Is forceps more useful than visualization for measurement of colon polyp size?

A novel nomogram for the prediction of perforation during endoscopic submucosal dissection for colorectal neoplasms

BACKGROUND

High perforation risk hinders the widespread adoption of ESD for colorectal neoplasms. This study was performed to determine the risk factors of colorectal endoscopic submucosal dissection (ESD)-induced perforation and develop a predictive model.

METHODS

A total of 1046 colorectal neoplasms in 1011 patients were retrospectively enrolled from January 2011 to December 2021, in a single tertiary center as the derivation cohort. We identified independent risk factors for perforation using univariate analysis and multi-variate logistic regression. A nomogram was developed based on the logistic regression model and prospectively applied to 266 colorectal neoplasms as the validation cohort. The performance of the predictive model was evaluated with the receiver operating characteristic curve, calibration plot, and decision curve analysis.

RESULTS

Independent pre-operative factors for colorectal ESD-induced perforation were tumor located in the left colon [odds ratio (OR) 2.39, P = 0.040], size ≥ 40 mm (OR 3.36, P < 0.001), ≥2/3 circumference (OR 7.55, P = 0.004), located across folds (OR 6.26, P < 0.001), and laterally spreading tumor (non-granular type, OR 2.34, P = 0.029; granular type, OR 2.46, P = 0.021). The nomogram model incorporating the pre-operative factors performed well in both the derivation and validation cohorts (areas under the curve of 0.750 and 0.806, respectively). Decision curve analysis demonstrated that the clinical benefit of the nomogram was favorable.

CONCLUSIONS

The novel nomogram, developed and prospectively validated, incorporating tumor size, location, and morphology can successfully predict perforation during ESD for colorectal neoplasms.

CT colonography has advantages over colonoscopy for size measurement of colorectal polyps

PURPOSE

The aim of this study was to compare the accuracy of colonoscopy (CS) and CT colonography (CTC) in the measurement of colorectal polyps using pathological size as a reference.

MATERIALS AND METHODS

The analysis included 61 colorectal polyps in 28 patients who underwent preoperative CTC at our institution. All polyps were endoscopically resected. Polyp sizes were measured by CS and CTC. Endoscopic polyp size was extracted from endoscopy records written by one of two endoscopists (A with 11 and B with 6 years of endoscopic experience, respectively), who estimated the size visually/categorically without any measuring devices. After matching the location, the polyp size was measured on CTC using manual three-dimensional (3D) measurement on a workstation. The sizes of resected polyps were also measured after pathological inspection. Differences of the polyp size between CTC and histology, and between CS and histology were compared using paired t tests. Differences in measurement between the two endoscopists were also analyzed.

RESULTS

The mean diameters of polyps measured using CS, CTC, and pathology were 10.5 mm, 9.2 mm, and 8.4 mm, respectively. There was a significant correlation between CS and pathology, as well as between CTC and pathology (both P < 0.0001). The correlation coefficient for CS (r = 0.86) was lower than that for CTC (r = 0.96). The correlations between CS and pathology for endoscopists A and B were 0.90 and 0.89, respectively.

CONCLUSION

Measurements of polyp size using CTC were closer to the pathological measurements compared to those by CS, which exhibited greater variability. This suggests that CTC may be more suitable for polyp size measurements in the clinical setting if patients undergo CTC concurrently with colonoscopy.

Patterns of Discordance Between Clinical and Pathologic Stage in Head and Neck Cancer

OBJECTIVE

To enhance understanding in patterns of discordance between clinical and pathological T and N staging in multiple sites of head and neck squamous cell cancer.

METHODS

A retrospective cohort of 580 newly diagnosed and surgically treated head and neck squamous cell carcinoma patients from a single institution over a 10-year period are presented. Clinical and pathologic staging are compared.

RESULTS

Notably, 33% of cases had staging discordance. Overall Cohen's kappa agreement was κ = 0.55 (moderate agreement). Highly discordant site stages with κ < 0.45 included: T2 oral cavity, T2 oropharynx, T3 larynx, and N1 lymph node. T2-4 oral cavity cancers were often overstaged, and more than one-third of T3 larynx cancers were understaged. Highly concordant site stages with κ>0.65 included: T1 larynx, T4 oropharynx, N0 lymph node, and N3 lymph node.

CONCLUSION

There exists a quantifiable and, in certain sites, clinically relevant pattern of discordance between clinical and pathologic staging. Tumor board multidisciplinary evaluation can highlight these discrepancies and aide in limiting effects on treatment decisions. However, discordant staging can affect the interpretation and application of prognostication, treatment, and data accuracy. Further investigation is warranted to improve clinical staging accuracy in areas of highest discordance.

LEVEL OF EVIDENCE

3 Laryngoscope, 2024.

A Preclinical Blinded Randomized-Controlled Trial Evaluating the Clinical Relevance of Polyp Size Measurement Using a Virtual Scale Endoscope

Background

The virtual scale endoscope (VSE) helps endoscopists measure colorectal polyp size more accurately compared to visual assessment (VA). However, previous studies were not adequately powered to evaluate the sizing of polyps at clinically relevant size thresholds and relative accuracy for size subgroups.

