Significant Polyps Research Articles

QuickView video preview software of colon capsule endoscopy: reliability in presenting colorectal polyps as compared to normal mode reading

Objective. Colon capsule endoscopy (CCE) proved to be highly sensitive in detection of colorectal polyps (CP). Major limitation is the time-consuming video reading. The aim of this prospective, double-center study was to assess the theoretical time-saving potential and its possible impact on the reliability of “QuickView” (QV), in the presentation of CP as compared to normal mode (NM). Methods.During NM reading of 65 CCE videos (mean patient´s age 56 years), all frames showing CPs were collected and compared to the number of frames presented by QV at increasing QV settings (10, 20, ... 80%). Reliability of QV in presenting polyps <6 mm and ≥6 mm (significant polyp), and identifying patients for subsequent therapeutic colonoscopy, capsule egestion rate, cleansing level, and estimated time-saving potential were assessed. Results. At a 30% QV setting, the QV video presented 89% of the significant polyps and 86% of any polyps with ≥1 frame (per-polyp analysis) identified in NM before. At a 10% QV setting, 98% of the 52 patients with significant polyps could be identified (per-patient analysis) by QV video analysis. Capsule excretion rate was 74% and colon cleanliness was adequate in 85%. QV´s presentation rate correlates to the QV setting, the polyp size, and the number of frames per finding. Conclusions. Depending on its setting, the reliability of QV in presenting CP as compared to NM reading is notable. However, if no significant polyp is presented by QV, NM reading must be performed afterwards. The reduction of frames to be analyzed in QV might speed up identification of candidates for therapeutic colonoscopy.

PTH-017 Strategy for Colorectal Cancer (CRC) Screening in Individuals with Significant Co-Morbid Conditions

IntroductionWith the advent of the Bowel cancer screening programme (BCSP) in the UK participants who have positive FOB tests are generally offered optical colonoscopy (OC) if considered safe, for early...

Colorectal adenomas: A case series of 5 cases

Adenomatous colorectal polyps are known to be precursor lesions for colorectal cancer. Colorectal adenomas are usually classified into two categories: tubular and villous. A mixed (tubulovillous) phenotype is also recognized. The aim of the study was to study the prevalence and pathological features of adenomatous polyps. We studied five cases of adenomas. Three were diagnosed as tubular adenomas and two were diagnosed as villous adenomas. Most of the significant polyps were identified in patients aged 50 years or older. In case of villas adenoma, the incidence of dysplasia rose with an increase in size.

OC-007 The National colonoscopy audit: a nationwide assessment of the quality and safety of colonoscopy in the UK

IntroductionColonoscopy is the gold standard procedure for the diagnosis and non-surgical management of colonic disease. Poor quality colonoscopy is associated with complications and reduced effectiveness in disease prevention. A previous...

Predicting Colonic Polyp Histology with White Light Endoscopy

Purpose: To determine the ability of endoscopists to predict polyp histology based on endoscopic appearance under white light using high definition colonoscopy. Methods: We prospectively collected data on consecutive patients undergoing routine colonoscopy at Walter Reed Army Medical Center from December 2009 to May 2010 as part of a quality improvement initiative. Data gathered included demographic, endoscopic and histologic characteristics. Prior to the study, endoscopists were instructed to categorize all polyps removed as tubular adenoma (TA), villous adenoma (VA), tubular villous adenoma (TVA), adenocarcinoma, or hyperplastic polyp using only white light. Actual histology was obtained on all retrieved polyps. For analysis purposes, actual and predicted histology were collated into 2 categories (benign [hyperplastic, normal tissue] and abnormal [adenomatous, adenocarcinoma]). Accuracy, sensitivity, specificity, positive/negative predictive values (PPV; NPV) and kappa statistics were calculated. Results: 1111 patients (56% male, 53% white, 56 years (18-91) (range)) were included in the study. The majority of patients (66%) had screening or surveillance colonoscopy. A total of 1049 polyps were identified (≤5mm, n=877; 6-9mm, n=137; ≥10mm, n=34), of which 45.6% (478) were benign, 53.4% (560) were adenomatous, and 1% (11) contained adenocarcinoma. Specificity for detecting benign histology was 48% (230/478) and a NPV of 78.2% (230/294). Sensitivity for detecting abnormal tissue (adenomatous; adenocarcinoma) histology was 86% (490/571) with a PPV of 66.4% (490/738). Of 11 histologically-proven adenocarcinoma, none were estimated to be normal tissue. This resulted in a kappa statistic of 0.381 (0.328-0.434) to accurately estimate polyp histology. Conclusion: Based on this study, endoscopists using high definition, white light endoscopy yielded an overall sensitivity for identifying abnormal polyps (adenomas, adenocarcinomas) of 86% and a specificity of 48%. Endoscopists tended to overestimate hyperplastic polyp histology, however they were unlikely to underestimate clinically significant lesions or polyps. None of the cancers were predicted to be benign histology. These findings suggest that white light endoscopy are modestly accurate in discriminating benign from abnormal tissue, however it is not sufficient to change our current practice of sampling all visualized polyps on colonoscopy.

