Pathogenesis of gastroesophageal reflux and Barrett esophagus

Helicobacter pylori infection is associated with reduced risk of Barrett's esophagus: a meta-analysis and systematic review

BACKGROUND

Helicobacter pylori (Hp) is a class I carcinogen in gastric carcinogenesis, but its role in Barrett's esophagus (BE) is unknown. Therefore, we aimed to explore the possible relationship.

METHODS

We reviewed observational studies published in English until October 2019. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for included studies.

RESULTS

46 studies from 1505 potential citations were eligible for inclusion. A significant inverse relationship with considerable heterogeneity was found between Hp (OR = 0.70; 95% CI, 0.51-0.96; P = 0.03) and BE, especially the CagA-positive Hp strain (OR = 0.28; 95% CI, 0.15-0.54; P = 0.0002). However, Hp infection prevalence was not significantly different between patients with BE and the gastroesophageal reflux disease (GERD) control (OR = 0.99; 95% CI, 0.82-1.19; P = 0.92). Hp was negatively correlated with long-segment BE (OR = 0.47; 95% CI, 0.25-0.90; P = 0.02) and associated with a reduced risk of dysplasia. However, Hp had no correlated with short-segment BE (OR = 1.11; 95% CI, 0.78-1.56; P = 0.57). In the present infected subgroup, Hp infection prevalence in BE was significantly lower than that in controls (OR = 0.69; 95% CI, 0.54-0.89; P = 0.005); however, this disappeared in the infection history subgroup (OR = 0.88; 95% CI, 0.43-1.78; P = 0.73).

CONCLUSIONS

Hp, especially the CagA-positive Hp strain, and BE are inversely related with considerable heterogeneity, which is likely mediated by a decrease in GERD prevalence, although this is not observed in the absence of current Hp infection.

Impact of Chronic Statins Use on the Development of Esophagitis in Patients with Gastroesophageal Reflux Disease

BACKGROUND AND AIMS

We aimed to assess whether chronic statins used (> 6 months) were protective of the development of esophagitis in patients with gastroesophageal reflux disease. In the presence of esophagitis, complications such as strictures, Barrett's esophagus, and adenocarcinoma were the most common. Statins, lipid lowering drugs with a pleiotropic effect, are recently implicated in various pathologies. Nevertheless, the possible impact of statins in esophagitis development has never been assessed.

METHODS

We performed a retrospective, cross-sectional, single center study that included 4148 gastroesophageal reflux disease patients from 2014 and 2018 at EMMS Nazareth Hospital. We divided the patients into 5 groups. The groups were split into positive control group, which was the nonesophagitis group, and the other 4 groups were A-D (as per Los Angeles classification).

RESULTS

Overall, out of the 4148 patients included, 48% were males and 2840 patients were in the control group. In groups A, B, C, and D there were 818, 402, 72, and 16 patients, respectively. Logistic regression analysis revealed that chronic statins usage is protective by preventing development esophagitis (OR 0.463 [95%CI 0.370-0.579], p < 0.0001). NSAIDS use, Hiatus hernia, and H. pylori were promoting factors (OR, 1.362, 1.779, and 1.811; 95% CI, 1.183-1.569, 1.551-2.040, and 1.428-2.298; P<0.0001, P<0.0001, and P<0.0001, respectively).

CONCLUSION

Using chronic statins was protective to the development of esophagitis among GERD patients. Our findings of potential clinical application mandate further randomized controlled trials to better assess the impact of statins on esophagitis.

Risk factors for Barrett's esophagus

Barrett's esophagus (BE) is a well-recognized precursor of esophageal adenocarcinoma (EAC) and is defined as ≥1 cm segment of salmon-colored mucosa extending above the gastroesophageal junction into the tubular esophagus with biopsy confirmation of metaplastic replacement of the normal squamous epithelium by intestinal-type columnar epithelium. The incidence of both BE and EAC has been increasing over the past few decades. As a result, preventing the development of BE by identifying and understanding its modifiable and non-modifiable risk factors may help reduce the incidence of EAC. Over the recent past, a tremendous amount of progress has been made towards improving our knowledge of risk factors and pathogenesis of BE. This article reviews the evidence for the various risk factors for developing BE.

Is Atrial Fibrillation a Risk Factor for Gastroesophageal Reflux Disease Occurrence?