Methods

We created 64 artificial polyps of varied sizes and Paris class morphology, randomly assigned 1:1 to be measured (383 total measurement datapoints with VSE and VA by 6 endoscopists blinded to true size) in a colon model. We added data from two previous trials (480 measurement datapoints). We evaluated for correct classification of polyps into size groups at 3 mm, 5 mm, 10 mm, and 20 mm size thresholds and the relative size measurement accuracy for diminutive polyps (≤5 mm), small polyps (5-9 mm), large polyps at 10-19 mm, and polyps (≥20).

Results

VSE had significantly less size group misclassifications at the 5 mm, and 10 mm thresholds (28 percent vs. 45 percent, P = 0.0159 and 26 percent vs. 44 percent, P = 0.0135, respectively). For the 3 mm and 20 mm thresholds, VSE had lower misclassifications; however, this was not statistically significant (36 percent vs. 46 percent, P = 0.3853 and 38 percent vs. 41 percent, P = 0.2705, respectively). The relative size measurement accuracy was significantly higher for VSE compared to VA for all size subgroups (diminutive (P < 0.01), small polyps (P < 0.01), 10-19 mm (P < 0.01), and ≥20 mm (P < 0.01)).

Conclusion

VSE outperforms VA in categorizing polyps into size groups at the clinically relevant size thresholds of 5 mm and 10 mm. Using VSE resulted in significantly higher relative measurement accuracy for all size subgroups.

Accuracy in Polyp Size Measurement Among Surgeons, Gastroenterologists, Trainees, and Experts: A Prospective Video-Based Study

INTRODUCTION

Polyp size determination plays an important role in endoscopic decision making and follow-up determination. However, there is a lack of knowledge of endoscopist accuracy for polyp sizing and efficacy of available tools for size measurement. Our aim was to compare the accuracy of visual assessment, snare, forceps, and virtual scale endoscope (VSE) in estimating polyp size among a diverse group of endoscopists.

METHODS

We conducted a prospective video-based study. One hundred twenty polyps measured and recorded along with all available measurement tools were randomized to visual assessment, snare, forceps, or VSE group. Eleven endoscopists conducted video-based measurement using the randomized measurement tool. Primary outcome was relative accuracy in polyp size measurement compared with caliper measurement immediately postresection.

RESULTS

One thousand three hundred twenty measurements were performed. VSE had statistically significantly higher relative accuracy when compared to forceps (79.3 vs 71.3%; P < 0.0001). Forceps had statistically significantly higher relative accuracy when compared to visual assessment (71.3 vs 63.6%; P = 0.0036). There was no statistically significant difference when comparing visual assessment and snare-based measurements (63.6 vs 62.8%; P = 0.797). Overall, 21.5% of polyps >5 mm were misclassified as ≤5 mm and 17.3% of polyps ≥10 mm were misclassified as <10 mm. VSE had the lowest percentage of polyps >5 mm misclassified as ≤5 mm (2.6%), polyps ≤5 mm misclassified as >5 mm (5.1%), and polyps <10 mm misclassified as ≥10 mm (1.7%).

DISCUSSION

Visual size estimation of polyps is inaccurate independently of training level, sex, and specialty. Size measurement accuracy can be improved using forceps and yields the highest relative accuracy when an adaptive scale technology is used.

Cold polypectomy techniques for small and diminutive colorectal polyps: a systematic review and network meta-analysis of randomized controlled trials

OBJECTIVE

In the management of small and diminutive polyps, cold polypectomy is favored over electrocautery polypectomy. However, the optimal cold polypectomy technique is still controversial. Hence, this review aims to investigate the most effective cold technique for small and diminutive colorectal polyps.

METHODS

We conducted a systematic review and network meta-analysis synthesizing randomized controlled trials (RCTs) which were retrieved by systematically searching PubMed, EMBASE, Web of Science, SCOPUS, and Cochrane through 10 February 2023. R software, (R version 4.2.0) and meta-insight software were used to pool dichotomous outcomes using risk ratio (RR) presented with the corresponding confidence interval (CI). Our protocol was prospectively published in PROSPERO with ID: CRD42022345619.

RESULTS

Nineteen RCTs with 3649 patients and 4800 polyps were included in our analysis. Cold techniques (cold forceps polypectomy (CFP), jumbo forceps polypectomy (JFP), dedicated cold snare polypectomy (D-CSP), conventional cold snare polypectomy (C-CSP), underwater cold snare polypectomy (U-CSP), and cold snare endoscopic mucosal resection (CS-EMR) were included in our comparative analysis. CFP was less effective in achieving complete histological resection than C-CSP (RR: 1.10 with 95% CI [1.03-1.18]), CS-EMR (RR: 1.12 with 95% CI [1.02-1.23]), D-CSP (RR: 1.17 with 95% CI [1.04-1.32]), and U-CSP (RR: 1.21 with 95% CI [1.07-1.38]). However, the rest of the comparisons showed no difference.

CONCLUSION

CFP is the least effective method for small and diminutive polyps' removal, and any snare polypectomy technique will achieve better results, warranting more large-scale RCTs to investigate the most effective snare polypectomy technique.

