Standard-definition Colonoscopy Research Articles

Recent advances in surveillance colonoscopy for dysplasia in inflammatory bowel disease.

Inflammatory bowel disease (IBD) has a global presence with rapidly increasing incidence and prevalence. Patients with IBD including those with ulcerative colitis and Crohn's disease have a higher risk of developing colorectal cancer (CRC) compared to the general population. Risk factors for CRC in patients with IBD include long disease duration, extensive colitis, primary sclerosing cholangitis, family history of CRC, stricture, and prior dysplasia. Surveillance colonoscopy for CRC in patients with IBD should be tailored to individualized risk factors and requires careful monitoring every year to every five years. The current surveillance techniques are based on several guidelines. Chromoendoscopy with targeted biopsy is being recommended increasingly, and high-definition colonoscopy is gradually replacing standard-definition colonoscopy. However, it remains unclear whether chromoendoscopy, virtual chromoendoscopy, or white-light endoscopy has better efficiency when a high-definition scope is used. With the development of new endoscopic instruments and techniques, the paradigm of surveillance strategy has gradually changed. In this review, we discuss cutting-edge surveillance colonoscopy in patients with IBD including a review of literature.

S336 Significant Improvement in the Overall Sessile Serrated Adenoma Detection Rates With High Definition Colonoscopy Compared to Standard Definition Colonoscopy

S336 Significant Improvement in the Overall Sessile Serrated Adenoma Detection Rates With High Definition Colonoscopy Compared to Standard Definition Colonoscopy

≥3 Nonadvanced Adenomas are More Common in the Era of Contemporary Colonoscopy and Not Associated With Metachronous Advanced Neoplasia.

Data from standard definition colonoscopy era demonstrate patients with an advanced adenoma (≥10 mm, villous features or high-grade dysplasia) or ≥3 nonadvanced adenomas are considered high-risk for metachronous advanced neoplasia (MAN). Low-risk adenoma (LRA) patients are those with 1 to 2, <10 mm tubular adenomas. High definition colonoscopy, split-dose bowel preparation, and attention to adenoma detection enhance diminutive adenoma detection. We compared baseline adenoma characteristics between patients undergoing colonoscopy in a historic cohort (HC) and contemporary cohort (CC) to determine if number of patients with ≥3 nonadvanced adenomas are increased in CC, and if those features are associated with MAN in CC. Patients undergoing their first colonoscopy in HC (<2006) and CC (≥2006) at age 50 and above were identified through natural language processing. Multivariable regression analysis compared baseline adenoma characteristics between HC and CC, and determined the association between baseline characteristics and MAN in CC patients. In total, 255,074 colonoscopies were performed between 1990 and 2015. A total of 9773 colonoscopies performed in the HC and 59,531 in the CC were included. At baseline, CC patients were more likely to have ≥3 nonadvanced adenomas [odds ratio (OR): 2.1, 95% confidence interval (CI): 1.7-2.6]. In 3,377 CC patients undergoing follow-up colonoscopy, the risk of MAN did not differ between patients with LRA versus those with ≥3 nonadvanced adenomas (6.3% vs. 4.6%, OR: 1.4, CI: 0.58-3.5) including 3-4 (6.1%, OR: 1.4, CI: 0.52-3.6) and ≥5 (7.7%, OR: 1.8, CI: 0.23-14.6), although few patients had ≥5 nonadvanced adenomas. Colonoscopy in the contemporary era increases detection of patients with ≥3 nonadvanced adenomas, which do not increase the risk of MAN compared with LRA patients. A similar surveillance to LRA patients should be considered for those patients.

Post-colonoscopy colorectal cancer rate in the era of high-definition colonoscopy.

