Endoscopic therapy for Barrett's esophagus

Predictors of esophageal stricture formation post endoscopic mucosal resection

BACKGROUND/AIMS

Stricture formation is a common complication after endoscopic mucosal resection. Predictors of stricture formation have not been well studied.

METHODS

We conducted a retrospective, observational, descriptive study by using a prospective endoscopic mucosal resection database in a tertiary referral center. For each patient, we extracted the age, sex, lesion size, use of ablative therapy, and detection of esophageal strictures. The primary outcome was the presence of esophageal stricture at follow-up. Multivariate logistic regression was used to analyze the association between the primary outcome and predictors.

RESULTS

Of 136 patients, 27% (n=37) had esophageal strictures. Thirty-two percent (n=44) needed endoscopic dilation to relieve dysphagia (median, 2; range, 1 to 8). Multivariate logistic regression analysis showed that the size of the lesion excised is associated with increased odds of having a stricture (odds ratio, 1.6; 95% confidence interval, 1.1 to 2.3; p=0.01), when controlling for age, sex, and ablative modalities. Similarly, the number of lesions removed in the index procedure was associated with increased odds of developing a stricture (odds ratio, 2.3; 95% confidence interval, 1.3 to 4.2; p=0.007).

CONCLUSIONS

Stricture formation after esophageal endoscopic mucosal resection is common. Risk factors for stricture formation include large mucosal resections and the resection of multiple lesions on the initial procedure.

How good is the neosquamous epithelium?

BACKGROUND/AIMS

Endoscopic radiofrequency ablation of dysplastic Barrett's esophagus (BE) combined with proton pump inhibitor therapy is commonly utilized for preventing progression of dysplastic BE to esophageal adenocarcinoma. Fundamental to the success of this and all ablative approaches is the healing of the ablated areas of BE with a stratified squamous epithelium referred to as 'neosquamous epithelium' (NSE). Although NSE appears 'normal' endoscopically, the reemergence of BE over time in the previously ablated segments raises the question of the health and integrity of NSE.

METHODS

The health of NSE was recently investigated in endoscopic biopsies in vitro in a group of patients after ablation while on proton pump inhibitors. Biopsies of NSE were compared to upper squamous epithelium (USE) from the same patients morphologically (light microscopy) and with respect to barrier function by measuring electrical resistance and fluorescein flux in mini-Ussing chambers.

RESULTS

Compared to USE, NSE exhibited dilated intercellular spaces and inflammation and defective barrier function by low electrical resistance and high fluorescein flux. Moreover, NSE exhibited downregulation of claudin-4, a highly expressed protein in squamous tight junctions.

CONCLUSION

NSE has defective barrier function in part due to downregulation of claudin-4. Since downregulation of claudin-4 increases paracellular permeability to cations, e.g. hydrogen ions, NSE is more vulnerable to attack and damage by acidic and weakly acidic refluxates--a phenomenon that may contribute in part to the reemergence of BE.

Survival in esophageal high-grade dysplasia/adenocarcinoma post endoscopic resection

BACKGROUND

Endoscopic resection followed by ablative therapy is frequently used to treat esophageal high-grade dysplasia or early esophageal adenocarcinoma.

AIMS

To study outcomes in patients with high-grade dysplasia compared to those with esophageal adenocarcinoma after endoscopic resection.

METHODS

Retrospective, observational, descriptive, single-centre study from a prospective database. We extracted data from 116 endoscopic resections. Survival was plotted using Kaplan-Meier curves multivariable Cox-proportional hazard assess for possible predictors of survival post-endoscopic resection was performed.

RESULTS

116 patients (64 esophageal adenocarcinoma, 52 high-grade dysplasia) underwent endoscopic resection from May 2003 to June 2010. Mean age was 71 ± 11 years for high-grade dysplasia and 72 ± 10 years for esophageal adenocarcinoma. Median follow-up was 17 months. Eighty-five patients had negative margins on endoscopic resection. Five-year survivals for high-grade dysplasia and esophageal adenocarcinoma were 86% (range 68-100%) and 78% (59-96%), respectively. Survival was not significantly different between groups (p=0.20). Overall mortality rate was 10.6% (9/85). At multivariable Cox regression increased Barrett's oesophagus length was associated with worse survival (HR 1.18 [1.06-1.33], p=0.0039). Survival was not affected by the pathology before resection: HR 2.4 [95%CI, 0.70-8.4], p=0.16.

CONCLUSIONS

Survival in patients with high-grade dysplasia of the oesophagus is similar to those with esophageal adenocarcinoma. Longer Barrett's oesophagus segments are associated with decreased survival.

Photodynamic Therapy for Barrett's Esophagus and Esophageal Carcinoma

This paper reviews the use of photodynamic therapy (PDT) in patients with Barrett's esophagus and esophageal carcinoma. We describe the history of PDT, mechanics, photosensitizers for PDT in patients with esophageal disease. Finally, we discuss its utility and limitations in this setting.

History, molecular mechanisms, and endoscopic treatment of Barrett's esophagus

This report is an adjunct to the American Gastroenterological Association Institute's medical position statement and technical review on the management of Barrett's esophagus, which will be published in the near future. Those documents will consider a number of broad questions on the diagnosis, clinical features, and management of patients with Barrett's esophagus, and the reader is referred to the technical review for an in-depth discussion of those topics. In this report, we review historical, molecular, and endoscopic therapeutic aspects of Barrett's esophagus that are of interest to clinicians and researchers.