Comparing size measurement of colorectal polyps using a novel virtual scale endoscope, endoscopic ruler or forceps: A preclinical randomized trial

Background and study aims  Accurate polyp size measurement is important for guideline conforming choice of polypectomy techniques and subsequent surveillance interval assignments. Some endoscopic tools (biopsy forceps [BF] or endoscopic rulers [ER]) exist to help with visual size estimation. A virtual scale endoscope (VSE) has been developed that allows superimposing a virtual measurement scale during live endoscopies. Our aim was to evaluate the performance of VSE when compared to ER and BF-based measurement. Methods  We conducted a preclinical randomized trial to evaluate the relative accuracy of size measurement of simulated colorectal polyps when using: VSE, ER, and BF. Six endoscopists performed 60 measurements randomized at a 1:1:1 ratio using each method. Primary outcome was relative accuracy in polyp size measurement. Secondary outcomes included misclassification of sizes at the 5-, 10-, and 20-mm thresholds. Results  A total of 360 measurements were performed. The relative accuracy of BF, ER, and VSE was 78.9 % (95 %CI = 76.2-81.5), 78.4 % (95 %CI = 76.0-80.8), and 82.7 % (95 %CI = 80.8-84.8). VSE had significantly higher accuracy compared to BF ( P  = 0.02) and ER ( P  = 0.006). VSE misclassified a lower percentage of polyps > 5 mm as ≤ 5 mm (9.4 %) compared to BF (15.7 %) and ER (20.9 %). VSE misclassified a lower percentage of ≥ 20 mm polyps as < 20 mm (8.3 %) compared with BF (66.7 %) and ER (75.0 %). Of polyps ≥10mm, 25.6 %, 25.5 %, and 22.5 % were misclassified as <10 mm with ER, BF, and VSE, respectively. Conclusions  VSE had significantly higher relative accuracy in measuring polyps compared to ER or BF assisted measurement. VSE improves correct classification of polyps at clinically important size thresholds.

JAG consensus statements for training and certification in colonoscopy

Introduction

In the UK, endoscopy certification is awarded when trainees attain minimum competency standards for independent practice. A national evidence-based review was undertaken to update and develop standards and recommendations for colonoscopy training and certification.

Methods

Under the oversight of the Joint Advisory Group (JAG), a modified Delphi process was conducted between 2019 and 2020 with multisociety expert representation. Following literature review and Grading of Recommendations, Assessment, Development and Evaluations appraisal, recommendation statements on colonoscopy training and certification were formulated and subjected to anonymous voting to obtain consensus. Accepted statements were peer reviewed by JAG and relevant stakeholders for incorporation into the updated colonoscopy certification pathway.

Results

In total, 45 recommendation statements were generated under the domains of: definition of competence (13), acquisition of competence (20), assessment of competence (8) and postcertification support (4). The consensus process led to revised criteria for colonoscopy certification, comprising: (1) achieving key performance indicators defined within British Society of Gastroenterology standards (ie, unassisted caecal intubation rate >90%, rectal retroversion >90%, polyp detection rate >15%+, polyp retrieval rate >90%, patient comfort <10% with moderate–severe discomfort); (2) minimum procedure count 280+; (3) performing 15+ procedures over the preceding 3 months; (4) attendance of the JAG Basic Skills in Colonoscopy course; (5) terminal ileal intubation rates of 60%+ in inflammatory bowel disease; (6) satisfying requirements for formative direct observation of procedure skills (DOPS) and direct observation of polypectomy skills (Size, Morphology, Site, Access (SMSA) level 2); (7) evidence of reflective practice as documented on the JAG Endoscopy Training System reflection tool; (8) successful performance in summative DOPS.

Conclusion

The UK standards for training and certification in colonoscopy have been updated, culminating in a single-stage certification process with emphasis on polypectomy competency (SMSA Level 2+). These standards are intended to support training, improve standards of colonoscopy and polypectomy, and provide support to the newly independent practitioner.

Comparing size measurements of simulated colorectal polyp size and morphology groups when using a virtual scale endoscope or visual size estimation: Blinded randomized controlled trial

OBJECTIVES

The virtual scale endoscope (VSE) allows projection of a virtual scale onto colorectal polyps allowing real-time size measurements. We studied the relative accuracy of VSE compared to visual assessment (VA) for the measuring simulated polyps of different size and morphology groups.

METHODS

We conducted a blinded randomized controlled trial using simulated polyps within a colon model. Sixty simulated polyps were evenly distributed across four size groups (1-5, >5-9.9, 10-19.9, and ≥20 mm) and three Paris morphology groups (flat, sessile, and pedunculated). Six endoscopists performed polyp size measurements using random allocation of either VA or VSE.

RESULTS

A total of 359 measurements were completed. The relative accuracy of VSE was significantly higher when compared to VA for all size groups >5 mm (P = 0.004, P < 0.001, P < 0.001). For polyps ≤5 mm, the relative accuracy of VSE compared to VA was not significantly higher (P = 0.186). The relative accuracy of VSE was significantly higher when compared to VA for all morphology groups. VSE misclassified a lower percentage of >5 mm polyps as ≤5 mm (2.9%), ≥10 mm polyps as <10 mm (5.5%), and ≥20 mm polyps as <20 mm (21.7%) compared to VA (11.2%, 24.7%, and 52.3% respectively; P = 0.008, P < 0.001, and P = 0.003).

