Antireflux surgery for Barrett's oesophagus

ENDOSCOPIC ABLATION COMBINED WITH FUNDOPLICATION PLUS ACID SUPPRESSION-DUODENAL DIVERSION PROCEDURE FOR LONG SEGMENT BARRETT´S ESOPHAGUS: EARLY AND LONG-TERM OUTCOME

BACKGROUND:

The addition of endoscopic ablative therapy plus proton pump inhibitors or fundoplication is postulated for the treatment of patients with long-segment Barrett´s esophagus (LSBE); however, it does not avoid acid and bile reflux in these patients. Fundoplication with distal gastrectomy and Roux-en-Y gastrojejunostomy is proposed as an acid suppression-duodenal diversion procedure demonstrating excellent results at long-term follow-up. There are no reports on therapeutic strategy with this combination.

AIMS:

To determine the early and long-term results observed in LSBE patients with or without low-grade dysplasia who underwent the acid suppression-duodenal diversion procedure combined with endoscopic therapy.

METHODS:

Prospective study including patients with endoscopic LSBE using the Prague classification for circumferential and maximal lengths and confirmed by histological study. Patients were submitted to argon plasma coagulation (21) or radiofrequency ablation (31). After receiving treatment, they were monitored at early and late follow-up (5–12 years) with endoscopic and histologic evaluation.

RESULTS:

Few complications (ulcers or strictures) were observed after the procedure. Re-treatment was required in both groups of patients. The reduction in length of metaplastic epithelium was significantly better after radiofrequency ablation compared to argon plasma coagulation (10.95 vs 21.15 mms for circumferential length; and 30.96 vs 44.41 mms for maximal length). Intestinal metaplasia disappeared in a high percentage of patients, and histological long-term results were quite similar in both groups.

CONCLUSIONS:

Endoscopic procedures combined with fundoplication plus acid suppression with duodenal diversion technique to eliminate metaplastic epithelium of distal esophagus could be considered a good alternative option for LSBE treatment.

Role of acid suppression in the development and progression of dysplasia in patients with Barrett's esophagus

Barrett's esophagus (BE) usually develops in patients with gastroesophageal reflux disease and therefore it has been suggested that esophageal acid exposure plays an import role in the initiation of BE and its progression towards esophageal adenocarcinoma (EAC). The mechanisms whereby acid exposure causes BE are not completely revealed and the potential role of esophageal acid exposure in carcinogenesis is unclear as well. Since acid exposure is thought to play an important role in the progression of BE, therapies aimed at preventing the development of EAC have primarily focused on pharmacological and surgical acid suppression. In clinical practice, acid suppression is effective in relieving reflux symptoms and decreases esophageal acid exposure in most patients. However, in some individuals, pathological acid exposure persists and these patients continue to be at risk for developing dysplasia or EAC. To date, published trials suggest that acid suppression is able to prevent the development and progression of dysplasia in patients with BE, but definite and compelling proof is still lacking. This article reviews the mechanisms of acid-induced carcinogenesis in BE and the role of acid suppression in the prevention of neoplastic progression.

A comparison of primary oesophageal squamous epithelial cells with HET-1A in organotypic culture

BACKGROUND INFORMATION

Carcinoma of the oesophagus is the sixth leading cause of cancer death in the western world and is associated with a 5-year survival of less than 15%. Recent evidence suggests that stromal-epithelial interactions are fundamental in carcinogenesis. The advent of co-culture techniques permits the investigation of cross-talk between the stroma and epithelium in a physiological setting. We have characterized a histologically representative oesophageal organotypic model and have used it to compare the most commonly used squamous oesophageal cell line, HET-1A, with primary oesophageal squamous cells for use in studies of the oesophageal epithelium in vitro.

RESULTS

When grown in an organotypic culture with normal fibroblasts, the oesophageal carcinoma cell lines OE21 (squamous) and OE19 (adenocarcinoma) morphologically resembled the tumour of origin with evidence of stromal invasion and mucus production, respectively. However, HET-1A cells, which were derived from normal squamous oesophageal cells, appeared dysplastic and failed to display evidence of squamous differentiation. By comparison with primary oesophageal epithelial cells, the HET-1A cells were highly proliferative and did not express the epithelial markers E-cadherin or CK5/6 (casein kinase 5/6), or the stratified epithelial marker ΔNp63, but did express the mesenchymal markers vimentin and N-cadherin.

