Comparing standard colonoscopy versus colonoscopy associated to a special technique of virtual chromoendoscopy named Fuji Intelligent Colour Enhancement (FICE) in the endoscopic surveillance of ulcerative colitis for neoplasia

This was a prospective, parallel trial, in which consecutive patients with long-lasting ulcerative colitis who were scheduled for surveillance colonoscopy at our centre are submitted to a withdrawal colonoscopy with standard with-light endoscopy or virtual chromoendoscopy with FICE. The intervention includes full colonoscopy with one of two type of colonoscopes which differred about the technology of image visualisation in vivo: standard resolution white light endoscopy (WLE) versus high-definition virtual chromoendoscopy with Fuji Intelligent Colour Enhancement (FICE). The endoscopic procedures are performed in a single day by endoscopists with more than 10 years of experience in IBD endoscopy and with experience in chromoendoscopy. The day before the procedure, the patients receive a bowel preparation. Bowel preparation is performed with a no fibers diet 5 days before the exam, a liquid diet the day before the procedure and 4 liters of liquids with macrogol the day before the examination. Before starting the procedure, the patients receive a sedation with intravenous midazolam (1-5 mg) and/or meperidine (25-50 mg) according to our institutional guideline (standard dose: midazolam 5 mg ev plus meperidine 50 mg; lower dosages in cases of cardiopulmonar comorbidities). In the WLE arm, standard white light colonoscopy is performed using the Olympus CV-180 Evis Exera II system (Olympus Corp., Tokyo, Japan) for both intubation and extubation. In the FICE arm, virtual chromoendoscopy is activated during extubation from the caecum and performed with a high-definition magnification colonoscope (Fujinon EG-590ZW, Fujinon Corp, Saitama, Japan), equipped with the EPX4400 processor. The patients enrolled are prospectively allocated to one arm or to the other one, according to the availability of the endoscopic instrument, a colonoscope with WLE or FICE, this latter being only one in our centre and therefore being available only after its washing and disinfection. In patients with the inclusion criteria, therefore, the experimental instrument (equipped with FICE) is choosen for colonoscopy if immediately available at the scheduled timetable of the procedure, otherwise the patient receives colonoscopy with any other standard colonoscope with white light endoscopy. Assessment of the colon to search for visible lesions is performed systematically during withdrawal of the instrument with a minimum diagnostic extubation time that was set at 10 minutes. Maximum duration of the intervention will be dependent by the number of lesions found and by the number and type of procedures required for biopsies or removal of each lesion. In both arms, the large bowel is divided into 6 segments (caecum, ascending colon, transverse colon, descending colon, sigmoid colon and rectum) and evaluated systematically in terms of bowel preparation, endoscopic disease activity (according to the Mayo subscore) and the presence and classification of any mucosal lesion according to its morphology, size, location and judgement on suspected neoplasia. In the WLE arm, areas suspected for neoplasia are defined as any mucosal irregularity, ulceration, polypoid or non-polypoid lesion that are not entirely consistent with chronic or active UC according to the usual clinical practice, as previously described. In the FICE arm, neoplasia is suspected according to a modified Kudo classification of pit patterns at the surface of each lesion. In particular, in the FICE arm,, lesions are defined not suspected for neoplasia if they show: - homogeneous, type I (round regular pit pattern, similar to the surrounding normal mucosa) or type II (round stellar or papillary pit pattern), Kudo pit patterns, without visible microvessels; - type III-L Kudo pit-pattern (tubular or round pit-pattern larger than the normal mucosa) if associated with a fibrin cap and without visible microvessels; - lesions unclassified by the conventional Kudo classification if associated with a fibrin cap and without visible microvessels. On the contrary, lesions are considered suspected for neoplasia if they show: - the combination of type I and II Kudo pit-patterns as a marker of pits heterogeneity; - type II Kudo pit-pattern with visible microvessels; - type III-L, III-S or IV Kudo pit pattern without a fibrin cap, with or without visible microvessels; - any type V (irregular, non-structural pit pattern) Kudo pit-patterns. In both arms, three types of histological samples are obtained for the detection of neoplasia: 1) random biopsies of otherwise normal flat mucosa, obtained every 10 cm from the caecum to the rectum; 2) targeted biopsies or full endoscopic resection of visible suspected neoplastic lesions (polypoid or non-polypoid), as appropriate; 3) targeted biopsies of unsuspected neoplastic lesions (polypoid or non-polypoid). All samples are collected in separate containers and then processed and stained by using standard methods. All specimens are analysed by two pathologists with expertise in IBD, who are blinded to the endoscopic report. The pathologists classify the inflammatory activity of each specimen into the following categories: no inflammation, mild to moderate inflammation or severe inflammation. Neoplastic changes are classified according to the new Vienna classification as low-grade intramucosal, high-grade intramucosal and invasive neoplasia. Non neoplastic lesions, including serrated and inflammatory polyps, are described according to current classifications.