Estimation Of Polyp Size Research Articles

Variability in, and factors associated with, sizing of polyps by endoscopists at a large community practice.

Background and aims Accurate sizing of polyps at time of colonoscopy is critical for determining surveillance intervals. Endoscopists routinely over- or underestimate the size of polyps at colonoscopy. We evaluated the variability in sizing of polyps among multiple endoscopists, and the effect of patient and physician related factors on polyp size estimation in a large community-based practice. Methods Adult patients who underwent a colonoscopy with polypectomy at five endoscopy centers in Minneapolis/St. Paul by one of 52 endoscopists in 2013 were included in this study. Association of patient, physician, and procedure related factors on polyp sizing was assessed. Results In the study time frame, 38 624 colonoscopies were performed at five ambulatory endoscopy centers. Of these, 16 336 had one or more polyp removed with size information available, and were included in this analysis. There was significant inter-physician variation for estimating polyp sizes larger than 5 mm (intraclass correlation coefficient [ICC] 0.13). Older patient age (OR 1.08, 95 %CI 1.06 – 1.11), and male physician gender (OR 1.92, 95 %CI 1.26 – 2.94) were associated with increased odds of physicians sizing polyps as larger in size. Surveillance procedures had a higher odds of larger polyp sizing compared to screening (OR 0.91, 95 %CI 0.86 – 0.97) and diagnostic procedures (OR 0.86, 95 %CI 0.78 – 0.94). Conclusion In a large community setting, variation of polyp sizing estimates exists between physicians. Male physicians were more likely to size polyps as larger in size. Older patients and patients undergoing surveillance procedures were more likely to have polyps that were sized as larger in size.

PWE-093 Early Outcomes of Bowelscope Screening (BoSS) Endoscopy & The Resulting Colonoscopies

Introduction Bowel scope screening (BoSS), a 1 off flexible sigmoidoscopy for 55 year olds, has recently been introduced as part of the Bowel Cancer screening in England. The outcomes & pathways of patients have been modelled around the landmark Atkins study and the long term effectiveness of the program will need time to be confirmed. The aim of this study was to review our early experience of the outcomes from BoSS including adenoma detection rate (ADR) and additional findings from colonoscopies following BoSS. Methods This was a retrospective study reviewing our BoSS outcomes from the start of BoSS programme from March 2015 to January 2016. This included detailed outcomes of the colonoscopies generated from BoSS. Results Over the 10 months of the study 658 BoSS were performed. The ADR was 11%. A total of 29 colonoscopies were generated with a conversion rate of 4.4%. Referral Patterns: When reviewing the referral patterns (21 male patients, 8 females), 7 could be considered inappropriate (24%) either because of over estimation of initial polyp size (n = 3; 10% were actual polyp size below 10 mm) or misdiagnosis of histology (n = 4; 14%> Histology hyperplastic). Of the appropriate referrals, 11 were due to polyps >1 cm (38%)(low risk), 5 (17%) were due to post polypectomy histology -high grade dysplasia and tubovillous (high risk), 4 (14%)were due to polyp >1 cm plus 2 or more adenomas (high risk), one was due to >20 hyperplastic polyps above the rectum and one was due to impossible polypectomy due to poor bowel preparation. Colonoscopic Findings: Of the 7 inappropriate referrals, 6 had only left sided pathology (85%), already diagnosed during BoSS and 1 (15%) had a 4 mm adenoma in the caecum. Of the appropriate referrals 14 of 22 (64%) had only left sided pathology detected. The median size was 6 mm (range 2–45 mm). 8 of 22 (36%) had right sided adenoma; median size 3 mm (range 2–12 mm), of which 4 were referred due to high risk adenomas, 3 due to low risk adenomas, and 1 due to more than 20 hypeplastic polyps above the rectum. Advanced Pathology: Interestingly, the most advanced adenomas in all colonoscopies but one, were the ones visualised at the sigmoidoscopy. One case with a 6 mm tubovillous adenoma in sigmoid had a 12 mm tubulous adenoma in the caecum. 1/22 cases had a 25 mm adenocarcinoma in the rectum. Conclusion Our early experience suggests that whilst ADR within the programme is almost double the recommendation, it is important to remain within the pathway in view of the yield of pathology generated which will improve with on-going experience and education. No predictive factor was found for right colon lesions. It is reassuring that the most advanced lesions were the one visualised at the sigmoidoscopy. Disclosure of Interest None Declared