CONCLUSION

Virtual scale endoscope had significantly higher relative accuracies for every polyp size group or morphology type aside from diminutive. VSE enables the endoscopist to better classify polyps into correct size categories at clinically relevant size thresholds of 5, 10, and 20 mm.

Factors influencing endoscopic estimation of colon polyp size in a colon model

BACKGROUND/AIMS

Colorectal polyps are removed to prevent progression to colorectal cancer. Polyp size is an important factor for risk stratification of malignant transformation. Endoscopic size estimation correlates poorly with pathological reports and several factors have been suggested to influence size estimation. We aimed to gain insight into the factors influencing endoscopic polyp size estimation.

METHODS

Images of polyps in an artificial model were obtained at 1, 3, and 5 cm from the colonoscope's tip. Participants were asked to estimate the diameter and volume of each polyp.

RESULTS

Fifteen endoscopists from three large-volume centers participated in this study. With an intraclass correlation coefficient of 0.66 (95% confidence interval [CI], 0.62-0.71) for diameter and 0.56 (95% CI, 0.50-0.62) for volume. Polyp size estimated at 3 cm from the colonoscope's tip yielded the best results. A lower distance between the tip and the polyp was associated with a larger estimated polyp size.

CONCLUSION

Correct endoscopic estimation of polyp size remains challenging. This finding can affect size estimation skills and future training programs for endoscopists.

Endoscopic Recognition and Classification of Colorectal Polyps

Colonoscopy allows the performing endoscopist to thoroughly evaluate superficial colon lesions based on morphologic features such as size, location, shape, and surface pattern and also perform endoscopic resection where appropriate. Different elements of polyp characterization have been incorporated into systems that standardize this evaluation process and elucidate the likelihood of submucosal invasion or malignancy. Lesions which have invaded the submucosa are more likely to metastasize and are often not appropriate for endoscopic resection. It is, therefore, essential for the proceduralist to understand the multiple elements of lesion characterization and how they fit into the existing classification schemes.

Regular endoscopic surveillance and polypectomy is effective in managing rectal adenoma progression following colectomy and ileorectal anastomosis in patients with familial adenomatous polyposis

AIM

Total colectomy with ileorectal anastomosis (TC-IRA) is a surgical option for patients with familial adenomatous polyposis (FAP). Regular endoscopic surveillance of the rectum is recommended to prevent rectal cancer. We aimed to document polyp progression in the rectum following TC-IRA and evaluate the role of polypectomy during surveillance.

METHOD

Patients with FAP who underwent TC-IRA between 1990 and 2017 were identified. Demographic, endoscopic and genetic data were retrieved. Cumulative rectal adenoma (polyp) counts were obtained, whilst accounting for any polypectomies during the study period. The rate of polyp progression and factors influencing secondary proctectomy were evaluated.

RESULTS

One hundred and ninety-nine patients fulfilled our inclusion criteria, of which 44% were male. The median age at colectomy was 19 (range 11-70) years and median preoperative rectal polyp count was 7 (range 0-50). All patients had an APC pathogenic variant, of which 151 (79%) were 5' of the mutation cluster region (MCR), 19 (10%) in the MCR, six (3%) were 3' of the MCR and 15 (8%) had a gross deletion. After a median follow-up of 8.6 (range1-27) years and a median of 11 (range 2-37) flexible sigmoidoscopies per patient, the median rate of polyp progression was 5.5 polyps/year (range 0-70.2). There was no evidence of polyp regression. Eight (4%) patients underwent secondary proctectomy for neoplasia, of which one (0.5%) had rectal adenocarcinoma. A total of 13,527 polyps were removed, a median of 35 polyps/patient (range 0-829). The rate of polyp progression was not significantly associated with genotypic or phenotypic factors.

CONCLUSION

Progression of rectal adenoma burden following TC-IRA appears to be slow and dependent on the length of follow-up. In the modern era of stringent endoscopic surveillance and therapeutic procedures such as cold snare polypectomy, the rate of secondary proctectomy and the risk of rectal cancer after TC-IRA are very low. These findings are important when counselling patients with regard to the choice of surgery for FAP and implementing endoscopic surveillance.

Construction of a novel predictive nomogram for difficult procedure of endoscopic submucosal dissection for colorectal neoplasms

OBJECTIVES

To determine the predictors of difficult colorectal endoscopic submucosal dissection (ESD) and to develop a preoperative predictive model for difficult colorectal ESD procedures.

METHODS

Colorectal neoplasms intended to be resected by ESD in our center between August 2013 and February 2019 were retrospectively enrolled. An ESD procedure which took more than 30 min, failed to remove the lesions en bloc or converted to surgery was defined as difficulty. Logistic regression analysis was conducted to find out the predictors of difficult ESD. A nomogram integrating independent predictors was developed and validated with respect to its discrimination, calibration and clinical application, using the receiver operating characteristic (ROC) curve, calibration plot and decision curve analysis (DCA), respectively.

