Virtual Chromoendoscopy for Colitis Surveillance: A Feasibility Study

Patients with colitis require regular 'surveillance' colonoscopy as their risk of developing colon cancer is at least 2.5 times that of the general population. However, cancer in colitis develops as flat lesions called dysplasia, that can be easily missed at routine colonoscopy. As a result NICE guidelines for colitis surveillance recommend the use of a technique called chromoendoscopy (CE) in which a water-soluble blue dye is sprayed through the colonoscope to coat and highlight the lining of the bowel, making dysplasia easier to see. Although CE is accepted as best practice for surveillance it is time-consuming, technically difficult and requires expertise to interpret the appearances. For these reasons, its use is not widespread and the vast majority of patients still receive the inferior 'routine' colonoscopy without CE. New technology means that the video image obtained during colonoscopy can be digitally enhanced and coloured at the press of a button - termed virtual chromoendoscopy (VCE). This could make surveillance colonoscopy shorter, more comfortable and cleaner (resulting in a more 'dignified' experience) as well as cheaper and less technically difficult. The main objectives to be explored in this feasibility study (and the larger trial) were informed by a PPI meeting, which placed the ability to detect dysplasia at equal importance with the participant's experience of the procedure in terms of speed, comfort and dignity. This is primarily a feasibility study to assess patient experience, recruitment and retention rates to the investigators' specified trial design, to support the development of a larger crossover trial to compare VCE to CE during surveillance colonoscopy for colitis.