Improved Curvature Estimation for Computer-aided Detection of Colonic Polyps in CT Colonography

Current schemes for computer-aided detection (CAD) of colon polyps usually use kernel methods to perform curvature-based shape analysis. However, kernel methods may deliver spurious curvature estimations if the kernel contains two surfaces, because of the vanished gradient magnitudes. The aim of this study was to use the Knutsson mapping method to deal with the difficulty of providing better curvature estimations and to assess the impact of improved curvature estimation on the performance of CAD schemes. The new method was compared to two widely used kernel methods in terms of the performance of two stages of CAD: initial detection and true-positive and false-positive classification. The evaluation was conducted on a database of 130 computed tomographic scans from 67 patients. In these patient scans, there were 104 clinically significant polyps and masses >5 mm. In the initial detection stage, the detection sensitivity of the three methods was comparable. In the classification stage, at a 90% sensitivity level on the basis of the input of this step, the new technique yielded 3.15 false-positive results per scan, demonstrating reductions in false-positive findings of 30.2% (P < .01) and 27.9% (P < .01) compared to the two kernel methods. The new method can benefit CAD schemes with reduced false-positive rates, without sacrificing detection sensitivity.

Outcomes following an initial unsuccessful colonoscopy: a 5-year complete audit of teaching hospital colonoscopy practice

IntroductionUnless the full colon is adequately visualised at colonoscopy there is a risk of missing significant pathology including advanced neoplasia and colorectal cancer (CRC). Incomplete colonoscopy occurs in 10%, and...

Tu1598 The Role of Double Balloon Enteroscopy in the Diagnosis and Treatment of Peutz-Jeghers Syndrome

Double balloon enteroscopy (DBE) allows investigation and treatment of the entire small bowel in most patients. Peutz-Jeghers syndrome (PJS) is an inherited autosomal dominant disorder characterised by small intestinal polyps and pigmented mucocutaneous lesions. Bleeding, anaemia, obstruction and/or intussusception are common complications of PJS. Polypectomy may obviate the need for repeated urgent surgery with or without small bowel resections and therefore patients with significant polyps are indicated for prophylactic polypectomies.AIMS & METHODSWe performed a total of 27 DBEs in 13 patients with Peutz-Jeghers syndrome (4 men, 7 women, mean age 31 years, range 12-52) using a Fujinon EN 450T5 enteroscope (out of all 256 DBEs performed in our Department so far).

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.

Colon Capsule Endoscopy compared to Conventional Colonoscopy under routine screening conditions

BackgroundColonoscopy (CSPY) for colorectal cancer screening has several limitations. Colon Capsule Endoscopy (PillCam Colon, CCE) was compared to CSPY under routine screening conditions.MethodsWe performed a prospective, single-center pilot study at a University Hospital. Data were obtained from November 2007 until May 2008. Patients underwent CCE on Day 1 and CSPY on Day 2. Outcomes were evaluated regarding sensitivity and specificity of polyp detection rate, with a significance level set at >5 mm.Results59 individuals were included in this study, the results were evaluable in 56 patients (males 34, females 22; median age 59). CCE was complete in 36 subjects. Polyp detection rate for significant polyps was 11% on CSPY and 27% on CCE.6/56 (11%) patients had polyps on CSPY not detected on CCE (miss rate).Overall sensitivity was 79% (95% confidence interval [CI], 61 to 90), specificity was 54% (95% CI, 35 to 70), positive predictive value (PPV) was 63% and negative predictive value (NPV) was 71%. Adjusted to significance of findings, sensitivity was 50% (95% CI, 19 to 81), specificity was 76% (95% CI, 63 to 86), PPV was 20% and NPV was 93%.ConclusionIn comparison to the gold standard, the sensitivity of CCE for detection of relevant polyps is low, however, the high NPV supports its role as a possible screening tool.Trial RegistrationNCT00991003.

