Diagnostic Efficacy of Narrow Band Imaging in Patients With Gastroesophageal Reflux Disease
Condition: Gastroesophageal Reflux Disease
MeSH terms: Gastroesophageal Reflux; Esophagitis, Peptic
Study type: Observational

Summary: 
      Gastroesophageal reflux disease (GERD) is a common disorder in Asia that includes erosive and
      non-erosive counterparts. The evaluation of intra-esophageal damage is of paramount
      importance because patients with erosive and those with non-erosive GERD have distinct
      manifestations and prognoses. Although proton-pump inhibitor (PPI) is the treatment of choice
      for erosive patients with excellent therapeutic response, the majority of reflux patients can
      be classified with non-erosive reflux disease (NERD).Narrow-band imaging (NBI) is a novel,
      noninvasive optical technique that adjusts reflected light to improve the contrast of
      capillary patterns compared with conventional illumination. Based on the standard procedure
      of sequential conventional white-light, NBI, and magnified NBI, the investigators have
      validated the reliability of the diagnostic testing. The investigators will also enroll NERD
      patients to test their therapeutic response to rabeprazole. The investigators can find out
      the best strategy to identify the PPI responder.
    

Detailed description: 
      Gastroesophageal reflux disease (GERD) is a common disorder in Asia that includes erosive and
      non-erosive counterparts. The evaluation of intra-esophageal damage is of paramount
      importance because patients with erosive and those with non-erosive GERD have distinct
      manifestations and prognoses. Although proton-pump inhibitor (PPI) is the treatment of choice
      for erosive patients with excellent therapeutic response, the majority of reflux patients can
      be classified with non-erosive reflux disease (NERD).1 Not all of them demonstrate a
      favorable response to PPI treatment because the pathogenesis of NERD is in part associated
      with psychosomatic pathways.2 Their therapeutic response to PPI is unpredictable. Therefore,
      how to improve the diagnosis of reflux-induced mucosal damage under endoscopy is a worthwhile
      endeavor.

      Minimal change esophagitis is commonly accepted as part of the spectrum of reflux esophagitis
      in Japan.3,4 This category is defined as "erythema without sharp demarcation, whitish
      turbidity, and/or invisibility of vessels due to these findings".3 Although the minimal
      change disease (MCD) can be recognized in a significant number of patients with reflux using
      endoscopy-first policy, the major drawback of this category from the Los Angeles system is
      due to a poor interobserver agreement (κ statistic = 0.2).

      Narrow-band imaging (NBI) is a novel, noninvasive optical technique that adjusts reflected
      light to improve the contrast of capillary patterns compared with conventional illumination.5
      This system is highly applicable in the detection of early-stage mucosal lesions, including
      oral cancer, Barrett's esophagus, gastric cancer, and colonic neoplasm.6-10 For the reflux
      patients we face on a daily basis, the NBI system has been proven to improve the
      intraobserver and interobserver reproducibilities in grading esophagitis with small erosive
      foci (improving overall κ value to 0.62 versus 0.45).11 Corresponding to the crowding of
      capillaries, inflamed mucosal breaks appear dark brown on NBI, which produces intense
      contrast against the normal squamous epithelium and the stomach mucosa. These properties may
      improve our ability to delineate the margins of small inflammatory foci. Based on this
      advantage, we plausibly hypothesize the use of this system may improve the description of MCD
      and enable the prediction of therapeutic response to PPI. Testing this hypothesis is the main
      goal of our study.

      Aim of the Study To assess the clinical utility and therapeutic implications of NBI in
      evaluating reflux patients with minimal mucosal damage.
    

Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        1. Symptomatic reflux subjects who receive esophagogastroscopy, aged from 20 to 70 years
             old.

          2. Patients with typical reflux symptoms (heartburn and/or acid regurgitation) at least 3
             times per week in recent 4 months.
      
Keywords: reflux; GERD