Recent studies have reported an association between gastroesophageal reflux disease (GERD) and atrial fibrillation (AF). The objective of the present study was to evaluate whether AF is one of the risk factors for GERD occurrence.In this hospital-based, retrospective, case-control study, the patients were classified into 2 groups. The patients diagnosed with new AF were assigned to the AF group (n = 1612); those diagnosed without AF and GERD were assigned to the control group (n = 1612). The subjects in the control group were selected from outpatients of total healthcare center without a history of AF or GERD, and matched for age and gender. We evaluated the incidence of GERD and risk factors for GERD occurrence between the 2 groups.The number of patients experiencing occurrence of GERD during the follow-up period was significantly higher in the AF group than those in the control group, respectively (129 patients vs 98 subjects, P = 0.037). The incidence of GERD was significantly higher in the AF group than in the control group by Kaplan-Meier analysis with log-rank test (P = 0.008). The AF group's adjusted hazard ratio of GERD occurrence against that of the control group was 1.37 (95% confidence interval [CI]: 1.16-1.57; P = 0.009) according to Cox's proportional hazard model.The presence of AF appears to increase the incidence of GERD and may be considered a risk factor for the development of GERD. Further, large prospective and cohort studies will be required to better establish the correlation of GERD with AF.

Rabeprazole and esomeprazole in mild-to-moderate erosive gastroesophageal reflux disease: A comparative study of efficacy and safety

Objective:

To compare the efficacy and safety of rabeprazole and esomeprazole in mild-to-moderate erosive gastroesophageal reflux disease (GERD).

Materials and Methods:

A randomized, single-blinded, outdoor-based clinical study was conducted on 60 patients of mild-to-moderate erosive GERD. After baseline clinical assessment and investigations, rabeprazole (40 mg) was prescribed to 30 patients and esomeprazole (40 mg) to another 30 patients for 4 weeks. The efficacy variables were change in GERD symptom scoring, endoscopic findings, and Quality of Life in Reflux and Dyspepsia (QOLRAD) scoring over 4 weeks.

Result:

Heartburn, acid regurgitation, and overall GERD symptom scoring (P = 0.01) were significantly decreased with rabeprazole in comparison to esomeprazole. The comparative study of all five domains of the QOLARD questionnaire including overall scoring revealed a statistically significant improvement in the rabeprazole group. Endoscopic findings in the rabeprazole group showed an absolute improvement of 30% and relative improvement of 55% over esomeprazole. Both the drugs were well tolerated having no significant difference in the incidence of adverse effects.

Conclusion:

Rabeprazole (40 mg) is a better choice for mild-to-moderate GERD compared with esomeprazole (40 mg) because of its better efficacy and safety profile.

Hiatal hernia and the risk of Barrett's esophagus

BACKGROUND AND AIM

Barrett's esophagus has been associated with the presence of hiatal hernia; however, to date no meta-analysis of the relationship has been performed. We aimed to conduct a systematic review and meta-analysis, providing a quantitative estimate of the increased risk of Barrett's esophagus associated with hiatal hernia.

METHODS

A search was conducted through four electronic databases (Medline, PubMed, Embase, and Current Contents Connect) to 4 April 2012, for observational studies of Barrett's esophagus patients. We calculated pooled odds ratios and 95% confidence intervals using a random effects model for the association of hiatal hernia with any length Barrett's esophagus, as well as with short segment Barrett's esophagus and long segment Barrett's esophagus. 33 studies comprising 4390 Barrett's esophagus patients were eligible for the meta-analysis.

RESULTS

Hiatal hernia was associated with an increased risk of Barrett's esophagus of any length (odds ratio 3.94; 95% confidence interval 3.02-5.13). Heterogeneity was present (I2 = 82.03%, P < 0.001), and the Egger test for publication bias was significant (P = 0.0005). The short segment Barrett's esophagus subgroup analysis likewise showed an increased risk (odds ratio 2.87; 95% confidence interval 1.75-4.70). The strongest association was between hiatal hernia and long segment Barrett's esophagus (odds ratio 12.67; 95% confidence interval 8.33-19.25). The increased risk was present even after adjusting for reflux and body mass index.

CONCLUSIONS

 The presence of hiatal hernia was associated with an increased risk of Barrett's esophagus, even after adjusting for clinically significant confounders. The strongest association was found between hiatal hernia and long segment Barrett's esophagus.