CONCLUSION

Studies of epithelial carcinogenesis will benefit from culture systems which allow manipulation of the stromal and epithelial layers independently. We have developed an organotypic culture using primary oesophageal squamous cells and fibroblasts in which a stratified epithelium with a proliferative basal layer that stains strongly for ΔNp63 develops. This model will be suitable for the study of the molecular events in the development of Barrett's oesophagus. The most commonly used normal oesophageal squamous cell line, HET-1A, does not have the characteristics of normal oesophageal squamous cells and should not be used in models of the normal oesophageal epithelium. Until more representative cell lines are available, future studies in oesophageal cancer will be reliant on the availability and manipulation of primary tissue.

The effect of long-term control of reflux by fundoplication on aberrant deoxyribonucleic acid methylation in patients with Barrett esophagus

OBJECTIVE

We investigated the relationship between reflux and aberrant deoxyribonucleic acid (DNA) methylation, comparing methylation in the columnar epithelium following successful fundoplication to that in subjects with a failed fundoplication.

SUMMARY BACKGROUND DATA

Gastroesophageal reflux is the main risk factor for Barrett esophagus and adenocarcinoma. In these diseases, there is a high level of DNA methylation.

METHODS

We enrolled 41 patients with Barrett esophagus and a fundoplication at least 5 years earlier for a 24-hour pH study, endoscopy, and collection of biopsies. Biopsies were obtained from 17 Barrett esophagus subjects who had not undergone esophageal surgery.

RESULTS

At the time of the study, 31 subjects were pH normal, 10 abnormal. Columnar biopsies were collected from 21 of the pH normal and 9 pH abnormal subjects, and all no surgery subjects. Complete regression of columnar mucosa was seen in 7 subjects with pH normal and 1 with pH abnormal. The length of Barrett esophagus did not differ between groups preoperatively, but was significantly less at the time of the study in the pH normal compared with pH abnormal or no surgery groups. Significantly, fewer genes were methylated in the pH normal than the pH abnormal or no surgery groups, which did not differ from each other. The number of methylated genes correlated with increased reflux, intestinal metaplasia, and increased columnar-lined esophagus length, but not acid-suppression medication.

CONCLUSIONS

Fundoplication that reduces reflux to normal levels can lead to regression of the columnar mucosa. Reflux is associated with aberrant DNA methylation, and control of reflux reduces deleterious genomic changes associated with cancer.

Hiatal hernia, lower esophageal sphincter incompetence, and effectiveness of Nissen fundoplication in the spectrum of gastroesophageal reflux disease

BACKGROUND AND AIMS

Gastroesophageal reflux disease (GERD) is a spectrum of disease that includes nonerosive reflux disease (NERD), erosive reflux disease (ERD), and Barrett's esophagus (BE). Treatment outcomes for patients with different stages have differed in many studies. In particular, acid suppressant medication therapy is reported to be less effective for treating patients with NERD and Barrett's esophagus. The aims of this study were to investigate (1) the role of mechanical factors including hiatal hernia and lower esophageal sphincter (LES) competence in the spectrum of GERD and (2) outcomes of Nissen fundoplication.

METHODS

From the records of patients who had undergone laparoscopic Nissen fundoplication after an abnormal pH study, we identified 50 symptomatic consecutive patients with each of the GERD stages: (1) NERD, (2) mild ERD, defined as esophagitis that was healed with acid suppression therapy, (3) severe ERD, defined as esophagitis that persisted despite medical therapy, and (4) BE. Exclusion criteria were normal distal esophageal acid exposure, esophageal pH monitoring performed elsewhere, antireflux surgery less than 1 year previously or previous fundoplication, and a named esophageal motility disorder or distal esophageal low amplitude hypomotility. Patients who could not be contacted for the study were also excluded. All patients completed a detailed preoperative questionnaire; underwent preoperative upper gastrointestinal endoscopy, stationary manometry, and distal esophageal pH monitoring; and were interviewed at least 1 year after operation.

RESULTS

One hundred sixty patients meeting the entry criteria were studied. The mean follow-up period was 36.7 months. The only significant preoperative symptom difference was that patients with BE had more moderately severe or severe dysphagia compared to patients with NERD. Patients with severe ERD or BE had a significantly higher prevalence of hiatal hernia, lower LES pressures, and more esophageal acid exposure. Hiatal hernia and hypotensive LES were present in most patients with severe ERD or BE but in only a minority of patients with NERD or mild ERD. Surgical therapy resulted in similarly excellent symptom outcomes for patients in all GERD categories.

