Published online Jan 28, 2020. doi: 10.3748/wjg.v26.i4.433
Peer-review started: October 13, 2019
First decision: December 5, 2019
Revised: January 10, 2020
Accepted: January 15, 2020
Article in press: January 14, 2020
Published online: January 28, 2020
Currently, there is no consensus on upper endoscopic examination technique to improve diagnostic yield. In recent years, quality of endoscopy is a hotly discussed topic and several papers and guidelines including the Asian consensus on standards of diagnostic upper endoscopy and the British Society of Gastroenterology guidelines have been published.
Despite recent advances in the surgical and oncological treatment of gastric cancer, it remains one of the leading causes of cancer death. It is imperative to improve detection of early gastric cancer in order to improve patient survival. An esophagogastroduodenoscopy (EGD) examination is an ubiquitous first line tool to investigate upper gastrointestinal symptoms in most countries worldwide and allows detection of early gastric cancer by direct inspection of the mucosa. Several factors may affect the quality of endoscopic examination itself; this includes but is not limited to pre-procedural preparation for endoscopy, appropriate sedation and use of image enhanced endoscopy. Educating endoscopists on examination methods to improve diagnostic yield during upper endoscopy is therefore the most effective intervention to improve detection of early gastric cancer in order to improve patient outcomes and survival. We are also at the dawn of the artificial intelligence age, and application of AIs into EGDs will greater enhance the ability of endoscopists to identify and diagnose early gastric and esophageal lesions.
Through this review, we aim to provide a succinct yet comprehensive summary of the recent literature on the advances in diagnostic EGDs. The authors hope that, through the article, endoscopists can identify potential areas of improvement to better their quality of upper endoscopy.
The PubMed database was queried for relevant articles published between January 2001 and August 2019 using several keywords that were relevant to upper endoscopy. References of selected articles were hand searched to include any studies that may have been omitted by the PubMed search. Studies which presented relevant or novel data were included into this review.
Pre-endoscopic preparation, endoscopy sedation, systemic examination, duration of examination, routine endoscopic biopsy and image enhanced endoscopy are factors which may improve quality of EGD examination. Premedication with simethicone or simethicone and N-acetylcysteine, use of Pronase and antispasmodics improves visualization in the stomach and esophagus. There is currently no evidence that taking more photos improves diagnostic yield, but a mandatory set of systemic images such as the systemic alphanumeric coded endoscopy approach may increase yield of high-risk lesions and may also reduce variability in inter-endoscopist interpretation of endoscopic reports. Several studies have shown that endoscopists with longer inspection times during EGD consistently detect more high risk and neoplastic lesions compared to counterparts with shorter examination times; however, the beneficial of longer examination time may be diminished in very experienced endoscopists. Novel image enhanced endoscopy techniques such as Blue laser imaging (BLI) and linked colour imaging (LCI) enhances detection of early esophageal cancer and gastric cancers. When approaching a suspicious gastric lesion, the magnifying endoscopy simple diagnostic algorithm helps the endoscopist further characterize the lesion. The presence of a demarcation time, irregular micro-surface and micro-vascular pattern is highly suspicious for an early gastric cancer.
Our review provides a succinct summary of the advances in diagnostic endoscopy in the past 2 decades. Several advances have been made recently in the field of image enhanced endoscopy with introduction of magnifying NBI, BLI and LCI. Being well acquainted with these techniques will allow the endoscopist to detect early gastric lesions more confidently. There is, however, still an urgent need to identify and standardize quality indicators and reporting in EGDs in order to better audit endoscopic quality and reduce variability in inter-endoscopist interpretation of endoscopic pictures.
More studies are required in order to demonstrate whether a systemic method of photo-documentation during EGD, routine endoscopic biopsy and use of image enhanced techniques will indeed improve diagnostic yield during endoscopy. Having a standardized set of quality indicators for every endoscopic examination will reassure patients and physicians that a quality endoscopy and inspection had been performed so that the risk of a missed lesion is minimized. Artificial Intelligence is extremely promising to aid endoscopists detect suspicious lesions, may reduce need for biopsy and assist physicians plan further treatment for suspicious lesions. Further innovation and research will improve the sensitivity and specificity of these AIs systems as well as the best way to incorporate the use of these systems in the current endoscopic workflow.