Risk indicators for dental erosive wear among 18-yr-old subjects in Oslo, Norway

The aim was to investigate risk indicators associated with dental erosive wear among 18-yr-old subjects in Oslo, Norway. Of 3,206 adolescents invited to participate in a screening examination for erosive wear, 1,456 were examined (giving a response rate of 45%). As part of the examination all participants completed a self-administered questionnaire. Associations between the presence of erosive lesions and the possible risk indicators were assessed by logistic regression analyses, taking into account the hierarchical relationships between the independent variables. Of all 18-yr-old subjects examined, 38% had at least one tooth with erosive lesions. Multivariate analyses showed significant associations between the presence of erosive wear and being male, brushing teeth once per day or less, episodes of vomiting, daily/weekly episodes of gastro-oesophageal reflux, consumption of fruit juice and sugary soft drinks several times per day, as well as consumption of sugary soft drinks daily to once per week. In conclusion, in addition to gender, dietary habits such as frequent consumption of fruit juice and sugary soft drinks, and the occurrence of reflux and vomiting, appear to be risk indicators for erosive wear. When counselling adolescents at risk, the gender-specific risk indicators should be taken into account.

Gastroesophageal reflux and atrial fibrillation: is there any correlation?

Atrial fibrillation (AF), gastroesophageal reflux disease (GERD) and hiatal hernias are commonly seen in clinical practice. GERD and hiatal hernias have been proposed to be a possible cause of AF. In this paper, we will briefly review GERD, AF and hiatal hernias, consider the available literature covering the association between these diseases and provide further insight into the topic in general.

Current trends in the management of gastroesophageal reflux disease: a review

Gastroesophageal reflux disease (GERD) is a chronic disorder of the upper gastrointestinal tract with global distribution. The incidence is on the increase in different parts of the world. In the last 30 to 40 years, research findings have given rise to a more robust understanding of its pathophysiology, clinical presentation, and management. The current definition of GERD (The Montreal definition, 2006) is not only symptom-based and patient-driven, but also encompasses esophageal and extraesophageal manifestations of the disease. The implication is that the disease can be confidently diagnosed based on symptoms alone. Nonerosive reflux disease (NERD) remains the predominant form of GERD. Current thinking is that NERD and erosive reflux disease (ERD) are distinct phenotypes of GERD rather than the old concept which regarded them as components of a disease spectrum. Non erosive reflux disease is a very heterogeneous group with significant overlap with other functional gastrointestinal disorders. There is no gold standard for the diagnosis of GERD. Esophageal pH monitoring and intraluminal impedance monitoring have thrown some light on the heterogeneity of NERD. A substantial proportion of GERD patients continue to have symptoms despite optimal PPI therapy, and this has necessitated research into the development of new drugs. Several safety concerns have been raised about chronic use of proton pump inhibitors but these are yet to be substantiated in controlled studies. The debate about efficacy of long-term medical treatment compared to surgery continues, however, recent data indicate that modern surgical techniques and long-term PPI therapy have comparable efficacy. These and other issues are subjects of further research.

The pathogenesis of Barrett's metaplasia and the progression to esophageal adenocarcinoma

The most important risk factor for the development of Barrett's esophagus is the reflux of both gastric and duodenal contents into the esophagus. The reason why Barrett's metaplasia develops only in a minority of patients suffering from gastroesophageal reflux disease remains unknown.The exact mechanism behind the transition of normal squamous epithelium into specialized columnar epithelium is also unclear. It is likely that stem cells are involved in this metaplastic change, as they are the only permanent residents of the epithelium. Several tumorigenic steps that lead to the underlying genetic instability, which is indispensable in the progression from columnar metaplasia to esophageal adenocarcinoma have been described. This review outlines the process of pathogenesis of Barrett's metaplasia and its progression to esophageal adenocarcinoma.

Prevalence of Barrett's esophagus remains low in the Korean population: nationwide cross-sectional prospective multicenter study

PURPOSE

In contrast to the Western population, the prevalence of Barrett's esophagus (BE) is rare in the Korean population. However, the recent increase in prevalence of gastroesophageal reflux disease (GERD) may affect the prevalence of BE. The aim of this study was to survey the prevalence of BE and evaluate its risk factors.

