New device improves detection of adenomas during colonoscopy
A polypropylene device that enhances mucosal visualization leads to significant improvements in bowel cancer screening, such as the detection rate of adenoma and cancer, especially in faecal occult blood (FOBt)-positive patients, according to the ADENOMA* study.
Named Endocuff Vision (EV), the device is mounted onto the distal tip of a colonoscope and features a row of eight soft projections. The projections fold backwards during insertion but are pulled forwards during withdrawal to hold back colonic folds. This feature is an improvement on the original Endocuff consisting of two rows of shorter, firmer projections, which have been previously reported to cause mucosal abrasions. [J Clin Gastroenterol 2015;49:413-418; Gut 2017;66:438-445; Endoscopy 2014;46:610-614]
In ADENOMA, a total of 1,772 patients (mean age 62 years; 57 percent male) underwent EV-assisted colonoscopy due to symptoms or surveillance, or following a positive FOBt. The procedure significantly increased the odds of adenoma detection by 22 percent as compared with standard colonoscopy (global adenoma detection rate [ADR], 40.9 percent vs 36.2 percent; p=0.02). [Gut 2018;doi:10.1136/gutjnl-2017-314889]
The improved ADR was primarily driven by a 10.8-percent increase in FOBt-positive screening patients (61.7 percent with EV-assisted colonoscopy vs 50.9 percent with standard procedure; p<0.001).
EV-assisted colonoscopy was also associated with higher detection of mean adenomas per procedure (0.95 vs 0.75, p=0.02), polyps (54.1 percent vs 48 percent; p=0.005), small serrated polyps (SSP; 2.3 percent vs 1.1 percent; p=0.03), left colon adenomas (26.1 percent vs 22.2 percent; p=0.03), small and diminutive adenomas (10.6 percent vs 7.7 percent; p=0.02 and 34.6 percent vs 30.8 percent; p=0.04, respectively), and cancers (4.1 percent vs 2.3 percent; p=0.02).
EV cuff removal rate was 4.1 percent, with angulation in a fixed sigmoid colon being the most common reason for removal (52.8 percent). Other reasons were new cancer diagnosis (19.4 percent), identification of colonic strictures (16.7 percent) and a new diagnosis of active colitis (2.8 percent).
Median intubation was quicker by a minute with EV-assisted colonoscopy (p=0.001), with no difference in caecal intubation rate or withdrawal time compared with standard colonoscopy. While well tolerated, the procedure resulted in a minor increase in discomfort on anal intubation in patients undergoing colonoscopy with no or minimal sedation. No significant adverse events related to EV cuff were documented.
The authors noted that the increase in ADR, mean adenomas per procedure and cancer in the EV-assisted colonoscopy arm was driven by an increase in patients who were FOBt positive and consequently had high rates of neoplastic pathology.
“These results suggest that EV improves visualization and ADR in a population where neoplastic pathology is more common,” they said.
EV improves visualization by holding back and everting colonic folds and allowing them to slowly revert to their anatomical position. In addition, the device stabilizes colonoscope position and helps prevent slippage back of the scope, avoiding rapid slide of areas of mucosa. According to the authors, such features may provide an explanation for improved detection of adenomas in the left colon, where colonic folds are most prominent, as well as of cancers.
However, a special caution was raised regarding interpretation of the increased cancer detection, which showed a large disparity in relation to large polyp detection, and of the clinical significance of increased SSP detection, which was a small change and low overall.
Nonetheless, EV facilitates quicker colonic intubation and proves noninferior in all aspects of patient comfort other than causing minimal discomfort on anal intubation. The device should therefore be recommended for use in patients at high risk of having adenomas, such as those undergoing colonoscopy following a positive FOBt, the authors said.
*Accuracy of Detection using Endocuff Optimisation of Mucosal Abnormalities