Duodenogastric reflux potentiates the injurious effects of gastroesophageal reflux

Pathophysiology of gastroesophageal reflux disease-which factors are important?

Background

Pathophysiology of gastroesophageal reflux disease (GERD) shows a multifactorial background. Different anatomical and functional alterations can be determined such as weakness of the lower esophageal sphincter (LES), changes in anatomy by a hiatal hernia (HH), an impaired esophageal motility (IEM), and/or an associated gastric motility problem with either duodeno-gastro-esophageal reflux (DGER) or delayed gastric emptying (DGE). The purpose of this study is to assess a large GERD-patient population to quantitatively determine different pathophysiologic factors contributing to the disease.

Methods

For this analysis only patients with documented GERD (pathologic esophageal acid exposure) were selected from a prospectively maintained databank. Investigations: history and physical, body mass index, endoscopy, esophageal manometry, 24 h-pH-monitoring, 24 h-bilirbine-monitoring, radiographic-gastric-emptying or scintigraphy, gastrointestinal quality of life index (GIQLI).

Results

In total, 728 patients (420 males; 308 females) were selected for this analysis. Mean age: 49.9 years; mean BMI: 27.2 kg/m² (range, 20-45 kg/m²); mean GIQLI of 91 (range: 43-138; normal level: 121); no esophagitis: 30.6%; minor esophagitis (Savary-Miller type 1 or Los Angeles Grade A): 22.4%; esophagitis [2-4]/B-D: 36.2%; Barrett's esophagus 10%. Presence of pathophysiologic factors: HH 95.4%; LES-incompetence 88%, DGER 55%, obesity 25.6%, IEM 8.8%, DGE 6.8%.

Conclusions

In our evaluation of GERD patients, the most important pathophysiologic components are anatomical alterations (HH), LES-incompetence and DGER.

Severity of GERD and disease progression

BACKGROUND

Many factors may play a role in the severity and progression of gastroesophageal reflux disease (GERD) since pathophysiology is multifactorial. Data regarding the progression of GERD are controversial: some reports of increased esophageal acid exposure (EAE) and mucosal damage were considered as evidence for a stable disease course, while others interprete these findings as disease progression. The aim of this study is to analyze a large patient-population with persisting symptoms indicative of GERD under protonpumpinhibitor-therapy and identify components characterizing disease severity and progression.

METHODS

Patients with symptoms indicative of GERD were included in the study in a tertiary referral center (Frankfurt, Germany). All selected patients were under long-term protonpumpinhibitor-therapy with persistant symptoms. All patients underwent investigations to collect data on their physical status, EAE, severity of esophagitis, anatomical changes, and esophageal functional defects as well as their relation to the duration of the disease. Incidence over time was plotted as survival curves and tested with Log-rank tests for the four main disease markers. Multivariate modeling with COX-regression model was used to estimate the general impact of the four main disease markers on the time course of the disease. In order to elucidate possible causal relationships over time, a path analysis (structural equation model) was calculated.

RESULTS

From the database with 1480 data sets, 972 patients were evaluated (542 males, 430 females). The mean age was 50.5 years (range18-89). The mean body mass index was 27.2(19-48). The mean time between the onset of symptoms and the diagnostic investigations was 8.2 years (1-50). A longer disease history for GERD was significantly associated with a higher risk for LES-incompetence. The mean duration from symptom onset to the time of clinical investigation was 9 years for patients with LES-incompetence (n = 563), compared to a mean of 6 years for those with mechanically intact LES (n = 95). A longer period from symptom onset to diagnostics was significantly associated with higher acid exposure. The pathway analysis was significant for the following model: 'history' (P < 0.001➔LES-incompetence & Hiatal Hernia➔(p < 0,001)➔pH-score (P < 0.001).Conclusion: LES-incompetence, the functional deterioration of the LES, and the anatomical alteration at the esophagogastric junction (Hiatal Hernia) as well as an increased EAE were associated with a long history of suffering from GERD. Path modeling suggests a causal sequence overtime of the main disease-parameters, tentatively allowing for a prediction of the course of the disease.

Melatonin in Prevention of the Sequence from Reflux Esophagitis to Barrett's Esophagus and Esophageal Adenocarcinoma: Experimental and Clinical Perspectives

Melatonin is a tryptophan-derived molecule with pleiotropic activities which is produced in all living organisms. This "sleep" hormone is a free radical scavenger, which activates several anti-oxidative enzymes and mechanisms. Melatonin, a highly lipophilic hormone, can reach body target cells rapidly, acting as the circadian signal to alter numerous physiological functions in the body. This indoleamine can protect the organs against a variety of damaging agents via multiple signaling. This review focused on the role played by melatonin in the mechanism of esophagoprotection, starting with its short-term protection against acute reflux esophagitis and then investigating the long-term prevention of chronic inflammation that leads to gastroesophageal reflux disease (GERD) and Barrett's esophagus. Since both of these condition are also identified as major risk factors for esophageal carcinoma, we provide some experimental and clinical evidence that supplementation therapy with melatonin could be useful in esophageal injury by protecting various animal models and patients with GERD from erosions, Barrett's esophagus and neoplasia. The physiological aspects of the synthesis and release of this indoleamine in the gut, including its release into portal circulation and liver uptake is examined. The beneficial influence of melatonin in preventing esophageal injury from acid-pepsin and acid-pepsin-bile exposure in animals as well as the usefulness of melatonin and its precursor, L-tryptophan in prophylactic and supplementary therapy against esophageal disorders in humans, are also discussed.

From Heartburn to Barrett's Esophagus, and Beyond

BACKGROUND

Gastroesophageal reflux disease (GERD) affects an estimated 20% of the population in the USA, and its prevalence is increasing worldwide. About 10-15% of patients with GERD will develop Barrett's esophagus (BE).

AIMS

The aims of this study were to review the available evidence of the pathophysiology of BE and the role of anti-reflux surgery in the treatment of this disease.

RESULTS

The transformation of the squamous epithelium into columnar epithelium with goblet cells is due to the chronic injury produced by repeated reflux episodes. It involves genetic mutations that in some patients may lead to high-grade dysplasia and cancer. There is no strong evidence that anti-reflux surgery is associated with resolution or improvement in BE, and its indications should be the same as for other GERD patients without BE.

CONCLUSIONS

Patients with BE without dysplasia require endoscopic surveillance, while those with low- or high-grade dysplasia should have consideration of endoscopic eradication therapy followed by surveillance. New endoscopic treatment modalities are being developed, which hold the promise to improve the management of patients with BE.

