Clinical Significance of Diminutive Colonic Polyps in Elderly Patients

Background and Objectives:

Colorectal cancer is the third leading cause of cancer-related death. Excision of premalignant polyps has a significant impact on reducing colorectal cancer mortality and morbidity. Colonoscopy is considered to be the gold standard for the diagnosis and affords an opportunity for treatment of colonic polyps. In recent years, serious debates have taken place because of the biological characteristics of diminutive polyps (DPs), polypectomy complications, and serious costs. There has not yet been a consensus on the management of DPs. The objectives of this study were to demonstrate the real clinical importance of DPs smaller than 5 mm in diameter, which are frequently seen in geriatric patients by new endoscopic techniques, and to help in determining screening and surveillance programs.

Methods:

The patients who underwent colonoscopy and were found to have a diminutive colorectal polyp (<5 mm from September 1, 2016 through September 1, 2017), were classified into 3 groups according to the imaging method used: flexible spectral imaging color enhancement (FICE), narrow band imaging (NBI), or I-SCAN. In all groups, demographic data were compared according to Paris classification (morphologic) and Kudo classification (correlation between the prediction of endoscopic diagnosis and final pathological examination) in terms of sensitivity, specificity, and negative and positive predictive values.

Results:

Two hundred sixty-seven patients were included in the study: 97 in the NBI group, 83 in the FICE group, and 87 in the I-SCAN group. There were no statistically significant differences between NBI, FICE, and I-SCAN in differentiating neoplastic and nonneoplastic polyps, according to the Kruskal-Wallis test (P = .809).

Conclusions:

The estimated progression rates of DPs to advanced adenomas or colorectal cancer (CRC) are very low. Missing these polyps or not excising them may lead to failure to diagnose some cancers. There is a need for further comprehensive studies of removing all polyps to determine whether non–high-risk lesions require further pathologic examination and to re-examine routine surveillance programs.

Vascularization from Flexible Imaging Color Enhancement (FICE) for polyp localization

Background. Virtual chromoendoscopy is an imaging technology that helps in better visualizing the gastrointestinal tract effectively. Recently, the flexible imaging color enhancement (FICE) technique developed by Fijifilm has been considered an alternative to traditional dye spraying. This results in a clearer visualization of the vascular patterns than through the traditional white light endoscopy imaging methods. The performance of vasculature based polyp localization in both traditional and corresponding virtual coloration by FICE was analyzed. Conclusion. Our analysis showed that FICE based images vascularization features provides a better discrimination of polyps than the traditional white light endoscopy images.

Electronic Imaging in Colonoscopy: Clinical Applications and Future Prospects

Electronic chromoendoscopy (EC) is an equipment-based technology which could be easily activated by push of a button. There are four EC techniques available for use at present: narrow band imaging (NBI), i-Scan, flexible spectral chromoendoscopy and blue laser imaging. Out of the four techniques, NBI has been extensively evaluated for the detection and characterization of dysplasia in colonic polyps and dysplasia associated with inflammatory bowel disease. In this review, we will focus on the new developments and applications of EC.

[Novel imaging methods in endoscopic diagnosis of gastrointestinal tumors]

Advances in imaging, digitization and all kinds of technologies result in development of potentially efficient imaging modalities, which enable magnification to subcellular levels, color differentiation and observation of pathophysiological processes. NBI, FICE, I-scan and KFE are new commercially available modalities.NBI is the most explored one. Its contribution has been shown in diagnosis of Barrett's neoplasia and esophageal squamous cell carcinoma and in characterization of early stomach cancer. It enables rather accurate characterization of changes in adenomatous colonic polyps; however it is not used for this purpose in clinical practice. It can demonstrate atrophy of small bowel mucosa in celiac disease, but it is not able to evaluate intraepithelial lymphocytosis. Its contribution in dysplasia detection in inflammatory bowel disease is not significant; chromoendoscopy remains the gold standard.The use of CFE remains experimental; the routine use is limited also due to its high cost.

Image-enhanced endoscopy technology in the gastrointestinal tract: what is available?

Gastrointestinal malignancy accounts for approximately a fifth of all cancer deaths in the United Kingdom. By the time patients are symptomatic, lesions are often advanced, with limited treatment options available. The development of effective endoscopic therapies means that neoplastic lesions can now be treated with improved patient outcomes. This has led to a paradigm shift, whereby the aim of digestive endoscopy is to identify premalignant conditions or early neoplastic change, in order to make an impact on their natural history. This has necessitated an improvement in imaging techniques in order to identify subtle mucosal changes that may harbour precancerous cells. At present there is an array of available imaging modalities, each with implications on cost, training and lesion detection. Here we describe the scientific rationale behind the major commercially available techniques as well as offering a glimpse at possible future directions.

