부산대학교 도서관

Hospital-based conventional oesophagogastroduodenoscopy (C-OGD) is invasive and associated with significant logistical and cost implications for the healthcare system. As a result, several authorities have highlighted the need to identify alternative, minimally-invasive screening tests for Barrett's oesophagus (BO) and oesophageal varices (OV) which are precursor conditions for oesophageal adenocarcinoma and variceal bleeding, respectively. This thesis investigated whether novel, portable and disposable transnasal endoscopy (TNE) techniques using the EG ScanTM and EndoSheath devices can provide a safe, accurate and more acceptable alternative to C-OGD for use in the clinic- and community- based settings. In the first chapter, a meta-analysis was conducted to obtain precise estimates on the performance of the TNE technique, in principle, using currently available devices (non-portable and non-disposable). This identified that the technical success rate of TNE can be equivalent to C-OGD, but with higher patient preference for the former compared to the latter. In order to give context to any new screening technique, it is important to evaluate any existing alternatives. Therefore, we conducted another systematic review and meta-analysis to evaluate the currently available screening tools for OV in patients with compensated cirrhosis. This revealed that platelet to spleen diameter ratio (PSR) was the most accurate and validated test based on current literature. More importantly, the implementation of PSR testing at a cut-off of 909, resulted in correctly saving unnecessary C-OGDs in a significant proportion of patients who do not have OV. On this background, the EG ScanTM was evaluated in two prospective diagnostic feasibility studies which showed that the test was safe, accurate and highly acceptable by patients on day 0 and day 14 after procedures compared to C-OGD. Finally, we performed a large, prospective, randomised trial in a USA population which demonstrated that mobile unit screening using portable TNE (EndoSheath®) in the community had comparable clinical effectiveness, safety and participation rates to hospital-based TNE and C-OGD techniques.