Surgical treatment of GERD. Comperative study of WTP vs. Toupet fundoplication - results of 151 consecutive cases

INTRODUCTION

Gastroesophageal reflux disease (GERD) is recognized as one of the most common disorders of the upper gastrointestinal tract (GIT). The best choice of management for advanced GERD is laparoscopic surgery.

AIM

To compare and evaluate the results of surgical treatment of GERD patients operated on using two different techniques.

MATERIAL AND METHODS

Between 2001 and 2012, 353 patients (211 female and 142 male), aged 17-76 years (mean 44), underwent laparoscopic antireflux surgery. The study included patients who underwent a Toupet fundoplication or Wroblewski Tadeusz procedure (WTP).

RESULTS

The mean age of the group was 47.77 years (17-80 years). Forty-nine (32.45%) patients had severe symptoms, 93 (61.58%) had mild symptoms and 9 (5.96%) had a single mild but intolerable sign of GERD. Eighty-six (56.95%) patients had a Toupet fundoplication and 65 (43.04%) had a WTP. The follow-up period was 18-144 months. The average operating time for Toupet fundoplication and the WTP procedure was 164 min (90-300 min) and 147 min (90-210 min), respectively. The perioperative mortality rate was 0.66%. The average post-operative hospitalization period was 5.4 days (2-16 post-operative days (POD) = Toupet) vs. 4.7 days (2-9 POD = WTP). No reoperations were performed. No major surgical complications were identified.

CONCLUSIONS

Wroblewski Tadeusz procedure due to a low percentage of post-operative complications, good quality of life of patients and a zero recurrence rate of hiatal hernia should be a method of choice.

EAES recommendations for the management of gastroesophageal reflux disease

BACKGROUND

Gastroesophageal reflux disease (GERD) is one of the most frequent benign disorders of the upper gastrointestinal tract. Management of GERD has always been controversial since modern medical therapy is very effective, but laparoscopic fundoplication is one of the few procedures that were quickly adapted to the minimal access technique. The purpose of this project was to analyze the current knowledge on GERD in regard to its pathophysiology, diagnostic assessment, medical therapy, and surgical therapy, and special circumstances such as GERD in children, Barrett's esophagus, and enteroesophageal and duodenogastroesophageal reflux.

METHODS

The European Association of Endoscopic Surgery (EAES) has tasked a group of experts, based on their clinical and scientific expertise in the field of GERD, to establish current guidelines in a consensus development conference. The expert panel was constituted in May 2012 and met in September 2012 and January 2013, followed by a Delphi process. Critical appraisal of the literature was accomplished. All articles were reviewed and classified according to the hierarchy of level of evidence and summarized in statements and recommendations, which were presented to the scientific community during the EAES yearly conference in a plenary session in Vienna 2013. A second Delphi process followed discussion in the plenary session.

RESULTS

Recommendations for pathophysiologic and epidemiologic considerations, symptom evaluation, diagnostic workup, medical therapy, and surgical therapy are presented. Diagnostic evaluation and adequate selection of patients are the most important features for success of the current management of GERD. Laparoscopic fundoplication is the most important therapeutic technique for the success of surgical therapy of GERD.

CONCLUSIONS

Since the background of GERD is multifactorial, the management of this disease requires a complex approach in diagnostic workup as well as for medical and surgical treatment. Laparoscopic fundoplication in well-selected patients is a successful therapeutic option.

Impact of inflammation-metaplasia-adenocarcinoma sequence and inflammatory microenvironment in esophageal carcinogenesis using surgical rat models

BACKGROUND AND AIMS

Chronic inflammation has been demonstrated to correlate with tumor onset and progression. Tumor-associated macrophages (TAMs) play an important role in inflammatory tumor microenvironment. We hypothesized that an inflammatory microenvironment around TAMs may promote the development of esophageal carcinomas when induced by duodenal content reflux without carcinogens.

ANIMALS AND METHODS

A total gastrectomy followed by esophagojejunostomy was performed on rats in order to induce chronic duodenal content reflux esophagitis. The animals were sacrificed sequentially, at the 20th, 30th, 40th and 50th week after surgery, and their esophagi were examined. The primary antibodies against CD68, CD163, pStat3 and Foxp3 were used. Expression and localization of infiltrated cells was assessed by immunohistochemical analysis.

RESULTS

At 20-weeks' post-surgery, squamous proliferative hyperplasia (PHP) and Barrett's metaplasia (BM) were observed. Adenocarcinoma (ADC) associated with BM, and squamous cell carcinoma (SCC) were observed 30-50 weeks' post-surgery. Numerous CD68 and pStat3-positive cells were identified surrounding PHP and BM after 20 weeks, and around ADC and SCC after 30 weeks. Moderate infiltration of CD163-positive macrophages was seen with BM, ADC, and SCC after 30 weeks. However, very few Foxp3-positive cells were observed around ADC and SCC.

CONCLUSION

Macrophages infiltrate the esophagus and activate the pStat3 pathway in stromal cells and epithelium. M2 phenotype macrophages infiltrate following infiltration of M1 macrophage and contribute to tumor development through regulatory T cells (Tregs). The involvement of immune cells such as TAMs and Tregs in the inflammatory microenvironment promotes esophageal carcinogenesis.

Pathophysiology and treatment of Barrett’s esophagus

Gastroesophageal reflux disease (GERD) affects an estimated 20% of the population in the United States. About 10%-15% of patients with GERD develop Barrett’s esophagus, which can progress to adenocarcinoma, currently the most prevalent type of esophageal cancer. The esophagus is normally lined by squamous mucosa, therefore, it is clear that for adenocarcinoma to develop, there must be a sequence of events that result in transformation of the normal squamous mucosa into columnar epithelium. This sequence begins with gastroesophageal reflux, and with continued injury metaplastic columnar epithelium develops. This article reviews the pathophysiology of Barrett’s esophagus and implications for its treatment. The effect of medical and surgical therapy of Barrett’s esophagus is compared.

