Abstract In vivo real-time assessment of the histology of diminutive (≤5 mm) colorectal polyps detected at colonoscopy can be achieved by means of an “optical biopsy” by using currently available ...endoscopic technologies. This systematic review and meta-analysis was performed by the American Society for Gastrointestinal Endoscopy (ASGE) Technology Committee to specifically assess whether acceptable performance thresholds outlined by an ASGE Preservation and Incorporation of Valuable endoscopic Innovations (PIVI) document for clinical adoption of these technologies have been met. We conducted direct meta-analyses calculating the pooled negative predictive value (NPV) for narrow-band imaging (NBI), i-SCAN, and Fujinon Intelligent Color Enhancement (FICE)–assisted optical biopsy for predicting adenomatous polyp histology of small/diminutive colorectal polyps. We also calculated the pooled percentage agreement with histopathology when assigning postpolypectomy surveillance intervals based on combining real-time optical biopsy of colorectal polyps 5 mm or smaller with histopathologic assessment of polyps larger than 5 mm. Random-effects meta-analysis models were used. Statistical heterogeneity was evaluated by means of I2 statistics. Our meta-analyses indicate that optical biopsy with NBI, exceeds the NPV threshold for adenomatous polyp histology, supporting a “diagnose-and-leave” strategy for diminutive predicted nonneoplastic polyps in the rectosigmoid colon. The pooled NPV of NBI for adenomatous polyp histology by using the random-effects model was 91% (95% confidence interval CI, 88–94). This finding was associated with a high degree of heterogeneity (I2 = 89%). Subgroup analysis indicated that the pooled NPV was greater than 90% for academic medical centers (91.8%; 95% CI, 89-94), for experts (93%; 95% CI, 91-96), and when the optical biopsy assessment was made with high confidence (93%; 95% CI, 90-96). Our meta-analyses also indicate that the agreement in assignment of postpolypectomy surveillance intervals based on optical biopsy with NBI of diminutive colorectal polyps is 90% or greater in academic settings (91%; 95% CI, 86-95), with experienced endoscopists (92%; 95% CI, 88-96) and when optical biopsy assessments are made with high confidence (91%; 95% CI, 88-95). Our systematic review and meta-analysis confirms that the thresholds established by the ASGE PIVI for real-time endoscopic assessment of the histology of diminutive polyps have been met, at least with NBI optical biopsy, with endoscopists who are expert in using this advanced imaging technology and when assessments are made with high confidence.
Summary Background Although colonoscopy is the accepted standard for detection of colorectal adenomas and cancers, many adenomas and some cancers are missed. To avoid interval colorectal cancer, the ...adenoma miss rate of colonoscopy needs to be reduced by improvement of colonoscopy technique and imaging capability. We aimed to compare the adenoma miss rates of full-spectrum endoscopy colonoscopy with those of standard forward-viewing colonoscopy. Methods We did an international, multicentre, randomised trial at three sites in Israel, one site in the Netherlands, and two sites in the USA between Feb 1, 2012, and March 31, 2013. Patients aged 18–70 years referred for colorectal cancer screening, polyp surveillance, or diagnostic assessment underwent same-day, back-to-back tandem colonoscopy with standard forward-viewing colonoscope and the full-spectrum endoscopy colonoscope. The patients were randomly assigned (1:1), via computer-generated randomisation with block size of 20, to which procedure was done first. The endoscopist was masked to group allocation until immediately before the start of colonoscopy examinations; patients were not masked. The primary endpoint was adenoma miss rates. We did per-protocol analyses. This trial is registered with ClinicalTrials.gov , number NCT01549535. Findings 197 participants were enrolled. 185 participants were included in the per-protocol analyses: 88 (48%) were randomly assigned to receive standard forward-viewing colonoscopy first, and 97 (52%) to receive full-spectrum endoscopy colonoscopy first. By per-lesion analysis, the adenoma miss rate was significantly lower in patients in the full-spectrum endoscopy group than in those in the standard forward-viewing procedure group: five (7%) of 67 vs 20 (41%) of 49 adenomas were missed (p<0·0001). Standard forward-viewing colonoscopy missed 20 adenomas in 15 patients; of those, three (15%) were advanced adenomas. Full-spectrum endoscopy missed five adenomas in five patients in whom an adenoma had already been detected with first-pass standard forward-viewing colonoscopy; none of these missed adenomas were advanced. One patient was admitted to hospital for colitis detected at colonoscopy, whereas five minor adverse events were reported including vomiting, diarrhoea, cystitis, gastroenteritis, and bleeding. Interpretation Full-spectrum endoscopy represents a technology advancement for colonoscopy and could improve the efficacy of colorectal cancer screening and surveillance. Funding EndoChoice.