Use of a novel polyp “ruler snare” improves estimation of colon polyp size

Prior studies have demonstrated that endoscopists' estimates of polyp size are imprecise. The aim of this study was to determine whether a modified polypectomy "ruler snare" improves the accuracy of assessment of polyp size in real time without the use of additional devices. Ten artificial polyps of predetermined sizes (4 to 25 mm) were affixed to the inside of a colon model. A standard polypectomy snare was modified by adding 5-mm graduated markings to the distal end of the plastic sheath. Study participants estimated the sizes of the artificial polyps during simulated colonoscopies, first using a standard snare and then with the modified ruler snare. Thirty-four private practice and academic gastroenterologists participated in the study. Endoscopists' ability to accurately classify polyps by size (diminutive, small, or large) improved from 48.5% to 60.3% with the ruler snare (P = .002). The greatest improvement in precision was seen among the large polyps, where accuracy increased from 35.9% to 58.2% with use of the ruler snare (P < .0001). Participants underestimated polyp size by a mean of 3.6 mm (interquartile range, -5 to -2 mm) with the standard snare and 1.8 mm (interquartile range, -3 to 0 mm) with the ruler snare, which corresponded to a 44.2% improvement in accuracy with the ruler snare (P < .05). The modified ruler snare improved polyp size assessment compared with a standard snare, particularly with large polyps. Overall, although size estimation continues to be imprecise, the addition of calibrated markings to a polypectomy snare is a simple and likely low-cost means to improve neoplasia surveillance recommendations.

PWE-017 Colonic polyp size estimation and distribution in a screening naive population: Abstract PWE-017 Table 1

Introduction Polyp distribution can effect the efficacy and modality of a population screening method. A number of studies in the past demonstrated that a significant proportion of adenomas lie proximal to the splenic flexure, 1 however sigmoidoscopy is being increasingly used for screening purposes. We set out to identify distribution and characteristics of colonic polyps in a screening naive population. Method We conducted a retrospective analysis of 1462 diagnostic and surveillance colonoscopies performed at MDH Malta, between 2012 and 2014. 587 reports contained the term polyp and were further analysed looking at demographics and polyp characteristics. Results Overall mean age was 60.5 years and 58.7% (n = 341) were males. A total of 1141 polyps were identified with an average of 0.8 polyps per procedure. Overall adenoma detection rate (ADR) was 27.5%. ADR was significantly higher in males (34.4%) than in females (21.4%); Chi-square p = 0.00. 88.2% (n = 1042) of polyps were diminutive (1–5 mm), 3.8% (n = 45) were small (6–9 mm) and the remaining 8.0% (n = 7795) were large (>=10 mm). Table 1demonstrates that whereas adenomas were prevalent throughout the entire colon, hyperplastic polyps were more prevalent distally (p = 0.00). Polyps with advanced histological features were however mostly left sided (p = 0.00); 79.2% and 80.0% of polyps with high grade dysplasia and submucosal invasion respectively. This was also true for large polyps, 78.9% of which (n = 59/95) were distal to the splenic flexure. Polyp size estimation at endoscopy was found to be an overestimate of the pathological specimen measurement (respective means = 8.41 mm and 6.17 mm; paired t-test p = 0.00), and this would have reduced polyp size classification across the 10 mm threshold in 33 instances. Conclusion Since a large proportion of advanced polyps were situated distal to the splenic flexure, sigmoidoscopy seems to be a plausible alternative to full colonoscopy as a screening alternative. Polyp size estimation at endoscopy resulted in mis-sizing of 33.3% of polyps across the 10 mm threshold and surveillance advice should be based on pathology specimens, when possible. Disclosure of interest None Declared. Reference Lemmel GT, Haseman JH, Rex DK, Rahmani E. Neoplasia distal to the splenic flexure in patients with proximal colon cancer. Gastrointest Endosc . 1996 Aug;44(2):109-11

Sa1440 Accuracy of Polypmeasurement During Colonoscopy

Colorectal cancer is the second leading cause of cancer related death in the United States and the third most commonly diagnosed cancer in the US . The size of polyps are an important factor in assessing a patient's risk for colorectal cancer. Therefore, accurate estimation of polyp size is an important part of CRC risk stratification and is one of the factors that determine future CRC surveillance. Many studies have shown that visual estimation of polyps is the most inaccurate of these methods, with endoscopists overestimating polyp size as high as 74% of the time.