Inhibition of nucleostemin upregulates CDX2 expression in HT29 cells in response to bile acid exposure: implications in the pathogenesis of Barrett's esophagus

BACKGROUND

Barrett's esophagus (BE), a squamous-to-columnar metaplasia, may originate from growth-promoting mutations in metaplastic stem cells. Nucleostemin is a protein highly expressed in undifferentiated embryonic stem cells. The objectives of this study were to explore the potential role of nucleostemin in the pathogenesis of BE METHODS: The expression profiles of 30,968 genes were compared between BE and normal esophageal tissues (n = 6 in each group) by using oligo microarray. Three siRNA plasmid expression vectors against nucleostemin, pRNAi-1, pRNAi-2, and pRNAi-3, were constructed and transfected into HT29 cells. In addition, HT29 cells were exposed to 100-1,000 microM chenodeoxycholic acid (CDC), a bile acid, for 2, 12, and 24 h, and then messenger RNA and protein expressions of nucleostemin and CDX2 were determined by reverse-transcriptase polymerase chain reaction and Western blotting.

RESULTS

Four hundred and twenty-six differentially expressed genes were detected in BE; 142 were upregulated and 284 downregulated. Nucleostemin was downregulated while CDX2 was upregulated. In vitro, all the recombinant plasmids inhibited the nucleostemin expression in transfected HT29 cells, with pRNAi-1 being the most effective. CDX2 expression was significantly increased in pRNAi-1-transfected HT29 cells, compared with that in the empty plasmid (pRNAT-U6.1/Neo) transfected or untransfected HT29 cells. In addition, CDX2 expression was increased whereas nucleostemin expression was decreased in a dose- and time-dependent manner in HT29 cells treated with CDC.

CONCLUSION

These findings suggest that the inhibition of nucleostemin expression in "esophageal stem cells" in response to bile acid exposure may be involved in the pathogenesis of BE through upregulating CDX2 expression.

Esophageal pH exposure and epithelial cell differentiation

It is proposed that epithelial changes induced by gastroesophageal reflux disease are related to the pH environment of the esophageal lumen. We hypothesized that the various types of esophageal epithelium are associated with specific pH environments that induce their formation. The aim of this study was to compare the luminal pH environment to the histology of the distal esophageal epithelium in patients with gastroesophageal reflux disease. A total of 197 symptomatic patients with increased esophageal acid exposure on 24-hour pH monitoring were grouped according to the histology based on biopsies from the distal esophagus: 17 with squamous epithelium, 126 with cardiac epithelium (CE), and 54 with Barrett's epithelium (BE). All were free of Helicobacter pylori infection and monitored off acid suppression therapy. Acid exposure was expressed as the percent of time the luminal pH was at intervals of 0-1, 1-2, 2-3, 3-4, 4-5, 5-6, and 6-7 over a 24-hour period. Patients with BE spent significantly more time at pH intervals 2-3, 3-4, and 4-5 than those with CE. This pattern switched at pH interval 5-6, where patients with cardiac mucosa spent more time than those with BE. Patients with squamous and CE had similar pH exposure at all intervals. Patients with BE have significantly longer exposure time at the pH interval of 2 to 5 compared to those with cardiac and squamous epithelium. This suggests that the exposure of stem cells to a luminal pH between 2 and 5 may trigger the differentiation of CE into intestinalized CE.

NERD, GERD, and Barrett's esophagus: role of acid and non-acid reflux revisited with combined pH-impedance monitoring

INTRODUCTION

Gastroesophageal reflux is the most important factor in the development of Barrett's metaplasia. The effect of acid reflux is commonly accepted today, but there is controversy about the role of non-acid reflux. With introduction of combined esophageal pH-impedance monitoring, a precise diagnostic test for acid and non-acid reflux is now available.

METHODS

Ninety two consecutive patients (33 women) off acid-suppressive therapy underwent diagnostic work-up for suspected gastroesophageal reflux disease including upper-GI endoscopy, esophageal manometry, barium swallow, and combined esophageal pH-impedance monitoring. Patients were subdivided into three groups according to symptoms and endoscopic appearance: typical symptoms without esophagitis (n = 28; NERD); erosive esophagitis (n = 52, ERD), and patients with intestinal metaplasia (n = 12, BE).

RESULTS

Pathologic acid reflux during pH-metry was found in 35.7%, 63.5%, and 75.0% for NERD, ERD, and BE patients, respectively (P = 0.022). Likewise, the percentage of time pH < 4 rose significantly during upright, supine, and total phases. In contrast, combined pH-impedance monitoring showed no significant difference between groups for the number of acid reflux events and for percentage of acid bolus reflux time. However, BE patients had significantly more non-acid reflux events and a higher percentage of non-acid bolus reflux time during the supine (P = 0.043, P = 0.020, respectively), but not during the upright phase (P = 0.740, P = 0.730, respectively).

CONCLUSION

Patients with BE are exposed to increased supine non-acid reflux and to increased acid reflux during upright and supine phases. This observation supports the concept that nocturnal non-acid reflux may play a role in the pathogenesis of BE.

Effect of cholecystectomy on gastric and esophageal bile reflux in patients with upper gastrointestinal symptoms

Epidemiologic data have shown that cholecystectomy is associated with a moderately increased risk of esophageal adenocarcinoma. The study objective was to evaluate the role of refluxed bile. A total of 696 patients with upper gastrointestinal symptoms were included in the study, of whom 55 had a history of cholecystectomy (CHE). Bilirubin exposure was measured in percent time above absorbance 0.25 in the stomach and above 0.14 in the esophagus. Total gastric and esophageal bilirubin exposure was similar in both groups. Supine gastric bile reflux was slightly increased after cholecystectomy (30.6 +/- 30.2 vs. CHE: 37.1 +/- 29.5, P < 0.05). In patients with erosive esophagitis or Barrett's esophagus, there were differences in total gastric exposure (24.3 +/- 22.6 vs. CHE: 36.7 +/- 26.8, P < 0.05) but not in esophageal exposure. Cholecystectomy slightly augments bile reflux into the stomach without detectable differences in the esophagus. Therefore, increased esophageal bile reflux following cholecystectomy as a potential cause for the associated cancer risk could not be substantiated.

Carcinogenesis in reflux disease--in search for bile-specific effects

Bile reflux may play a key role for esophageal carcinogenesis in reflux disease. In search for bile-specific effects, the animal model of esophageal cancer was applied in a mutagenesis assay. Big Blue transgenic mice were operated with microsurgical techniques. Seven had total gastrectomy with esophagojejunostomy creating esophageal reflux of bile and five had a sham operation. After 24 weeks, the mutation frequency (MF) was measured through standard Big Blue mutagenesis assay in the esophageal mucosa and the duodenum as control. Esophageal reflux resulted in esophagitis in the distal esophagus. The MF in esophageal mucosa was 1.6 times higher in animals with reflux than in sham-operated animals; it was identical in the duodenum. In conclusion, the mutagenic potential of bile reflux has been confirmed. However, mechanisms of carcinogenesis in the esophageal cancer model other than chronic inflammation could not be identified because of the only moderately increased MF.

