Prospective Collection of Endoscopic and Histopathologic Data From Endoscopic Procedures Performed in UZ Gent

Background Endoscopy and more specifically polypectomy during endoscopy is well established as an effective way of reducing cancer mortality. The majority of lesions detected and removed at colonoscopy are adenomas <10mm in size without advanced histology. These lesions have a low risk of progression to malignancy and are relatively easily removed by standard snare polypectomy with low complication rates. Polyps that are sessile or flat and greater than 20mm in size are found in approximately 1% of all colonoscopies and are more difficult to manage. These lesions, known as large sessile lesions (LSL), have a high rate of advanced histology. Traditionally they have been managed by referral for open or laparoscopic surgery, which is definitive, but invasive, costly, and associated with a significant mortality risk in patients with advanced age or comorbidities. Endoscopic Mucosal Resection (EMR) has emerged in recent years as an alternative to surgery that is now becoming the standard of care. It is an outpatient procedure which is effective, safe and less costly than surgery when delivered at a tertiary referral centre.

Prospective studies have been successful in addressing several aspects of the resection of LSL, producing robust information on the efficacy of the procedure, recurrence rates, bleeding complications and mortality and costs when compared to surgery. Assessment and management strategies for bleeding and deep mural injury or perforation have been derived from analysis of the data. Snare tip soft coagulation of the resection margin post-EMR has been shown to reduce recurrence in a randomised controlled trial.

There remain a number of unanswered questions regarding the endoscopic resection of large lesions and a new study incorporating a greater number of endoscopy units around the world will allow these to be addressed as well as answer questions on the clinical effectiveness of the technique. Enhancing the prediction of submucosal invasive cancer, advanced lesion classification, validation of the assessment of deep injury, treatment of lesion margins post resection to reduce recurrence, prevention and prophylaxis of bleeding, and subtype analyses of the different histological groups of colonic lesions will be examined.

In addition, other techniques such as endoscopic submucosal dissection (ESD) and full thickness resection (FTR) have emerged in recent years and require assessment of their performance versus endoscopic mucosal resection in prospective observational studies.

The same techniques (EMR and ESD) are used to resect lesions in the upper gastrointestinal tract (oesophagus, stomach, and small intestine) and the same prospective observations are necessary to assess effectiveness of these techniques and outcomes to improve future upper gastrointestinal endoscopy.