METHODS

Patients between 18 and 75 years of age who visited 11 Korean tertiary referral centers between April and July 2006 for routine upper endoscopic examination were surveyed using a symptom questionnaire. Biopsies were performed on the columnar lined epithelium (CLE) of the distal esophagus, and diagnosis was confirmed with detection of specialized intestinal metaplasia.

RESULTS

The study comprised 2,048 patients (mean age 51.4 years, 965 males). The frequency of heartburn or acid regurgitation was 8.7% and 13.1%, respectively. Reflux esophagitis was diagnosed in 10.1% of patients (207 patients); however, most patients had mild reflux. CLE was found in 82 patients; however, only one patient had long-segment CLE. The prevalence of BE was 1% (21 patients). The risk factors for BE were age (P = 0.006), presence of heartburn [odds ratio (OR) 4.33, 95% confidence interval (CI) 1.66-11.34, P = 0.007], acid regurgitation (OR 3.37, 95% CI 1.35-8.42, P = 0.01), sliding hernia (OR 6.21, 95% CI 1.78-21.72, P = 0.001), and reflux esophagitis (OR 10.28, 95% CI 4.31-24.50, P < 0.0001) on univariate analysis. On multivariate analysis, presence of typical reflux symptoms (P = 0.02) and reflux esophagitis (P < 0.001) were significant.

CONCLUSIONS

Prevalence of Barrett's esophagus remains low in Koreans; however, risk of developing BE has increased in patients with GERD symptoms and reflux esophagitis.

Evaluation of the heme oxygenase-1 expression in esophagitis and esophageal cancer induced by different reflux experimental models and diethylnitrosamine

PURPOSE: To study the expression of heme-oxygenase-1 (HO-1), an enzyme induced by oxidative stress, in specimens obtained from an experimental model in rats that evaluated the role of gastric and duodenal reflux in esophageal carcinogenesis. METHODS: Esophageal specimens embedded in paraffin obtained from different experimental groups of rats were used for immunohistochemistry analysis of HO-1 expression. The rats had been divided into the following groups and were killed after 22 weeks: (1) cardioplasty to induce acid reflux; (2) esophagoduodenal anastomosis to induce duodenal reflux; (3) no treatment; (4) cardioplasty + diethylnitrosamine (DEN); (5) esophagoduodenal anastomosis + DEN; and (6) DEN. The study sample comprised 3 specimens from each group with the most severe histopathological lesions found on each study branch. RESULTS: The expression of HO-1 was seen only in rat specimens submitted to esophagoduodenal anastomosis (Groups 2 and 5), and the analysis of mean fluorescence intensity revealed a significant increase of HO-1 expression (4.8 and 4.6 fold, respectively) when compared with the control group (Group 3) (p<0.05). The main target for HO-1 induction was the inflammatory cells inside the tumor or in subepithelial areas. Rats exposed to gastric reflux had no HO-1 expression. CONCLUSION: Reflux esophagitis induced by reflux of duodenal contents, which provoked considerable oxidative stress, may play an important role in esophageal carcinogenesis. Acid reflux did not induce oxidative stress in this experimental model.

Upper gastrointestinal endoscopic findings in the era of highly active antiretroviral therapy

BACKGROUND

The current literature suggests that there has been a decrease in opportunistic diseases among HIV-infected patients since the widespread introduction of highly active antiretroviral therapy (HAART) in 1995.

OBJECTIVES

The aim of the study was to investigate the impact of HAART and CD4 lymphocyte count on diseases of the upper gastrointestinal (UGI) tract, digestive symptoms, and endoscopic and histological observations.

METHODS

A review of 706 HIV-infected patients who underwent GI endoscopy was undertaken. The cohort was divided into three groups: group 1 (G1), pre-HAART, consisting of 239 patients who underwent endoscopy between January 1991 and December 1994; group 2 (G2), early HAART, consisting of 238 patients who underwent endoscopy between January 1999 and December 2002; and group 3 (G3), recent HAART, consisting of 229 patients who underwent endoscopy between January 2005 and December 2008. Parameters studied included age, gender, opportunistic chemoprophylaxis, antiretroviral therapies, CD4 cell counts, symptoms, observations at the first UGI endoscopy and histology.

