Clinical Trial: New Technology to Differentiate Normal Gastric Mucosa From Helicobacter Pylori Associated Gastritis and Gastric Atrophy

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Optical Enhancement System ™ Plus Optical Magnification Utility in the Identification of Normal Gastric Mucosa, Helicobacter Pylori Associated Gastritis, and Gastric Atroph

Brief Summary:

Endoscopy is a tool that has greatly influenced gastroenterological diagnosis. However, conventional endoscopy is limited to detecting lesions on the basis of gross morphological changes and therefore a certainly diagnosis depends on biopsy sampling of macroscopically obvious endoscopic features, or blind biopsy sampling of normal appearing mucosa with the risk of missed pathology and sampling errors.

Gastric cancer is the second most common cause of cancer related death. One of the main roles of upper gastrointestinal endoscopy is to identify gastric cancer at an early stage. The importance of identifying H. pylori infection is because it plays a very important role in gastric carcinogenesis, progressing from chronic gastritis through atrophic gastritis, intestinal metaplasia, dysplasia and finally cancer. The importance of recognition a precancerous gastric lesion is because we can detect most tumors at an early stage and improve the survival.

Most studies conclude that it is difficult to diagnose H. pylori related gastritis and gastric atrophy on the basis of endoscopic findings. Histology is therefore currently considered to be the gold standard for detecting H. pylori infection. The reliability of detecting H. pylori infection histologically depends on the site, number, and size of gastric biopsy specimens, as well as on expertise in staining and visualizing the bacteria. Considerable error also occurs in identifying gastric atrophy using blind biopsy sampling, and neither the original nor the revised version of the Sydney system reliably identifies more than half the cases in patients with confirmed gastric atrophy.


Detailed Summary:

Recently an image-enhanced endoscopic technology using a pre-processor band-limited light called Optical Enhancement system (OE system™), was developed by HOYA Co. (Tokyo, Japan) and is now equipped with the latest endoscopy system (Pentax Video Processor EPK-i7010; HOYA Co.). This new technology combines digital signal processing in a similar way to I-scan and optical filters that limit the spectral characteristics of the illumination light. Previous I-scan technology uses white light alone as an 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 higher contrast images of microvascular pattern on the mucosal surface in combination with high magnification as shown by NBI with optical magnification. The basic concept of OE is to overcome the darkness of NBI witch results in less usefulness for detectability in wide-range observation in the gastrointestinal lumen. The new innovated optical filters achieve higher overall transmittance by connecting the peaks of the hemoglobin absorption spectrum (415 nm, 540 nm and 570 nm) creating a continuous wavelength spectrum. There are two modes with different OE filters (Mode 1 and Mode 2). Mode 1 is designed mainly to improve visualization of microvessels with a sufficient amount of light, and 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 much more light than that of the Mode 1 filter.

In addition to this, new scopes have been developed which combines high definition images with optical magnification called Magniview™. These scopes increase the image up to 136 times with a better quality of image than standard scop
Sponsor: Instituto Ecuatoriano de Enfermedades Digestivas

Current Primary Outcome:

  • Utility OE System™ + Magniview™ in the diagnosis of normal gastric mucosa. Number of patients with type 1 in the Anagnostopoulos GK et al. classification. [ Time Frame: two months ]
    Anagnostopoulos GK et al. classified the gastric body mucosal in four types: type 1, honeycomb−type subepithelial capillary network (SECN) with regular arrangement of collecting venules and regular, round pits. Type 1 pattern for predicting normal gastric mucosa.
  • Utility OE System™ + Magniview™ in the diagnosis of Helicobacter pylori associated gastritis. Number of patients with type 2,3 in the Anagnostopoulos GK et al. classification. [ Time Frame: two months ]
    Anagnostopoulos GK et al. classified the gastric body mucosal in four types: type 2, honeycomb−type SECN with regular, round pits, but loss of collecting venules; type 3, loss of normal SECN and collecting venules, with enlarged white pits surrounded by erythema. Types 2 and 3 patterns for predicting a Helicobacter pylori infection.
  • Utility OE System™ + Magniview™ in the diagnosis of gastric atrophy. Number of patients with type 4 in the Anagnostopoulos GK et al. classification. [ Time Frame: two months ]
    Anagnostopoulos GK et al. classified the gastric body mucosal in four types: type 4, loss of normal SECN and round pits, with irregular arrangement of collecting venules. Type 4 patterns for predicting gastric atrophy.


Original Primary Outcome: Same as current

Current Secondary Outcome: Measures inter and intra-observer reproducibility in the assessment of the endoscopic patterns detected. [ Time Frame: two months ]

A data set containing photographs of the gastric lesions will be presented to three blinded endoscopists who will confirm or not the findings. Inter and intra-observer reproducibility will be measured based on comparison of still images between the three investigators. To evaluate the intra-observer agreement each investigator will assess the images three times and the answers will be compared. To evaluate the inter-observer agreement all answers between the three investigators will be compared. To examine inter and intra observer agreement, kappa values will be calculated.


Original Secondary Outcome: Same as current

Information By: Instituto Ecuatoriano de Enfermedades Digestivas

Dates:
Date Received: October 19, 2015
Date Started: November 2015
Date Completion:
Last Updated: May 1, 2016
Last Verified: May 2016