i-Scan for the detection of Helicobacter pylori
Research type
Research Study
Full title
i-Scan for the detection of Helicobacter pylori: a randomised controlled study
IRAS ID
155418
Contact name
Julian Teare
Contact email
Sponsor organisation
Imperial College
Research summary
Research Summary
This study aims to assess whether i-Scan, an intra-endoscopic imaging technique is an accurate and reliable tool in detecting and characterising Helicobacter pylori (H pylori) and comparing this to standard endoscopic imaging with white light endoscopy (WLE), narrow band imaging (NBI) and histology.The ultimate goal of endoscopy will be the ‘optical biopsy’ i.e. forgoing the need to take histological samples to make a diagnosis in order to reduce complication rates, cost and time. There are a number of imaging techniques which promise to improve our diagnostic rates for pathology, but there have been few comparative studies.
This is randomized controlled parallel trial in a 1:1 ratio with examination of the upper gastrointestinal tract with WLE followed by either NBI or i-scan. Patients attending the department for routine examinations for dyspepsia and abdominal pain will be randomised into 2 study arms (1- WLE and NBI, and the other – WLE and i-scan).The investigator carrying out the procedure will be blinded to the indication for the procedure until a full examination with both white light endoscopy and either NBI or i-scan has been used as this could lead to bias. They will determine if H pylori is present, and if so the severity of infection with WLE and again with either NBI or i-scan depending on their study arm. Histopathological confirmation of H pylori and an assessment to the degree of infection will be assessed with samples taken using the updated Sydney system (5 gastric samples from different parts of the stomach).
The endoscopists reviewing the images will be blinded to all patient information and indications throughout the study period. Questionnaires will then be given to the endoscopists to determine what endoscopic features led them to their diagnosis.Summary of Results
Helicobacter pylori infection is a common cause of chronic gastritis worldwide and an established risk factor for developing gastric malignancy. The endoscopic appearances predicting H. pylori status are an ongoing area of research, as are their diagnostic accuracies. This study aimed to establish the diagnostic accuracy of several mucosal features predictive of H. pylori negative status and formulate a simple prediction model for use at the time of endoscopy.Patients undergoing upper gastrointestinal endoscopy were recruited prospectively. During the endoscopy, the presence or absence of specific endoscopic findings was noted. Standardised biopsies were used as the diagnostic reference standard. The results informed a logistic regression model used to produce a simple diagnostic algorithm. This model was subsequently validated using a further cohort of 30 patients.
153 patients were recruited and completed the study protocol. The prevalence of active H. pylori infection was 18.3% (28/153). The overall diagnostic accuracy of the simple prediction model was 80.0%, and 100% of patients with active H. pylori infection were correctly classified. The presence of a stomach appearance of 'regular arrangement of collecting venules' (RAC) showed a positive predictive value for H. pylori naïve status of 90.7%, rising to 93.6% for patients under the age of 60.
A simple endoscopic model may be accurate for predicting H. pylori status of a patient, and the need for biopsy-based tests. The presence of RAC in the stomach is an accurate predictor of H. pylori negative status, particularly in patients under the age of 60.
REC name
London - Stanmore Research Ethics Committee
REC reference
14/LO/1525
Date of REC Opinion
13 Oct 2014
REC opinion
Further Information Favourable Opinion