Colorectal polyps in ulcerative colitis and Crohn's colitis.

AIM: Patients with long-standing inflammatory bowel disease (IBD) have higher risk for developing dysplasia and colorectal cancer and consequently surveillance colonoscopy is required. The colonic lesion in these patients are often flat and subtle and may be difficult to detect by white light standard endoscopy. We aimed to review the potential of novel electronic optical enhancement techniques to enhance endoscopic diagnosis and therapeutic management of dysplasia in IBD and emerging strategies that may be useful. METHODS: We identified eligible and appropriate articles by electronic search of PubMed, MEDLINE and EMBASE between January 1980 and June 2015 using key words: dysplasia, colorectal cancer and IBD, surveillance in IBD, novel endoscopic techniques in IBD, therapeutic endoscopy in IBD, endoscopic mucosal resection, endoscopic submucosal dissection, pseudopolyps, dysplasia associated lesion or mass, adenoma associated lesion or mass, chromoendoscopy, autofluorescence, virtual chromoendoscopy, confocal endomicroscopy. RESULTS: Segmental random biopsies during white-light colonoscopy have been the recommended strategy for many years. Chromoendoscopy with colonic dye spray has been gradually implemented in recent years in order to highlight abnormalities in the mucosa and target biopsies. Simultaneously, a new generation of high-definition endoscopes with electronic filter technology that provide a detailed assessment of the mucosal and vascular colonic pattern havebeen developed and these have been adopted in clinical practise. Furthermore, the introduction of confocal laser endomicroscopy (CLE) offers the possibility to assess and characterize lesions in real-time histology and it can predict dysplastic changes with high accuracy. With the evolving novel techniques and fresh evidence, modification of the current surveillance guidelines were required. Therefore, the SCENIC consensus guidelines have been recently published and have defined the best endoscopic techniques to detect and characterize dysplasia and the clinical implications and management of dysplasia in IBD patients. CONCLUSION: Many uncertainties still remain whetherdye chromoendoscopy with targeted biopsies will be established as standard practice. However, optical enhancement endoscopic techniques are promising to perform surveillance colonoscopy with targeted biopsies for better assessment and management of the dysplastic lesions in IBD. Further studies are required to determine the best strategy for the diagnosis and treatment of dysplasia in IBD patients.

Novel diagnostic and therapeutic techniques for surveillance of dysplasia in patients with inflammatory bowel disease.

The risk for developing dysplasia and colorectal cancer in patients with longstanding inflammatory bowel disease (IBD) involving the colon is well documented. Random biopsies during white-light, standard-definition colonoscopy (33 to 50 biopsies) with or without dye spraying chromoendoscopy has been the recommended strategy in North America to detect dysplastic lesions in IBD. However, there are several limitations to this approach including poor physician adherence, poor sensitivity, increased procedure time and considerable cost. The new generation of high-definition endoscopes with electronic filter technology provide an opportunity to visualize colonic mucosal and vascular patterns in minute detail, and to identify subtle flat, multifocal, polypoid and pseudopolypoid neoplastic and non-neoplastic lesions. The application of these new technologies in IBD is slowly being adopted in clinical practice. In addition, the advent of confocal laser endomicroscopy provides an opportunity to explore real-time histology, thus redefining the understanding and characterization of the lesions in IBD. There is emerging evidence that serrated adenomas are also associated with longstanding IBD colitis and may be recognized as another important contributing factor to colorectal cancer development. The circumscribed neoplastic lesions can be treated using endoscopic therapeutic management such as mucosal resection or, especially, endoscopic submucosal dissection. This may replace panproctocolectomy in selected patients. The authors review the potential of these techniques to transform endoscopic diagnosis and therapeutic management of dysplasia in IBD.