RESUMEN
(Virtual) chromoendoscopy (CE) improves the detection of small or flat colorectal polyps; however, the evidence in high-risk groups, such as patients of Lynch syndrome (LS), is low. Our aim was to identify and update the evidence for the recommendations regarding surveillance of LS patients, for which the current underlying evidence for use of (virtual) CE was explored. A systematic literature search in PubMed, EMBASE, and Cochrane library was conducted, for all studies comparing (virtual) CE with white-light endoscopy in LS patients. Studies are explained in detail, with special attention to study design, type of (virtual) CE, and timing of polypectomy. Eight studies (409 patients) were included. Five were nonrandomized back-to-back studies and three were randomized back-to-back studies (one parallel and two cross-over design). In six studies the polyps were directly removed, while in two studies polyps were removed only during the second caecal withdrawal. Five studies researched CE with indigo carmine and three studies investigated virtual CE. Due to the heterogeneity between studies, no statistical analysis could be performed. There was a large variety in study design, timing of polypectomy, different (virtual) CE techniques and the patients that were included. Based on current literature, no firm conclusions can be drawn with respect to the additional value of (virtual) CE in the surveillance of patients with LS. However, training of endoscopists in detection and removal of nonpolypoid colorectal neoplasms is crucial, as well as stricter adherence to LS surveillance guidelines in daily clinical practice. For future research, standardization in study designs is needed.