participants were requested to answer questionnaires concerning sociodemographic characteristics, lifestyle habits and drugs usage. The mucin phenotype, Cdx2 expression, cyclooxygenase-2 expression, cellular proliferation and apoptosis of Barrett's mucosa were immunohistochemically investigated in the biopsy samples taken from Barrett's esophagus. The influence of these factors on the newly developed squamous re-epithelialization of Barrett's mucosa after endoscopic biopsy excision was evaluated.

RESULTS

By multivariate analysis, the independent factors that favored squamous re-epithelialization were the gastric mucin predominant phenotype of Barrett's mucosa and the absence of Cdx2 protein expression. In Barrett's mucosa with the gastric predominant mucin phenotype, proton pump inhibitor administration, the absence of reflux esophagitis and a low proliferating cell nuclear antigen index were found to be independent predictors for squamous re-epithelialization.

CONCLUSIONS

The absence of the intestinal predominant mucin phenotype was a positive predictor for newly developed squamous re-epithelialization at the site of biopsy of Barrett's mucosa. Only Barrett's esophagus with the gastric predominant mucin phenotype may predict a favorable response to acid suppressive therapy.

Correlation of gastroesophageal reflux disease symptoms characteristics with long-segment Barrett's esophagus

Thus far, there has been a paucity of studies that have assessed the value of the different gastroesophageal reflux disease (GERD) symptom characteristics in identifying patients with long-segment Barrett's esophagus versus those with short-segment Barrett's esophagus. To determine if any of the symptom characteristics of GERD correlates with long-segment Barrett's esophagus versus short-segment Barrett's esophagus. Patients seen in our Barrett's clinic were prospectively approached and recruited into the study. All patients underwent an endoscopy, validated GERD symptoms questionnaire and a personal interview. Of the 88 Barrett's esophagus patients enrolled into the study, 47 had short-segment Barrett's esophagus and 41 long-segment Barrett's esophagus. Patients with short-segment Barrett's esophagus reported significantly more daily heartburn symptoms (84.1%) than patients with long-segment Barrett's esophagus (63.2%, P = 0.02). There was a significant difference in reports of severe to very severe dysphagia in patients with long-segment Barrett's esophagus versus those with short-segment Barrett's esophagus (76.9%vs. 38.1%, P = 0.02). Longer duration in years of chest pain was the only symptom characteristic of gastroesophageal reflux disease associated with longer lengths of Barrett's mucosa. Reports of severe or very severe dysphagia were more common in long-segment Barrett's esophagus patients. Only longer duration of chest pain was correlated with longer lengths of Barrett's esophagus.

Dickkopf homologs in squamous mucosa of esophagitis patients are overexpressed compared with Barrett's patients and healthy controls

OBJECTIVES

Esophageal mucosal response to acid exposure varies from minimal changes to erosions/ulcerations and Barrett's metaplasia. While differences in acid contact time have been suggested, the reason for these different responses is not completely understood. The aim of this study was to identify and compare gene expression differences between normal distal and proximal squamous esophageal mucosa (SM) in esophagitis patients with that of healthy controls and Barrett's patients.

METHODS

Gene microarray was performed on laser-capture microdissected epithelial cells isolated from biopsy specimens followed by real-time PCR. The effect of acidic pH (pH 4.5) on Dickkopf Homolog 1 (Dkk-1) expression in the human esophageal epithelial cell line (Het-1A) was determined.

RESULTS

Gene microarray analysis demonstrated that the upregulation of five genes in the distal compared with the proximal SM in esophagitis patients was greater than the healthy controls and Barrett's patients. Overexpression of Dkk-1 and Dkk-4 was further confirmed by real-time PCR. Dkk-1 and Dkk-4 mRNA levels in the distal SM of the esophagitis patients were 7.0- and 3.1-fold higher, respectively, than in the distal SM of the Barrett's patients and 4.1- and 4.1-fold higher than in healthy controls, respectively. Dkk-1 protein expression in the distal esophagitis SM was also higher than the Barrett's patients and healthy controls. Acidic pH exposure of Het-1A cells resulted in Dkk-1 upregulation at the level of both mRNA and protein.