RESULTS

A total of 368 colorectal neoplasms in 355 patients were included. The independent predictors for difficult colorectal ESD were size ≥2 cm (odds ratio [OR] = 6.102, p < .001), positive non-lifting sign (OR = 6.569, p = .005), lesions located in left colon (OR = 2.475, p = .036) or rectum (OR = 2.183, p = .048), laterally spreading tumors (LSTs) (OR = 2.501, p = .008) and less colorectal ESD experience (≤20 cases) (OR = 2.3091, p = .028). The nomogram model incorporating the above predictors performed well in both of the training and validation sets (area under the cure [AUC] = 0.786 and 0.784, respectively). DCA demonstrated the clinical benefit of the nomogram was superior to that of each independent predictor alone.

CONCLUSIONS

The nomogram incorporating tumor size, location, morphology, non-lifting sign and ESD experience of operator can be conveniently used to facilitate the preoperative prediction of difficult colorectal ESD.

Factors associated with inaccurate size estimation of colorectal polyps: A multicenter cross-sectional study

BACKGROUND AND AIM

Accurate polyp size estimation is essential in deciding the therapeutic strategy of colorectal polyps and endoscopic surveillance intervals. However, many endoscopists frequently make incorrect size estimations without being aware of their errors. This cross-sectional study aimed to clarify the characteristics of endoscopists associated with inaccurate estimation.

METHODS

We previously conducted a web trial involving 261 endoscopists in 51 institutions in Japan to assess their ability to estimate polyp size. Participants answered questions about polyp size using visual estimates in a test involving images of 30 polyps. Here, we investigated the relationships between inaccurate size estimation and the backgrounds of participants. The rates of overestimation and underestimation of polyp size were also compared to clarify any trends in the answers of participants with low accuracy (< 50%).

RESULTS

Multivariable logistic regression analysis revealed that the number of colonoscopic procedures in the past year was the only factor associated with a low accuracy of polyp size estimation (odds ratio 0.750, 95% confidence interval 0.609-0.925; P = 0.007). Endoscopists with low accuracy had a greater tendency to overestimate polyp size (42.3% overestimation and 21.2% underestimation, P < 0.001) compared with other endoscopists (16.6% overestimation and 17.9% underestimation, P = 0.951).

CONCLUSIONS

Endoscopists with limited experience of colonoscopy in the past year were more likely to make frequent errors in size estimation. Furthermore, endoscopists making inaccurate size estimations had a propensity to overestimate polyp size.

Usefulness of a Colonoscopy Cap with an External Grid for the Measurement of Small-Sized Colorectal Polyps: A Prospective Randomized Trial

Accurate measurement of polyp size during colonoscopy is crucial. The usefulness of cap-assisted colonoscopy and external grid application on monitor (gCAP) was evaluated for polyp size measurement in this 3-year, single-center, single-blind, randomized trial. Using the endoscopic forceps width as reference, the discrepancy percent (DP), error rate (ER), and measurement time were compared between gCAP and visual estimation (VE) after randomization. ER was calculated within a 20% and 33% limit. From the 111 patients, 280 polyps were measured. The mean polyp sizes were 4.0 ± 1.7 mm and 4.2 ± 1.8 mm with gCAP and VE, respectively (p = 0.368). Compared with that by the forceps method, DP was significantly lower in the gCAP group than in the VE group. Moreover, ER was significantly lower in the gCAP group within its preset limit. The measurement time was 4 s longer in the gCAP group than in the VE group (8.2 ± 4.8 s vs. 4.2 ± 1.5 s; p < 0.001). However, the forceps method lasted 28 s longer than the others. On subgroup analysis by size, gCAP was more accurate for polyp size ≥ 5 mm. The gCAP method was more accurate for polyp size measurement than VE, especially for polyps ≥ 5 mm, and was more convenient than the forceps method.

White light and/or magnifying endoscopy with narrow band imaging for superficial nonampullary duodenal epithelial tumors

BACKGROUND AND AIM

A reliable optical diagnosis of superficial nonampullary duodenal epithelial tumors (SNADETs) to guide optimal treatment strategy is lacking. The aim of this study was to simulate the treatment outcomes based on optical diagnosis using white light imaging (WLI) or magnifying endoscopy with narrow band imaging (MNBI) and to evaluate the method to extract optimal lesions suitable for cold snare polypectomy (CSP) or not.

METHODS

We created a decision tree model using WLI and MNBI diagnosis for ideal treatment for SNADETs. Optical diagnoses of Vienna category 3 lesions (C3), category 4/5 (C4/5) were defined based on the WLI scoring system or the MNBI pattern diagnosis. Ideal treatments were CSP for C3 < 10mm, and endoscopic mucosal resection, endoscopic submucosal dissection or surgery for lesions ≥10mm or C4/5. Ideal treatment results based on optical diagnosis were analyzed according to actual pathological results.

RESULTS

A total of 218 lesions with pre-operative diagnosis of SNADETs were included for analysis. Percentage of ideal treatment for C3 < 10mm based on WLI or MNBI or both was 88%, 83% and 97%. When WLI and MNBI diagnoses predicted the same histology, the specificity, positive predictive value and accuracy were significantly higher than those of WLI or MNBI alone (p < .05).

