Interobserver agreement on landmark and flexure identification in colon capsule endoscopy.

PURPOSE: When an optical colonoscopy is carried out, Scope Guide can assist the endoscopist in determining the localization. In colon capsule endoscopy (CCE), this support is not available. To our knowledge, the interobserver agreement on landmark identification has never been studied. This study aims to investigate the interobserver agreement on landmark identification in CCE. METHODS: An interobserver study was carried out comparing the landmark identification (the ileocecal valve, hepatic flexure, splenic flexure, and anus) in CCE investigations between an external private contractor and three in-house CCE readers with different levels of experience. All CCE investigations analyzed in this study were carried out as a part of the Danish screening program for colorectal cancer. Patients were between 50 and 74 years old with a positive fecal immunochemical test (FIT). A random sample of 20 CCE investigations was taken from the total sample of more than 800 videos. RESULTS: Overall interobserver agreement on all landmarks was 51%. Interobserver agreement on the first cecal image (ileocecal valve), hepatic flexure, splenic flexure, and last rectal image (anus) was 72%, 29%, 22%, and 83%, respectively. The overall interobserver agreement, including only examinations with adequate bowel preparation (n = 16), was 54%, and for individual landmarks, 73%, 32%, 24%, and 85%. CONCLUSION: Overall interobserver agreement on all four landmarks from CCE was poor. Measures are needed to improve landmark identification in CCE investigations. Artificial intelligence could be a possible solution to this problem.

Colon capsule endoscopy versus CT colonography after incomplete colonoscopy. Application of artificial intelligence algorithms to identify complete colonic investigations.

BACKGROUND: Guidelines suggest computed tomography colonography (CTC) following incomplete optical colonoscopy (OC). Colon capsule endoscopies (CCE) have been suggested as an alternative, although completion rates have been unsatisfactory. Introduction of artificial intelligence (AI)-based localization algorithms of the camera capsules may enable identification of incomplete CCE investigations overlapping with incomplete OCs. OBJECTIVE: The study aims to investigate relative sensitivity of CCE compared with CTC following incomplete OC, investigate the completion rate when combining results from the incomplete OC and CCE, and develop a forward-tracking algorithm ensuring a safe completeness of combined investigations. METHODS: In this prospective paired study, patients with indication for CTC following incomplete OC were included for CCE and CTC. Location of CCE abortion and OC abortion were registered to identify complete combined investigations. AI-based algorithm for localization of capsules were developed reconstructing the passage of the colon. RESULTS: In 237 individuals with CTC indication; 105 were included, of which 97 underwent both a CCE and CTC. CCE was complete in 66 (68%). Including CCEs which reached most oral point of incomplete OC, 73 (75%) had complete colonic investigations; 78 (80%) had conclusive investigations. Relative sensitivity of CCE compared with CTC was 2.67 (95% confidence interval (CI) 1.76;4.04) for polyps >5 mm and 1.91 (95% CI 1.18;3.09) for polyps >9 mm. An AI-based algorithm was developed. CONCLUSION: Sensitivity of CCE following incomplete OC was superior to CTC. Introducing and improving algorithm-based localization of capsule abortion may increase identification of overall complete investigation rates following incomplete OC.ClinicalTrials.gov identifier: NCT02826993.

Back-to-back colon capsule endoscopy and optical colonoscopy in colorectal cancer screening individuals.

AIM: The aim was to determine the polyp detection rate and per-patient sensitivity for polyps > 9 mm of colon capsule endoscopy (CCE) compared with colonoscopy as well as the diagnostic accuracy of CCE. METHOD: Individuals who had a positive immunochemical faecal occult blood test during screening had investigator blinded CCE and colonoscopy. Participants underwent repeat endoscopy if significant lesions detected by CCE were considered to have been missed by colonoscopy. RESULTS: There were 253 participants. The polyp detection rate was significantly higher in CCE compared with colonoscopy (P = 0.02). The per-patient sensitivity for > 9 mm polyps for CCE and colonoscopy was 87% (95% CI: 83-91%) and 88% (95% CI: 84-92%) respectively. In participants with complete CCE and colonoscopy examinations (N = 126), per-patient sensitivity of > 9 mm polyps in CCE (97%; 95% CI: 94-100%) was superior to colonoscopy (89%; 95% CI: 84-94%). A complete capsule endoscopy examination (N = 134) could detect patients with intermediate or greater risk (according to the European guidelines) with an accuracy, sensitivity, specificity and positivity rate of 79%, 93%, 69% and 58% respectively, using a cut-off of at least one polyp > 10 mm or more than two polyps. CONCLUSION: CCE is superior to colonoscopy in polyp detection rate and per-patient sensitivity to > 9 mm polyps, but only in complete CCE examinations. The rate of incomplete CCE examinations must be improved.

Human visceral adipose tissue and the plasminogen activator inhibitor type 1.

OBJECTIVE: The objective of this study was to systematically evaluate the molecular basis of the association between visceral fat mass and plasma plasminogen activator inhibitor-1 (PAI-1) levels in man. DESIGN: A comprehensive approach comprising observational, in vitro, and human intervention studies. MEASUREMENTS AND RESULTS: We confirmed an exclusive relationship between visceral fat and plasma PAI-1 levels (r=0.79, P<0.001) and corroborated preferential PAI-1 release from adipose tissue explants. Yet, messenger RNA analysis and in vivo measurement of PAI-1 release from visceral fat (AV-differences over the omentum) not only excluded visceral adipose tissue as a relevant source of circulating PAI-1, but also excluded visceral fat as a significant source of proinflammatory mediators such as tumor necrosis factor-alpha, IL-1 or transforming growth factor-beta that could induce PAI-1 expression in tissues other than visceral fat. Short-term interventions with acipimox and growth hormone (GH) as well as statistical evaluation excluded free fatty acids and GH as metabolic links. Further analysis of the metabolic data in a stepwise regression model indicated that plasma PAI-1 levels and visceral fat rather are co-correlates that both relate to impaired lipid handling. CONCLUSION: Our PAI-1 studies show that visceral fat mass and plasma PAI-1 levels are co-correlated rather than causatively related, with lipid load as common denominator.