Endoscopic surveillance in Crohn's disease and ulcerative colitis: who needs what and when?

Crohn's disease and ulcerative colitis are chronic inflammatory diseases resulting from an inappropriate innate and adaptive immune response towards commensal microbiota. Patients with Crohn's disease and ulcerative colitis carry an increased risk of developing colon cancer and/or small bowel carcinoma, respectively. The colorectal cancer risks of ulcerative colitis and Crohn's disease with comparable surface area involvement and disease duration are very similar. Early disease onset, disease extent, severity of inflammation, a family history of sporadic colorectal cancer, efficacy and duration of medical therapy, coexisting primary cholangitis and mucosal dysplasia are all risk factors for colorectal cancer. Regular endoscopic surveillance is endorsed by leading professional societies and outlined in guidelines and consensus statements. The yield of endoscopic surveillance, particularly to detect dysplasia, can be improved with chromoendoscopy with methylene blue dye spray-targeted biopsies, autofluorescence plus high-resolution endoscopy, chromoendoscopy-guided confocal laser microscopy and confocal laser microscopy in combination with narrow band imaging and high-resolution endoscopy. Proper bowel preparation, complete, careful inspection of the entire colon, a minimum withdrawal time and adherence to recommended management guidelines ensure a high-quality study and improve surveillance. Dysplasia can be graded by the Vienna or Riddell classification. Colectomy is recommended for patients with flat high-grade dysplasia confirmed by an expert gastrointestinal pathologist.