Image-enhanced capsule endoscopy for characterization of small bowel lesions

Video capsule endoscopy has revolutionized direct endoscopic imaging of the gut. Small-bowel video capsule endoscopy (SBVCE) is now the first-line procedure for exploring the small bowel in case of obscure digestive bleeding and has also some room in case of Crohn's disease, coeliac disease and polyposis syndrome. In case of obscure digestive bleeding the main lesions are angioectasias, erosions/ulcerations and tumors. As for conventional optical endoscopy search was done for improving the detection and characterization of small-bowel lesions. The Fujinon Intelligent Chromoendoscopy (FICE) has been adapted on the software of the SBVCE (Given Imaging(®)/Medtronics). Although there are some conflicting results on the efficacy of FICE for detecting more lesions than with conventional light, it is now recognized that FICE - particularly the setting 1 - may enhance the delineation or characterization of lesions. The use of three-dimensional representation technique is now feasible but still needs further research.

Optimizing lesion detection in small-bowel capsule endoscopy: from present problems to future solutions

This review presents issues pertaining to lesion detection in small-bowel capsule endoscopy (SBCE). The use of prokinetics, chromoendoscopy, diagnostic yield indicators, localization issues and the use of 3D reconstruction are presented. The authors also review the current status (and future expectations) in automatic lesion detection software development. Automatic lesion detection and reporting, and development of an accurate lesion localization system are the main software challenges of our time. The 'smart', selective and judicious use (before as well as during SBCE) of prokinetics in combination with other modalities (such as real time and/or purge) improves the completion rate of SBCE. The tracking of the capsule within the body is important for the localization of abnormal findings and planning of further therapeutic interventions. Currently, localization is based on transit time. Recently proposed software and hardware solutions are proposed herein. Moreover, the feasibility of software-based 3D representation (attempt for 3D reconstruction) is examined.

Progress in digestive endoscopy: Flexible Spectral Imaging Colour Enhancement (FICE)-technical review

Background. A substantial advance in digestive endoscopy that has been made during the last decade is represented by digital chromoendoscopy, which was developed as a quicker and sometimes better alternative to the gold standard of dye spraying. Fujifilm developed a virtual coloration technique called Flexible spectral Imaging Color Enhancement (FICE). FICE provides a better detection of lesions of "minimal" esophagitis, of dysplasia in Barrett's esophagus and of squamous cell esophageal cancer. The use of FICE resulted in an improvement in the visualization of the early gastric cancer, being less invasive, and time consuming than the classic dye methods. Current evidence does not support FICE for screening purposes in colon cancer but it definitely improves characterization of colonic lesions. Its use in inflammatory bowel disease is still controversial and in video capsule endoscopy is considered a substantial progress. Conclusions. The use of FICE endoscopy in routine clinical practice can increase the diagnostic yield and can provide a better characterization of lesions. Future studies to validate its use, the good choice of channels, and the "perfect indications" and to provide common definitions and classifications are necessary.

Image-enhanced endoscopy is critical in the surveillance of patients with colonic IBD

Cancer risk in patients with inflammatory bowel disease (IBD) involving the colon is high and increases with time. The quality and efficacy of colonoscopic surveillance is variable. Chromoendoscopy with targeted biopsies is superior to standard white light endoscopy with random biopsies. Although commonly practiced, the technique of random colonic biopsies has poor yield for dysplasia and has little clinical consequence. Studies have shown a limited role for electronic-based image-enhanced endoscopy, including narrow band imaging, in detecting IBD dysplasia. Efforts should focus on the dissemination of the technique of chromoendoscopy in routine clinical practice through training and quality metrics.

Advanced endoscopic imaging: a review of commercially available technologies

The rapid strides made in innovative endoscopic technology to improve mucosal visualization have revolutionized endoscopy. Improved lesion detection has allowed the modern endoscopist to provide real-time optical diagnosis. Improvements in image resolution, software processing, and optical filter technology have resulted in the commercial availability of high-definition endoscopy as well as optical contrast techniques such as narrow-band imaging, flexible spectral imaging color enhancement, and i-scan. Along with autofluorescence imaging and confocal laser endomicroscopy, these techniques have complemented and enhanced traditional white light endoscopy. They have the potential to serve as red-flag techniques to improve detection of mucosal abnormalities as well as allow optical diagnosis and virtual histology of detected lesions. This review will focus on these emerging commercially available technologies and aims to provide an overview of the technologies, their clinical applicability, and current status.

