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Title: Detection and removal of sub-centimetre polyps
Author: Din, Said
ISNI:       0000 0004 5370 0174
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2015
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Introduction: Colonoscopic polypectomy has been shown to reduce the incidence and mortality of colorectal cancer. Most polyps encountered during colonoscopy are small and approximately 10% will have advanced pathology. Therefore, it is important that colonoscopy and polypectomy is performed to a high standard. Aim: To determine if simple interventions can be used to improve the detection and removal of sub-centimetre polyps. Methods: 1. A systematic review of 7 randomised controlled trials was performed to determine if chromoendoscopy increased the polyp detection rate compared with conventional white light endoscopy. 2. Data from the English BCSP was analysed to describe the variation in polypectomy techniques employed for the removal of sub-centimetre polyps in relation to polyp characteristics, completeness of histological excision and safety. 3. An observational prospective study was undertaken to determine the efficacy of cold snare polypectomy with a thin wire mini-snare (0.30mm) versus a thick wire mini snare (0.47mm). 4. A single centre, randomised controlled trial was performed to compare the efficacy of standard cold snare polypectomy versus a novel suction pseudopolyp technique. Results: In the systematic review, chromoendoscopy showed a significant increase in the detection of neoplastic and non-neoplastic polyps, but there was no increase in the detection of larger or advanced polyps compared with conventional white light endoscopy. Analysis of the BCSP database showed that removal of sub-centimetre polyps is safe despite wide variations in practice. The use of cold resection techniques and EMR has increased over time (p<0.001). However, assessment for the completeness of histological resection is limited with almost two thirds of cases reported as not assessable. In the observational prospective study, completeness of endoscopic excision was significantly better with the thin wire snare compared with the thick wire snare (90.2% vs. 73.3%, p<0.05). In the RCT comparing standard cold snare polypectomy with the suction pseudopolyp technique, no clinically significant difference was observed between the two techniques (92.6% vs 98.6%, p=0.08). No perforation or bleeding requiring hemostasis occurred in either of these two studies. Discussion: From this body of work it is apparent that chromoendoscopy, cold snare polypectomy with a thin wire snare and the suction pseudopolyp technique are safe, quick and effective. These simple interventions are easy to learn and can be performed by all colonoscopists to improve the detection and removal of polyps.
Supervisor: Corfe, Bernard ; Johal, Shawinder Sponsor: Not available
Qualification Name: Thesis (M.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available