Subsquamous intestinal metaplasia: implications for endoscopic management of Barrett's esophagus

Post-ablation buried neoplasia in Barrett's esophagus

Endoscopic eradication therapy (EET) with maximal acid suppression is the cornerstone for the management of patients with Barrett's esophagus (BE) associated dysplasia. The occurrence of buried dysplastic glands after re-epithelialization of a neo-squamous epithelium is of concern for endoscopists. Here, we present a patient with BE and high-grade dysplasia successfully treated by EET who developed buried dysplastic BE during surveillance. A review of literature on buried dysplasia after successful endoscopic therapy of BE is also discussed.

Allaying uncertainty in diagnosing buried Barrett's esophagus

Subsquamous intestinal metaplasia (SSIM) in the setting of Barrett's esophagus (BE) is a technically challenging diagnosis. While the risk for progression of BE involving the surface mucosa is well documented, the potential risk for development of advanced neoplasia associated with SSIM has been controversial. This study aimed to determine the effects of specimen adequacy, presence of dysplasia, and interobserver agreement for SSIM interpretation. Adult patients (n = 28) who underwent endoscopic therapy for BE with high-grade dysplasia or intramucosal carcinoma (HGD/IMC) between October 2005 and June 2013 were included. Initial evaluation (n = 140 slides) by an experienced gastrointestinal pathologist was followed by an interobserver study by 8 pathologists. Forty-seven (34%) slides had insufficient subsquamous tissue to assess for SSIM. SSIM was found in 19% of all slides and 29% of slides with sufficient subsquamous tissue. At least one slide had SSIM in 54% to 64% of patients. Subsquamous low grade dysplasia (LGD) was found in 4 (15%) slides with SSIM and subsquamous HGD/IMC was found in 5 (19%) slides with SSIM. At the patient level, 8 (53%) had no dysplasia, 4 (27%) had LGD and 3 (20%) had HGD/IMC. Overall agreement for SSIM by slide was 92% to 94% (κ = 0.73 to κ = 0.82, moderate to strong agreement), and by patient was 82% to 94% (κ = 0.65 to κ = 0.87, moderate to strong agreement). This study confirms the need for assessing specimen adequacy and assessing the prevalence of SSIM and is the first to assess interobserver agreement for SSIM and dysplasia within SSIM.

Combined therapy of gabapentin with pantoprazole exhibited better protective action against forestomach and pylorus ligation-induced gastric esophageal reflux disease in albino Wistar rats

The current study was undertaken to evaluate the effect of combined therapy of gabapentin and pantoprazole against forestomach and pylorus ligation-induced gastric esophageal reflux disease (GERD) in albino Wistar rats. Rats were randomly divided into five groups, each group consisting of six rats, fasted for 24 h, underwent forestomach and pylorus ligation, received normal saline (3 ml/kg, p.o.), normal control, toxic control, pantoprazole (30 mg/kg, p.o.), gabapentin (50 mg/kg, p.o.), or their combination. After 10 h, animals were killed by cervical dislocation and evaluated for pH of gastric content, volume of gastric juice, total acidity, and esophagitis index. Esophageal tissues were further analyzed for biochemical parameters such as superoxide dismutase, glutathione, catalase, thiobarbituric acid reactive substances, and protein carbonyl, and scanning electron microscopy (SEM) and histopathology were used for morphological evaluation. The results show the combination therapy of gabapentin and pantoprazole significantly inhibited the volume of gastric juice and total acidity esophagitis index and significantly increased the pH of gastric juice. Treatment with gabapentin and pantoprazole exhibited maximum antioxidant effect in comparison with monotherapy. Marked protection and restoration of normal morphology was observed through SEM and histopathology in the combination therapy as compared to monotherapy. Finally, it was concluded that combination therapy of pantoprazole and gabapentin has beneficial effect against GERD.

Computer-Aided Analysis of Gland-Like Subsurface Hyposcattering Structures in Barrett’s Esophagus Using Optical Coherence Tomography

(1) Background: Barrett’s esophagus (BE) is a complication of chronic gastroesophageal reflux disease and is a precursor to esophageal adenocarcinoma. The clinical implication of subsurface glandular structures of Barrett’s esophagus is not well understood. Optical coherence tomography (OCT), also known as volumetric laser endomicroscopy (VLE), can assess subsurface glandular structures, which appear as subsurface hyposcattering structures (SHSs). The aim of this study is to develop a computer-aided algorithm and apply it to investigate the characteristics of SHSs in BE using clinical VLE data; (2) Methods: SHSs were identified with an initial detection followed by machine learning. Comprehensive SHS characteristics including the number, volume, depth, size and shape were quantified. Clinical VLE datasets collected from 35 patients with a history of dysplasia undergoing BE surveillance were analyzed to study the general SHS distribution and characteristics in BE. A subset of radiofrequency ablation (RFA) patient data were further analyzed to investigate the pre-RFA SHS characteristics and post-RFA treatment response; (3) Results: SHSs in the BE region were significantly shallower, more vertical, less eccentric, and more regular, as compared with squamous SHSs. SHSs in the BE region which became neosquamous epithelium after RFA were shallower than those in the regions that remained BE. Pre-ablation squamous SHSs with higher eccentricity correlated strongly with larger reduction of post-ablation BE length for less elderly patients; (4) Conclusions: The computer algorithm is potentially a valuable tool for studying the roles of SHSs in BE.

