LONGER COLONOSCOPY WITHDRAWAL TIME IS ASSOCIATED WITH THE DETECTION OF POLYPOID DYSPLASIA IN INFLAMMATORY BOWEL DISEASE

Background
Colonoscopy withdrawal time (CWT) of at least 6-9 minutes is the minimum time needed for adequate adenoma detection in the general population. The ideal CWT in patients with inflammatory bowel disease (IBD) has not been determined. We aimed to identify the optimal CWT associated with the detection of polypoid dysplasia in patients with IBD.

Methods
This is a single center, retrospective study from 1/1/2017-9/1/2022 of adult patients 18 years of age with IBD in endoscopic healing (absence of erosions/ulcers in Crohn’s disease; Mayo ulcerative colitis (UC) endoscopic sub-score of 0 or 1) undergoing surveillance via high-definition white light colonoscopy. We excluded incomplete colonoscopies, dye-chromoendoscopy exams and patients with previous colonic surgeries. CWT was defined as the time from cecal intubation to withdrawal from the anal canal rounded to the nearest minute. The primary outcome was the association of CWT with the presence of polypoid dysplasia (adenomas and sessile serrated polyps (SSP)) evaluated as a composite outcome. The secondary outcome was to identify an optimal CWT cutoff associated with polypoid dysplasia detection.

Results
A total of 259 patients (mean age 56 ± 14.8 years; 51.3% female, 68% with UC; 8.9% with primary sclerosing cholangitis) underwent 330 colonoscopies. A total of 12 patients (4.6%) had a personal history of invisible dysplasia while 24.7% (n=64) had a history of polypoid dysplasia and 10% had a family history of colorectal cancer. Colonoscopies were performed by IBD specialists in 40.9% (n=135), gastroenterology fellows in 9.7% (n=32) and non-targeted biopsies were obtained in 97.3% (n=321) of colonoscopies performed. The median CWT in the whole cohort was 22 minutes (interquartile range 15-29).

Invisible dysplasia was noted in 2.1% (n=7) while polypoid dysplasia was detected in 17.3% (n=57; 43 adenomas and 16 SSP) of procedures. Baseline characteristics comparing the groups with and without polypoid dysplasia are shown in Table 1. The mean CWT was significantly higher in the polypoid dysplasia group at 32.6 ± 22.3 minutes vs. 22.7 ± 11.1 minutes in procedures without polypoid dysplasia (p=0.002) (Table 1). On multivariable analysis, advanced age (p < 0.001), personal history of adenoma/SSP (p=0.01) and CWT (p <0.001) were independently associated with polypoid dysplasia (Table 2).

A CWT of 15 minutes (odds ratio (OR) 2.71, 95% CI: 1.11-6.6; p=0.02) and not ≥ 9 minutes (OR 2.57, 95% CI: 0.33-20.2; p=0.35) is significantly associated with detection of polypoid dysplasia.

Conclusion
In our cohort of patients with IBD undergoing surveillance via high-definition white light colonoscopy, the mean CWT was independently associated with the detection of polypoid dysplasia. A CWT of at least 15 minutes and not 9 minutes was significantly associated with the detection of polypoid dysplasia.