Improving the safety and efficacy of colorectal neoplasia endoscopic resection

Abstract

INTRODUCTION

Endoscopic mucosal resection (EMR) is standard of care for the management of benign large non-pedunculated colorectal polyps (LNPCPs); however, electrocautery related complications and colonoscopy surveillance remain a burden for patients and health services. Alarmingly, despite the superior safety and cost-effectiveness of EMR, colorectal surgery continues to be inappropriately utilised in many centres for the resection of benign polyps. This thesis investigated key research gaps within endoscopic resection modalities, surveillance outcomes, optical diagnosis and EMR training pathways.

METHODS

Large prospective single and multicentre trials were conducted to address the aims of this thesis. Studies underwent ethics approval with written, informed consent obtained from all patients.

RESULTS

Cold snare EMR of LNPCPs, whilst safer than conventional hot snare EMR, is at the expense of significantly higher recurrence rates.

In the presence of a clear resection scar at first surveillance colonoscopy, recurrence is exceedingly rare at long-term follow up for contemporary hot snare EMR with margin thermal ablation.

Early post-resection surveillance remains critical, with synchronous LNPCPs highly prevalent in EMR cohorts and a more frequent finding when index lesions are non-granular.

Risk assessment for submucosal invasive cancer is predictable using LNPCP characteristics and can be simplified in a decision tree algorithm to optimise optical diagnosis and resection modality selection.

Challenging lesions for EMR-naïve endoscopists can be accurately predicted and incorporated into a numerical score to guide case selection for EMR training.

CONCLUSIONS

Overall, this thesis has widespread implications on endoscopic practice with a likely influence on international consensus guidelines. Optimisation of technique, training pathways and surveillance intervals will potentially reduce procedural burden and improve outcomes for patients and health services.