Regression of Barrett's esophagus: the role of acid suppression, surgery, and ablative methods

The Natural Course of Gastroesophageal Reflux Disease: A Critical Appraisal of the Literature

Interpreting natural course studies have been very difficult due to their retrospective design, lack of standardization, reliability of reported mucosal findings, liberal use of antireflux medications and accuracy of chart documentation. Studies provided a wide range of progression rates of patients from nonerosive reflux disease (NERD) to erosive esophagitis (EE). However, direct progression from NERD to Barrett's esophagus appears to be an uncommon phenomenon. Importantly, progression of NERD patients was commonly reported to low grades of EE, which are currently considered inconclusive of gastroesophageal reflux disease. Reports of progression rates from low grades to high grades EE also vary considerably. Progression of patients with EE, without metaplastic epithelium underneath the inflammation, to Barrett's esophagus is relatively uncommon. Recently, it was also recognized that regression from high grades to low grades EE and from EE to NERD is a common phenomenon affecting up to 25% of the patients from each group.

Cleavage of E-Cadherin Contributes to Defective Barrier Function in Neosquamous Epithelium

BACKGROUND

After ablation of Barrett's esophagus (BE), the esophagus heals with neosquamous epithelium (NSE). Despite normal endoscopic appearance, NSE exhibits defective barrier function with similarities to defects noted in the distal esophageal epithelium in patients with gastroesophageal reflux disease (GERD).

AIM

To determine whether patients with NSE, unlike patients with healthy esophageal epithelium, have C-terminal fragments (CTFs) of e-cad detectable on tissue biopsy. Secondly, to determine whether patients with NSE have elevated levels of N-terminal fragments (NTFs) of e-cad in the serum.

METHODS

Fifteen patients with ablated long-segment BE, who had healing with formation of NSE, were enrolled in this pilot study. Western blots for CTFs and NTFs were performed on biopsies of NSE. Venous blood was obtained to assess levels of NTFs. Endoscopic distal esophageal biopsies from patients without esophageal disease served as tissue controls. Control blood samples were obtained from healthy subjects.

RESULTS

Blots of NSE were successful in 14/15 patients, and all 14 (100 %) had a 35-kD CTF of e-cad, while CTFs were absent in healthy control tissues. Despite CTFs in NSE, serum NTFs of e-cad in NSE were similar to controls, p > 0.05. However, unlike healthy controls, blots of NSE also showed NTFs with molecular weights of 70-90 kD.

CONCLUSIONS

Cleavage of e-cad, as evidenced by the presence of CTFs and NTFs on biopsy, contributes to defective barrier function in NSE. However, unlike findings reported in GERD patients, serum NTFs are not elevated in NSE patients. This difference may reflect poor absorption with tissue entrapment of NTFs in previously ablated areas with poorly perfused NSE.

Does Barrett's esophagus regress after surgery (or proton pump inhibitors)?

Barrett's esophagus, the condition in which metaplastic columnar epithelium that predisposes to cancer development replaces the squamous epithelium that normally lines the distal esophagus, is a complication of gastroesophageal reflux disease (GERD). Metaplasia is a potentially reversible condition, and partial regression of Barrett's metaplasia has been documented with effective medical or surgical therapy for GERD. The important issue for patient management is not whether antireflux treatment causes Barrett's esophagus to regress, but rather whether antireflux therapy prevents cancer in Barrett's esophagus. Proton pump inhibitors (PPIs) would be expected to prevent this cancer because they heal reflux esophagitis, reduce exposure to a potential carcinogen (acid), and might prevent acid-induced proliferation and cancer-promoting cytokine secretion by esophageal epithelial cells. Furthermore, observational studies have shown that PPI use is associated with a decreased incidence of neoplasia in Barrett's esophagus. In theory, successful antireflux surgery, which eliminates the reflux of both acid and bile, should be better for cancer prevention than medical therapy, which only decreases the reflux of acid. However, high-quality studies show no significant difference in cancer incidence between medically and surgically treated patients with GERD and Barrett's esophagus. Furthermore, for individual patients with nondysplastic Barrett's metaplasia, the cancer risk is so small and the number needed to treat for cancer prevention with surgery so large, that it does not matter whether or not surgery provides a tiny margin of extra protection against cancer beyond that provided by medical therapy. The cost and risks of the operation overwhelm any small, additional cancer protective benefit. Antireflux surgery is very effective at controlling the endoscopic signs and symptoms of GERD, but the operation should not be recommended to patients solely with the rationale that it protects against cancer better than medical therapy.