CONCLUSIONS

A decision tree model using lesion diameter, WLI scoring and MNBI pattern diagnosis is hypothetically useful to select ideal lesions for CSP among SNADETs. Optical diagnosis using both WLI and MNBI is more useful than WLI or MNBI alone.

Polyp Progression in Paediatric Patients With Familial Adenomatous Polyposis: A Single-centre Experience

OBJECTIVES

Prophylactic colectomy at a premalignant stage is the cornerstone of management of familial adenomatous polyposis (FAP). Before surgery, colonoscopy surveillance is recommended in children with FAP. This study aimed to examine the natural history of FAP in children by evaluating adenoma progression and factors influencing timing of colectomy.

METHOD

Patients with FAP younger than 18 years at first surveillance colonoscopy and who had undergone more than 1 colonoscopy were identified. Demographic, endoscopic, genetic, and surgical data were retrieved. Cumulative adenoma (polyp) counts were obtained while accounting for any polypectomies during the study period. The rate of polyp progression and factors influencing the timing of colectomy were evaluated.

RESULTS

Eighty-four patients (50% boys; mean age at first colonoscopy 13 years [standard deviation 1.97]) were identified, of which 83 had a family history of FAP. At first colonoscopy, 67 (79%) had <100 adenomas and 29 (35%) had colonic polyps identified despite rectal sparing. The median rate of polyp progression per patient was 12.5 polyps/year (range 0-145). Of the 45 (54%) patients who had undergone surgery, 41 (91%) underwent colectomy with ileorectal or ileodistal sigmoid anastomosis. Polyp progression did not alter the choice of surgical intervention in any patient.

CONCLUSION

Our results suggest that adenoma number remains relatively stable in the majority of children under surveillance. Tailored surveillance intervals according to phenotype are a more appropriate strategy as recommended by recently published guidelines.

Risk of developing metachronous advanced colorectal neoplasia after resection of low-risk diminutive versus small adenomas

BACKGROUND AND AIMS

Current postpolypectomy guidelines classify 1 to 2 diminutive (1-5 mm) nonadvanced adenomas (NAAs) and 1 to 2 small (6-9 mm) NAAs as low-risk adenomas and recommend the same surveillance interval for both lesions. We compared the risk of metachronous advanced colorectal neoplasia (ACRN) for both groups.

METHODS

We studied 8602 patients who underwent removal of ≥1 NAA and follow-up colonoscopic surveillance. Patients were categorized into 4 groups based on size and number of baseline NAAs: group 1, ≤2 diminutive NAAs (n = 6379); group 2, ≤2 small NAAs (n = 1672); group 3, ≥3 diminutive NAAs (n = 293); and group 4, ≥3 small NAAs (n = 258). Size was classified based on the largest NAA.

RESULTS

The 5-year cumulative incidence rates of metachronous ACRN in groups 1, 2, 3, and 4 were 2.7%, 5.1%, 10.7%, and 15.1%, respectively. Groups 2, 3, and 4 had a higher risk of metachronous ACRN than group 1. Compared with group 1, the adjusted hazard ratios for metachronous ACRN were 2.06 (95% confidence interval [CI], 1.46-2.91) for group 2, 2.75 (95% CI, 1.53-4.96) for group 3, and 4.49 (95% CI, 2.62-7.70) for group 4. However, the risk of metachronous ACRN was not significantly different between groups 3 and 4 (adjusted hazard ratio, 1.62; 95% CI, .76-3.44).

CONCLUSIONS

Among patients with ≤2 NAAs, patients with 1- to 5-mm NAAs had a lower risk of metachronous ACRN than those with 6- to 9-mm NAAs. The guidelines should consider extending surveillance intervals in patients with ≤2 diminutive NAAs.

British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England post-polypectomy and post-colorectal cancer resection surveillance guidelines

These consensus guidelines were jointly commissioned by the British Society of Gastroenterology (BSG), the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and Public Health England (PHE). They provide an evidence-based framework for the use of surveillance colonoscopy and non-colonoscopic colorectal imaging in people aged 18 years and over. They are the first guidelines that take into account the introduction of national bowel cancer screening. For the first time, they also incorporate surveillance of patients following resection of either adenomatous or serrated polyps and also post-colorectal cancer resection. They are primarily aimed at healthcare professionals, and aim to address:Which patients should commence surveillance post-polypectomy and post-cancer resection?What is the appropriate surveillance interval?When can surveillance be stopped? two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument provided a methodological framework for the guidelines. The BSG's guideline development process was used, which is National Institute for Health and Care Excellence (NICE) compliant.two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps The key recommendations are that the high-risk criteria for future colorectal cancer (CRC) following polypectomy comprise either:two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps This cohort should undergo a one-off surveillance colonoscopy at 3 years. Post-CRC resection patients should undergo a 1 year clearance colonoscopy, then a surveillance colonoscopy after 3 more years.

Should we use papilla morphology to estimate the size of the terminal common bile duct during endoscopic retrograde cholangiopancreatography?