[Surgical treatment of duodeno-gastro-esophageal reflux disease: duodenal switch]

AIMS

To evaluate the efficacy of duodenal switch operation for patients with duodeno-gastroesophageal reflux disease.

METHODS

Four female patients with therapy resistant epigastric pain and biliary regurgitation were enrolled in the study. In all cases, abnormal duodeno-gastric reflux was confirmed by 24-hour Bilitec monitoring. The average age of the patients was 41.75 years (range 32-53) and three of them had a cholecystectomy in the past. Importantly, all patients had previously undergone fundoplication, which had to be repeated in one of them due to recurrent symptoms. More recently, a duodenal switch procedure was performed in these four patients. Their mean follow-up time was 24.25 months (range 21-30).

RESULTS

Duodenal switch was performed without any perioperative complications. A good clinical outcome was found in all patients on their follow up; however, an abnormal acidic exposure was found in one case on 24-hour oesophageal pH monitoring.

CONCLUSION

Recurrent epigastric complaints developing after anti-reflux surgery in patients with a previous diagnosis of gastroesophageal reflux disease might be due to an abnormal duodeno-gastric reflux. Previous cholecystectomy may increase the risk of biliary reflux. Duodenal switch procedure can be applied with good results in patients with therapy resistant abnormal duodeno-gastric reflux confirmed with Bilitec monitoring.

Importance of duodenogastric reflux in gastro-oesophageal reflux disease

BACKGROUND

Bile in the oesophagus occurs frequently in patients with gastro-oesophageal reflux disease (GORD) and has been linked to Barrett's metaplasia and cancer. Although duodenogastric reflux is a prerequisite for bile in the oesophagus, little is known about its importance in GORD.

METHODS

Some 341 patients with GORD were assessed by simultaneous 24-h gastric and oesophageal bilirubin monitoring. Definitions of increased bilirubin exposure were based on the 95th percentiles in healthy volunteers. The relationship between gastric and oesophageal bilirubin exposure and the correlation with disease severity were analysed.

RESULTS

Of the 341 patients with GORD, 130 (38.1 per cent) had increased gastric and 173 (50.7 per cent) had increased oesophageal bilirubin exposure. Of the 173 patients with bile in the oesophagus, 89 (51.4 per cent) had normal and 84 (48.6 per cent) had increased gastric bilirubin exposure. Of these 84 patients, 75 (89 per cent) had oesophagitis or Barrett's oesophagus (P = 0.003). These effects were mainly related to differences in supine reflux.

CONCLUSION

Bile in the oesophagus originates from either normal or increased gastric bilirubin exposure. Patients with increased duodenogastric reflux are more likely to have oesophagitis or Barrett's oesophagus. These findings highlight the role of duodenogastric reflux as an additional factor in the pathogenesis of GORD.

Le reflux biliaire duodéno-gastrique et gastro-œsophagien

This study reviews current data regarding duodenogastric and gastroesophageal bile reflux-pathophysiology, clinical presentation, methods of diagnosis (namely, 24-hour intraluminal bile monitoring) and therapeutic management. Duodenogastric reflux (DGR) consists of retrograde passage of alkaline duodenal contents into the stomach; it may occur due to antroduodenal motility disorder (primary DGR) or may arise following surgical alteration of gastoduodenal anatomy or because of biliary pathology (secondary DGR). Pathologic DGR may generate symptoms of epigastric pain, nausea, and bilious vomiting. In patients with concomitant gastroesophageal reflux, the backwash of duodenal content into the lower esophagus can cause mixed (alkaline and acid) reflux esophagitis, and lead, in turn, to esophageal mucosal damage such as Barrett's metaplasia and adenocarcinoma. The treatment of DGR is difficult, non-specific, and relatively ineffective in controlling symptoms. Proton pump inhibitors decrease the upstream effects of DGR on the esophagus by decreasing the volume of secretions; promotility agents diminish gastric exposure to duodenal secretions by improving gastric emptying. In patients with severe reflux resistant to medical therapy, a duodenal diversion operation such as the duodenal switch procedure may be indicated.

Cdx-2 expression in squamous and metaplastic columnar epithelia of the esophagus

The molecular pathogenesis of Barrett's esophagus is poorly understood. Evidence suggests that at a phenotypic level, the metaplastic process begins with the transformation of squamous epithelium in the distal esophagus to cardiac mucosa, which subsequently becomes intestinalized. The homeobox gene Cdx-2 has been shown to be an important transcriptional regulator of embryonic differentiation and maintenance of adult intestinal type epithelium. We hypothesized that Cdx-2 gene expression levels increase with the phenotypic transformation of normal squamous mucosa to the intestinalized columnar mucosa of Barrett's esophagus. Endoscopic biopsies were obtained at the gastroesophageal junction in patients with symptoms of gastroesophageal reflux disease and classified according to histology: normal squamous mucosa (n = 62), cardiac mucosa (n = 19), oxynto-cardiac mucosa (n = 14), and intestinal metaplasia (n = 15). Duodenal biopsies (n = 26) served as the columnar control. After laser capture microdissection and RNA isolation, gene expression levels of Cdx-2 were measured in each tissue type by quantitative reverse transcription polymerase chain reaction. Consistent with its known function, Cdx-2 gene expression levels were highest in duodenal mucosa and nearly absent in squamous epithelium. There was a stepwise increase in Cdx-2 gene expression from cardiac to Barrett's epithelium (P < 0.001). Expression levels of Cdx-2 in cardiac and oxynto-cardiac mucosa were 40-70 times higher and Barrett's mucosa 400 times higher than that found in squamous epithelium. Relative expression of the homeobox gene Cdx-2, known to induce differentiation of intestinal type epithelium, increases in a stepwise fashion during the phenotypic transformation of distal esophageal squamous mucosa to cardiac columnar mucosa and to the intestinalized columnar mucosa of Barrett's esophagus. Therefore, Cdx-2 may be a potential biomarker to detect the early transition to Barrett's esophagus.

