Innovations in endoscopic resection of the upper gastrointestinal tract

Abstract

The management of early upper gastrointestinal neoplasia has transformed significantly with advanced endoscopic resection (ER) techniques. Lesions that once required invasive surgery can now be removed safely and effectively using ER. This thesis investigates the outcomes of innovative ER techniques in two uncommon lesions in a Western society: early gastric cancer (EGC) and large duodenal adenomas (DA).

Endoscopic submucosal dissection (ESD) in EGCs with negligible risk of lymph node metastasis (LNM) are considered an absolute indication (AI) for endoscopic cure, while those with higher LNM risks, typically requiring surgical resection, are considered a relative indication (RI) for ESD due to patient frailty or preference. In a prospective study of 149 patients undergoing 157 ESDs, no significant difference was found in overall survival and disease-free survival at a median follow-up of 51.6 months between AI-EGC and RI-EGC cohorts. ESD was safe and effective with low rates of serious adverse events, providing survival advantages to patients who are poor surgical candidates, likely sufficient to span their remaining life expectancy.

In a cohort study comparing cold snare endoscopic mucosal resection (CS-EMR) against conventional EMR with thermal margin ablation in 104 large (≥15mm) DAs, CS-EMR had significantly lower rates of intraprocedural and post-procedural bleeding but was compromised by higher rates of residual and recurrent adenoma. This adds significant patient and healthcare surveillance burdens and highlights the limitations of CS-EMR.

ER has supplanted surgery as the primary therapeutic strategy for early upper gastrointestinal neoplasia. We demonstrated meaningful survival benefits associated with ESD for RI-EGC in a comorbid Western population, avoiding surgical morbidity. Furthermore, the advantages and limitations of CS-EMR in the duodenum create a framework for ongoing refinements in EMR techniques, prioritising improvements in procedural safety.