OBJECTIVE

A small common bile duct (CBD) diameter has been associated with complications and with a difficult biliary cannulation. Previous studies suggested that this diameter can be predicted during the endoscopic retrograde cholangiopancreatography (ERCP) simply by observing the papillary morphology. Despite this published suggestion there is no study addressing this topic. This study evaluated a possible association between the morphology of the major papilla and the diameter of the terminal CBD (t-CBD).

METHODS

Observational cross-sectional study including consecutive patients with naïve papillae was referred for ERCP in two affiliated university hospitals. The transverse (p-transv) and longitudinal measures (p-long) of the papilla were obtained using a visual method. Papillae were classified into nonprominent, prominent, bulging or other. The t-CBD was measured 1 cm from the papilla using fluoroscopic images in prone/supine. Measurements were performed by two senior endoscopists and outcomes were evaluated using correlation and linear regression model.

RESULTS

We included 245 patients with a median age of 76 years. The median p-transv for each type of papillae was as follows: nonprominent = 6 mm, prominent = 9 mm, bulging = 15 mm and other = 6 mm; P < 0.001. The median t-CBD for nonprominent = 7.62 mm, prominent = 8.34 mm, bulging = 8.60 mm and other = 8.52 mm; P = 0.40. The correlation between the transverse and longitudinal measures of papilla and the t-CBD were 0.0092 and 0.0614, respectively. In the regression model, the t-CBD diameter was not explained by papilla's size or morphology (R = 1.70%; P = 0.80).

CONCLUSION

The morphology of the papilla must not be used as a predictor of the diameter of the CBD as there is no correlation between these two items.

Risk of Developing Metachronous Advanced Colorectal Neoplasia After Polypectomy in Patients With Multiple Diminutive or Small Adenomas

INTRODUCTION

Current post-polypectomy guidelines recommend a 3-year surveillance interval for ≥3 nonadvanced adenomas (NAAs) without discrimination between diminutive (1-5 mm) and small (6-9 mm) adenomas. We compared the risk of metachronous advanced colorectal neoplasia (ACRN) among these groups.

METHODS

We studied 9,733 patients who underwent ≥1 adenoma removal and follow-up colonoscopic surveillance. Patients were classified based on baseline adenoma characteristics: group 1, 1-2 NAAs (n = 8,051); group 2, ≥3 diminutive NAAs (n = 293); group 3, ≥3 small NAAs (n = 258); and group 4, advanced adenomas (AAs) (n = 1,131).

RESULTS

The mean age of the study population was 45.8 ± 8.2 years. In group 4, most patients (94.5%) had 1 AA. The 3- and 5-year cumulative incidence rates of metachronous ACRN in groups 1, 2, 3, and 4 were 0.9%, 2.8%, 3.5%, and 4.0% and 3.1%, 10.7%, 15.1%, and 8.5%, respectively. Groups 2, 3, and 4 had a higher risk of metachronous ACRN than group 1. Compared with those for group 1, adjusted hazard ratios (95% confidence interval) for metachronous ACRN were 2.07 (1.16-3.68), 3.29 (1.94-5.56), and 2.73 (2.00-3.72) for groups 2, 3, and 4, respectively. However, this relationship was statistically insignificant between groups 2, 3, and 4. Compared with those for group 2, adjusted hazard ratios (95% confidence intervals) for groups 3 and 4 were 1.59 (0.76-3.30) and 1.32 (0.72-2.42), respectively, and 0.83 (0.47-1.46) for group 4 compared with group 3. The results of patients aged ≥50 years were identical to those of all patients.

DISCUSSION

Risk of metachronous ACRN was not different between patients aged ≥50 years who underwent polypectomy of ≥3 diminutive NAAs, ≥3 small NAAs, and AA, thus supporting current guidelines that recommend a uniform surveillance interval for these lesions.

Comparison of Underwater vs Conventional Endoscopic Mucosal Resection of Intermediate-Size Colorectal Polyps

BACKGROUND & AIMS

Endoscopic mucosal resection (EMR) with submucosal injection is an established method for removing colorectal polyps, although the en bloc resection rate decreases when polyp size exceeds 10 mm. Piecemeal resection increases local recurrence. Underwater EMR (UEMR) is an effective technique for removal of sessile colorectal polyps and we investigated whether it is superior to conventional EMR (CEMR).

METHODS

We conducted a multicenter randomized controlled trial at 5 institutions in Japan. Patients with endoscopically diagnosed, intermediate-size (10-20 mm) sessile colorectal lesions were randomly assigned to undergo UEMR or CEMR. Only the most proximal lesion was registered. The UEMR procedure included immersion of the entire lumen in water and snare resection of the lesion without submucosal injection of normal saline. We analyzed outcomes of 108 colorectal lesions in the UEMR group and 102 lesions in the CEMR group. R0 resection was defined as en bloc resection with a histologically confirmed negative resection margin. The primary endpoint was the difference in the R0 resection rates between groups.