The impact of reflux composition on mucosal injury and esophageal function

The components of refluxed gastric juice are known to cause mucosal injury, but their effect on esophageal function is less appreciated. Our aim was to determine the effect of acid and/or bile on mucosal injury and esophageal function. From 1993-2004, 402 patients with reflux symptoms had 24-hour pH and Bilitec monitoring, manometry, and endoscopy with biopsies. Mucosal injury (esophagitis or Barrett's esophagus) and esophageal function (lower esophageal sphincter [LES] characteristics and body contractility) in patients with acid reflux, bile reflux, or both were compared with patients without reflux. Reflux was present in 273/402 patients; of these, 37 (13.5%) had increased exposure to bile, 82 (30.0%) had increased exposure to acid, and 154 (56.4%) had increased exposure to both. Mucosal injury was most common with increased mixed acid and bile exposure, followed by acid alone, and was uncommon with bile alone (P < 0.0001). Functional deterioration paralleled mucosal injury (P < 0.0001). Mixed acid and bile exposure was present in more than half of patients with reflux and was associated with the most severe mucosal injury and the greatest deterioration of esophageal function. This suggests that composition of gastric juice is the primary determinant of inflammatory mucosal injury and subsequent loss of esophageal function.

Superoxide dismutase prevents development of adenocarcinoma in a rat model of Barrett's esophagus

AIM

To test whether antioxidant treatment could prevent the progression of Barrett's esophagus to adenocarcinoma.

METHODS

In a rat model of gastroduodenoesophageal reflux by esophagojejunal anastomosis with gastric preservation, groups of 6-10 rats were randomized to receive treatment with superoxide dismutase (SOD) or vehicle and followed up for 4 mo. Rat's esophagus was assessed by histological analysis, superoxide anion and peroxinitrite generation, SOD levels and DNA oxidative damage.

RESULTS

All rats undergoing esophagojejunostomy developed extensive esophageal mucosal ulceration and inflammation by mo 4. The process was associated with a progressive presence of intestinal metaplasia beyond the anastomotic area (9% 1st mo and 50% 4th mo) (94% at the anastomotic level) and adenocarcinoma (11% 1st mo and 60% 4th mo). These changes were associated with superoxide anion and peroxinitrite mucosal generation, an early and significant increase of DNA oxidative damage and a significant decrease in SOD levels (P<0.05). Exogenous administration of SOD decreased mucosal superoxide levels, increased mucosal SOD levels and reduced the risk of developing intestinal metaplasia beyond the anastomotic area (odds ratio = 0.326; 95%CI: 0.108-0.981; P = 0.046), and esophageal adenocarcinoma (odds ratio = 0.243; 95%CI: 0.073-0.804; P = 0.021).

CONCLUSION

Superoxide dismutase prevents the progression of esophagitis to Barrett's esophagus and adenocarcinoma in this rat model of gastrointestinal reflux, supporting a role of antioxidants in the chemoprevention of esophageal adenocarcinoma.

How to make a Barrett esophagus: pathophysiology of columnar metaplasia of the esophagus

Barrett esophagus is defined as a specialized intestinal replacing the squamous epithelium of the esophageal mucosa in response to gastroesophageal reflux. Barrett metaplasia is a healing process that develops to protect the esophagus from further damage. Although mechanisms by which Barrett metaplasia evolves toward dysplasia and adenocarcinoma have been extensively studied, the process by which squamous epithelium is replaced by specialized intestinal metaplasia is poorly understood. Barrett esophagus develops when defense mechanisms in the esophageal mucosa (luminal secretion of mucus, bicarbonate, growth factors, etc.) are overwhelmed by an ongoing cycle of mucosal injury and repair. Hydrogen ion, pepsin, trypsin, and bile acids are considered harmful agents that synergistically invade the esophageal mucosa. Areas of destroyed squamous epithelium are then progressively reepithelized by a columnar epithelium that may originate from multipotent stem cells located within the basal layer of the normal esophageal mucosa or in the ducts of submucosal glands.

Three year’s experience with the Stretta procedure: did it really make a difference?

BACKGROUND

Endoscopic treatment is merging as a new option for GERD treatment. Many modalities have been used with modest short-term success, but no long-term follow-ups have been published. We present our 3-yr experience at Vanderbilt University using endoscopic radiofrequency energy (Stretta procedure) for GERD treatment.

METHODS

Patients with follow-up >6 months were prospectively studied under IRB protocol. All were mailed SF-12 health status questionnaire and GERD specific quality-of-life (QOLRAD) questionnaires, queries about satisfaction with Stretta, and medication use. All were invited for 24-hour pH study.

RESULTS

Eighty-six Stretta procedures were performed between 8/2000 and 7/2003 on 85 patients; all were outpatients, 89% under conscious sedation. Seventy-seven patients qualified for the study; 61 completed the survey, 24 returned for pH study. Follow-up was 26.2 +/- 7.5 months (6-36). All were on daily PPIs, with proven GERD by pH study or endoscopy. Mean preoperative acid exposure time was 7.8+/-2.6%, mean DeMeester score was 40.2+/-17.6. Postoperative mean acid exposure time was 5.1+/-3.3 (p=0.001), DeMeester score was 29.5+/-20.5 (p=0.041). Normal postoperative acid exposure time (pH<4 in <4.2%) was achieved in 42% of patients tested. Patients were then divided according to medication use at the end of f/u in 2 groups: Responders (off or >50% decrease in PPI dose), and nonresponders (on >50% of original PPI dose, or had fundoplication). Response rate was 60% (39 patients), 8 nonresponders underwent fundoplication (12%). Satisfaction rate was 73%. Statistically significant difference was found between the 2 groups in all measurements; SF-12 physical and mental score for responders were 45.5+/-10.2, and 52.6+/-7.8; and for nonresponders were 37.8+/-11.2 and 40.9+/-11.3 (p=0.012, p=0.0001), respectively. Statistically significant difference was also found between responders and nonresponders in postoperative acid exposure (4.5+/-3.34 vs 7.2+/-2.3, p=0.034), and DeMeester score (26.3+/-20.4 vs 39.7+/-20.2, p=0.05). Paired T test was used to compare pre- and postoperative acid exposure in each group; statistically significant difference was found only among responders: total reflux time was 7.50+/-2.3 preop and 4.5+/-3.34 postop (p=0.0001), whereas for nonresponders it was 8.6+/-3.7 and 7.2+/-2.3 (p=0.8), DeMeester scores pre- and postop among responders were 40.0+/-19.7 and 26.3+/-20.4, respectively (p=0.016), whereas for nonresponders it was 40.5+/-14.3 and 39.7+/-20.2 (p=0.79).

CONCLUSIONS

Stretta is a safe modestly effective, totally endoscopic treatment for GERD. Symptomatic improvement when achieved is often associated with correlating improvement in distal acid exposure. This exposure normalizes in nearly half the treated patients.