CONCLUSIONS

Compared to mild ERD and NERD, severe ERD and BE are associated with significantly greater loss of the mechanical antireflux barrier as reflected in the presence of hiatal hernia and LES measurements. Restoration of the antireflux barrier and hernia reduction by laparoscopic Nissen fundoplication provides similarly excellent symptom control in all patients.

Androgen receptors may act in a paracrine manner to regulate oesophageal adenocarcinoma growth

BACKGROUND

The role of androgen receptors (ARs) in tumorigenesis, including transcription of fibroblast growth factors (FGFs), is established in prostate cancer. This study examined the role of ARs and FGFs in oesophageal adenocarcinoma (EAC), where tumour incidence in males is higher.

METHODS

AR gene expression was analysed using quantitative RT-PCR; AR, fibroblast growth factor receptor-1 (FGFR-1) and fibroblast growth factor-8 isoform b (FGF-8b) protein by immunohistochemistry; and serum steroid levels (testosterone, progesterone, luteinising hormone and follicle stimulating hormone (FSH)) by immunoassay. A human oesophageal adenocarcinoma cell line was grown subcutaneously in nude mice.

RESULTS

AR gene expression was of significantly higher levels than oesophageal adenocarcinomas (n=21, p=0.002) and in the squamous carcinoma line (OE21) compared with the adenocarcinoma lines (OE33 and OE19). Median serum testosterone levels in oesophageal carcinoma patients were higher than in age-matched controls (p=0.01) and reduced postoperatively, in patients undergoing curative resection (p=0.006). No significant differences were observed in hormones except FSH, where preoperative levels were significantly higher in the EAC group. AR protein was expressed in normal oesophageal squamous epithelial cells and also in the stroma of 18/23 EAC samples. FGFR-1 protein was expressed in malignant epithelium of 23/23 tumour samples. OE19 xenografts grew faster in male versus female mice (tumour weight at day 21, 1.14 g and 0.28 g, respectively, p=0.005) and had elevated FGF receptor expression.

CONCLUSIONS

AR expressed in the stroma of oesophageal adenocarcinomas may induce paracrine effects following stimulation by androgens (including tumour-derived), possibly via FGFs, including FGF-8b.

Managing gastroesophageal reflux disease for the lifetime of the patient: evaluating the long-term options

Lifetime management goals of gastroesophageal reflux disease (GERD) are to control esophageal as well as extraesophageal symptoms, maintain a stable noninflamed esophageal mucosa, and prevent complications. Large randomized clinical trials and >16 years of worldwide experience have confirmed the high rate of efficacy and excellent safety profile of proton pump inhibitor (PPI) therapy in individuals with all grades of GERD, making these agents the mainstay of treatment. Despite these outcomes, some individuals may desire an alternative to pharmacologic therapy. In such patients, laparoscopic fundoplication may produce symptom relief and healing of esophagitis, but its invasiveness, cost, and inherent surgical risks have created an interest in a variety of endoscopic therapies for reflux disease. Several short-term uncontrolled trials of these endoscopic therapies have reported encouraging preliminary results; however, careful patient selection as well as clinician experience is critical for their success. In addition to clinician expertise with the procedure, success has been observed only in patients with nonerosive GERD and a hiatal hernia <3 cm, abnormal pH monitoring, and normal esophageal motility studies, as well as in those who have experienced at least partial symptom relief with PPI therapy. Endoscopic therapy should not be considered the standard of care in patients with erosive disease or large hiatal hernias.

Laparoscopic treatment of gastro-oesophageal reflux disease

Laparoscopic antireflux surgery is now well established as a treatment of moderate to severe gastro-oesophageal reflux disease. It is indicated for patients with reflux symptoms who have not responded fully to medical therapy or who do not wish to continue medication for the rest of their lives. The evidence base for the determination of appropriate practice has expanded considerably in recent years with the publication of several important randomized trials. These trials have confirmed the superiority of fundoplication compared to medical therapy for the treatment of these patients. They have also demonstrated that the laparoscopic approach achieves an improved short-term outcome compared to the equivalent open approach. Additional trials suggest that the routine application of partial fundoplication procedures achieves equivalent reflux control and fewer side-effects than total fundoplication. Longer-term outcome studies have also been reported recently, with success rates of approximately 90% claimed at 5-8 years. Hence, laparoscopic fundoplication is now the 'gold standard' for the management of patients with more severe gastro-oesophageal reflux disease. New endoscopic treatments for reflux will need to achieve similar outcomes before they can replace the laparoscopic approach.