AIMTo investigate the post-colonoscopy colorectal cancer (PCCRC) rate for high-definition (HD) colonoscopy compared with that for standard-definition colonoscopy reported previously.METHODSUsing medical records at Sano Hospital (SH) and Dokkyo Medical University Koshigaya Hospital (DMUKH), we retrospectively obtained data on consecutive patients diagnosed as having CRC between January 2010 and December 2015. The definition of PCCRC was diagnosis of CRC between 7 and 36 mo after initial high-definition colonoscopy that had detected no cancer, and patients were divided into a PCCRC group and a non-PCCRC group. The primary outcome was the rate of PCCRC for HD colonoscopy. The secondary outcomes were factors associated with PCCRC and possible reason for occurrence of early and advanced PCCRC.RESULTSAmong 892 CRC patients, 11 were diagnosed as having PCCRC and 881 had non-PCCRC. The PCCRC rate was 1.7% (8/471) at SH and 0.7% (3/421) at DMUKH. In comparison with the non-PCCRC group, the PCCRC group had a significantly higher preponderance of smaller tumors (39 mm vs 19 mm, P = 0.002), a shallower invasion depth (T1 rate, 25.4% vs 63.6%, P = 0.01), a non-polypoid macroscopic appearance (39.0% vs 85.7%, P = 0.02) and an earlier stage (59.7% vs 90.9%, P = 0.03). Possible reasons for PCCRC were “missed or new” in 9 patients (82%), “incomplete resection” in 1 (9%), and “inadequate examination’” in 1 (9%). Among 9 “missed or new” PCCRC, the leading cause was non-polypoid shape for early PCCRC and blinded location for advanced PCCRC.CONCLUSIONThe PCCRC rate for HD colonoscopy was 0.7%-1.7%, being lower than that for standard-definition colonoscopy (1.8%-9.0%) reported previously employing the same methodology.

Next-generation narrow band imaging system for colonic polyp detection: a prospective multicenter randomized trial.

Previous studies have yielded conflicting results on the colonic polyp detection rate with narrow-band imaging (NBI) compared with white-light imaging (WLI). We compared the mean number of colonic polyps detected per patient for NBI versus WLI using a next-generation NBI system (EVIS LUCERA ELITE; Olympus Medical Systems) used with standard-definition (SD) colonoscopy and wide-angle (WA) colonoscopy. this study is a 2 × 2 factorial, prospective, multicenter randomized controlled trial. this study was conducted at five academic centers in Japan. patients were allocated to one of four groups: (1) WLI with SD colonoscopy (H260AZI), (2) NBI with SD colonoscopy (H260AZI), (3) WLI with WA colonoscopy (CF-HQ290), and (4) NBI with WA colonoscopy (CF-HQ290). the mean numbers of polyps detected per patient were compared between the four groups: WLI with/without WA colonoscopy and NBI with/without WA colonoscopy. Of the 454 patients recruited, 431 patients were enrolled. The total numbers of polyps detected by WLI with SD, NBI with SD, WLI with WA, and NBI with WA were 164, 176, 188, and 241, respectively. The mean number of polyps detected per patient was significantly higher in the NBI group than in the WLI group (2.01 vs 1.56; P = 0.032). The rate was not higher in the WA group than in the SD group (1.97 vs 1.61; P = 0.089). Although WA colonoscopy did not improve the polyp detection, next-generation NBI colonoscopy represents a significant improvement in the detection of colonic polyps.

Novel diagnostic and therapeutic techniques for surveillance of dysplasia in patients with inflammatory bowel disease.

The risk for developing dysplasia and colorectal cancer in patients with longstanding inflammatory bowel disease (IBD) involving the colon is well documented. Random biopsies during white-light, standard-definition colonoscopy (33 to 50 biopsies) with or without dye spraying chromoendoscopy has been the recommended strategy in North America to detect dysplastic lesions in IBD. However, there are several limitations to this approach including poor physician adherence, poor sensitivity, increased procedure time and considerable cost. The new generation of high-definition endoscopes with electronic filter technology provide an opportunity to visualize colonic mucosal and vascular patterns in minute detail, and to identify subtle flat, multifocal, polypoid and pseudopolypoid neoplastic and non-neoplastic lesions. The application of these new technologies in IBD is slowly being adopted in clinical practice. In addition, the advent of confocal laser endomicroscopy provides an opportunity to explore real-time histology, thus redefining the understanding and characterization of the lesions in IBD. There is emerging evidence that serrated adenomas are also associated with longstanding IBD colitis and may be recognized as another important contributing factor to colorectal cancer development. The circumscribed neoplastic lesions can be treated using endoscopic therapeutic management such as mucosal resection or, especially, endoscopic submucosal dissection. This may replace panproctocolectomy in selected patients. The authors review the potential of these techniques to transform endoscopic diagnosis and therapeutic management of dysplasia in IBD.

