Diagnosis of Gastritis, H. Pylori Infection and Atrophic Gastritis in Dyspeptic Patients
Condition: Gastritis, Atrophic; Helicobacter Pylori Infection; Intestinal Metaplasia; Gastritis
MeSH terms: Infections; Communicable Diseases; Gastritis; Gastritis, Atrophic; Atrophy; Metaplasia
Study type: Observational

Summary: 
      Gastric cancer is the third most common cause of cancer-related death worldwide (1). Upper
      endoscopy is necessary to detect neoplastic macroscopic features at an early stage, but
      subtle abnormalities in the gastric mucosa are often missed or misdiagnosed (1). Helicobacter
      pylori (Hp) is involved in the pathogenesis of gastric diseases, such as, peptic ulcers,
      gastric lymphoma, and gastric cancer. Therefore, the necessity to recognize malignant gastric
      lesions at an early stage is imperative.
    

Detailed description: 
      Previous I-SCAN™ technology uses white light as illumination light and digital
      post-processing of the reflection afterwards creates images yielding the virtual
      chromoendoscopic image. Emission of white light alone causes a potential limitation for the
      current I-SCAN™ technology to obtain high-quality images of microvascular patterns on the
      mucosal surface compared to narrow band imaging (NBI) with optical magnification.

      Pentax Medical (HOYA, Tokyo, Japan) developed the Optical Enhancement™ (OE) System, which
      combines bandwidth-limited light with an endoscopy video system. The OE System combines
      digital signal processing with optical filters that limit the spectral characteristics of the
      illuminating light, connecting the peaks of the hemoglobin absorption spectrum (415 nm, 540
      nm, and 570 nm) to create a continuous wavelength spectrum. This system has two modes that
      use different filters to optimize the visualization of specific features. Mode 1 is designed
      to improve visualization of microvessels with enough light. Mode 2 is designed to improve
      contrast of white-light observation by bringing the color tone of the overall image closer to
      that of natural color (white color tone) with more light than Mode 1 filter.

      In addition, high definition optical magnification endoscopes have been developed and can
      combine high-definition imaging with optical magnification to produce detailed images with
      magnification of up to 136×. This imaging technique facilitates the evaluation of the
      superficial vascular aspects of the mucosa, enabling the identification of early signs of
      inflammation or lesions not previously seen with conventional endoscopy.
    

Intervention name(s): High-Definition white light endoscopy.; High-definition magnification with digital chromoendoscopy.
Intervention type(s): Diagnostic Test; Diagnostic Test
Intervention description(s): evaluation of the gastric mucosa with high-definition white light endoscopy (EG-29i10 gastroscope and EPKi7010 video processor). The endoscopy images will be seen on a 27inch, flat panel, high definition LCD monitor (Radiance™ ultraSC-WU27-G1520 model) by; Subject will be evaluated by upper endoscopy with the OE System (EPK-i7010 HD Video Processor and MagniView™ EG-2990Zi Video Gastroscope) with intravenous sedation in a standardized manner. This technique involves the use of a distal black rubber hood (OE-A58; Pentax) at the tip of the endoscope, to fix the distance between the tip of the endoscope and the gastric mucosa at 2 mm. The OE System will be used in mode 1 and mode 2 without optical magnification, to obtain an overview of the gastric body and identify any gross changes in the mucosa, then optical magnification will be implemented.
Observational model: Cohort
Time perspective: Cross-Sectional
Sampling method: Probability Sample
Study population: 
        A sample size was estimated with a 95% confidence interval and a 10% margin of error, based
        on the results of C. Robles et al. All consecutive participants will have dyspepsia
        according to the Rome IV criteria, and needs to be ≥18 years old. Participants need to have
        an epigastric pain syndrome (defined as localized pain or burning pain in the upper abdomen
        at least once a week, which was intermittent, nongeneralized, not relieved by defecation,
        and did not meet the criteria for pathology of the gallbladder or sphincter of Oddi);
        and/or a postprandial distress syndrome (defined as the presence of a nagging feeling of
        postprandial fullness after normal-volume meals, and/or early satiety that prevented the
        completion of a regular meal several times a week). The criteria need to be present within
        the 3 months prior to enrolment, and to have started ≥6 months prior to diagnosis of
        dyspepsia.
      
Biospecimen description: 
      Gastric mucosa
    
Keywords: endoscopy; gastritis