Developments in optical imaging for gastrointestinal surgery

To improve outcomes for patients with cancer, in terms of both survival and a reduction in the morbidity and mortality that results from surgical resection and treatment, there are two main areas that require improvement. Accurate early diagnosis of the cancer, at a stage where curative and, ideally, minimally invasive treatment is achievable, is desired as well as identification of tumor margins, lymphatic and distant disease, enabling complete, but not unnecessarily extensive, resection. Optical imaging is making progress in achieving these aims. This review discusses the principles of optical imaging, focusing on fluorescence and spectroscopy, and the current research that is underway in GI tract carcinomas.

Evidence-based endoscopic management of Barrett's esophagus

Barrett’s esophagus (BE) develops as a consequence of chronic esophageal acid exposure, and is the major risk factor for esophageal adenocarcinoma (EAC). The practices of endoscopic screening for—and surveillance of—BE, while widespread, have failed to reduce the incidence of EAC. The majority of EACs are diagnosed in patients without a known history of BE, and current diagnostic tools are lacking in their ability to stratify patients with BE into those at low risk and those at high risk for progression to malignancy. Nonetheless, advances in endoscopic imaging and mucosal therapeutics have provided unprecedented opportunities for intervention for BE, and have vastly altered the approach to management of BE-associated mucosal neoplasia.

Patterns of recurrent and persistent intestinal metaplasia after successful radiofrequency ablation of Barrett's esophagus

OBJECTIVE

Radiofrequency ablation can eradicate Barrett's esophagus successfully in the majority of cases. We sought to determine (1) how often intestinal metaplasia is detected during follow-up endoscopy after successful ablation and (2) patterns of persistent/recurrent intestinal metaplasia.

METHODS

Patients ablated successfully during a phase II clinical trial of radiofrequency ablation for Barrett's esophagus were followed using endoscopic surveillance according to a defined protocol. Systematic biopsies were performed in all patients throughout the neosquamous epithelium as well as at the gastroesophageal junction, and patterns of recurrent or persistent intestinal metaplasia were documented.

RESULTS

Fifty-three patients were ablated successfully during this single-institution clinical trial. A total of 151 follow-up endoscopies were performed (range, 1-5 endoscopies per patient) and 2492 biopsies were obtained, of which 604 (24%) were from the gastroesophageal junction. The median follow-up period was 18 months (range, 3-50 months). Recurrent/persistent intestinal metaplasia was detected in 14 patients (26%) in 3 distinct patterns: endoscopically invisible intestinal metaplasia underneath the neosquamous epithelium (buried glands) in 3 patients, visible recurrence in the tubular esophagus in 3 patients, and intestinal metaplasia of the gastroesophageal junction (with a squamous-lined tubular esophagus) in 10 patients. Dysplasia or cancer was not detected in any patient during the follow-up period.

CONCLUSIONS

Recurrent/persistent intestinal metaplasia after successful radiofrequency ablation of Barrett's esophagus is relatively common. This finding has implications for the continued surveillance of patients who are ablated successfully.

Management strategies of Barrett's esophagus

Barrett’s esophagus is a condition resulting from chronic gastro-esophageal reflux disease with a documented risk of esophageal adenocarcinoma. Current strategies for improved survival in patients with Barrett's adenocarcinoma focus on detection of dysplasia. This can be obtained by screening programs in high-risk cohorts of patients and/or endoscopic biopsy surveillance of patients with known Barrett’s esophagus (BE). Several therapies have been developed in attempts to reverse BE and reduce cancer risk. Aggressive medical management of acid reflux, lifestyle modifications, antireflux surgery, and endoscopic treatments have been recommended for many patients with BE. Whether these interventions are cost-effective or reduce mortality from esophageal cancer remains controversial. Current treatment requires combinations of endoscopic mucosal resection techniques to eliminate visible lesions followed by ablation of residual metaplastic tissue. Esophagectomy is currently indicated in multifocal high-grade neoplasia or mucosal Barrett’s carcinoma which cannot be managed by endoscopic approach.

Characterization of buried glands before and after radiofrequency ablation by using 3-dimensional optical coherence tomography (with videos)

BACKGROUND

Radiofrequency ablation (RFA) is an endoscopic technique used to eradicate Barrett's esophagus (BE). However, such ablation can commonly lead to neosquamous epithelium overlying residual BE glands not visible by conventional endoscopy and may evade detection on random biopsy samples.

OBJECTIVE

To demonstrate the capability of endoscopic 3-dimensional optical coherence tomography (3D-OCT) for the identification and characterization of buried glands before and after RFA therapy.

DESIGN

Cross-sectional study.

SETTING

Single teaching hospital.

PATIENTS

Twenty-six male and 1 female white patients with BE undergoing RFA treatment.

INTERVENTIONS

3D-OCT was performed at the gastroesophageal junction in 18 patients before attaining complete eradication of intestinal metaplasia (pre-CE-IM group) and in 16 patients after CE-IM (post-CE-IM group).

MAIN OUTCOME MEASUREMENTS

Prevalence, size, and location of buried glands relative to the squamocolumnar junction.

RESULTS

3D-OCT provided an approximately 30 to 60 times larger field of view compared with jumbo and standard biopsy and sufficient imaging depth for detecting buried glands. Based on 3D-OCT results, buried glands were found in 72% of patients (13/18) in the pre-CE-IM group and 63% of patients (10/16) in the post-CE-IM group. The number (mean [standard deviation]) of buried glands per patient in the post-CE-IM group (7.1 [9.3]) was significantly lower compared with the pre-CE-IM group (34.4 [44.6]; P = .02). The buried gland size (P = .69) and distribution (P = .54) were not significantly different before and after CE-IM.

LIMITATIONS

A single-center, cross-sectional study comparing patients at different time points in treatment. Lack of 1-to-1 coregistered histology for all OCT data sets obtained in vivo.

CONCLUSION

Buried glands were frequently detected with 3D-OCT near the gastroesophageal junction before and after radiofrequency ablation.