Technical innovations in endoscopic tissue resection to optimise clinical outcomes

Introduction/Aims Over the past decade, endoscopic resection (ER) has transformed the management of early gastrointestinal (GI) neoplasia. ER is minimally invasive, cost-effective and equally efficacious when compared to surgery. However, refinements in ER technique continue to be pursued to further optimise patient outcomes. In this thesis we aimed to address three key areas of ER technique relating to incomplete resection and lesion recurrence. This thesis also aimed to address the lack of formal training pathways to achieve proficiency in complex ER techniques. Methods Multi-centre prospective trials were conducted to address the aims outlined above. All studies received ethical approval. Written, informed consent was obtained from all patients. Results Cold snare polypectomy using a standardised method of resection, in which a wide-margin of normal tissue is resected around the target lesion, demonstrated very low rates of incomplete resection were observed, independent of snare design. Lesion assessment using virtual chromoendoscopy alone is efficacious for stratifying the risk of invasive cancer in large non-pedunculated colorectal polyps (LNPCPs) with a high-rate of inter-observer agreement. The technique of en bloc resection is not superior to piece-meal resection for benign, size-matched (20–25mm) LNPCPs. Thermal ablation of the defect margin after endoscopic mucosal resection (EMR-T) in the colon is safe and highly effective in reducing recurrence at surveillance colonoscopy. This technique also demonstrated efficacy in the duodenum. Use of a novel scoring system (the size, morphology, site and access [SMSA] score) to reliably predict outcomes from ER may provide a framework for development of formal training pathways in advanced ER techniques. Conclusions ER is now considered the primary therapy for management of early GI neoplasia. The findings from this thesis confirm the safety of adjunctive ER techniques in improving patient outcomes. Further, the technical innovations described in the thesis are likely to be incorporated in updated societal guidelines as essential components of high-quality ER technique. In addition, the use of a standardised scoring system may allow development of training programs to allow endoscopists to demonstrate proficiency in complex ER techniques