The Diagnostic Accuracy of Esophageal Capsule Endoscopy in Patients With Gastroesophageal Reflux Disease and Barrett's Esophagus: A Blinded, Prospective Study

Abstract and Introduction

Background: Esophageal capsule endoscopy (ECE) is a novel technique that offers noninvasive evaluation of esophageal pathology in gastroesophageal reflux disease (GERD) patients.
Objective: To assess the diagnostic accuracy of ECE for Barrett's esophagus (BE), erosive esophagitis, and hiatal hernia and to assess the safety profile of ECE.
Methods: Patients with GERD symptoms and those undergoing BE surveillance were prospectively enrolled. All patients underwent ECE followed by standard upper endoscopy. ECE findings were interpreted by examiners blinded to endoscopy results. The gold standard was the findings at endoscopy and ECE results were compared with those at endoscopy.
Results: One hundred patients were enrolled of which 94 completed the study. At upper endoscopy, BE was suspected in 53 (mean length 3.1 cm) and confirmed in 45 patients. Erosive esophagitis and hiatal hernia were identified in 18 and 70 patients, respectively. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ECE for BE in GERD patients were 67%, 87%, 60%, and 90%, respectively. The sensitivity, specificity, PPV, and NPV of ECE for BE patients undergoing surveillance were 79%, 78%, 94%, and 44%, respectively. The sensitivity, specificity, PPV, and NPV for erosive esophagitis were 50%, 90%, 56%, and 88% and for hiatal hernia were 54%, 67%, 83%, and 33%, respectively.
Conclusions: Current diagnostic rates of ECE for BE are not yet accurate enough for application in clinical practice. An improvement in technology and learning curve assessments are required, until then standard upper endoscopy remains the gold standard.

Gastroesophageal reflux disease (GERD) is one of the most prevalent gastrointestinal (GI) disorders in the western countries. It is estimated that approximately 50% of all adults in the United States experience GERD symptoms monthly, whereas 14-20% report symptoms at least once a week.^[1,2,3] It has been suggested that GERD is the third most prevalent disease in the United States with direct and indirect costs of almost $10 billion annually.^[4] It is not only associated with a huge economic burden but also adversely affects quality of life.^[5,6] Complications of GERD include esophageal strictures, reflux esophagitis, Barrett's esophagus (BE), and esophageal adenocarcinoma. Up to one-third of patients have endoscopic evidence of erosive esophagitis and up to one-fifth have complicated reflux disease characterized by reflux esophagitis, esophageal strictures, and BE.^[7]

Barrett's esophagus is a well-recognized premalignant condition for the development of esophageal adenocarcinoma^[8,9] and is characterized by a metaplastic transformation of the squamous epithelium to a columnar type containing goblet cells on histologic evaluation.^[10] The condition entails a 30- to 50-fold greater risk of developing esophageal adenocarcinoma and has an incidence of development of adenocarcinoma that approaches 0.5% annually.^[11,12] Esophageal adenocarcinoma is a highly lethal cancer and is the most rapidly increasing cancer in the United States and western Europe with an incremental increase of 4-10% per year.^[13] Endoscopic screening of subjects (although controversial) with chronic reflux symptoms has been recommended as a method of detecting BE and early cancer.^[14,15] Patients with BE are then routinely enrolled in surveillance programs in an attempt to identify those who might benefit from treatment at a preinvasive stage of esophageal adenocarcinoma with the ultimate goal of reducing cancer-related deaths.^[14,16] Upper endoscopy (EGD) is employed to diagnose BE; however, the cost and invasiveness of this diagnostic tool limits its utilization in many patients.^[17] There is a need for an alternative, simple, and less invasive diagnostic tool for evaluating GERD patients and screening for BE.

The recent development of wireless capsule endoscopy is a major technological advance that allows direct noninvasive visualization of the GI tract from the esophagus to the distal small bowel and has become the mainstay in evaluating suspected disease of the small bowel.^[18,19] Esophageal capsule endoscopy (ECE) is a new and exciting technique that has a dual-camera wireless capsule endoscope, which offers an alternative approach to visualize the esophagus without the need for sedation, and without the discomfort and risks of conventional endoscopy.^[17] Since its approval by the FDA (November 2004), data on its clinical use and indications are limited.

The primary aim of this blinded, prospective study was to assess the diagnostic accuracy of ECE for BE in patients presenting with GERD symptoms or for surveillance of BE. The secondary aims were to evaluate the diagnostic accuracy of ECE for erosive esophagitis and hiatal hernia, and assess the safety and adverse event profile of ECE.

Am J Gastroenterol. 2008;103(3):525-532. © 2008  Blackwell Publishing

Cite this: The Diagnostic Accuracy of Esophageal Capsule Endoscopy in Patients With Gastroesophageal Reflux Disease and Barrett's Esophagus: A Blinded, Prospective Study - Medscape - Mar 01, 2008.