The ADENOMA Study. Accuracy of Detection using Endocuff Vision™ Optimization of Mucosal Abnormalities: study protocol for randomized controlled trial

Optimizing Screening Colonoscopy: Strategies and Alternatives

Screening colonoscopy is the most effective screening procedure for the prevention of colorectal cancer. The efficacy of colonoscopy is highly dependent on the overall quality of how this procedure is indicated, planned, prepared, and performed. The quality is directly linked to the number of polyps and/or adenomas detected or, in other words, to the number of polyps or adenomas missed during the procedure. The quality has a direct impact on the rate of interval carcinoma and on the range of how the incidence and occurrence of colorectal cancer is reduced. This review summarizes the current status on general measures and procedure improvements and standards as well as technical advances which have been suggested and established to improve the quality of polyp and adenoma detection rate. This includes selection and preparation of the patients, planning, methodological and technical performance of the procedure, and technical advances of the endoscope technology in order to improve screening results. It also covers new technologies with wide angle endoscopes (Ewave) and IT-based approaches using artificial intelligence to such as ai4GI for the polyp detection and image analysis.

Improved adenoma detection with Endocuff Vision: the ADENOMA randomised controlled trial

OBJECTIVE

Low adenoma detection rates (ADR) are linked to increased postcolonoscopy colorectal cancer rates and reduced cancer survival. Devices to enhance mucosal visualisation such as Endocuff Vision (EV) may improve ADR. This multicentre randomised controlled trial compared ADR between EV-assisted colonoscopy (EAC) and standard colonoscopy (SC).

DESIGN

Patients referred because of symptoms, surveillance or following a positive faecal occult blood test (FOBt) as part of the Bowel Cancer Screening Programme were recruited from seven hospitals. ADR, mean adenomas per procedure, size and location of adenomas, sessile serrated polyps, EV removal rate, caecal intubation rate, procedural time, patient experience, effect of EV on workload and adverse events were measured.

RESULTS

1772 patients (57% male, mean age 62 years) were recruited over 16 months with 45% recruited through screening. EAC increased ADR globally from 36.2% to 40.9% (P=0.02). The increase was driven by a 10.8% increase in FOBt-positive screening patients (50.9% SC vs 61.7% EAC, P<0.001). EV patients had higher detection of mean adenomas per procedure, sessile serrated polyps, left-sided, diminutive, small adenomas and cancers (cancer 4.1% vs 2.3%, P=0.02). EV removal rate was 4.1%. Median intubation was a minute quicker with EAC (P=0.001), with no difference in caecal intubation rate or withdrawal time. EAC was well tolerated but caused a minor increase in discomfort on anal intubation in patients undergoing colonoscopy with no or minimal sedation. There were no significant EV adverse events.

CONCLUSION

EV significantly improved ADR in bowel cancer screening patients and should be used to improve colonoscopic detection.

TRIAL REGISTRATION NUMBER

NCT02552017, Results; ISRCTN11821044, Results.

The B-ADENOMA Study: Bowelscope - Accuracy of Detection using Endocuff Optimisation of Mucosal Abnormalities: Study Protocol for randomised controlled trial

BACKGROUND AND STUDY AIMS

 UK Bowel Cancer Screening flexible sigmoidoscopy (BowelScope) currently offers patients aged 55 a one-off flexible sigmoidoscopy for adenoma clearance to decrease colorectal cancer incidence by interrupting the adenoma-carcinoma sequence. Recent evidence has shown maximum benefit in increasing adenoma detection rate (ADR) using the Endocuff Vision device in the left side of the colon and in screening patients. Currently, ADR is low and shows unacceptable variation in BowelScope. ADR is a quality indicator in screening sigmoidoscopy and higher rates have been shown to reduce colorectal cancer incidence.

PATIENTS AND METHODS

 This will be a prospective, multicenter, UK-based randomized controlled trial (RCT) comparing ADR in Endocuff-assisted versus standard bowel cancer screening flexible sigmoidoscopy (BowelScope). All patients aged 55 to 61 years invited to BowelScope screening and able to give informed consent will be eligible for recruitment. Exclusion criteria include absolute contraindications to flexible sigmoidoscopy, known or suspected large bowel obstruction or pseudo-obstruction, colonic strictures or polyposis syndromes, known severe diverticular segment, active colitis, inability to give informed consent, anticoagulation precluding polypectomy and pregnancy. Patients will be randomized on the day of procedure to Endocuff-assisted flexible sigmoidoscopy or standard flexible sigmoidoscopy, stratified by age group and sex. Baseline, endoscopy and polyp data were collected as well as nurse and patient assessment of comfort. Polyp histology was collected when available. Patients will be asked to return a comfort questionnaire the following day and were followed up for 14 days for complications.

RESULTS

 The ADENOMA trial will be designed to demonstrate a significant improvement in ADR with maximal effect in the left colon and in fecal occult blood test-positive screening patients. This trial will be the first RCT to look at Endocuff Vision in bowel cancer screening flexible sigmoidoscopy. We will aim to establish whether Endocuff vision improves ADR in this population.

New device to implement the adenoma detection rate

It is well-known that colonoscopy is considered the gold standard for colon cancer prevention. Although performed by experienced endoscopists, the matter remains of polyps missed during this examination. The reasons may include the size, shape and location of the lesions. Many colorectal cancer screening programs have been proposed to increase the adenoma detection rate. The substantial difference between these methods is whether the improvement in vision, particularly the detection of irregularities of the mucosa, is inside the endoscope electronic components (magnification, wide-angle vision, narrow band imaging, flexible spectral imaging colour enhancement, i-Scan) or outside the same, by the use of specific caps (EndoCuff, EndoVision, EndoRings). Endocuff is a plastic device mounted at the end of the scope with a constant vision field of the entire colon. The aim of this study is to explore the potential clinical and technical benefits of Endocuff.