PTH-015 Specialist gastroenterology involvement inStreptococcus bovispositive cultures

Introduction There is well documented evidence linking Streptococcus bovis (S bovis) bacteraemia to colonic neoplasms and polyps. As patients with S bovis bacteraemia can be found across various specialities, our aim was to audit the consistency of appropriate specialist referral for assessment of colonic pathology. Methods All cases of S bovis bacteraemia occurring between October 2000 and June 2009 were identified using information provided by the department of microbiology. Medical records were reviewed for clinical details, evidence of features of endocarditis and referral to gastroenterologists. The standard of best practice was all cases should be referred for appropriate specialist review. Results There were 20 cases of S bovis bacteraemia from the total of 3454 positive cultures (0.6%). There were 11 male and 9 female and all were Caucasian with a mean age of 80.7 years. Four (20%) had endocarditis and four had abnormal liver enzymes. Seventeen patients had a microbiology report in the notes and 13 had Microbiologist advice to consider cardiac and/or colonic pathology. The gastroenterology team9s opinion was sought for 10 (50%) patients and 10 patients underwent one or more investigations including gastroscopy, colonoscopy, flexible sigmoidoscopy and CT of the abdomen. 60% of these investigations were performed on gastroenterology team9s advice and the rest were done on the admitting team9s initiative. In seven patients (35%) their prognosis at the time the bacteraemia was judged to be so poor as to preclude further investigation. Of the 10 patients who were investigated, six (60%) had positive findings. Two patients had colorectal adenocarcinoma (one rectum and one sigmoid); one had a stricture diagnosed on CT abdomen; and three had significant polyps (one or more tubulovillous adenomas with low grade dysplasia >1 cm). 60% of the patients in the study (12) were already deceased at the time of the audit and one patient had had a repeat colonoscopy after 1 year and had further polyps removed. Conclusion A lack of uniformity was observed in proper referral for gastroenterologist assessment and investigation. The age and multiple comorbidities of these patients made further investigations clinically inappropriate in 35% in this study. In the absence of proper guidelines regarding investigation of patients with S bovis bacteraemia for bowel pathology, we recommend seeking formal gastroenterology advice in all such patients. At the Royal Bournemouth Hospital, the department of microbiology has decided to inform the gastroenterology team of all S bovis positive cultures. Following these measures, this audit will be repeated.

A meta-analysis evaluating the accuracy of colon capsule endoscopy in detecting colon polyps

Colon capsule endoscopy (CCE) is a new, noninvasive method for examining the entire colon. The reported yield of CCE in detecting colorectal polyps has shown variable results. To assess the accuracy of CCE by pooling data of existing trials. Meta-analysis. The fixed-effects or random-effects model was used as appropriate, based on whether homogeneity or heterogeneity, respectively, was indicated by the Cochran Q test. Studies that estimated the accuracy of CCE were identified. Two investigators independently conducted the search and data extraction. A total of 626 individuals were included in this meta-analysis. Each patient underwent CCE and conventional colonoscopy. Per-patient sensitivity and specificity, with 95% confidence intervals (CI). Findings were categorized as "significant polyps," that is, a report of a polyp >6 mm in size or 3 or more polyps of any size, or "any polyp," that is, a report of any polyp found, independent of size. Pooled data on sensitivity and specificity with a 95% CI were estimated. For any polyp found, the pooled data showed per-patient CCE sensitivity of 73% (95% CI, 68%-77%) and specificity of 89% (95% CI, 81%-94%). For significant polyps, the respective values were 69% (95% CI, 62%-75%) and 86% (95% CI, 82%-90%). A small number of studies met inclusion criteria. CCE is a reasonable method for screening asymptomatic individuals for colorectal polyps. It may be particularly useful for patients with "incomplete" colonoscopy, those with contraindications for conventional colonoscopy, and those unwilling to undergo colonoscopy because of its perceived inconvenience and discomfort.