High-definition endoscopy with i-Scan for evaluation of small colon polyps: the HiSCOPE study

BACKGROUND

Traditional white-light endoscopy cannot reliably distinguish between small (<10 mm) adenomatous and hyperplastic colon polyps. High-definition white-light (HDWL) endoscopy and i-Scan may improve in vivo characterization of small colon polyps.

OBJECTIVE

To compare HDWL endoscopy and HDWL plus i-Scan for the assessment of small colon polyps and to measure performance against the American Society for Gastrointestinal Endoscopy (ASGE) thresholds for assessment of diminutive colon polyps.

DESIGN

Prospective cohort study.

SETTING

Single academic hospital.

PATIENTS

Patients undergoing bowel cancer screening colonoscopy.

INTERVENTION

In vivo assessment of all polyps <10 mm by using HDWL and i-Scan image enhancement.

MAIN OUTCOME MEASUREMENTS

The primary outcome measure was overall diagnostic accuracy of in vivo assessment of colon polyps <10 mm. Secondary outcome measures were sensitivity and specificity for adenomatous histology, negative predictive value for adenomatous histology of diminutive rectosigmoid polyps, and accuracy of prediction of polyp surveillance intervals.

RESULTS

A total of 209 polyps in 84 patients were included. There were no significant differences between HDWL endoscopy and i-Scan in characterization of polyps <10 mm (accuracy 93.3% vs 94.7%; P = 1.00; sensitivity 95.5% vs 97.0%; P = .50; specificity 89.3% vs 90.7%; P = 1.00). The negative predictive value for adenomatous histology of diminutive rectosigmoid polyps was 100% with both HDWL endoscopy and i-Scan. U.K. and U.S. polyp surveillance intervals were predicted with 95.2% accuracy with HDWL endoscopy and 97.2% accuracy with i-Scan.

LIMITATIONS

Single-center study.

CONCLUSION

HDWL endoscopy may be as accurate as HDWL with i-Scan image enhancement for the in vivo characterization of small colon polyps. Both modalities fulfil the ASGE performance thresholds for the assessment of diminutive colon polyps. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01761279.).

Advanced imaging technologies increase detection of dysplasia and neoplasia in patients with Barrett's esophagus: a meta-analysis and systematic review

BACKGROUND & AIMS

US guidelines recommend surveillance of patients with Barrett's esophagus (BE) to detect dysplasia. BE conventionally is monitored via white-light endoscopy (WLE) and a collection of random biopsy specimens. However, this approach does not definitively or consistently detect areas of dysplasia. Advanced imaging technologies can increase the detection of dysplasia and cancer. We investigated whether these imaging technologies can increase the diagnostic yield for the detection of neoplasia in patients with BE, compared with WLE and analysis of random biopsy specimens.

METHODS

We performed a systematic review, using Medline and Embase, to identify relevant peer-review studies. Fourteen studies were included in the final analysis, with a total of 843 patients. Our metameter (estimate) of interest was the paired-risk difference (RD), defined as the difference in yield of the detection of dysplasia or cancer using advanced imaging vs WLE. The estimated paired-RD and 95% confidence interval (CI) were obtained using random-effects models. Heterogeneity was assessed by means of the Q statistic and the I(2) statistic. An exploratory meta-regression was performed to look for associations between the metameter and potential confounders or modifiers.

RESULTS

Overall, advanced imaging techniques increased the diagnostic yield for detection of dysplasia or cancer by 34% (95% CI, 20%-56%; P < .0001). A subgroup analysis showed that virtual chromoendoscopy significantly increased the diagnostic yield (RD, 0.34; 95% CI, 0.14-0.56; P < .0001). The RD for chromoendoscopy was 0.35 (95% CI, 0.13-0.56; P = .0001). There was no significant difference between virtual chromoendoscopy and chromoendoscopy, based on Student t test analysis (P = .45).

CONCLUSIONS

Based on a meta-analysis, advanced imaging techniques such as chromoendoscopy or virtual chromoendoscopy significantly increase the diagnostic yield for identification of dysplasia or cancer in patients with BE.

Ancillary imaging techniques and adenoma detection

Advancements in image technology have allowed recognition of mucosal architecture in more detail and may improve adenoma detection. This review provides a technical overview on individual imaging technologies and their effect on detection of adenomas. Only high-definition endoscopy has been shown to improve detection of small adenomas. None of the digital chromoendoscopy technologies improves adenoma detection. Limited studies on autoimmunfluorescence imaging in conjunction with high-definition endoscopy may improve detection of small adenomas.