CONCLUSIONS

Dkk-1 and Dkk-4 may potentially be involved in the development of different injuries in response to pathological gastroesophageal acid reflux.

The extent of oesophageal acid exposure overlap among the different gastro-oesophageal reflux disease groups

BACKGROUND

Studies have demonstrated that patients with Barrett's oesophagus have the highest oesophageal acid exposure profile, followed by erosive oesophagitis and non-erosive reflux disease patients, but the exact extent of overlap remains unknown.

AIM

To determine the extent of overlap in oesophageal acid exposure among the different gastro-oesophageal reflux disease groups.

METHODS

A total of 121 patients with gastro-oesophageal reflux disease underwent an upper endoscopy and were classified as having Barrett's oesophagus, erosive oesophagitis and non-erosive reflux disease-all (non-erosive reflux disease-positive and functional heartburn). Subsequently, patients underwent pH testing and overlap in oesophageal acid exposure among the different gastro-oesophageal reflux disease groups was determined.

RESULTS

Of those enrolled, 24 had Barrett's oesophagus, 30 erosive oesophagitis and 28 were non-erosive reflux disease-positive. Mean oesophageal acid exposure time was 224.8 +/- 35, 134.3 +/- 21.9 and 141.3 +/- 19.8 min for Barrett's oesophagus, erosive oesophagitis and non-erosive reflux disease-positive respectively. Per cent overlap for total, upright and supine time between non-erosive reflux disease-positive and erosive oesophagitis was 47.4%, 64.7% and 81.8%, between Barrett's oesophagus and erosive oesophagitis was 47.8%, 40.7% and 24%, and between Barrett's oesophagus and non-erosive reflux disease-positive was 31.6%, 37.5% and 20.8% respectively.

CONCLUSIONS

Our study demonstrated a high oesophageal acid exposure overlap between patients with non-erosive reflux disease-positive and erosive oesophagitis, Barrett's oesophagus and erosive oesophagitis, as well as Barrett's oesophagus and non-erosive reflux disease-positive patients.

Clinical predictors of Barrett's esophagus length

BACKGROUND

Assessment of clinical factors associated with Barrett's esophagus (BE) length remained within the realm of anecdotal reports or one center's experience. The aim of this multicenter study was to determine which clinical factors are highly correlated with the length of BE.

METHODS

Patients diagnosed with BE were recruited into the study from 5 academic centers in the United States. All patients had an upper endoscopy that documented BE by the presence of intestinal metaplasia in biopsy specimens. All patients were evaluated by a validated demographic questionnaire and the GERD Symptom Checklist.

RESULTS

A total of 263 patients with BE were recruited into the study. Mean BE length length for the entire sample was 4 +/- 3.3 cm. A longer hiatal hernia (r = 0.22, p < 0.01), any dysplasia (t = -2.3, p < 0.05), H2 receptor antagonist (H2-RA) consumption (t = 1.98, p < 0.05), and nonsmoking (t = -2.5, p < 0.05) were correlated with a longer segment of BE. Proton pump inhibitors (PPI) (t = 1.96, p < 0.05) were correlated with a shorter segment of BE.

CONCLUSIONS

PPIs were correlated with shorter lengths of BE. In contrast, a longer hiatal hernia, any dysplasia, nonsmoking, or use of H2-RAs were correlated with a longer BE segment.

Multiple management modalities in esophageal cancer: epidemiology, presentation and progression, work-up, and surgical approaches

Annually, approximately 13,200 people in the U.S. are diagnosed with esophageal cancer and 12,500 die of this malignancy. Of new cases, 9,900 occur in men and 3,300 occur in women. In part I of this two-part series, we explore the epidemiology, presentation and progression, work-up, and surgical approaches for esophageal cancer. In the 1960s, squamous cell cancers made up greater than 90% of all esophageal tumors. The incidence of esophageal adenocarcinomas has risen considerably over the past two decades, such that they are now more prevalent than squamous cell cancer in the western hemisphere. Despite advances in therapeutic modalities for this disease, half the patients are incurable at presentation, and overall survival after diagnosis is grim. Evolving knowledge regarding the etiology of esophageal carcinoma may lead to better preventive methods and treatment options for early stage superficial cancers of the esophagus. The use of endoscopic ultrasound and the developing role of positron emission tomography have led to better diagnostic accuracy in this disease. For years, the standard of care for esophageal cancer has been surgery; there are several variants of the surgical approach. We will discuss combined modality approaches in part II of this series.