[Endoscopic argon plasma thermo-coagulation of Barrett's esophagus using different powers: histopathological and post procedure symptons analysis]

OBJECTIVE

To establish the ideal power to be employed in order to get the effective ablation and the lowest rate of symptoms at argon plasma thermocoagulation in Barrett's esophagus (BE).

METHODS

Twenty-eight asymptomatic patients with BE, were randomly divided in two groups of different ablation powers, 50W or 70W. After endoscopic ablation and biopsies from the treated area for histological analyses, symptoms were evaluated through a questionnaire answered by phone.

RESULTS

Thirteen patients without specialized columnar metaplasia were excluded and the remaining fifteen patients, seven men (46,7%) and eight women (53,3%), with an average age of 53 years +10,4, composed the two groups: 10 patients at the 70W power and 5 at the 50W power group. There was no significant difference between the groups regarding age, BE extent, percentage of coagulated esophageal circumference and the duration of symptoms. Pain was the most important symptom, with a mean duration of 10,3 + 9,7 days. When power was compared to symptoms, although not statistically significant, a moderate negative correlation was noted. Endoscopic biopsies showed ablation restricted to the mucosa's superficial layer in 40% of the cases in the lower power group, and only 10% in the higher power group, although deeper layers of the mucosa were compromised. There were no statistical significant differences when comparing the different powers to the penetration through the mucosa's layers and the symptoms.

CONCLUSION

There are evidences that the 70W potency argon plasma coagulation for BE leads to a lower incidence of residual specialized columnar metaplasia under the new scamous epithelium.

Endoluminal therapy for esophageal disease: an introduction

This introductory article summarizes decades of research from many dedicated gastrointestinal endoscopists. It provides a background to Barrett esophagus (BE), exploring the risk of progression to dysplasia and esophageal adenocarcinoma. Two premalignant conditions, BE and colon adenoma, are compared, including their progression to esophageal adenocarcinoma and colon and rectal carcinoma, respectively. A comparison of the risks of surgical treatment and post-surgical complications of these cancers and of the strikingly different paradigms for their prevention is presented. The article concludes with the rationale for endoscopic treatment of Barrett disease.

Neosquamous epithelium does not typically arise from Barrett's epithelium

PURPOSE

Neosquamous epithelium (NSE) can arise within Barrett's esophagus as a consequence of medical or surgical acid reduction therapy, as well as after endoscopic ablation. Morphologic studies have suggested that NSE can develop from adjacent squamous epithelium, submucosal gland ducts, or multipotent progenitor cell(s) that can give rise to either squamous or Barrett's epithelium, depending on the luminal environment. The cells responsible for Barrett's epithelium self-renewal are frequently mutated during neoplastic progression. If NSE arises from the same cells that self-renew the Barrett's epithelium, the two tissues should be clonally related and share genetic alterations; if NSE does not originate in the self-renewing Barrett's, NSE and Barrett's esophagus should be genetically independent.

EXPERIMENTAL DESIGN

We isolated islands of NSE and the surrounding Barrett's epithelium from 20 patients by microdissection and evaluated each tissue for genetic alterations in exon 2 of CDKN2A or exons 5 to 9 of the TP53 gene. Nine patients had p16 mutations and 11 had TP53 mutations within the Barrett's epithelium.

RESULTS

In 1 of 20 patients, a focus of NSE had a 146 bp deletion in p16 identical to that found in surrounding Barrett's epithelium. The NSE in the remaining 19 patients was wild-type for p16 or TP53.

CONCLUSION

Our mutational data support the hypothesis that, in most circumstances, NSE originates in cells different from those responsible for self-renewal of Barrett's epithelium. However, in one case, NSE and Barrett's epithelium seem to have arisen from a progenitor cell that was capable of differentiating into either intestinal metaplasia or NSE.

The effect of photodynamic therapy (PDT) on oesophageal motility and acid clearance in patients with Barrett’s oesophagus

BACKGROUND

Barrett's oesophagus is the major risk factor for oesophageal adenocarcinoma. It is proposed that long-term re-epithelialisation, which has been achieved following ablation using 5-aminolaevulinic acid (5-ALA) photodynamic therapy (PDT) may reduce the risk of malignant change. However, it is not known whether PDT modifies oesophageal motility.

AIM

To assess oesophageal pH and motility before and after PDT ablation in treated and untreated areas of the oesophagus.

METHODS

Twelve patients (10 male) with Barrett's oesophagus, median segment length 4 cm, were treated with PDT ablation. Twenty-four hours pH assessment and oesophageal manometry were performed before and 4-6 weeks after ablation. PDT was carried out using 635 nm red light, 4-6h after administration of 30 mg/kg 5-ALA. Proximal (untreated) and distal (treated) oesophageal resting pressure, wave amplitude, percentage peristalsis and percentage study time oesophageal pH<4, were assessed. Proton pump inhibitors (PPI) were administered throughout the study.