Polyp Size Estimation Strategies during Endoscopy Procedures: A Review

Colorectal cancer is the seventh cause of death and a relevant public health problem. This aggressive cancer is commonly identified during a routine endoscopy examination by characterizing a set of polyps that may appear along the colon and rectum. The polyps are usually described by the tissue appearance, shape, rigidity, surface irregularity, resectability, among others. In particular, the polyp size is an important index since large polyps are labeled as advanced adenomas with strong evidence that such adenomas may turn into cancer. Additionally, this index may also determine the procedure and surgical polyp management because of the bleeding risk. In some protocols, the polyp size indicates a closer surveillance, with additional genetic analyses. Currently, polyp size estimation is a challenge because several limitations such as the endoscopy camera distortions, illumination and exacerbated physiological conditions, abrupt motion and expert subjectivity. This work presents a state-of-the-art review of the current semi-automatic computational approaches for estimating the polyp size, aiming to reduce the subjectivity while exploring the gastrointestinal tract.

Use of disposable graduated biopsy forceps improves accuracy of polyp size measurements during endoscopy.

To determine the accuracy of endoscopic polyp size measurements using disposable graduated biopsy forceps (DGBF). Gradations accurate to 1 mm were assessed with the wire of disposable graduated biopsy forceps. When a polyp was noted, endoscopists determined the width of the polyp; then, the graduated biopsy forceps was inserted and the largest diameter of the tumor was measured. After excision, during surgery or endoscopy, the polyp was measured using the vernier caliper. One hundred and thirty-three colorectal polyps from 119 patients were studied. The mean diameter, by post-polypectomy measurement, was 0.92 ± 0.69 cm; 83 were < 1 cm, 36 were between 1 and 2 cm, and 14 were > 2 cm. The mean diameter, by visual estimation, was 1.15 ± 0.88 cm; compared to the actual size measured using vernier calipers, the difference was statistically significant. The mean diameter measured using the DGBF was 0.93 ± 0.68 cm; compared to the actual size measured using vernier calipers, this difference was not statistically significant. The ratio between the mean size estimated by visual estimation and the actual size was significantly different from that between the mean size estimated using the DGBF and the actual size (1.26 ± 0.30 vs 1.02 ± 0.11). The accuracy of polyp size estimation was low by visual assessment; however, it improved when the DGBF was used.

Physician assessment and management of complex colon polyps: a multicenter video-based survey study.

The management of complex colorectal polyps varies in practice. Accurate descriptions of the endoscopic appearance by using a standardized classification system (Paris classification) and size for complex colon polyps may guide subsequent providers regarding curative endoscopic resection vs. need for surgery. The accuracy of this assessment is not well defined. Furthermore, the factors associated with decisions for endoscopic vs. surgical management are unclear. To characterize the accuracy of physician assessment of polyp morphology, size, and suspicion for malignancy among physician subspecialists performing colonoscopy and colon surgery. In addition, we aimed to assess the influence of these polyp characteristics as well as physician type and patient demographics on recommendations for endoscopic vs. surgical resection of complex colorectal polyps. An online video-based survey was sent to gastroenterologists (GIs) and gastrointestinal surgeons affiliated with six tertiary academic centers. The survey consisted of high-definition video clips (30-60 s) of six complex colorectal polyps (one malignant) and clinical histories. Respondents were blinded to histology. Respondents were queried regarding polyp characteristics, suspicion for malignancy, and recommendations for resection. The survey response rate was 154/317 (49%). Seventy-eight percent of respondents were attending physicians (91 GIs and 29 surgeons) and 22% were GI trainees. Sixteen percent of respondents self-identified as specialists in complex polypectomy. Accurate estimation of polyp size was poor (28.4%) with moderate interobserver agreement (k=0.52). Accuracy for Paris classification was 47.5%, also with moderate interobserver agreement (k=0.48). Specialists in complex polypectomy were most accurate, whereas surgeons were the least accurate in assigning Paris classification (66.0 vs. 28.7%, P<0.0001). Specialists in complex polypectomy were most likely to correctly identify the malignant lesion compared with other physicians (87.5 vs. 56.2%, P=0.008). Surgical removal of colon adenomas was recommended least frequently by specialists in complex polypectomy (3.1%) compared with nonspecialists in complex polypectomy (13.3%); surgeons were most likely to recommend surgical resection (17.2%, P=0.009). There were no differences in recommendations for endoscopic vs. surgical resection observed on the basis of years in practice, polyp morphology (polypoid vs. nonpolypoid), polyp location (right vs. left colon), or patient ASA class. In this large survey of GIs and surgeons, physician specialty was strongly associated with accurate polyp characterization and a recommendation for endoscopic resection of complex polyps. Surgeons were most likely to recommend surgical resection of complex nonmalignant colorectal polyps compared with specialists in complex polypectomy who were the least likely. Therefore, collaboration with specialists in complex polypectomy may be helpful in determining the appropriate management of complex colon polyps. Further teaching is needed among all specialists to improve accurate communication and ensure optimal management of these lesions.