Impact of the biliary diversion procedure on carcinogenesis in Barrett's esophagus surgically induced by duodenoesophageal reflux in rats

OBJECTIVE

To determine whether the elimination of bile reflux in the established esophagojejunostomy model of Barrett's esophagus (BE) will reduce or eliminate the risk of developing esophageal adenocarcinoma.

SUMMARY BACKGROUND DATA

Reflux of duodenal juice as well as gastric acid plays an important role in the pathogenesis of BE and adenocarcinoma. Duodenoesophageal reflux (DER) per se induces these diseases without carcinogen. However, it is unclear whether antireflux surgery induces regression of BE and prevents adenocarcinoma.

METHODS

Two hundred F344 male rats underwent one of following 3 operations: (1) total gastrectomy and esophagojejunostomy to induce DER, followed by killing after 20 (n = 13), 30 (n = 12), and 50 weeks (n = 30); (2) biliary diversion procedure, converted to Roux-en-Y method, to avoid bile regurgitation into the esophagus at 20 (n = 29) and 30 weeks (n = 32) after the operation to induce DER, followed by killing 50 weeks after initial operation; or (3) total gastrectomy and Roux-en-Y esophagojejunostomy followed by killing after 50 weeks served as controls (n = 28).

RESULTS

BE developed in more than half of the animals exposed to DER for 20 weeks, in more than 90% of rats with DER for 30 weeks, and in 100% of animals exposed to DER for 50 weeks. In the incidence and the length of BE, there is no difference between the animals that underwent biliary diversion at 20 (62%) and 30 weeks (94%) and those that had DER for 20 (54%) and 30 weeks (92%), respectively. Incidence of adenocarcinoma was significantly lower in the rats that underwent the biliary diversion procedure after 30 (19%) and 20 weeks (3%) than in the rats that had DER for 50 weeks (60%) (P < 0.005). None of the control animals that underwent Roux-en-Y esophagojejunostomy developed BE and carcinoma.

CONCLUSIONS

It is likely that the converting procedure from the esophagojejunostomy to induce DER to biliary diversion does not lead to regression of BE but prevents the development of esophageal adenocarcinoma in the rats.

Endoscopic treatment modalities for gastroesophageal reflux disease

A debate has been going for decades between surgeons and gastroenterologists about the treatment of choice for gastroesophageal reflux disease (GERD). The lower esophageal sphincter (LES) has been historically far from the reach of gastroenterologists, who adopted the symptomatic treatment as their approach to reflux disease through reduction of gastric acid. As for surgeons, reaching the LES was only possible by invading the thoracic or abdominal cavity. Although their approach was later refined to become "minimally" invasive, it was still deemed too invasive by others to allow it to be the "gold standard." Simple logic should lead one to think about the "natural route" as the easiest way to reach the LES. This concept has opened the door for the new era of GERD treatment through "endoscopic modality." Seven different techniques are currently being used to treat patients with GERD. We review the mechanism of action, potential side effects, efficacy, durability, and results from the most recent or largest experience of each. This review shows that endoscopic treatment has definitely earned its place as a viable option for GERD treatment in selected patients. With the available data from clinical trials, it is not possible to determine the best modality available, and the endoscopic treatment of choice is to be determined with further studies.

Laparoscopic Nissen repair: indications, techniques and long-term benefits

BACKGROUND

The Nissen fundoplication or total 360 degrees fundoplication is probably the most frequently used anti-reflux procedure throughout the world. With the advent of laparoscopic surgery the popularity among surgeons to perform a laparoscopic Nissen fundoplication has even increased.

AIM

The purpose of this paper is to provide an overview of the experience of laparoscopic Nissen fundoplication over the past 15 years.

METHOD

We performed an extensive review of the literature in order to ascertain the representative papers. In addition, available consensus papers, especially with regard to indication and technique, were assessed. Indication for a laparoscopic Nissen fundoplication should depend on documentation of the presence of disease as well as objective testing of the functional disorders and the complications. The technique of Nissen fundoplication is discussed controversially. Consensus exists with regard to floppiness of the wrap, necessary closure of the crurae and the use of a calibration method during the performance of the wrap.

RESULTS

The laparoscopic technique creates a learning curve, which needs to be respected. Large prospective series in recent years have shown a complication rate between 5% and 10%, depending on the definition of the complication. In these last prospective series good and excellent results have been reported, of between 85% and 95%. Reflux recurrence is reported as between 1% and 8.5%, with a concomitant dysphagia rate of 0%-10%.

CONCLUSIONS

The Nissen fundoplication is currently performed throughout the world, most frequently in a minimally invasive technique. Several randomized trials that have been performed in the past years document that the Nissen fundoplication is an effective procedure for the treatment of pathological gastro-oesophageal reflux disease when a critical indication is used for well-defined patients.

Antireflux surgery for Barrett's oesophagus

Barrett's oesophagus is usually the result of severe reflux disease. Relief of reflux symptoms is the primary aim of treatment in patients with Barrett's oesophagus who do not have high-grade dysplasia. Some studies with medium-term (2-5 years) follow up show that antireflux surgery can provide good or excellent symptom control, with normal oesophageal acid exposure, in more than 90% of patients with Barrett's oesophagus. Antireflux surgery, but not medical therapy, can also reduce duodenal nonacid reflux to normal levels. There is no conclusive evidence that antireflux surgery can prevent the development of dysplasia or cancer, or that it can reliably induce regression of dysplasia, and patients with Barrett's oesophagus should therefore remain in a surveillance programme after operation. Some data suggest that antireflux surgery can prevent the development of intestinal metaplasia (IM) in patients with reflux disease but no IM. The combination of antireflux surgery plus an endoscopic ablation procedure is a promising treatment for patients with Barrett's oesophagus with low-grade dysplasia.

Metaplastic columnar mucosa in the cervical esophagus after esophagectomy

OBJECTIVE

To evaluate the pathogenesis of metaplastic processes within the esophagus using a human model in which the exact duration of reflux was known.

SUMMARY BACKGROUND DATA

The pathogenesis of Barrett's esophagus (BE) is incompletely understood. Patients undergoing esophagectomy and gastric tube reconstruction represent a good model for studying the pathophysiology of columnar cell metaplasia of the human esophagus because the cervical esophagus is rarely or never exposed to gastric contents before the surgical procedure.