RESULTS

There were no significant differences in oesophageal motility in treated or untreated areas of the oesophagus after PDT compared to pre-treatment values. Patients who continued to experience oesophageal acid exposure required more treatments to achieve complete Barrett's ablation.

CONCLUSIONS

Oesophageal motility following ALA-PDT suggests a trend toward enhanced wave propagation however continued oesophageal acid exposure may affect PDT efficacy.

Barrett's esophagus: pathologic considerations and implications for treatment

Barrett's esophagus (BE) is a complication of chronic reflux that results in the replacement of esophageal squamous epithelium with columnar epithelium. BE is endoscopically recognized and pathologically confirmed. The presence of goblet cells is diagnostic. The pathologist must also determine if dysplasia or invasive cancer is present. Acceptable terms for dysplasia are no dysplasia, indefinite for dysplasia, low-grade dysplasia (LGD), or high-grade dysplasia (HGD). It can be difficult to differentiate HGD from intramucosal cancer (IMC) in an endoscopic biopsy specimen. Treatment based on this differentiation is problematic. Indications for treatment of BE are similar to those of patients without BE. Treatment will not cause clinically significant regression of BE or prevent progression to cancer. Cancer development following successful antireflux surgery is uncommon.

Technology Insight: ablative techniques for Barrett's esophagus—current and emerging trends

New mucosal ablative techniques that can be used in the esophagus have emerged over the past two decades. These techniques have been developed primarily to treat the precursors of esophageal adenocarcinoma: dysplasia in Barrett's esophagus and early esophageal cancer. Although high-grade dysplasia and early stage cancer can be treated with esophagectomy, the inherent morbidity and mortality of esophageal adenocarcinoma and the morbidities, difficulties, costs and limitations of the current technology mean that there has been a significant increase in interest and research regarding alternative treatments such as ablative techniques. At this stage it is not clear which of the numerous endoscopic ablative techniques available-photodynamic therapy, laser therapy, multipolar electrocoagulation, argon plasma coagulation, endoscopic mucosal resection, radiofrequency ablation or cryotherapy-will emerge as superior. In addition, it has yet to be determined whether the risks associated with ablation therapy are less than the risk of Barrett's esophagus progressing to cancer. Whether ablation therapy eliminates or significantly reduces the risk of cancer, eliminates the need for surveillance endoscopy, or is cost-effective, also remains to be seen. Comparative trials that are now underway should help to answer these questions.

Hepatocyte paraffin 1 immunoexpression in esophageal brush samples

BACKGROUND

Intestinal metaplasia (IM) is often a component of Barrett esophagus (BE) and is characterized by a distinctive type of epithelium. Because IM has the potential to progress to dysplasia or adenocarcinoma, an accurate identification of its presence is important clinically. A cytopathologic diagnosis of IM on esophageal brushings by morphology alone can be difficult. The authors investigated the role of hepatocyte paraffin 1 (Heppar-1) immunostaining as a possible marker of IM in cytologic samples of BE.

METHODS

Eleven samples each of BE with and without IM diagnosed on esophageal brushings were retrieved from the cytopathology files of The Johns Hopkins Hospital over an 8-year period (1993-2001). All 22 specimens were confirmed histologically on subsequent tissue biopsies. Slides initially were prepared by cytospin and stained with Papanicolaou stain. After destaining, the slides were immunostained with hepatocyte paraffin 1 (Heppar-1) antibody at 1:100 dilution employing conventional methodology.

RESULTS

Among the samples of BE with IM, 9 of 11 samples (82%) were immunoreactive for Heppar-1, compared with 0 of 11 specimens of BE with only cardiac-type metaplasia. The immunoexpression was cytoplasmic and granular and was seen only focally in the glandular fragments.

CONCLUSIONS

Heppar-1 was a moderately sensitive (82%) and highly specific (100%) immunomarker for IM in BE. It was easy to use in limited cytologic samples that originally were stained with Papanicolaou stain and is recommended for inclusion in morphologically difficult samples of BE with questionable IM. The immunostaining pattern predominantly was focal, necessitating a careful evaluation of positive reactions on cytologic samples.

Epidemiology, pathophysiology, and treatment of Barrett's esophagus: reducing mortality from esophageal adenocarcinoma

The definition of BE has evolved over time. BE is the key premalignant lesion for developing EAC. The epidemiology and pathophysiology of BE is outlined, and risk factors for BE and EAC are reviewed. GERD plays a crucial role in the pathophysiology and the clinical identification of BE. Endoscopy with biopsy is the best tool for diagnosing and surveying patients with BE. Detection of early neoplasia is the present approach to reduce EAC mortality. Novel technology should assist in the early detection of dysplasia to enable targeted therapy. Effective chemopreventive strategies may reduce the risk of progression to EAC.