Sa1504 Diagnostic Yield of High-Definition Colonoscopy Versus Standard-Definition Colonoscopy for the Detection of Colonic Polyps: a Meta-Analysis of Randomized Controlled Trials

Sa1504 Diagnostic Yield of High-Definition Colonoscopy Versus Standard-Definition Colonoscopy for the Detection of Colonic Polyps: a Meta-Analysis of Randomized Controlled Trials

High Definition vs Standard Definition Colonoscopy for Polyp and Adenoma Detection in a Screening Population. A Comparison in a “Real-Life Setting”

High Definition vs Standard Definition Colonoscopy for Polyp and Adenoma Detection in a Screening Population. A Comparison in a “Real-Life Setting”

High-definition vs. standard-definition colonoscopy in the characterization of small colonic polyps: results from a randomized trial

The resolution of endoscopes has increased in recent years. Modern Fujinon colonoscopes have a charge-coupled device (CCD) pixel density of 650,000 pixels compared with the 410,000 pixel CCD in standard-definition scopes. Acquiring high-definition scopes represents a significant capital investment and their clinical value remains uncertain. The aim of the current study was to investigate the impact of high-definition endoscopes on the in vivo histology prediction of colonic polyps. Colonoscopy procedures were performed using Fujinon colonoscopes and EPX-4400 processor. Procedures were randomized to be performed using either a standard-definition EC-530 colonoscope or high-definition EC-530 and EC-590 colonoscopes. Polyps of <10 mm were assessed using both white light imaging (WLI) and flexible spectral imaging color enhancement (FICE), and the predicted diagnosis was recorded. Polyps were removed and sent for histological analysis by a pathologist who was blinded to the endoscopic diagnosis. The predicted diagnosis was compared with the histology to calculate the accuracy, sensitivity, and specificity of in vivo assessment using either standard or high-definition scopes. A total of 293 polyps of <10 mm were examined–150 polyps using the standard-definition colonoscope and 143 polyps using high-definition colonoscopes. There was no difference in sensitivity, specificity or accuracy between the two scopes when WLI was used (standard vs. high: accuracy 70% [95% CI 62–77] vs. 73% [95% CI 65–80]; P=0.61). When FICE was used, high-definition colonoscopes showed a sensitivity of 93% compared with 83% for standard-definition colonoscopes (P=0.048); specificity was 81% and 82%, respectively. There was no difference between high- and standard-definition colonoscopes when white light was used, but FICE significantly improved the in vivo diagnosis of small polyps when high-definition scopes were used compared with standard definition.

603 Quality Indicators to Enhance Adenoma Detection Rate: Should There Be Reconsideration of the Current Standard?

603 Quality Indicators to Enhance Adenoma Detection Rate: Should There Be Reconsideration of the Current Standard?

The American College of Gastroenterology High Definition Chromocolonoscopy Study: Findings and Implications for Colorectal Cancer Screening