pH probe positioning for 24-hour pH-metry by manometry or pH step-up

OBJECTIVES

Before pH measurement, manometry is recommended for precise pH probe positioning. We investigated whether the pH probe could be positioned accurately by the pH difference between the oesophagus and the stomach (pH step-up).

METHODS

Dual-channel 24-h pH-metry with probes positioned 5 cm above either the manometrically determined upper lower oesophageal sphincter margin or the pH step-up was performed in healthy volunteers and reflux patients. To determine the pH step-up, the pH probe was pulled back from the stomach until a sudden rise to pH greater than four occurred. Probe position, reflux episodes and the fraction of the time pH was less than four were compared using the Wilcoxon test for difference and the Hodges-Lehman estimate inclusive confidence interval for equivalence. The pH step-up method was evaluated further during proton pump inhibitor therapy and after drug discontinuation.

RESULTS

The pH probe was positioned 2 cm and 1 cm closer to the stomach by the pH step-up method in the volunteers and reflux patients, respectively. A small increase in upright reflux episodes but not in supine reflux episodes was registered by the probe positioned by pH step-up. No significant differences in the fraction of the time pH was less than four were obtained between the two probes. The Hodges-Lehman calculation proved equivalence for both methods of probe positioning for 24-h pH-metry. During proton pump inhibitor therapy, no pH step-up was detectable in three volunteers and in one patient. On the first day after discontinuing therapy, the pH step-up method yielded clear-cut results again.

CONCLUSION

The pH probe for diagnostic 24-h pH-metry and, with some limitations, also for 24-h pH-metry for therapy control, can be positioned accurately by the pH step-up method.

A predictive model for length of Barrett's esophagus with hiatal hernia length and duration of esophageal acid exposure

BACKGROUND

A significant correlation between the duration and height of esophageal acid exposure and the length of Barrett's mucosa has been demonstrated. The aims of this study were to determine if there is a correlation between hiatal hernia length and Barrett's esophagus length, and to develop a predictive model for Barrett's esophagus length by using hiatal hernia length and duration of esophageal acid exposure.

METHODS

Consecutive patients with Barrett's esophagus diagnosed endoscopically were enrolled in the study. Barrett's esophagus was defined by the presence of intestinal metaplasia in biopsy specimens obtained from salmon-colored mucosa extending into the esophagus. Barrett's mucosa 3 cm or greater in length was considered long-segment Barrett's esophagus; and less than 3 cm long was considered short-segment Barrett's esophagus. Hiatal hernia was considered present if the esophagogastric junction was displaced 1 cm or more proximal to the diaphragmatic hiatus.

RESULTS

Twenty-four men (mean age 66.1 +/-2.4 [SE]) with Barrett's esophagus were included in this study. Mean Barrett's length was 4.1 +/-0.7 cm. The Pearson correlation coefficient between hiatal hernia length and Barrett's esophagus length was 0.62 (p < 0.01). Similarly, there was a significant correlation between esophageal acid exposure and Barrett's length (r = 0.62; p < 0.01). Multiple linear regression analysis revealed that hiatal hernia length and duration of esophageal acid exposure were associated significantly with length of Barrett's mucosa (R(2) = 0.54; p < 0.001). A regression equation was developed expressing mean Barrett's length (cm) = 0.79 + (0.68) hernia length (cm) + (0.075) duration of esophageal acid exposure (% time pH < 4).

CONCLUSIONS

The length of Barrett's mucosa correlated with the length of hiatal hernia. A predictive model for Barrett's length by using hiatal hernia length and duration of esophageal acid exposure was developed. This suggested that these two pathophysiologic factors are good predictors of the length of Barrett's mucosa.