RESULTS

When G1, G2 and G3 were compared, significant increases were seen over time in the following parameters: the percentage of women, the mean CD4 cell count, and the frequencies of reflux symptoms, gastroesophageal reflux disease (GERD), inflammatory gastropathy, gastric ulcer and Helicobacter pylori (HP) infection. Significant decreases were seen in the frequencies of the administration of anti-opportunistic infection prophylaxis, odynophagia/dysphagia, acute/chronic diarrhoea, candida oesophagitis, nonspecific oesophageal ulcer and Kaposi sarcoma. No significant change was observed in the other parameters, i.e. digestive bleeding, duodenal ulcer and inflammatory duodenopathy.

CONCLUSION

These results suggest a correlation between the improvement of immunity as a result of more efficient antiviral therapy and the decrease in the frequency of digestive diseases in AIDS, mainly opportunistic pathologies. However, HP infection, reflux symptoms and GERD have increased in the HAART era.

Trends in Barrett's esophagus diagnosis in Southern Europe: implications for surveillance

The incidence of Barrett's esophagus (BE) and esophageal adenocarcinoma has increased in Western countries in recent decades. The aim of this study is to describe the changes in incidence and prevalence of BE diagnosis, dysplasia, and adenocarcinoma development in BE patients in a South-European Mediterranean area. Retrospective population-based analyses of endoscopy and pathology reports from 1976 to 2001 was performed. Data from patients with diagnosis of BE and/or esophageal carcinoma were collected. The study period was divided in four quartiles for statistical calculations; parametric and nonparametric tests were used. A 6.9-fold increase was found in the diagnosis of long-segment BE from the first to the fourth quartile, and a 9.3-fold increase in short-segment BE from 1995 to 2000, in contrast to a much smaller increase of 1.9-fold increase in the number of upper gastrointestinal endoscopies. The adjusted incidence of BE diagnosis increased from 0.73 to 9.73 cases/100,000 (first to fourth quartile, respectively) and the adjusted prevalence from 6.51 to 76.04 cases/100,000 (1985-2001). The incidence of dysplasia was 2.13% per year (95% confidence interval: 0.05-11.3%) - 1.78% for low-grade dysplasia and 0.36% for high-grade dysplasia - giving a total incidence of 1 per 47 patient-years. The incidence of adenocarcinoma during follow-up was 0.48% per year (95% confidence interval: 0.006-2.62%), for an incidence of 1 per 210 patient-years. Nineteen patients with BE (14 long-segment BE, 5 short-segment BE) were diagnosed with esophageal adenocarcinoma, with eight being diagnosed during endoscopic surveillance. Only 14 (8%) adenocarcinoma patients diagnosed during the study period had a history of BE. BE diagnosis has dramatically increased over recent decades in our population, unrelated to an increase in endoscopies. Progression to low-grade dysplasia and adenocarcinoma is rare. Surveillance may have a low impact on the survival of adenocarcinoma patients in Southern Europe.

CagA-positive Helicobacter pylori infection is not associated with decreased risk of Barrett's esophagus in a population with high H. pylori infection rate

BACKGROUND & AIM

The role that H. pylori infection plays in the development of and Barrett's esophagus (BE) is uncertain. We tested the hypothesis that infection with cagA+ Helicobacter pylori strains protects against the development of BE.

METHODS

We studied 104 consecutive patients, residents in an area with a high prevalence of H. pylori infection, with BE and 213 sex- and age-matched controls. H. pylori infection and CagA antibody status were determined by western blot serology.

RESULTS

H. pylori prevalence was higher in patients with BE than in controls (87.5% vs. 74.6%; OR. 2.3; 95% CI: 1.23-4.59). Increasing age was associated with a higher prevalence of H. pylori (p < 0.05). The prevalence of CagA+ H. pylori serology was similar in patients with BE and controls (64.4% vs. 54.5%; NS). Type I H. pylori infection (CagA+ and VacA+) was similar in patients with BE and controls (44.2% vs. 41.3%; NS). Logistic regression analysis identified alcohol (O.R. 7.09; 95% CI 2.23-22.51), and H. pylori infection (OR: 2.41; 95%CI: 1.20-4.84) but not CagA+ serology as independent factors.

CONCLUSION

Neither H. pylori infection nor H. pylori infection by CagA+ strains reduce the risk of BE in a population with high prevalence of H. pylori infection.

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.

Gastroesophageal reflux in familial dysautonomia: correlation with crisis frequency and sensory dysfunction

OBJECTIVES

Familial dysautonomia (FD), a genetic disorder resulting in sensory and autonomic nervous system dysfunction, is associated with a high frequency of gastroesophageal reflux (GER). In this study the authors attempted to determine if GER prevalence correlated with dysautonomic crisis frequency and small fiber sensory dysfunction.