Purpose: Non-polypoid (flat and depressed) colon neoplasms are an increasingly recognized precursor for colorectal cancer (CRC) in Western populations. High-definition chromoscopy is used to increase the yield of colonoscopy for non-polypoid lesions; however, its role in average-risk patients undergoing routine screening remains uncertain. Methods: Average-risk patients referred for screening colonoscopy at 4 medical centers in the U.S. were randomized to high-definition chromocolonoscopy or high-definition white light colonoscopy. The primary outcomes, patients with at least one adenoma and number of adenomas per patient, were compared between the 2 groups. Secondary outcomes included patients with flat or depressed lesions, as defined by the Paris classification. Results: A total of 660 patients were randomized (chromocolonoscopy: 321, white light: 339). Overall, the mean number of adenomas per patient was 1.2 ± 2.1, the mean number of flat polyps per patient was 1.4 ± 1.9, and the mean number of flat adenomas per patient was 0.5 ± 1.0. There were no significant differences between the 2 groups in the number of patients with a least one adenoma (55.5% versus 48.4%, p=0.07), number of adenomas per patient (1.3 ± 2.4 versus 1.1 ± 1.8, p=0.08), number of advanced adenomas per patient (0.06 ± 0.37 versus 0.04 ± 0.25, p=0.3), and number of advanced adenomas < 10 mm per patient (0.02 ± 0.26 versus 0.01 ± 0.14, p=0.4). Two invasive cancers were found, one in each group; neither was a flat lesion. Chromocolonoscopy detected significantly more flat adenomas per patient (0.6 ± 1.2 versus 0.4 ± 0.9, p=0.01), adenomas < 5 mm in diameter per patient (0.8 ± 1.3 versus 0.7 ± 1.1, p=0.03) and non-neoplastic lesions per patient (1.8 ± 2.3 versus 1.0 ± 1.3, p < 0.0001). Conclusion: High-definition chromocolonoscopy did not result in an increase in overall adenoma detection, and yielded a modest increase in flat adenoma and small adenoma detection, compared with high-definition white light colonoscopy. Our findings do not support the routine use of high-definition chromocolonoscopy for CRC screening in average-risk patients. The high adenoma detection rates observed in this study may be due to the high definition technology. A direct comparison of the adenoma detection rates of highdefinition colonoscopy compared to standard definition colonoscopy appears warranted. Am J Gastroenterol 2009; 104:S560-S576; doi:10.1038/ajg.2009.492

Does the High Definition Imaging Induce a Learning Effect in Clinical Practice? A Comparison of High Definition White Light Colonoscopy and Standard Definition Colonoscopy for Adenoma Detection in 2011 Patients

Purpose: Improving adenoma detection rates during colonoscopy is one of the important measures of quality of colonoscopy. High definition colonoscopies may lead to better detection of subtle mucosal changes and thus adenomas. Aims of this study were to determine whether the use of high-definition white light colonoscopy (HD) results in better adenoma detection when compared with standard definition white light(SD) colonoscopy in a clinical practice setting and to observe whether the introduction of high definition technology improved adenoma detection in both groups(learning effect). Methods: We performed a retrospective study comparing HD (Olympus 180 series) colonoscopy with SD (Olympus 140-160 series) colonoscopy. Study participants were patients who underwent screening, surveillance and diagnostic colonoscopies in our GI suite between 09/2006 and 08/2007. HD scopes were randomly placed in 3 out of 6 rooms. The default mode of colonoscopes in 3 out of 6 rooms was HD and the endoscopist could not choose between the HD and SD mode. The assignment of cases and endoscopists to all rooms was random. Adenoma detection rates in the both groups-SD and HD were estimated using test for two proportions and Fisher's exact test. Test of trend was used to examine differences in detection of adenomas in both groups over time. Results: A total of 2011 patients (mean age 63.4, SD12.6; 54.2% men) participated in the study, of whom 1188 patients were assigned to SD and 823 were assigned to HD. Patients' characteristics were similar in both groups for demographics and risk factors. Adenomas were detected more frequently in HD group (28.55%) then in the SD group (23.40%) and this was statistically significant with p value 0.01. When the two techniques were compared in consecutive 5 subgroups, each of 164 patients over the time, adenomas detection rates increased in both groups over the time. Figure 1 illustrates the overview of adenomas detection rates per groups of 164 study patients each, over the time.Figure 1: Overview of adenoma detection rates per groups of 164 study patients each.: Blue line interrupted — ‘o’ - number of patients in whom adenomas were detected during SD colonoscopies , blue line not interrupted: adjusted trend (test of trend) Black line interrupted — line ‘+’ - number of patients in whom adenomas were detected during HD colonoscopies per group of 164 patients each, Black line not interrupted-adjusted trendConclusion: The use of HD colonoscopy resulted in a statistically significant increased adenoma detection rate in a general clinical practice setting. Over the course of the study, the adenoma detection rate increased for both SD and HD groups suggesting a learning effect associated with the use of HD colonoscopy. Disclosure: Dr Michael Wallace received research grants support from Mauna Kea Technology, Olympus, Fujinon.