RESULTS

The proportions of R0 resections were 69% (95% confidence interval [CI] 59%-77%) in the UEMR group vs 50% (95% CI 40%-60%) in the CEMR group (P = .011). The proportions of en bloc resections were 89% (95% CI 81%-94%) in the UEMR group vs 75% (95% CI 65%-83%) in the CEMR group (P = .007). There was no significant difference in median procedure time (165 vs 175 seconds) or proportions of patients with adverse events (2.8% in the UEMR group vs 2.0% in the CEMR group).

CONCLUSIONS

In a multicenter randomized controlled trial, we found that UEMR significantly increased the proportions of R0 resections for 10- to 20-mm sessile colorectal lesions without increasing adverse events or procedure time. Use of this procedure should be encouraged. Trials registry number: UMIN000018989.

Reproducibility and accuracy of visual estimation of polyp size in large colorectal polyps

BACKGROUND

Previous studies indicate that visual size estimation (in situ) of polyp size tends to differ from postfixation measurements, which effects allocation to surveillance intervals. Little is known about interobserver variation of in-situ measurements of large polyps. The primary objective was to assess interobserver variation of in situ measurements of large colorectal polyps. Secondary objectives were the agreement of in situ measurements with postfixation measurements, and the agreement on detection of ≥20 mm polyps between these measurements.

MATERIAL AND METHODS

Interobserver variability of in situ polyp size measurements was assessed between a diagnostic colonoscopy and the secondary therapeutic colonoscopy by dedicated endoscopists, in patients that were referred for an advanced polypectomy. After excision pre- and postfixation polyp sizes were measured with a ruler in three dimensions.

RESULTS

A total of 40 patients, with 45 polyps, were included in the study. The average difference between the two in situ measurements was 2.4 mm (95% confidence interval (CI): -0.4-5.2). The differences between the first in situ, second in situ and pre-fixation measurement in comparison to postfixation measurements were 1.8 mm (95% CI: -1.2-4.9), 0.1 mm (95% CI: -1.5-1.8) and 1.0 mm (95% CI: -0.2-2.2). Cohen's Kappa on detection of ≥20 mm polyps in agreement with postfixation measurements was 0.65 in the primary and 0.88 in the secondary in situ measurements.

CONCLUSION

This study shows a variation between in situ size measurements of large polyps. Improvements in daily clinical routines can be made by using an instrument to compare polyp size with and refraining from rounding sizes up or down. A randomized controlled trial assessing which instruments should be used for in-situ measurements of large polyps is warranted, in order to optimize size measurements of large colorectal polyps.

Intra and inter-observer agreement on polyp detection in colon capsule endoscopy evaluations

Background

Colon capsule endoscopy is a promising technique for evaluation of the colon, but its reproducibility is still unknown.

Objective

This study assesses intra and inter-observer agreement in evaluations of colon capsule endoscopy videos.

Methods

Forty-two complete colon capsule endoscopy investigations were analysed by three experts and two beginners. Intra-observer agreement was assessed in paired readings of two experts and two beginners. Agreement was determined by the intraclass correlation coefficient: poor (<0.5), moderate (0.5-0.75), good (0.75-0.9) and excellent (>0.9).

Results

Agreement on 'indication for a following colonoscopy' based on the number and size of detected polyps and bowel cleansing quality was poor among all observers. Agreement among experts on the detection of large polyps and number of polyps was moderate, but agreement on bowel cleansing quality was poor. Beginners were in moderate agreement with the experts on polyp detection. Intra-observer agreement in experts was moderate to excellent for the detection of large polyps (≥10 mm), excellent for the number of polyps, and poor to moderate for bowel cleansing quality. Intra-observer agreement in beginners was poor to moderate for all variables.

Conclusions

This study shows a poor agreement on 'indication for a following colonoscopy', but a high intra and inter-observer agreement for polyp detection among experts, as well as a moderate agreement between beginners and experts.Trial registration: NCT02303756.

Mis-sizing of Adenomatous Polyps is Common among Endoscopists and Impacts Colorectal Cancer Screening Recommendations

Background/Aims

To determine the accuracy of identifying ≥6-mm adenomatous polyps during colonoscopy and define its impact on subsequent interval screening.

Methods

We conducted a retrospective study of patients who underwent colonoscopies at Banner University Medical Center, Tucson from 2011 to 2015. All patients with ≥6-mm adenomatous polyps based on their colonoscopy report were included. Adenomatous polyps were excluded if they did not meet the criteria. Discrepancies in the polyp size were determined by calculating the percentage of size variation (SV). Clinical mis-sizing was defined as SV >33%.

Results

The polyps analyzed were predominantly <10 mm in size. Approximately 13% of the examined polyps met the inclusion criteria, and 40.7% of the adenomas were ≥10 mm. A total of 189 ≥6-mm adenomatous polyps were collected from 10 different gastroenterologists and a colorectal surgeon. Adenomatous polyps were clinically mis-sized in 56.6% of cases and overestimated in 71.4%. Among the adenomas reviewed, 22% of mis-sized polyps and 11% of non-mis-sized polyps resulted in an inappropriate surveillance interval.

Conclusions

We found that more than half of ≥6-mm adenomatous polyps are mis-sized and that there is a tendency to overestimate adenoma size among endoscopists. This frequently leads to inappropriate intervals of surveillance colonoscopy.