Complete ablation of esophageal epithelium with a balloon-based bipolar electrode: a phased evaluation in the porcine and in the human esophagus

BACKGROUND

The aim of this study was to evaluate the endoscopic and the histologic effects of a balloon-based bipolar radiofrequency electrode for ablation of porcine and human esophageal epithelium.

METHODS

All procedures were performed with a balloon-based, bipolar radiofrequency system that creates a circumferential, thin-layer epithelial ablation zone within the esophagus. In Phase I, multiple ablations were created in 10 farm swine, followed by acute euthanasia and histologic assessment for completeness of epithelial removal and ablation depth. In Phase II, multiple ablations were created in 19 farm swine, with varying power and energy density, followed by endoscopy at 2 and 4 weeks to assess stricture formation. In Phase III, 3 ablations were created in 12 farm swine, with varying energy density (5, 8, 10, 12, 15, or 20 J/cm 2 ) at 350 W. Animals were euthanized at 48 hours. Histologic examination determined the percentage of epithelium removed and the ablation depth. In Phase IV, 3 patients underwent esophageal epithelial ablation before esophagectomy, creating separate lesions proximal to the tumor. Completeness of epithelial ablation and ablation depth was quantified histologically.

RESULTS

In Phase I, complete removal of esophageal epithelium was achieved at energy density settings of 9.7 to 29.5 J/cm 2 . In Phase II, 9.7 and 10.6 J/cm 2 produced no stricture, whereas more than 20 J/cm 2 produced a stricture in every case. In Phase III, 8-20 J/cm 2 resulted in 100% epithelial ablation. Five and 8 J/cm 2 spared the muscularis mucosae, whereas 10 J/cm 2 caused injury to the muscularis mucosae but preserved the submucosa. In Phase IV, histologic examination demonstrated full-thickness epithelial removal in areas of electrode contact. Ablation extended only to the muscularis mucosae, without injury to submucosa.

CONCLUSIONS

In the porcine and the human esophagus, circumferential, full-thickness ablation of epithelium without direct injury to the submucosa is possible and was well tolerated. In all cases, depth of ablation was linearly related to energy density of treatment.

Proton pump inhibitors are associated with reduced incidence of dysplasia in Barrett's esophagus

BACKGROUND AND AIMS

Esophageal acid exposure is important in the pathogenesis of Barrett's esophagus (BE), and possibly in the progression of BE to dysplasia and carcinoma. The aim of this study is to compare the development of dysplasia in BE patients treated with or without proton pump inhibitor (PPI) or histamine 2-receptor antagonist (H2RA).

METHODS

We analyzed prospectively collected data by a single endoscopist on patients with BE in a VA (Veterans Affairs) setting over a 20-yr time period (1981-2000). A pathologist used standard criteria to diagnose BE/dysplasia. Pharmacy information after 1994 was retrieved from a computerized database, and from research files for the period before that. The receipt and the duration of H2RA and/or PPI use was compared between those with and without dysplasia. The incidence of dysplasia was examined in a Kaplan-Meier survival analysis stratified by PPI treatment status, and the risk of dysplasia was examined in a Cox multiple regression analysis controlling for demographic features, length of BE, and the year of BE diagnosis.

RESULTS

We analyzed data for 236 unique veteran patients with a mean age at BE diagnosis of 61.5 yr, 86% Caucasian, and 98% male. During 1,170 patient-yr of follow-up, 56 patients developed dysplasia giving an annual incidence rate of 4.7%. Of those, 14 had high-grade dysplasia. The cumulative incidence of dysplasia was significantly lower among patients who received PPI after BE diagnosis than in those who received no therapy or H2RA; log rank test (p < 0.001). Furthermore, among those on PPIs, a longer duration of use was associated with less frequent occurrence of dysplasia. In multivariate analysis, the use of PPI after BE diagnosis was independently associated with reduced risk of dysplasia, hazards ratio: 0.25 (95% CI 0.13-0.47), p < 0.0001. Longer segments of BE and Caucasian race were other independent risk factors for developing dysplasia. In general, similar findings were observed when only cases with high-grade dysplasia were analyzed.

CONCLUSIONS

These results indicate that PPI therapy is associated with a significant reduction in the risk of developing dysplasia in patients with BE. However, more studies are required to confirm this finding.

A critical review of the diagnosis and management of Barrett's esophagus: the AGA Chicago Workshop

BACKGROUND & AIMS

The diagnosis and management of Barrett's esophagus (BE) are controversial. We conducted a critical review of the literature in BE to provide guidance on clinically relevant issues.