METHODS

Thirty-two patients underwent manometry, simultaneous 24-hour pH and bilirubin monitoring, and endoscopy with biopsy 3 to 10.4 years after esophagectomy. The presence of columnar mucosa in the cervical esophagus was confirmed on histologic examination. The findings on endoscopy and histology were related to clinical data and the results of pH and bilirubin monitoring 1 cm proximal to the esophagogastrostomy.

RESULTS

Fifteen (46.9%) of the 32 patients had metaplastic columnar mucosa within their cervical esophagus. Metaplasia was significantly more common in patients with a preoperative diagnosis of BE. The length of metaplastic mucosa correlated significantly with the degree of esophageal acid exposure, but the presence of abnormal bilirubin exposure was unrelated to the presence of metaplasia. The prevalence of metaplasia did not change with increasing time. Intestinal metaplasia was found within the columnar-lined segment in three patients 8.5, 9.5, and 10.4 years after esophagectomy. All patients with intestinal metaplasia had abnormal exposure of both acid and bilirubin, but the presence of combined reflux was not significantly higher in these patients compared with patients with nonintestinalized segments of columnar mucosa.

CONCLUSIONS

Esophageal columnar metaplasia is a common complication after gastric pull-up esophagectomy. Metaplasia is more likely to develop in patients with previous BE than other patients. Metaplasia develops in response to squamous epithelial injury in predisposed individuals.

Association between cholecystectomy and adenocarcinoma of the esophagus

BACKGROUND & AIMS

Barrett's esophagus, which is linked to adenocarcinoma of the esophagus, is associated with reflux of bile. Duodenogastric reflux is increased after cholecystectomy. This study aims to evaluate if cholecystectomy is associated with an increased risk of adenocarcinoma of the esophagus.

METHODS

A population-based cohort study of cholecystectomized patients in Sweden between 1965 and 1997 cross-linked with the Swedish Cancer Register.

RESULTS

Cholecystectomized patients had an increased risk of adenocarcinoma of the esophagus (standardized incidence ratio [SIR], 1.3; 95% confidence interval [CI], 1.0-1.8). Esophageal squamous-cell carcinoma was not found to be associated with cholecystectomy (SIR, 0.9; 95% CI, 0.7-1.1). Patients with gallstone disease on whom surgery was not performed did not have an increased risk of adenocarcinoma or squamous-cell carcinoma of the esophagus.

CONCLUSIONS

Cholecystectomy is associated with a moderately increased risk of adenocarcinoma of the esophagus, possibly by the toxic effect of refluxed duodenal juice on the esophageal mucosa. Further studies are needed regarding the link between bile reflux and esophageal carcinogenesis.

Evaluation of the intestinal microflora in the rat model for esophageal adenocarcinoma

Surgically induced duodenal reflux results in cancer development in the rat esophagus. One proposed mechanism of carcinogenesis relies on the production of carcinogens in the presence of bacterial overgrowth. Against this background, intestinal microflora in the rat jejunum was analyzed before and after reflux-inducing surgery. Total gastrectomy and esophagojejunostomy were performed on Sprague-Dawley rats to produce esophageal reflux of duodenal juice (n = 12). Three days before surgery they were randomized into three groups: animals which received tap water; animals which received acidified water at pH 1.8; and animals subjected to oral decontamination with triple antibiotics. During surgery and at autopsy after 2 weeks, intestinal juice was aspirated and analyzed immediately for bacterial content. The physiologic microflora of the rat jejunum contained Lactobacillus spp. and Bacteroides spp., both of which were resistant to the antibiotic regimen. Bacterial overgrowth with fecal bacteria was found following surgery. Acidified water did not alter the intestinal microflora. Triple antibiotics eliminated Escherichia coli and Proteus spp. and reduced the concentration of Enterococcus spp. Bacterial overgrowth by bacteria of the fecal flora occurs in the rat model of esophageal adenocarcinoma with the potential to catalyze the production of carcinogens.

Antireflux surgery, highly selective vagotomy and duodenal switch procedure: post-operative evaluation in patients with complicated and non-complicated Barrett's esophagus

Antireflux surgery, highly selective vagotomy (HSV) and Roux-en-Y duodenojejunostomy have been suggested for control of pathophysiological factors involved in patients with Barrett's esophagus (BE). The aim of this study was to evaluate prospectively the results of this technique in patients with complicated (n = 21) and noncomplicated (n=45) BE. Complete evaluation of esophageal function, endoscopic histologic and clinical control was carried out before and 2 years after surgery. Post-operative results show recurrence of ulcer in patients with complicated BE, but no recurrence in patients with non-complicated BE. Preoperative esophageal ulcer and stricture were present in 85.3% and 14.3%, respectively, of patients with complicated BE. In this group, recurrence of these complications was 38.1% and 9.5% respectively. The technique offers excellent results in patients with non-complicated BE. However, in patients with complicated BE, the recurrence rate is higher, mainly because of the persistence of acid reflux into the esophagus.

Intestinal metaplasia in patients with columnar lined esophagus is associated with high levels of duodenogastroesophageal reflux

OBJECTIVE

To evaluate the rate of duodenogastroesophageal reflux in patients with columnar lined esophagus compared with patients with gastroesophageal reflux disease without columnar lined esophagus, and to analyze whether it is related to the presence of specialized columnar epithelium in the metaplastic segment.

SUMMARY BACKGROUND DATA

The carcinomatous degeneration of columnar lined esophagus originates from a specialized columnar epithelium. The appearance of this metaplastic phenomenon is clearly related to severe prolonged gastroesophageal reflux, but only some of these patients finally develop columnar lined esophagus. For this reason other factors have been suggested, particularly the role played by the reflux of duodenal contents into the esophagus.

METHODS

The authors studied 15 healthy volunteers (control group), 10 patients with reflux symptoms but without endoscopic lesions, 20 patients with reflux esophagitis without columnar lined esophagus, and 35 patients with columnar lined esophagus (complicated with ulcers or stenosis in 8 cases), of whom 22 had intestinal metaplasia. To assess the reflux of duodenal contents into the esophagus, all the patients underwent Bilitec 2000 and 24-hour esophageal pH monitoring.

RESULTS

The presence of bilirubin in the material refluxed into the esophagus was greater in the patients with columnar lined esophagus than in the rest of the groups. Likewise, duodenogastroesophageal reflux was greater in the columnar lined esophagus patients who had intestinal metaplasia.

CONCLUSIONS

Duodenogastroesophageal reflux may play a major role in the development of columnar lined esophagus, especially in patients with intestinal metaplasia.