Background Endoscopic resection of large colorectal lesions is associated with high complication rates. Objective To evaluate the effect of prophylactic clip closure of polypectomy sites after ...resection of large (≥2 cm) sessile and flat colorectal lesions. Design Retrospective study. Setting Tertiary referral center. Patients and Interventions Patients with lesions 2 cm or larger who underwent EMR performed by using low-power coagulation current between January 2000 and February 2012. Beginning in June 2006, polypectomy sites were prophylactically closed with clips when possible. Patients had telephone follow-up at 30 days or later to track complications. Main Outcome Measurements Delayed hemorrhage, postpolypectomy syndrome, and perforation. Results There were 524 lesions 2 cm or larger in 463 patients, of which 247 (47.1%) were not clipped, 52 (9.9%) were partially clipped, and 225 (42.9%) were fully clipped. There were 31 delayed hemorrhages, 2 perforations, and 6 cases of postpolypectomy syndrome. The delayed hemorrhage rate was 9.7% in the not clipped group versus 1.8% in the fully clipped group. Multivariate analysis showed that not clipping (odds ratio OR 6.0; 95% CI, 2.0-18.5), location proximal to the splenic flexure (OR 2.9; 95% CI, 1.05-8.1), and polyp size (OR 1.3; 95% CI, 1.1-1.7 for each 10-mm increase in size) were associated with delayed bleeding. Limitation Retrospective design. Conclusions Prophylactic clipping of resection sites after endoscopic removal of large (≥2 cm) colorectal lesions using low-power coagulation current reduced the risk of delayed postpolypectomy hemorrhage. A randomized, prospective trial of clipping large polypectomy sites is warranted.
Background A simple endoscopic classification to accurately predict deep submucosal invasive (SM-d) carcinoma would be clinically useful. Objective To develop and assess the validity of the NBI ...international colorectal endoscopic (NICE) classification for the characterization of SM-d carcinoma. Design The study was conducted in 4 phases: (1) evaluation of endoscopic differentiation by NBI-experienced colonoscopists; (2) extension of the NICE classification to incorporate SM-d (type 3) by using a modified Delphi method; (3) prospective validation of the individual criteria by inexperienced participants, by using high-definition still images without magnification of known histology; and (4) prospective validation of the individual criteria and overall classification by inexperienced participants after training. Setting Japanese academic unit. Main Outcome Measurements Performance characteristics of the NICE criteria (phase 3) and overall classification (phase 4) for SM-d carcinoma; sensitivity, specificity, predictive values, and accuracy. Results We expanded the NICE classification for the endoscopic diagnosis of SM-d carcinoma (type 3) and established the predictive validity of its individual components. The negative predictive values of the individual criteria for diagnosis of SM-d carcinoma were 76.2% (color), 88.5% (vessels), and 79.1% (surface pattern). When any 1 of the 3 SM-d criteria was present, the sensitivity was 94.9%, and the negative predictive value was 95.9%. The overall sensitivity and negative predictive value of a global, high-confidence prediction of SM-d carcinoma was 92%. Interobserver agreement for an overall SM-d carcinoma prediction was substantial (kappa 0.70). Limitations Single Japanese center, use of still images without prospective clinical evaluation. Conclusion The NICE classification is a valid tool for predicting SM-d carcinomas in colorectal tumors.
