Background and Aims
Incomplete resection of colorectal neoplasia decreases the efficacy of colonoscopy.
Conventional resection (CR) of polyps, performed in a gas-distended colon, is the
current standard, but incomplete resection rates of approximately 2% to 30% for nondiminutive
(>5 mm), nonpedunculated lesions are reported. Underwater resection (UR) is a novel
technique. The aim of this study was to determine the incomplete resection rates of
colorectal lesions removed by UR versus CR.
Methods
In a randomized controlled trial, patients with small (6-9 mm) and large (≥10 mm)
nonpedunculated lesions were assigned to CR (gas-distended lumen) or UR (water-filled,
gas-excluded lumen). Small lesions in both arms were removed with a dedicated cold
snare. For CR, large lesions were removed with a hot snare after submucosal injection.
For UR, large lesions were removed with a hot snare without submucosal injection.
Four-quadrant biopsy samples around the resection sites were used to evaluate for
incomplete resection.
Results
Four hundred sixty-two eligible polyps (248 UR vs 214 CR) from 255 patients were removed.
Incomplete resection rates for UR and CR were low and did not differ (2% vs 1.9%,
P = .91). UR was performed significantly faster for lesions ≥10 mm in size (10-19 mm,
2.9 minutes vs 5.6 minutes, P < .0001); ≥20 mm, 7.3 minutes vs 9.5 minutes, P = .015).
Conclusions
Low incomplete resection rates are achievable with UR and CR. UR is effective and
safe with the advantage of faster resection and potential cost savings for removal
of larger (≥10 mm) lesions by avoiding submucosal injection. As an added approach,
UR has potential to improve the cost-effectiveness of colonoscopy by increasing efficiency
and reducing cost while maintaining quality. (Clinical trial registration number:
NCT02889679.)
Graphical abstract
Graphical Abstract
Abbreviations:
CR (conventional resection), UR (underwater resection), VANCHCS (Veterans Affairs Northern California Health Care System)To read this article in full you will need to make a payment
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Article info
Publication history
Published online: October 16, 2019
Accepted:
September 27,
2019
Received:
June 22,
2019
Footnotes
DISCLOSURE: All authors disclosed no financial relationships.
Identification
Copyright
© 2020 by the American Society for Gastrointestinal Endoscopy
