Diminutive Colorectal Polyps Research Articles

ASGE Technology Committee systematic review and meta-analysis assessing the ASGE PIVI thresholds for adopting real-time endoscopic assessment of the histology of diminutive colorectal polyps

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.

Small and diminutive colorectal polyps: risk of malignancy

The prevalence of advanced histological features in diminutive (≤5 mm) and small (6-9 mm) colon polyps is low, and they are considered to have low potential for malignant transformation. Performing a polypectomy increases the costs associated with a colonoscopy as well as the risk of complications. Newer diagnostic techniques have prompted the approach of ‘predict, resect and discard’ for diminutive and small polyps, a strategy whereby real time diagnosis of polyps would serve as a substitute for histopathological diagnosis to reduce costs.

Diminutive colorectal polyp resection comparing hot and cold snare and cold biopsy forceps polypectomy. Results of a pilot randomized, single-center study (with videos).

Background: The optimal method of diminutive polypectomy (< 6 mm) is unknown. Objective: To assess the rates of incomplete resection of diminutive polyps of the colon using three standard polyp resection techniques (hot snare, cold snare, and cold biopsy forceps). Design: Randomized, pilot study. Settings: Single-center endoscopy center. Patients: Patients undergoing routine outpatient colonoscopies. Interventions: Polypectomy was performed using the method to which the patient was randomized. Following retrieval of the polyp, the polypectomy base was lifted by submucosal injection of normal saline and then excised using the cold snare device. If no tissue could be removed, then at least four cold biopsies using forceps of the remaining margin were obtained. Main outcome measures: Adequacy of resection of diminutive polyps, which was defined as no visible adenoma or hyperplastic tissue seen in the base tissue on histology. Results: A total of 60 patients were enrolled (57 % male), the mean age was 60 (range 33 – 82), and 62 polyps were randomized from 37 patients. The mean polyp size was 3.6 mm (range 2 – 5 mm) and 37 polyps (60 %) were adenomatous. Overall incomplete polyp resection rate was 9 % (95 %CI 3 – 19 %), 5 of 37 (14 %) for adenomas. By the study arm, the incomplete resection rates were 1 of 18 (6 %) for hot snare, 2 of 21 (10 %) for cold snare, and 2 of 18 (11 %) for cold biopsy forceps. The majority of polyp bases were removed with cold biopsy forceps since most of the endoscopists did not feel that the saline lift cold snare method was feasible or appropriate. Limitations: Small sample size; endoscopic mucosal resection (EMR) of the polyp base tissue was not routinely performed. Conclusions: Recruiting patients to a pilot study that randomized polyps to one of three common methods of polypectomy for diminutive polyps was feasible, and approximately 1 in 10 diminutive polyps found on colonoscopy were incompletely resected by standard polypectomy methods.

Real-time optical diagnosis for diminutive colorectal polyps using narrow-band imaging: the VALID randomised clinical trial

BackgroundDiminutive (≤5 mm) colorectal polyps are common, and overwhelmingly benign. Routinely, after polypectomy, they are examined pathologically to determine the surveillance intervals. Advances in equipment and techniques, such as narrow-band...

In Vivo Diagnosis of Colorectal Polyps by GI Endoscopists Using HD Narrow-Band Imaging

Introduction: To determine if ASGE thresholds for changing the management of diminutive colorectal polyps can be met by systematically training gastroenterology fellows and faculty in the application of the NICE classification during routine colonoscopy. Methods: Two gastroenterology fellows and 2 attending physicians, all without prior NBI training were given a pretest and a post-test involving typing of polypoid lesions in accordance with the NICE classification. In between tests was an interactive practice session with active feedback including slides with questions and answers. Custom NICE classification reference cards were posted in the endoscopy rooms for optional rapid review. Commercially available Olympus colonoscopes CF-H180 were used with the xenon light source. The Evis Exera II video processor was used with a 26-inch LCD monitor positioned within 2-3 arm lengths. Excluded from predictions were cases of prior colon cancer, colectomy, IBD, or polyposis syndrome. Polyps were detected under white-light, narrow-band illumination was activated, and stills of the polyp to be assessed were captured. For each detected polyp the location, Paris classification of morphology, NICE classification, prediction of colorectal polyp histology, and level of confidence in the prediction were documented. Polyps were resected by snare or biopsy forceps and placed in individual transport jars for pathology. Polyp size and histology was measured and assessed by a pathologist blinded to the histology prediction. Results: Eight hundred fifty-three colonoscopies were performed by 4 gastroenterology endoscopists. Three hundred patients with median age of 62 years underwent polypectomy, yielding 583 polyps. Compared to the histopathology diagnosis, the trained endoscopist predicted the correct colonoscopy surveillance interval in 81-99% of patients depending upon the surveillance interval recommended for those with 1-2 low-risk adenomas. Post-NBI training test results were mostly concordant (±4.6%) with confident prediction-histology agreement rates. The negative predictive value for NBI-assisted adenomatous polyp screening ranged from 86-90%. Conclusion: Routine use of the NICE classification in assessing colorectal polyps can increase early diagnostic yield and support both “remove and discard” or “leave in place” strategies. We focused on the training of endoscopists using previously published methods and materials including computer-based and didactic training that lasted no more than 20 minutes. Eliminating the time spent estimating polyp size and relying on actual measurement of polyp size expedites NBI training and ensures the endoscopist’s surveillance interval recommendations are based solely on the ability to distinguish polyps.

