There Is an Endoscopic Mucosal Transition Zone on the Ileocecal Valve
Douglas K. Rex, MD, MASGE, reviewing Rex DK, et al. Gastrointest Endosc 2023 Mar 31.
Experienced endoscopists are aware that the mucosa on the ileocecal valve (ICV) lips has a 3- to 10-mm-wide transition zone between normal colonic mucosa and the overt villi of the ileum. This zone lacks overt villi, but the pits are larger, more tubular, and with more prominent blood vessels than in normal colonic mucosa. This zone has not been formally characterized before now.
Investigators reported that the zone is consistently visible unless obliterated by inflammation or a circumferential adenoma. The mucosal pits in the transition zone resemble those of an adenoma and may make accurate identification of the border of an adenoma on the ICV difficult.
COMMENTFamiliarity with the features of the ICV mucosal transition zone is useful in evaluating and treating adenomas located around the ICV orifice. The use of a distal attachment cap can help expose and characterize the ICV mucosa and access ICV lesions for resection. The difficulty in identifying adenoma margins when adenomas sit on the transition zone may contribute to the higher recurrence rate of ICV adenomas after endoscopic resection.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
CITATION(S)
Rex DK, Lahr RE, Guardiola JJ, DeWitt JM, Zhang D. Characterization of endoscopic features and histology of a distinct mucosal transition zone on the ileocecal valve. Gastrointest Endosc 2023 Mar 31. (Epub ahead of print) (https://doi.org/10.1016/j.gie.2023.03.021)