PWE-066 Endoscopic Versus Histological Assessment Of Colonic Polyp Size

IntroductionColonic polyp size is a factor in determining management and prognosis of patients. Polyp diameters greater than 9 mm require ongoing colonoscopic surveillance.1 Accurate endoscopic estimation of polyp size can...

PWE-009 Measurement Of Colonic Polyps. Is Visual Estimation Accurate?

IntroductionColon polyp size is a critical biomarker for clinical management of colonic polyps. Larger polyps have a greater malignant potential. During colonoscopy, it is important to correctly measure the size...

Sa1522 Endoscopic vs Histological Assessment of Colonic Polyp Size

Colonic polyp size is an important factor in determining management and prognosis of patients undergoing colonoscopy. Polyp size > 40 mm has been implicated as a risk factor for submucosal invasion of cancer(1). UK guidelines indicate that polyps greater than 10 mm require ongoing endoscopic surveillance at a minimum interval of 3 years(2). Accurate endoscopic estimation of polyp size can be affected by depth perception and parallax errors. Histological assessment may be used but may not always be possible if piecemeal resection or endoscopic vascular reduction had been undertaken.

Variation in polyp size estimation among endoscopists and impact on surveillance intervals

Accurate estimation of polyp size is important because it is used to determine the surveillance interval after polypectomy. To evaluate the variation and accuracy in polyp size estimation among endoscopists and the impact on surveillance intervals after polypectomy. Web-based survey. A total of 873 members of the American Society for Gastrointestinal Endoscopy. Participants watched video recordings of 4 polypectomies and were asked to estimate the polyp sizes. Proportion of participants with polyp size estimates within 20% of the correct measurement and the frequency of incorrect surveillance intervals based on inaccurate size estimates. Polyp size estimates were within 20% of the correct value for 1362 (48%) of 2812 estimates (range 39%-59% for the 4 polyps). Polyp size was overestimated by >20% in 889 estimates (32%, range 15%-49%) and underestimated by >20% in 561 (20%, range 4%-46%) estimates. Incorrect surveillance intervals because of overestimation or underestimation occurred in 272 (10%) of the 2812 estimates (range 5%-14%). Participants in a private practice setting overestimated the size of 3 or of all 4 polyps by >20% more often than participants in an academic setting (difference= 7%; 95% confidence interval, 1%-11%). Survey design with the use of video clips. Substantial overestimation and underestimation of polyp size occurs with visual estimation leading to incorrect surveillance intervals in 10% of cases. Our findings support routine use of measurement tools to improve polyp size estimates.