Tu1157 Gastroenterology Trainees Can Perform Real Time Optical Diagnosis of Diminutive Colorectal Polyps Using Narrow Band Imaging

BACKGROUND Proposed clinical thresholds for optical diagnosis of colorectal polyps recommend ≥90% agreement between opticaland histopathology-based surveillance intervals, and ≥90% negative predictive value in the rectosigmoid colon. Experienced gastroenterologists have exceeded these thresholds in studies, but the performance of trainees is unknown. We aimed to prospectively assess real-time trainee performance of optical diagnosis of diminutive colorectal polyps. METHODS We studied the optical diagnoses of colorectal polyps using narrow band imaging (NBI) in gastroenterology trainees over a 9-month period during a prospective, randomized polyp detection tandem colonoscopy trial. Trainees viewed a computer-based learning module on NBI International Colorectal Endoscopic (NICE) classification and took a test that required minimum 90% accuracy prior to the study. For each polyp found at colonoscopy, trainees stated the diagnosis (neoplastic vs. non-neoplastic) and confidence level in the diagnosis (high vs. low), then removed and submitted it for histopathologic diagnosis. Central, blinded pathology was the reference standard. An optical diagnosis was high confidence if the polyp had at least one of the features of neoplasm or non-neoplasm and none of the features of the opposing diagnosis. Otherwise, low confidence

Sa1526 Newly Found Polyps After Removal of Diminutive Colorectal Polyps: Cold SNARE Polypectomy vs. Conventional Polypectomy

Sa1526 Newly Found Polyps After Removal of Diminutive Colorectal Polyps: Cold SNARE Polypectomy vs. Conventional Polypectomy

Mo1501 Attending Endoscopists and Gastroenterology (GI) Trainees Have Similar Performance When Characterizing Diminutive Colorectal Polyps With Narrow Band Imaging (NBI)

Mo1501 Attending Endoscopists and Gastroenterology (GI) Trainees Have Similar Performance When Characterizing Diminutive Colorectal Polyps With Narrow Band Imaging (NBI)

297 Characterization of Diminutive Colorectal Polyp Histology Using Narrow Band Imaging (NBI) by Attending Gastroenterologists: Effectiveness of a Novel Training Method

297 Characterization of Diminutive Colorectal Polyp Histology Using Narrow Band Imaging (NBI) by Attending Gastroenterologists: Effectiveness of a Novel Training Method

Tu1439 Resection of Diminutive Colorectal Polyps Comparing Hot SNARE, Cold SNARE and Cold Forceps Polypectomy. Results of a Randomized, Single Center Pilot Study

Tu1439 Resection of Diminutive Colorectal Polyps Comparing Hot SNARE, Cold SNARE and Cold Forceps Polypectomy. Results of a Randomized, Single Center Pilot Study

Current status and future perspectives of endoscopic diagnosis and treatment of diminutive colorectal polyps.

During colonoscopy, small and diminutive colorectal polyps are commonly encountered. It is estimated that at least one adenomatous polyp is detected in almost half of all patients undergoing screening colonoscopy. In contrast, the 'predict, resect, and discard' strategy for diminutive and small colorectal polyps is a current topic especially in Western countries. 'Is this an acceptable policy in Japan?' Herein, we report the results of a questionnaire survey with regard to the management of diminutive colorectal polyps, including the thoughts of Japanese endoscopists regarding the 'predict, resect, and discard' strategy. At the moment, we propose that this strategy should be used by skilled endoscopists only.

Natural history of diminutive colorectal polyps: long-term prospective observation by colonoscopy.