METHODS

A multidisciplinary group of 18 participants evaluated the strength and the grade of evidence for 42 statements pertaining to the diagnosis, screening, surveillance, and treatment of BE. Each member anonymously voted to accept or reject statements based on the strength of evidence and his own expert opinion.

RESULTS

There was strong consensus on most statements for acceptance or rejection. Members rejected statements that screening for BE has been shown to improve mortality from adenocarcinoma or to be cost-effective. Contrary to published clinical guidelines, they did not feel that screening should be recommended for adults over age 50, regardless of age or duration of heartburn. Members were divided on whether surveillance prolongs survival, although the majority agreed that it detects curable neoplasia and can be cost-effective in selected patients. The majority did not feel that acid-reduction therapy reduces the risk of esophageal adenocarcinoma but did agree that nonsteroidal antiinflammatory drugs are associated with a cancer risk reduction and are of promising (but unproven) value. Participants rejected the notion that mucosal ablation with acid suppression prevents adenocarcinoma in BE but agreed that this may be an appropriate strategy in a subgroup of patients with high-grade dysplasia.

CONCLUSIONS

Based on this review of BE, the opinions of workshop members on issues pertaining to screening and surveillance are at variance with published clinical guidelines.

Photodynamic therapy for Barrett's esophagus with dysplasia and/or early stage carcinoma: long-term results

BACKGROUND

Photodynamic therapy has been shown to eliminate Barrett's dysplasia. This report presents long-term follow-up data after photodynamic therapy of Barrett's esophagus with high-grade dysplasia, low-grade dysplasia, or early stage carcinoma.

METHODS

Porfimer-photodynamic therapy was performed in 103 patients. The Nd:YAG laser was used to photoablate small areas of residual or untreated Barrett's mucosa. Acid suppression was maintained in all patients (omeprazole, 20 mg twice a day).

RESULTS

Mean follow-up was 50.65 (SD 20.57) months (range 2-122 months). For the 82 patients not lost to follow-up, mean follow-up was 58.5 (12.89) months (range 41-132 months). After photodynamic therapy, the length of Barrett's mucosa decreased by a mean of 6.92 cm (range 1-22 cm). Of the 65 patients with high-grade dysplasia, 60 (94%) had elimination of high-grade dysplasia. Three (4.6%) patients developed subsquamous adenocarcinoma. Subsquamous, nondysplastic, metaplastic epithelium was found in 4 patients (4.9%). Strictures occurred in 18% with one session of photodynamic therapy, and 50% with two treatments, 30% overall. For the 103 patients, intention-to-treat success rates were 92.9%, 77.5%, and 44.4% for, respectively, low-grade dysplasia, high-grade dysplasia, and early stage carcinoma groups.

CONCLUSION

Porfimer-photodynamic therapy with supplemental Nd:YAG photoablation and continuous treatment with omeprazole reduces the length of Barrett's mucosa, eliminates high-grade dysplasia, and, by comparison with historical data, may reduce the expected frequency of carcinoma.

Multipolar electrocoagulation

Multipolar electrocoagulation (MPEC) is a readily available technique that can be applied for endoscopic ablation of Barrett's esophagus. MPEC, in combination with high dose proton pump inhibitor therapy or antireflux surgery, results in normal squamous epithelium in most patients without major adverse effects. The ultimate clinical role of MPEC has not been determined but may be adjunctive to other techniques in appropriately selected patients at high risk for neoplastic progression.

Gastroesophageal reflux disease revisited

GERD should be viewed as three distinct groups of patients: NERD, erosive esophagitis, and Barrett's esophagus. This new paradigm will shift our focus to mechanisms leading to symptom generation in each group and foster specific therapeutic modalities that benefit each individual group of patients.

What you need to know about Barrett's esophagus

The incidence of Barrett's esophagus is increasing and this diagnosis is being seen more frequently in endoscopy units. Barrett's esophagus is a premalignant condition where the cells that normally line the esophagus are replaced with specialized columnar cells. Patients with Barrett's require close surveillance to monitor their condition and screen for the development of esophageal adenocarcinoma. This article provides an overview of Barrett's esophagus to better prepare gastroenterology nurses for educating and caring for this population of patients. Included is a discussion of the pathophysiology, signs and symptoms, and diagnostics of this disease entity. Current treatment options including medical management with proton pump inhibitors, endoscopic mucosal ablation techniques such as photodynamic therapy, and surgical intervention are also discussed. Current patient education approaches are also discussed.

Gastroesophageal reflux disease--should we adopt a new conceptual framework?