Assessing Endoscopist Accuracy of Measuring Colon Polyp Size

Purpose: Colonoscopy is the gold standard for colorectal cancer screening and prevention. When a polyp is identified prior to removal, the endoscopist will estimate the polyp size. Inaccurately sized adenomas could lead to incorrect surveillance recommendations. The primary aim of our study was to assess the accuracy between actual polyp size versus estimated polyp size of colon polyps by endoscopists. Methods: A prospective survey using polyp images ranging from 4-12 mm in size. A total of 18 images were used and half had forceps opened to help better estimate polyp size. Participants evaluated each polyp image, estimated the size, ranked their confidence in estimating polyp size and frequency of forceps use in measuring polyp size. The polyp size estimations were compared to the true polyp size for each image. Results: 130 physicians (128 GI/2 CRS) participated, 86% male with a mean age of 47 years (range 28-70 yrs). Nine polyp images without forceps had a mean absolute error between the estimate and actual polyp size of 3.65 mm. Average mean absolute error between the polyp size estimate and the actual polyp size for polyp images with forceps was 1.91 mm. The average relative difference between estimated and actual polyp size in the non-forceps group was 0.50 mm and 0.28 mm in the forceps group. Forceps improved accuracy by an average of 1.74 mm (p<0.0001). Using relative difference values, use of forceps improved accuracy of polyp size estimation by 22.2% (p<0.0001). Given an absolute 20% margin of error from the true polyp size, 20-47% subjects accurately estimated the size of the nine polyps without forceps as a reference while this range increased to 26-72% for the same nine polyps with forceps present in the images. Difficulty in assessing polyp size using forceps was noted for small polyps. Confidence of estimating polyp size was low, 18% of subjects had high confidence. Confidence increased to 49% when forceps were used as a reference. There was no direct link seen in increasing confidence and increased accuracy. Each point increase in confidence level, the accuracy in polyp size estimation increased by 0.2-3 mm (p=0.347). Each point increase in confidence level, the accuracy in polyp size with forceps was reduced by 0.19 mm (p=0.426). Subjects used forceps to estimate polyp size 40.6% of the time, only 22% used forceps >75% of the time. Subjects measured the polyp size externally after polypectomy 26.8% of cases. Conclusion: Accurately estimating polyp size during colonoscopy is a challenge for the endoscopist. Similar to other areas of endoscopy, variation amongst endoscopists exists. Our study shows the use of forceps as a measuring tool can improve polyp size accuracy and has another role beside tissue acquisition.

PTU-044 Joint Endoscopic/Laparoscopic Procedures for Management of Complex Colonic Polyps

IntroductionPolypectomy during colonoscopy can be challenging and is potentially dangerous. Patients with particularly challenging polyps have been traditionally referred for segmental colectomy.Laparo-endoscopic resection (LER) has been found to be safe...

Endoscopic Mis-sizing of Polyps Changes Colorectal Cancer Surveillance Recommendations

Adenomatous polyps greater than 1 cm are defined as advanced adenomas. Inaccurate size estimation can lead to inappropriate surveillance recommendations of colorectal adenomas. The aim of this study was to determine the impact of endoscopic polyp mis-sizing on colorectal cancer surveillance recommendations. This is a prospective study. This study was conducted in a gastroenterology practice at a US academic medical center. Patients undergoing colorectal cancer screening and surveillance colonoscopies from 2010 to 2011 were included. Endoscopic size estimates of polyps 10 to 25 mm were compared with postfixation histopathologic polyp measurements for 15 different gastroenterologists. Only adenomatous polyps removed in entirety by snare polypectomy were included in the analysis. Size variation was defined as (endoscopic estimate - histopathologic size)/(histopathologic size). Clinical mis-sizing was defined as a size variation of >33%. The mean size variation, the percentage of clinical mis-sizing, and the percentage of inappropriate surveillance recommendation due to size variation >33% were reported per endoscopist. : Included for analysis were 4990 procedures from 15 gastroenterologists. A total of 230 polyps from 200 patients met inclusion criteria. The average age was 62.6 years (SD 10.1), and 52% were men. The mean size variation between the endoscopic polyp size estimation and the histopathologic polyp was 73.6% (range of mean size variation, 13%-127%). 62.6% (range, 0%-91%) of included polyps had clinical mis-sizing. Of included polypectomies, 35.2% (range, 0%-67%) resulted in an inappropriate surveillance recommendation due to clinical mis-sizing even after considering histology and synchronous polyps. This was a single-center study. There is marked variation in endoscopists' ability to accurately size adenomatous polyps. Some endoscopists rarely mis-size adenomas, and their surveillance recommendations are appropriate in regard to sizing. However, other endoscopists inaccurately size adenomas, and this leads to inappropriate surveillance of colorectal polyps. In this study, approximately 1 of 3 included polypectomies yielded inappropriate surveillance recommendations because of clinical mis-sizing.