METHODS

Of an initial population of 252 FD patients who had survived past their seventh year and were alive during the year of study from June 1, 2001 to June 1, 2002, 174 (69.0%) had sufficient data in their patient files to be included in this retrospective analysis. Subjects were stratified into three groups: those with no GER, those medically treated for GER and those surgically treated for GER with fundoplication. Data were obtained regarding frequency and severity of dysautonomic crises and sensory function including pain sensation, cold and warm thresholds and vibration perception.

RESULTS

There were no significant differences among the three groups regarding age or severity of sensory dysfunction. However, dysautonomic crises were significantly more frequent in FD patients who were presumed to have more intractable GER, as they had required fundoplication (P < 0.05).

CONCLUSIONS

The data confirm the high incidence of GER in the FD population and demonstrate that GER is independent of severity of sensory dysfunction. In addition, the authors demonstrate that fundoplication does not alleviate the central autonomic cause of retching, the dysautonomic crisis.

Review article: oesophageal complications and consequences of persistent gastro-oesophageal reflux disease

The major oesophageal complications associated with persistent gastro-oesophageal reflux disease (GERD) include erosive oesophagitis, ulceration, strictures and gastrointestinal (GI) bleeding. Although the causes of these complications are uncertain, studies indicate that erosive oesophagitis may progress to the development of ulcers, strictures and GI bleeding. Pharmacological treatment with proton pump inhibitors is favoured over that with H(2)-receptor antagonists for the treatment of strictures. The treatment of strictures is accomplished with dilation and many favour the concomitant use of proton pump inhibitors. Most gastroenterologists are seeing far fewer oesophageal strictures these days since the introduction of proton pump inhibitors. In addition, research has shown that oesophageal complications have a greater impact on patients suffering from night-time GERD than on those suffering from daytime GERD. Barrett's oesophagus is a significant complication associated with persistent GERD and those at risk generally experience a longer duration of symptoms, especially those with a high degree of severity. In addition, there is a strong relationship between Barrett's oesophagus and oesophageal adenocarcinoma. This is in part due to the association of obesity and the development of hiatal hernias. Furthermore, endoscopic screening is being used to detect Barrett's oesophagus and oesophageal adenocarcinoma in persons suffering from chronic GERD, even though screening may not have an impact on outcomes (Sharma P, McQuaid K, Dent J, et al. A critical review of the diagnosis and management of Barrett's esophagus: The AGA Chicago Workshop. Gastroenterology 2004; 127: 310-30.).

Resultados das cirurgias "floppy nissen rossetti" e "floppy nissen longa " realizadas por videolaparascopia em pacientes com esôfago de barrett: estudo prelimilar

OBJETIVO: Com base na literatura e estatística pessoal sobre os resultados da Fundoplicatura "Nissen Rossetti" sem ligadura dos vasos curtos(FNR) no tratamento cirúrgico de pacientes com Doença do Refluxo Gastro-esofágico(DRGE) e Esôfago de Barrett (EB), idealizou-se este trabalho com o objetivo de comparar, através de pH metria prolongada pós-operatória e dados clínicos, os resultados desta cirurgia com os alcançados com a Fundoplicatura de Nissen "Longa" com ligadura dos vasos curtos (FNL). MÉTODO: Durante o período de maio de 2000 e março de 2003, foram avaliados, no pós operatório, 28 pacientes com DRGE e EB, dos quais 12 submetidos a FNR(grupo I) e 16 a FNL(grupo II). Valorizou-se os sintomas, surgimento de disfagia pós-operatória e a persistência do refluxo ácido após a cirurgia, medido através da pH metria pós-operatória. RESULTADOS: Ambas as cirurgias aliviaram os sintomas de pirose e regurgitação no segundo dia de pós-operatório. A disfagia transitória ocorreu mais frequentemente nos casos de FNR que FNL, 41%(6) e 6,25%(1) respectivamente. Disfagia permanente não foi observada em nenhum dos dois grupos. A pH metria pós- operatória seis meses após as cirurgias mostrou que os pacientes do grupo I não ficaram totalmente protegidos do refluxo, com 25% de pH metrias positivas, enquando os do grupo II ficaram quase que totalmente protegidos, com 6,25% de exames positivos. CONCLUSÕES: Embora seja um estudo preliminar e com um período curto de observação, chamamos a atenção para a lembrança do perigo que representa o refluxo persistente após a cirurgia, para um paciente com esôfago de Barrett e apresentamos uma proposta de fundoplicatura longa e frouxa, ou seja diferente da tendência atual(válvula curta e frouxa) para o tratamento cirúrgico dos pacientes com esôfago de Barrett, que acreditamos merecer uma reflexão por parte dos cirurgiões e estudiosos do assunto.