Gastroesophageal reflux disease (GERD) has traditionally been approached as a spectrum of diseases. Over the years, this important concept affected our current understanding of the pathophysiologic mechanisms resulting in GERD. Additionally, it had a profound impact on our therapeutic approach and treatment algorithms. However, literature review reveals that there is scant data to support the spectrum paradigm. Consequently, we propose categorizing GERD into three unique groups of patients: nonerosive reflux disease, erosive esophagitis, and Barrett's esophagus. Thus far, studies have demonstrated very little movement between these groups. Although the spectrum concept focused our attention on esophageal mucosal injury, the new proposed conceptual model shifts our attention to esophageal symptoms. Furthermore, dividing GERD into three unique groups of patients will allow us to concentrate on the different mechanisms that lead to the development of each of these GERD-related disorders and thus help us to focus on the specific therapeutic modalities that will benefit each individual group of patients.

Circumferential endoscopic mucosal resection in the swine esophagus assisted by a cap attachment

BACKGROUND

The feasibility and safety of piecemeal, circumferential endoscopic mucosal resection of the distal esophagus are unknown. This study assessed this procedure in a porcine model.

METHODS

Different techniques of endoscopic mucosal resection were tested in Phase I of the study in two animals. During Phase II, 6 pigs underwent piecemeal cap-assisted EMR of the distal esophagus. The mucosa of one half of the circumference of the distal 5 cm of the esophagus was resected. After complete endoscopic re-epithelization, endoscopic mucosal resection was performed on the remaining unresected hemi-circumference. Healing was promoted by daily administration of lansoprazole and documented by weekly endoscopy.

OBSERVATIONS

In Phase I, one perforation occurred during initial testing of cap-assisted endoscopic mucosal resection. Subsequent cap-assisted endoscopic mucosal resection led to homogenous and uniform piecemeal resection of mucosa. In Phase II, circumferential cap-assisted endoscopic mucosal resection was performed in 6 pigs without perforation or major bleeding. Complete endoscopic re-epithelization occurred over a mean of 3.6 weeks (range: 3-5). Strictures developed in 3 animals.

CONCLUSIONS

Piecemeal circumferential cap-assisted endoscopic mucosal resection is safe and feasible in the normal swine esophagus. Proper technique for cap-assisted piecemeal endoscopic mucosal resection is necessary to minimize the risk of perforation. Procedural complications include esophageal stricture formation.

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

OBJECTIVE

Gastroesophageal reflux disease (GERD) plays a major role in the development of Barrett's esophagus. Recently, we demonstrated that duration of esophageal acid exposure in the distal esophagus correlates with the length of Barrett's mucosa. The aim of this study was to determine whether there is a relationship between the rate of the change in acid exposure along the esophagus and the length of Barrett's esophagus.

METHODS

A total of 17 patients (16 men and one woman; mean age 66 +/- 15 yr, range 41-83 yr) with varying lengths of biopsy-proven Barrett's esophagus were recruited prospectively into the study. Ambulatory 24-h esophageal pH monitoring was performed using a commercially available pH probe with four sensors located 5 cm apart. For each patient, a least squares regression line of the fraction of the study that the pH was <4 against the height of the sensor above the lower esophageal sphincter was fit. The slope of the regression line was used to represent the rate of change in acid exposure. Linear regression analysis was conducted to analyze the relationship between the rate of change in acid exposure and the length of Barrett's mucosa.

RESULTS

The mean Barrett's length was 5 +/- 3 cm (range 1-11 cm). Linear regression demonstrated a statistically significant relationship between the rate of change in acid exposure and the length of Barrett's esophagus for the 24-h duration of the study, as well as for the fraction of the study that patients were in the upright position (p = 0.0096 and 0.0076, respectively). For the supine position, the relationship did not reach statistical significance (p = 0.095).

CONCLUSIONS

We demonstrated a significant relationship between the rate of change in acid exposure and the length of Barrett's mucosa. Thus, as the rate at which recorded acid exposure values increases from the proximal to distal esophagus, the length of Barrett's esophagus significantly increases (for percent total time and upright position).