Endoscopic removal of colorectal adenomatous polyps effectively prevents cancer. However, the treatment strategy for diminutive polyps (diameter ≤ 5 mm) remains controversial. Understanding the natural history of diminutive polyps is a prerequisite to their effective management. We prospectively examined the natural history of diminutive polyps by long-term surveillance colonoscopy. A total of 207 polyps detected in 112 patients from December 1991 through March 2002 were studied. To avoid potential effects on size and morphological characteristics, all polyps were selected randomly and were followed without biopsy. Polyp size was estimated by comparing the lesion with the diameter of a biopsy forceps. Mean follow up was 7.8 years (SD, 4.8; range, 1.0-18.6; median, 7.5; interquartile range 3.4-11.2). Twenty-four polyps were resected endoscopically, and the histopathological diagnosis was mucosal high-grade neoplasia (Category 4) for one polyp, and mucosal low-grade neoplasia (Category 3) for 23 polyps. Mean linear size of the polyps was 3.2 mm (SD, 1.0; range, 1.3-5.0) at initial colonoscopy and 3.8 mm (SD 1.6; range 1.3-10.0) at final colonoscopy (P<0.01). Left-sided polyps showed a higher growth rate than right-sided polyps, and a type IIIL2 pit pattern was associated with a lower growth rate than a type IIIL1 pattern. We clarified the natural history of diminutive polyps by long-term follow-up colonoscopy. The benign course of diminutive polyps should be considered in the design of treatment strategies.

Current management of diminutive colorectal polyps in Taiwan.

The majority of polyps detected during colonoscopy are diminutive polyps, for which the cost of pathological analysis is substantial. In our analysis of a screening cohort of 10737 subjects undergoing screening colonoscopy, a total of 15877 neoplastic lesions were detected, of which 10816 (68.1%) were diminutive lesions. Of those diminutive lesions, 90 (0.83%) had a villous component, 14 (0.1%) had high-grade dysplasia, and none had invasive cancer. Only 1.3% of patients were advised to decrease their surveillance interval because of unfavorable histology. Laws regulating medical practice, uncertainty regarding the accuracy of endoscopic diagnosis of diminutive polyps outside of academic centers, and the relatively low cost of pathological analysis are among the barriers to adopting a 'resect and discard' practice in Taiwan.

Advanced imaging for detection and differentiation of colorectal neoplasia: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1 ESGE suggests the routine use of high definition white-light endoscopy systems for detecting colorectal neoplasia in average risk populations (weak recommendation, moderate quality evidence). 2 ESGE recommends the routine use of high definition systems and pancolonic conventional or virtual (narrow band imaging [NBI], i-SCAN) chromoendoscopy in patients with known or suspected Lynch syndrome (strong recommendation, low quality evidence). 2b ESGE recommends the routine use of high definition systems and pancolonic conventional or virtual (NBI) chromoendoscopy in patients with known or suspected serrated polyposis syndrome (strong recommendation, low quality evidence). 3 ESGE recommends the routine use of 0.1 % methylene blue or 0.1 % - 0.5 % indigo carmine pancolonic chromoendoscopy with targeted biopsies for neoplasia surveillance in patients with long-standing colitis. In appropriately trained hands, in the situation of quiescent disease activity and adequate bowel preparation, nontargeted, four-quadrant biopsies can be abandoned (strong recommendation, high quality evidence). 4 ESGE suggests that virtual chromoendoscopy (NBI, FICE, i-SCAN) and conventional chromoendoscopy can be used, under strictly controlled conditions, for real-time optical diagnosis of diminutive (≤ 5 mm) colorectal polyps to replace histopathological diagnosis. The optical diagnosis has to be reported using validated scales, must be adequately photodocumented, and can be performed only by experienced endoscopists who are adequately trained and audited (weak recommendation, high quality evidence). 5 ESGE suggests the use of conventional or virtual (NBI) magnified chromoendoscopy to predict the risk of invasive cancer and deep submucosal invasion in lesions such as those with a depressed component (0-IIc according to the Paris classification) or nongranular or mixed-type laterally spreading tumors (weak recommendation, moderate quality evidence). Advanced imaging techniques will need to be applied in specific patient groups in routine clinical practice and to be taught in endoscopic training programs.

Diminutive and Small Colorectal Polyps: The Pathologist's Perspective.

Recent progress in advanced endoscopic imaging and electronic chromoendoscopy allows the real-time endoscopic estimation of the histologic type of polyps, mainly for the differentiation of adenomas from hyperplastic polyps. Accordingly, a "resect-and-discard" strategy applied to diminutive colorectal polyps is now one of the emerging issues among gastroenterologists. The strategy has a practical advantage in terms of the potential cost savings. However, it has a number of limitations in the medical, academic, and legal aspects. The major pitfalls include the endoscopic investigation of colorectal polyps with a wide variety of histogenetic origins, including serrated polyps, and the lack of a standardized method for polyp size measurement. Another issue is the importance of the pathologic diagnosis for legal purposes and medical research. Moreover, it is not certain whether the implementation of the strategy has economic benefit in countries with an undervalued reimbursement system for pathologic examination. There is no doubt that a highly confident optical diagnosis of polyp type is a novel valuable tool. It can provide a more steady symbiosis between gastroenterologists and pathologists to allow a more evident diagnosis and management of patients with colorectal polyps.