Background The prevalence of sessile serrated adenomas and/or polyps (SSA/Ps) is uncertain. Objective To determine the prevalence of SSA/Ps and SSA/Ps with cytologic dysplasia (SSA/P-CD) by using a ...colonoscopist with a high lesion detection rate and an expert in serrated lesion pathology. Design Retrospective screening colonoscopy study. Setting Academic endoscopy unit. Patients A total of 1910 average risk, asymptomatic patients aged ≥50 years underwent screening colonoscopy between August 2005 and April 2012 by a single colonoscopist with a high lesion detection rate. Interventions Slides of all lesions in the serrated class proximal to the sigmoid colon and all rectal and sigmoid colon serrated lesions >5 mm in size were reviewed by an experienced GI pathologist. Main Outcome Measurements Prevalence of SSA/Ps, defined as the proportion of patients with ≥1 SSA/P. Results There were 1910 patients, of whom 389 had 656 lesions in the serrated class. Review by the experienced GI pathologist determined a prevalence of SSA/Ps without cytologic dysplasia of 7.4% and SSA/Ps-CD of 0.6% (total SSA/P prevalence 8.1%). SSA/Ps and SSA/Ps-CD comprised 5.6% and 0.3%, respectively, of all resected polyps. The mean size of SSA/Ps was 7.13 mm (standard deviation SD 4.66), and 51 of 77 (66.2%) polyps ≥10 mm in the serrated class were SSA/Ps. Limitations Retrospective design. Conclusion A colonoscopist with a high lesion detection rate and an experienced pathologist identified a high prevalence (8.1%) of SSA/Ps in a screening population. SSA/Ps are more common than previously believed.
Background Colonoscopy is less effective in the proximal compared with the distal colon. Objective To describe the success rate, yield, and safety of retroflexion of the right side of the colon after ...a careful forward-viewing examination. Design Prospective observational study. Setting Tertiary-care hospital outpatient endoscopy center and associated ambulatory surgery center. Patients A total of 1000 consecutive adults undergoing elective screening or surveillance colonoscopy, without previous bowel resection, inflammatory bowel disease, or polyposis syndromes. Intervention After cecal intubation, a careful examination of the cecum to the hepatic flexure was performed in the forward view with removal of all identified polyps. The colonoscope was then reinserted to the cecum and retroflexed, and examination was performed to the hepatic flexure in retroflexion. Main Outcome Measurements Success rate, per-polyp and per-patient miss rates, and adverse events rate of retroflexion. Results Retroflexion was successful in 94.4% of patients. Looping in the insertion tube was the apparent cause of 89% of failed attempts. The forward view identified 634 proximal colon polyps and 497 adenomas, and retroflexion identified an additional 68 polyps and 54 adenomas, representing a per-adenoma miss rate of 9.8% and an intention-to-treat, per-patient adenoma miss rate of 4.4%. Older age, male sex, and polyps seen on the forward view predicted polyps seen on retroflexion. There were no adverse events. Limitations Single-center, uncontrolled study with only 2 endoscopists. Conclusions Right-sided colon retroflexion is generally achievable and safe in our hands. The yield is comparable to that expected from a second examination in the forward view.
Background Proximal colon serrated polyps likely contribute to the decreased protection of colonoscopy against right-sided colorectal cancer. Objective To estimate the prevalence and extrapolated ...detection rate of proximal serrated polyps at screening colonoscopy. Design Retrospective study. Patients The study involved secondary analyses that used two databases. The first includes screening colonoscopies performed by 15 attending gastroenterologists at two academic endoscopy units between 2000 and 2009. The second includes average-risk patients who had previously participated in a randomized trial comparing high-definition chromocolonoscopy and white-light colonoscopy. Main Outcome Measurements Prevalence of proximal serrated polyps found by the highest-level detectors and proximal serrated polyp detection rates corresponding to adenoma detection rates of 25% in men and 15% in women, respectively. Results We analyzed 6681 procedures from the first database. Mean (± standard deviation) detection rates for adenomas and proximal serrated polyps were 38% ± 7.8% (range 17%-47%) and 13% ± 4.8% (1%-18%), respectively. There was a significant correlation between detection rates for adenomas and proximal serrated polyps for men ( R = 0.71; P = .003) and women ( R = 0.73; P = .002). Adenoma detection rates of 25% for men and 15% for women both corresponded to a detection rate of 4.5% for proximal serrated polyps. The prevalence of proximal serrated polyps found by the highest-level detector was 18%. The corresponding rate derived from the high-definition screening colonoscopy database was 20%. Limitations Retrospective study. Conclusion The prevalence of proximal colon serrated polyps in average-risk patients undergoing screening colonoscopy is higher than previously reported. An extrapolated proximal serrated polyp detection rate of 5% is suggested for average-risk men and women.
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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