Variation in Estimation of Polyp Size Among Endoscopists

Variation in Estimation of Polyp Size Among Endoscopists

PTU-204 Accuracy of visual estimation of adenoma size: a comparison with direct measurement in the pathology department

IntroductionLarge adenomatous colonic polyps (>10 mm) are associated with an increased risk of development of adenocarcinoma. Recent national guidelines require the ability to distinguish polyps above and below 10 mm...

PTU-214 An in-vitro study to assess, and improve, the accuracy of colonic polyp sizing among nurse endoscopists, trainees and consultant gastroenterologists

IntroductionKnowing if polyps are larger than 10mm is critical when determining colonoscopic surveillance strategies. Judging polyp size from the endoscopic view alone becomes important if polyps are not retrieved intact....

Graduated injection needles and snares for polypectomy are useful for measuring colorectal polyp size

Background Accurate measurement of polyp size during colonoscopy is important; however, visual estimation of polyp size is inaccurate, and it is cumbersome to use additional accessories to measure polyp size whenever polyps are detected. Aims To evaluate the accuracy and usefulness of graduated devices that can also be used for polypectomy. Methods The ends of the outer sheath of the injection needles and snares were marked at intervals of 5 mm (total 30 mm). Four endoscopists measured 53 polyps of 36 patients in the following manner: visual estimation, estimation with biopsy forceps, and measurement with graduated devices. Actual size of all polyps measured through a calliper was used as reference standard. Results The difference between actual size and size measured by visual estimation was statistically significant (1.27 mm, P < 0.001), whilst the differences between actual size and size measured by biopsy forceps (0.06 mm, P = 1.00) or graduated devices (0.15 mm, P = 0.620) were not. The linear correlation between the estimates and the actual sizes showed that the graduated device gave the largest positive linear correlation (0.986, P < 0.001) of the three measurement methods tested. Conclusions The graduated devices are efficient methods when measuring polyp size and performing polypectomy in a single step.

Capsule endoscopy compared with conventional colonoscopy for detection of colorectal neoplasms

Colon capsule endoscopy (CCE) may be a means to overcome the low adherence to colorectal cancer screening. The device is an ingestible capsule with a video camera at both ends that can take photographs as it progresses through the gastrointestinal tract. PillCam colon (PCC1) may be used for structural evaluation of the large bowel following an adequate cleaning procedure. PCC1 measures 11 mm × 31 mm and has dual cameras that enable the device to acquire video images from both ends with a wide coverage area, automatic light control and a frame rate of four frames per second. The system includes a sensor array and data recorder connected to the patient during the procedure. The recorded data are downloaded to the Given Imaging Rapid workstation for review of the colon video. The second generation of PillCam Colon (PCC2) is similar to PCC1 and incorporates new developments. The angle of view has been increased to 172 degrees. It has an adaptive frame rate, alternating from 35 frames per second while in motion to 4 images when virtually stationary. The new RAPID(®) software now includes a simple graphic interface tool for polyp size estimation. The procedure of bowel cleansing until capsule ingestion is similar to that used for traditional colonoscopy. However it is more rigorous as the bowel cleanliness for capsule colonoscopy has to be excellent or at least good to result in an adequate sensitivity of the method. Briefly, it consists of 3.5-4 L of split dose polyethylene glycol. Oral NaP boosters are administered after 1-2 h if the capsule has entered the small bowel. Sodium phosphate (NaP) seems to be a necessary adjunct to the regimen because the total transit time is doubled without NaP. The cleansing level was considered to be good to excellent in 72%-88% in studies with PCC1. The sensitivity for significant polyps (> 6 mm or more than 3 polyps >3 mm) ranged from 63%-88% with specificities between 64%-94%. PCC2 showed an improved sensitivity of 89% and a specificity of 76%. CCE seems to be a safe and effective method of visualizing the colonic mucosa through colon fluids without the need for sedation or insufflation of air. The sensitivity of CCE to detect polyps, advanced adenomas and cancer is lower compared to optical colonoscopy but improvements will be made in the near future. With an increased recording duration, even a panenteric examination of the whole gastrointestinal tract may be possible.