Rate and Risk Factors of the Advanced Adenomas Among Diminutive Colorectal Polyps.

Only 49% of diminutive colorectal polyps are neoplastic, but a tiny percentage contains advanced histology. We aimed to determine the rate of advanced diminutive polyps and to evaluate the influence of age, gender, number, and localization. Patients undergoing a videocolonoscopy in October 2010 and April 2012 were collected prospectively. Subjects with polyps ≤5mm in diameter were recruited into the study. The presence of a villous component of >25% and a high degree of dysplasia were categorized as polyps with advanced histology. Two hundred eight diminutive polyps were identified in 102 patients. Twenty (9.6%) diminutive polyps in 13 (12.74%) patients showed advanced histology. The probability of having an advanced diminutive polyp was higher in patients who have more than one polyp or have polyps localized all along the colon or only to the distal part (p < 0.001 and p = 0.002). Having more than one polyp increases the likelihood of having advanced diminutive polyp according to a multivariate analysis (p = 0.003). Polyps accompanying any dysplastic diminutive polyp, being one of multiple polyps, and distributed all along the colon or localized to only the distal part have an increased probability of being an advanced diminutive polyp (p < 0.001, p = 0.047, p < 0.001, and p = 0.008). Multivariate logistic regression demonstrated that only any accompanying dysplastic diminutive polyp increases the probability of a polyp being advanced diminutive (p = 0.034). Diminutive polyps could have advanced histology. Multiple polyps located in the whole colorectum or to the distal part or accompanying any advanced polyps may harbor an advanced histology and should be removed.

Cold Snaring Better Than Forceps for Diminutive Polyps

There is a growing trend toward the use of resection methods without electrocautery for diminutive colorectal polyps. Use of cold snaring has become

Cold Snare Polypectomy Vs. Cold Forceps Polypectomy Using Double-Biopsy Technique for Removal of Diminutive Colorectal Polyps: A Prospective Randomized Study

There are few data on cold snare polypectomy (CSP) in direct comparison with cold forceps polypectomy (CFP) for colonoscopic resection of diminutive colorectal polyps (DCPs; ≤5 mm). The primary aim of this study was to compare the histologic polyp eradication rate of CSP with that of CFP using double-biopsy technique. This was a randomized controlled trial at a single academic hospital. Of the 165 patients invited, 54 consecutive patients having 117 eligible polyps were enrolled in this study. To evaluate histologic eradication of polyps, two or more additional biopsies were taken from the base and edges of the polypectomy site. The mean size of polyps was 3.66 mm (±1.13). Most polyps evaluated were tubular adenomas (69.9%). The rate of histologic eradication was significantly higher in the CSP group than in the CFP group (93.2% vs. 75.9%, P=0.009). The time taken for polypectomy was significantly shorter in the CSP group (14.29 vs. 22.03 s, P<0.001). Failure of tissue retrieval was noted in 6.8% of polyps resected by CSP. Multivariate analysis revealed that the method of polypectomy (CFP) and the polyp size (≥4 mm) were independent predictors associated with incomplete histologic eradication (odds ratio (OR) 4.750 (95% confidence interval (CI): 1.459-15.466), OR 4.375 (95% CI: 1.345-14.235); all P<0.05, respectively). CSP is superior to CFP for the endoscopic removal of DCPs with regard to completeness of polypectomy. CSP technique should be considered the primary method for endoscopic treatment of polyps in the 4-5-mm size range (ClinicalTrials.gov number: NCT01646242).

Clinical Practice Variation in the Management of Diminutive Colorectal Polyps: Results of a National Survey of Gastroenterologists

We investigated physician beliefs and behaviors regarding diminutive colorectal polyps and the contribution of these beliefs to variable detection rates. One hundred sixty-seven members of the American College of Gastroenterology took a Web-based survey. We compared respondents and nonrespondents using demographic and practice information from the American Medical Association Physician Masterfile. Respondents varied in their definition of diminutive polyps. Respondents acknowledged leaving diminutive polyps in place during colonoscopy in various scenarios. Years in practice, confidence in endoscopic histologic diagnosis, and never having seen advanced histology in a diminutive polyp were predictive of leaving polyps in place. The majority of respondents were at least somewhat agreeable to leaving diminutive polyps in place if guidelines endorsed this practice. Gastroenterologists vary in their removal of diminutive polyps. The results have implications for the interpretation and management of variable polyp detection rates.

Diminutive colorectal polyps—is narrow-band imaging ready for prime time?

Diminutive colorectal polyps—is narrow-band imaging ready for prime time?