Cholecystectomy, peptic ulcer disease and the risk of adenocarcinoma of the oesophagus and gastric cardia

BACKGROUND

Gastro-oesophageal reflux is a strong risk factor for oesophageal adenocarcinoma. Bile and pancreatic enzymes may be particularly carcinogenic. Cholecystectomy causes an increased gastric level of these constituents. A decreased risk of oesophageal adenocarcinoma has been observed in persons infected with cagA-positive Helicobacter pylori. There is a strong correlation between ulcer disease and Helicobacter pylori infection. The aim of this study was to determine whether previous cholecystectomy or peptic ulcer disease affects the risk of oesophageal carcinoma.

METHODS

Data were collected as a nationwide population-based case-control study in Sweden between 1995 and 1997. Multivariate adjusted odds ratios (ORs) were calculated with logistic regression.

RESULTS

There was no statistically significant association between cholecystectomy and the risk of oesophageal carcinoma. Among persons with previous peptic ulcer, the adjusted OR for oesophageal adenocarcinoma was below unity (OR = 0.6, 95 per cent confidence interval 0.3-1.1). The relative risk estimates for cardia adenocarcinoma and oesophageal squamous cell carcinoma were close to unity.

CONCLUSION

Cholecystectomy, despite its effect on the composition of gastric juice, does not appear to increase the risk of adenocarcinoma of the oesophagus or gastric cardia. While the data do not contradict a protective effect of H. pylori, the results are also consistent with absence of such an effect.

Columnar mucosa and intestinal metaplasia of the esophagus: fifty years of controversy

OBJECTIVE

To outline current concepts regarding etiology, diagnosis, and treatment of intestinal metaplasia of the esophagus and cardia.

SUMMARY BACKGROUND DATA

Previously, endoscopic visualization of columnar mucosa extending a minimum of 3 cm into the esophagus was sufficient for the diagnosis of Barrett's esophagus, but subsequently the importance of intestinal metaplasia and the premalignant nature of Barrett's have been recognized. It is now apparent that shorter lengths of intestinal metaplasia are common, and share many features of traditional 3-cm Barrett's esophagus.

METHODS

Themes and concepts pertaining to intestinal metaplasia of the esophagus and cardia are developed based on a review of the literature published between 1950 and 1999.

RESULTS

Cardiac mucosa is the precursor of intestinal metaplasia of the esophagus. Both develop as a consequence of gastroesophageal reflux. Intestinal metaplasia, even a short length, is premalignant, and the presence of dysplasia indicates progression on the pathway to adenocarcinoma. Antireflux surgery, as opposed to medical therapy, may induce regression or halt progression of intestinal metaplasia. The presence of high-grade dysplasia is frequently associated with an unrecognized focus of adenocarcinoma. Vagal-sparing esophagectomy removes the diseased esophagus and is curative in patients with high-grade dysplasia. Invasion beyond the mucosa is associated with a high likelihood of lymph node metastases and requires lymphadenectomy.

CONCLUSIONS

Despite improved understanding of this disease, controversy about the definition and best treatment of Barrett's esophagus continues, but new molecular insights, coupled with careful patient follow-up, should further enhance knowledge of this disease.

Variability in the composition of physiologic duodenogastric reflux

Duodenogastric reflux has long been associated with various diseases of the foregut. Even though bile is often used as a marker, duodenogastric reflux consists of other components such as pancreatic juice and duodenal secretions. The aim of this study was to investigate the occurrence of duodenogastric reflux, its components, and the variability of its composition in normal subjects. Twenty healthy volunteers (7 men and 13 women) whose median age was 24 years underwent combined 24-hour bilirubin and gastric pH monitoring and intraluminal gastric aspiration. All probes were placed at 5 cm below the lower border of the lower esophageal sphincter. Aspiration was performed hourly and at any time when bilirubin and/or pH monitoring showed signs of duodenogastric reflux. Elastase and amylase were measured in the aspirate. All volunteers had episodes of physiologic duodenogastric reflux. A total of 70 episodes of duodenogastric reflux were registered with a median of three episodes (range 1 to 8) per subject. Most bile reflux occurred separately from pancreatic enzyme reflux. Pancreatic enzyme aspirate was significantly more often associated with a rise in pH in comparison to bile reflux (P <0.01). Duodenogastric reflux is a physiologic event with varying composition. Both bile and pancreatic enzyme reflux frequently occur separately. These findings could explain the disagreement regarding assessment and interpretation of duodenogastric reflux in the past. Thus monitoring of duodenogastric reflux requires more than the detection of just one component.

The impact of an antireflux procedure on intestinal metaplasia of the cardia

OBJECTIVE

The aim of this study was to determine whether antireflux surgery is more effective in producing loss of intestinal metaplasia located only at the gastroesophageal junction than it has been in patients with intestinal metaplasia extending up into the distal esophagus.

SUMMARY BACKGROUND DATA

Biopsies of a normal appearing gastroesophageal junction will demonstrate cardiac mucosa containing goblet cells--the hallmark of intestinal metaplasia--in 10% to 15% of patients who are evaluated for symptoms of gastroesophageal reflux. The incidence of adenocarcinoma of the esophagus and cardia is rising faster than any other cancer in America, and most of these cancers are found adjacent to areas of intestinal metaplasia. Antireflux surgery in patients with Barrett's esophagus may provide protection from progression to dysplasia and cancer; however, it does not reliably cause regression of the intestinal metaplasia. Less is known about the potential for intestinal metaplasia limited to the cardia (CIM) to regress.

METHODS

Sixty patients with intestinal metaplasia of the esophagus or cardia had antireflux surgery. Patients in the intestinal (CIM) group (n = 15) had no endoscopically visible segment of columnar epithelium. Patients in the Barrett's group (n = 45) had columnar epithelium visible within the esophagus. Median follow-up was 25 months in each group.

RESULTS

Postoperative biopsies showed complete loss of intestinal metaplasia in 73% of the patients with CIM compared with 4.4% of the patients with Barrett's. Low-grade dysplasia, present in 10 patients preoperatively, regressed in 7 patients (70%). No patient progressed to high-grade dysplasia or cancer.

CONCLUSIONS

Loss of intestinal metaplasia after antireflux surgery is rare in patients with Barrett's, but occurred in most patients with CIM. This suggests that cardiac epithelium is dynamic and that microscopic areas of intestinal metaplasia are able to regress much more frequently than longer, visible segments of intestinal metaplasia.