Role of mucosal ablative therapy in the treatment of the columnar-lined esophagus

With the high prevalence of gastroesophageal reflux-like symptoms in the United States and the association between GERD symptoms and the premalignant condition of BE, there is more and more demand for new and efficacious techniques to treat BE. A wide variety of endoscopic mucosal ablative techniques have been developed with promising initial results. Long-term control of neoplastic risk, however, has not been demonstrated, and most studies demonstrate that there is still potentially some intestinal mucosa present underneath squamous mucosa. Currently, more study is needed to determine which patient groups require therapy of any kind and to determine which therapies would be the most efficacious. Genetic markers may aid in identification of subgroups that are at risk for cancer and help to identify those who would respond to mucosal therapy. Even in patients who have HGD, subgroups of patients who have focal HGD have been found to have better prognosis than those who have more widespread HGD. Currently, there is sufficient information to consider mucosal ablative techniques in patients who are not good surgical candidates. Photodynamic therapy, APC, KTP, Nd:YAG and argon lasers, MPEC, and EMR may provide good alternatives, depending on the degree of dysplasia, the extent of disease, and the age of the patient. Photodynamic therapy and Nd:YAG laser therapy have been applied to more neoplastic lesions, whereas KTP:YAG, APC, and multipolar coagulation have been successful in nondysplastic Barrett's mucosa. In the future, there will be more information to justify the application of mucosal ablative therapy in selected patients.

Impact of esophageal acid exposure on the endoscopic reversal of Barrett's esophagus

OBJECTIVE

Normalization of esophageal acid exposure had been assumed to be necessary for the reversal of Barrett's esophagus with endoscopic therapy. This assumption is examined by evaluating the esophageal pH in a group of patients undergoing reversal therapy with fixed high-dose proton pump inhibitor therapy and endoscopic multipolar electrocoagulation (MPEC).

METHODS

Patients with Barrett's esophagus of 2-6 cm in length were treated with omeprazole (40 mg b.i.d.). They underwent 24-h esophageal pH monitoring 5 cm above the upper margin of the lower esophageal sphincter determined by a water-perfused catheter. They then underwent MPEC therapy to an endpoint of elimination of Barrett's (reversal) by both endoscopy and biopsy 6 months after the last MPEC session or failure to achieve visual (endoscopic) reversal after six treatment sessions.

RESULTS

Twenty patients had 24-h pH testing and reached a reversal endpoint. Three patients had abnormal pH tests, two total and supine and one supine only. These patients had documented reversal. The remaining 17 patients had normal pH testing but five failed reversal therapy.

CONCLUSION

Barrett's esophagus can be completely reversed with endoscopic therapy despite abnormal esophageal acid exposure. Also, patients can fail reversal even with normal esophageal acid exposure. The necessary reduction of esophageal acid exposure for reversal therapy has yet to be defined.

Another look at Barrett's esophagus. Current thinking on screening and surveillance strategies

Barrett's esophagus remains a major health problem and a risk factor for the development of esophageal adenocarcinoma. Given the low incidence of this disorder, efforts should be made to identify risk factors that target patients with GERD or known Barrett's esophagus who would most benefit from screening and surveillance strategies. It is clear that identifying esophageal adenocarcinoma at an early and treatable stage reduces morbidity and mortality. However, currently available screening tools (endoscopy with surveillance biopsies every 2 years) are expensive and not easily applied. Identification of tumor markers and other specific risk factors may be helpful in predicting who is at risk for dysplasia. Current therapeutic strategies are successful in the treatment of GERD symptoms, but further research and longer follow-up studies are needed to determine if these strategies bring about regression of Barrett's esophagus, reversal of dysplasia, or prevention of cancer.

Effective and safe endoscopic reversal of nondysplastic Barrett's esophagus with thermal electrocoagulation combined with high-dose acid inhibition: a multicenter study

BACKGROUND

Barrett's esophagus is a metaplastic change in the esophageal lining with an increased risk for adenocarcinoma. Multiple endoscopic techniques have been applied in an effort to reverse Barrett's. This is a multicenter trial defining the efficacy and safety of multipolar electrocoagulation combined with high-dose acid inhibition.

METHODS

Patients with a 2- to 6-cm segment of Barrett's esophagus without dysplasia were enrolled at 3 centers. They were treated with omeprazole 40 mg twice daily and then with up to 6 sessions with electrocoagulation aimed at eliminating all the endoscopically apparent Barrett's. Four quadrant large-capacity biopsies every 2 cm were centrally assessed for residual intestinal metaplasia.

RESULTS

Fifty-eight patients reached the endpoint of failure of visual reversal of Barrett's after 6 treatment sessions or a 6-month follow-up after the last session. Eighty-five percent had visual reversal and 78% both visual and histologic reversal. Four patients had histologic evidence of residual intestinal metaplasia. Transient esophageal symptoms were common. One patient developed a stricture requiring dilation and one required overnight hospitalization for chest pain.

CONCLUSIONS

The majority of patients with 2 to 6 cm of nondysplastic Barrett's esophagus can be safely reversed with this combination therapy. Long-term follow-up will be necessary to document the durability of the new squamous epithelium.

