Browsing by Subject "serrated lesions"

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    Narrow-band imaging versus white light for the detection of proximal colon serrated lesions: a randomized, controlled trial
    (Elsevier, 2016-01) Rex, Douglas K.; Clodfelter, Ryan; Rahmani, Farrah; Fatima, Hala; James-Stevenson, Toyia N.; Tang, John C.; Kim, Hak Nam; McHenry, Lee; Kahi, Charles J.; Rogers, Nicholas A.; Helper, Debra J.; Sagi, Sashidhar V.; Kessler, William R.; Wo, John M.; Fischer, Monika; Kwo, Paul Y.; Department of Medicine, School of Medicine
    Background The value of narrow-band imaging (NBI) for detecting serrated lesions is unknown. Objective To assess NBI for the detection of proximal colon serrated lesions. Design Randomized, controlled trial. Setting Two academic hospital outpatient units. Patients Eight hundred outpatients 50 years of age and older with intact colons undergoing routine screening, surveillance, or diagnostic examinations. Interventions Randomization to colon inspection in NBI versus white-light colonoscopy. Main Outcome Measurements The number of serrated lesions (sessile serrated polyps plus hyperplastic polyps) proximal to the sigmoid colon. Results The mean inspection times for the whole colon and proximal colon were the same for the NBI and white-light groups. There were 204 proximal colon lesions in the NBI group and 158 in the white light group (P = .085). Detection of conventional adenomas was comparable in the 2 groups. Limitations Lack of blinding, endoscopic estimation of polyp location. Conclusion NBI may increase the detection of proximal colon serrated lesions, but the result in this trial did not reach significance. Additional study of this issue is warranted. (Clinical trial registration number: NCT01572428.)
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    The “valley sign” in small and diminutive adenomas: prevalence, interobserver agreement, and validation as an adenoma marker
    (Elsevier, 2016) Rex, Douglas K.; Ponugoti, Prasanna; Kahi, Charles; Department of Medicine, IU School of Medicine
    Background Classification schemes for differentiation of conventional colorectal adenomas from serrated lesions rely on patterns of blood vessels and pits. Morphologic features have not been validated as predictors of histology. Aim Describe the prevalence of the “valley sign” and validate it as a marker of conventional adenomas Methods Three experts judged the prevalence of the valley sign in 301 consecutive small adenomas. Medical students were taught to recognize the valley and tested on their recognition of the valley sign. Consecutive diminutive polyps were video-recorded and used to validate the association of the valley sign with conventional adenomas. Results The prevalence of the valley sign in 301 consecutive adenomas <10 mm in size, determined by 3 experts, ranged from 35% to 50%. Kappa values for agreement among the 3 experts were 0.557, 0.679, and 0.642. Ten medical students were taught to interpret the valley sign and recognized it with accuracy of 96% or higher in 50 selected photographs of diminutive polyps. Four medical students evaluated video-recordings of 170 consecutive diminutive polyps for the presence of the valley sign. Kappa values for the interpretation of the valley sign ranged from 0.52 to 0.68 among the students. The sensitivity of the valley sign for adenoma ranged from 40.2% to 54.9%, and specificity ranged from 90.2% to 91.7%. The valley sign was strongly associated with adenomas (p<0.0001). Conclusions The valley sign is insensitive but highly specific for conventional adenoma in diminutive polyps. It may enhance classification schemes for differentiation of adenomas from serrated lesions based on vessels and pits.