Is a Second Right-Side Colon Examination Needed When Using Mucosal Exposure Devices? Yes
Douglas K. Rex, MD, MASGE, reviewing Vemulapalli KC, et al. Gastrointest Endosc 2021 Jul 17.
Double right-sided colon examination has been advocated as a way to reduce interval cancers, which are more common in the proximal colon. Mucosal exposure devices, such as Endocuff Vision (ECV; Olympus Corp, Center Valley, Pa), AmplifEYE (Cantel, Minneapolis, Minn), and the distal cap, improve detection in most studies. It is unclear whether a second right-side colon examination is warranted if the first examination is performed using a mucosal exposure device.
In this study, 1331 eligible, consecutive patients underwent colonoscopy performed with a mucosal exposure device – almost exclusively ECV. A second examination of the right side of the colon was then performed, also using ECV.
The first examination miss rates for adenomas, sessile serrated lesions (SSLs), and hyperplastic polyps (HPs) were 15.8%, 14.1%, and 16.7%, respectively. The second examination was performed primarily in retroflexion (97.4% of cases), with the remainder performed in the forward view if retroflexion was unsuccessful. Miss rates for lesions ≥10 mm in size were also substantial for adenomas, SSLs, and HPs at 13.3%, 14.7%, and 11.1%, respectively.
Exactly half of the missed lesions were detected during reinsertion of the colonoscope, and half of them were detected during the second withdrawal.
![d-rex](/wp-content/uploads/d-rex.jpg)
COMMENTThe challenge in understanding absolute miss rates in this study is that during a withdrawal through the right side of the colon in retroflexion, it’s difficult to know if the point where the examination in retroflexion stops is the same amount of colon examined in the first withdrawal. Thus, the examination in retroflexion may extend distally into the transverse colon, ie, farther distally than the first withdrawal. Despite that, the observation that half the missed lesions were identified during the second insertion to the cecum means that a second right-side colon examination is warranted even when using a mucosal exposure device.
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)
Vemulapalli KC, Lahr RE, Lee CJ, Abdullah N, Rex DK. Yield of a second right colon segment examination during colonoscopy after a first examination using a mucosal exposure device. Gastrointest Endosc 2021 Jul 17. (Epub ahead of print) (https://doi.org/10.1016/j.gie.2021.07.012)