Pathogenesis of gastroesophageal reflux and Barrett esophagus

Barrett esophagus is a metaplastic condition that affects the lower esophagus and is a complication of gastroesophageal reflux disease (GERD). Under normal circumstances, the reflux of gastric contents into the esophagus is prevented by a complex barrier at the esophagogastric junction. Dysfunction of the lower esophageal sphincter and the presence of a hiatal hernia lead to failure of this barrier. Esophageal mucosal damage results from the chronic exposure of the esophageal mucosa to gastroduodenal contents and the lack of an effective mucosal defense. This article is an overview of the dysfunction of the esophagogastric junction that leads to GERD. The role of the contents of the reflux and that of Helicobacter pylori infection in the pathogenesis of Barrett esophagus are also summarized.

Pathogenesis of gastroesophageal reflux and Barrett esophagus

Barrett esophagus is a metaplastic condition that affects the lower esophagus and is a complication of gastroesophageal reflux disease (GERD). Under normal circumstances, the reflux of gastric contents into the esophagus is prevented by a complex barrier at the esophagogastric junction. Dysfunction of the lower esophageal sphincter and the presence of a hiatal hernia lead to failure of this barrier. Esophageal mucosal damage results from the chronic exposure of the esophageal mucosa to gastroduodenal contents and the lack of an effective mucosal defense. This article is an overview of the dysfunction of the esophagogastric junction that leads to GERD. The role of the contents of the reflux and that of Helicobacter pylori infection in the pathogenesis of Barrett esophagus are also summarized.

Practice patterns for surveillance of Barrett's esophagus in the united states

BACKGROUND

Endoscopic surveillance of Barrett's esophagus is recommended to detect dysplasia or cancer at an early and potentially treatable stage. However, little is known about the clinical practice patterns for endoscopic surveillance in the United States.

METHODS

A questionnaire regarding surveillance intervals, techniques and management approaches for patients with Barrett's esophagus was mailed to 1000 randomly selected members of the Clinical Practice Section of the American Gastroenterological Association.

RESULTS

The response rate was 455 of 1000 (45%). Not all respondents answered all questions. Seventy-nine percent of respondents were in community practices, and 21% were in academic practices. Nearly all (96%) performed endoscopic surveillance, but it was practiced more commonly in the community (334 of 341 [98%]) than in the academic setting (83 of 93 [89%], p < 0.001). For patients without dysplasia, endoscopic surveillance was most commonly performed every 2 years (264 of 415 [64%]). Patients with low-grade dysplasia usually had surveillance endoscopy at 6-month intervals (215 of 413 [52%]), whereas those with high-grade dysplasia most commonly had endoscopy every 3 months (201 of 404 [50%]). These surveillance patterns did not differ between the academic and community groups. Random biopsies were performed by 93 of 403 (23%), 4-quadrant biopsies by 310 (77%). Most physicians (83%) used standard capacity forceps. Brush cytology was done uncommonly (69 of 414 [17%]). The most common indications for esophagectomy were high-grade dysplasia by 82% and cancer by 83%. Ablation therapy was performed for Barrett's esophagus without dysplasia by 3.5%, Barrett's with dysplasia by 20%, and cancer by 8%.

CONCLUSIONS

Surveillance for Barrett's esophagus is widely practiced in the United States but there is considerable variation in interval and technique. A clearer consensus on endoscopic surveillance is warranted to optimize care of patients with Barrett's esophagus.

New treatment for Barrett's oesophagus

Barrett's esophagus is characterised by the presence of specialised intestinal metaplasia in the lower esophagus. Its importance is related primarily to its link with adenocarcinoma of the lower esophagus, often preceded by dysplastic changes. The incidence of this carcinoma has increased dramatically over the last few decades. Although modern treatments, particularly acid suppression with proton pump inhibitors, have been most useful in controlling the reflux symptoms associated with Barrett's esophagus, they have not reduced the incidence of adenocarcinoma of the esophagus. The same can be said about anti-reflux surgery. Surgical excision of Barrett's esophagus has been advocated when high-grade dysplasia is detected; this carries considerable morbidity and mortality, so alternative treatments are being developed. This update summarises recent information concerning newer treatments aimed at eradicating Barrett's esophagus. These vary from thermal coagulation (using electrocoagulation and heater probes) to lasers, photodynamic therapy and mechanical methods. Of these, photodynamic therapy using a porphyrin precursor (5-amino-laevulinic acid) seems to give the most consistent satisfactory results with a minimum of complications. However, persistence of some metaplastic cells beneath the neo-squamous layer remains a problem. Ongoing effective acid control (by medical or surgical therapy) is also essential to prevent recurrence of Barrett's esophagus. Future research is aimed at perfecting these methods. Ultimately, it may be possible to understand the molecular biology which could help to predict which patients are at greatest risk of developing dysplastic and carcinomatous changes.