Observational study;Confocal endomicroscopy in the diagnosis of colorectal neoplasia.

Interventions: Both techniques (conventional colonoscopy and confocal endomicroscopy) are routinely used in clinical practice at the Department of Gastroenterology of our hospital. In this regard, patients participating in the study will not undergo additional (invasive) examination. As the duration of the chromoscopy-guided confocal endomicroscopy procedure is somewhat longer than the standard procedure, the patient-burden will possibly increase, mainly due to the ‘back-to-back’ evaluation. The potential advantage is the achievement of higher diagnostic accuracy of preneoplastic lesions in this high-risk population.
During confocal endomicroscopy fluorescein will be administred intravenously, to generate confocal images. This is a safe contrast-agent which has been previously used for the diagnosis of ophtalmologic diseases (e.g. corneal infections). Additionally, fluorescein has been already used in more than 1000 patients undergoing confocal endomicroscopy, without relevant adverse events. Allergic reactions, in particular nausea seldom occur. Also, transient yellow discoloration of urine and skin may occur.
The general risks associated to the colonoscopic procedure are detailed in the endoscopy-folder of the GI Endoscopy Unit of the University Hospital Maastricht.
Primary outcome(s): The primary outcome measure will be the number of patients with at least one adenoma after conventional colonoscopy compared with the number of patients with at least one adenoma after pan-chromoendoscopy.
Study Design: N/A: single arm study, Open (masking not used), N/A , unknown, Crossover