Management of Barrett's esophagus with and without dysplasia

Barrett's esophagus (BE), a premalignant lesion to esophageal adenocarcinoma is associated with long-standing, gastroesophageal reflux disease (GERD). BE is a multi-phase process: during the initiation phase, genetically predisposed individuals (mostly white men) suffering from clinical or occult reflux damage their distal esophagus and form a new cell phenotype (incomplete intestinal metaplasia). During the formation phase, this phenotype occupies an area of variable surface (short or long-segment BE). During the progression phase, the metaplastic epithelium either remains dormant or progresses to dysplasia and adenocarcinoma. We review the recent clinical and basic research literature that explores the interaction of the refluxate (acid, bile, etc.) with BE. Acid and bile reflux variably affect BE and may cause dysplasia or adenocarcinoma. Regardless of the underlying biology, a patient with BE may suffer from GERD symptoms or may remain asymptomatic. Acid may be synergistic to bile or it could be antagonistic and protective. Acid suppressive therapy, if profound and continuous enough to abolish symptoms and esophageal acid exposure, may decrease proliferation, increase differentiation and reduce BE surface. Overexpression of cyclooxygenase-2 (COX-2), not entirely independent of acid/bile reflux, may increase proliferation and increase the invasiveness and metastatic potential of Barrett's metaplasia and neoplasia. Clinically, both acid and bile reflux need to be inhibited, either with potent acid-suppressing drugs or anti-reflux surgery. Cyclooxygenase inhibition using aspirin, NSAIDs or the safer COX-2 inhibitors added to these anti-reflux therapies may enhance the therapeutic benefit. Many questions remain unanswered. We still do not know why only a fraction of patients with GERD develop BE, what factors of the refluxate (acid, bile, etc.) initiate metaplasia and/or promote carcinogenesis, which patients are at risk for malignancy, and what is the best chemopreventive strategy. Ablation therapies and endoscopic mucosal resection are still under study.

Chemoprevention of esophageal adenocarcinoma by COX-2 inhibitors in an animal model of Barrett's esophagus

BACKGROUND & AIMS

Carcinogenesis in Barrett's esophagus (BE) is associated with an increased expression of cyclooxygenase (COX) 2. However, there has been no direct evidence that inhibition of COX-2 prevents cancer in BE. We studied the effect of MF-Tricyclic, a selective COX-2 inhibitor, on the development of BE and adenocarcinoma in a rat model.

METHODS

Four weeks after esophagojejunostomy, 105 Sprague-Dawley rats were randomized to a chow containing MF-Tricyclic or Sulindac, or a placebo. Ninety-six (92%) rats completed the study and were sacrificed at 28 +/- 2 weeks. The animals were assessed for the presence of cancer, tumor volume, BE, degree of inflammation, and COX-2 expression and activity.

RESULTS

MF-Tricyclic and Sulindac reduced the relative risk of development of esophageal cancer by 55% (95% confidence interval [CI] = 43%-66%, P < 0.008) and by 79% (95% CI = 68%-87%, P < 0.001), respectively, compared with controls. No significant differences were noted in the risk of esophageal cancer between the MF-Tricyclic and the Sulindac group (P = 0.34). The median tumor volume was not significantly different among the 3 groups (P = 0.081). Moderate to severe degree of inflammation was significantly more common (P = 0.005) in the control compared with the MF-Tricyclic and the Sulindac group; however, the prevalence of BE was not significantly different between groups (P = 0.98). Rats in the control group had higher tissue PGE2 level compared with the MF-Tricyclic and Sulindac groups (P = 0.038).

CONCLUSIONS

Selective and nonselective COX-2 inhibitors can inhibit inflammation, COX-2 activity, and development of adenocarcinoma induced by reflux. This provides direct evidence that COX-2 inhibitors may have chemopreventive potential in BE.