Debate: Diminutive Polyps Noted at CT Colonography Need Not Be Reported

Colorectal polyps less than 6 mm in size pose a negligible risk to the development of colorectal carcinoma. The sensitivity and specificity for detection of diminutive lesions on all available examinations including CT colonography (CTC) and optical colonoscopy (OC) is relatively low. In the context of regular screening, the low clinical significance and slow to negligible growth of diminutive polyps, as well as the low detection performance of CTC and OC for these lesions, would contribute to wasted health care resource and excess morbidity if each diminutive polyp were referred for potential resection. Respect for patient safety, attention to proper use of resources, and appropriate focus on larger, clinically significant polyps lead the authors to the conclusion that colonic polyps of less than 6 mm should not be separately reported.

The Benefits of Computed Tomographic Colonography in Reducing a Long Colonoscopy Waiting List

Purpose The Radiology Department, Royal Jubilee Hospital, Victoria, BC, with the support of gastroenterologists and surgeons, was awarded a BC Innovation fund to run a pilot project of computed tomographic colonography to reduce an unacceptably long 2-year colonoscopy waiting list. Funds were approved in April 2007 for a 1-year project, which was completed on March 31, 2008. Methods This article describes the challenges of delivering a high-volume computed tomographic colonography program at a busy community hospital, with discussion of the results for the 2,005 patients who were examined. Results Colonoscopy was avoided in 1,462 patients whose computed tomographic studies showed no significant lesions. In the remainder of patients, only lesions larger than 5 mm were reported, with a total of 508 lesions identified in 433 patients. There were 57 cancers of which 52 were reported as either definite or possible cancers, whereas 5 were not seen on initial scans. Some of the patients with cancer had been on the colonoscopy waiting list for 2 years. In addition, there were 461 patients with significant extracolonic findings, including 84 who required urgent or semi-urgent further management for previously unsuspected conditions, such as pneumonia, aneurysms larger than 5 cm, and a range of solid renal, hepatic, and pancreatic masses. There were no procedural complications from the computed tomographic colon studies. Conclusions We have shown that it is feasible to run a high volume CTC service in a general hospital given hospital support and funding. The benefits in this group of over 2000 patients included avoidance of colonoscopy in over 70% of patients, detection of significant polyps or cancer in approximately 20% of patients, and identification of clinically important conditions in 7%–18% depending on the definition used. The estimated costs including capital, operating, and professional fees were in the range of $400.

CT Colonography Versus Optical Colonoscopy for Screening Asymptomatic Patients for Colorectal Cancer: A Patient, Intervention, Comparison, Outcome (PICO) Analysis

The American College of Radiology has recently endorsed the use of computed tomographic colonography (CTC) for colon cancer screening. With advances in technology and postprocessing software, the quality of computed tomographic colonographic studies has improved, and new techniques are being developed to reduce radiation exposure and increase patient acceptance of the procedure. The aim of colorectal cancer screening is to reduce the incidence of malignancy by identifying and removing presymptomatic lesions. The aim of this study was to answer the clinical question: In an asymptomatic patient at average risk for colon cancer, is CTC equivalent to optical colonoscopy (OC) for detecting clinically significant polyps? A systematic literature review was conducted to evaluate CTC compared to OC, using the patient, intervention, comparison intervention, outcome (PICO) search strategy. The PubMed search used Medical Subject Headings, including the terms "computed tomography colonography," "colonoscopy," "screening," and "polyp." Each of the retrieved articles was assigned a level of evidence using the Centre for Evidence-Based Medicine's hierarchy of validity for diagnostic studies. PICO search criteria and review of abstracts identified 16 relevant studies. Using the Centre for Evidence-Based Medicine's hierarchy of validity, there were three level 1c studies, two level 2a studies, three level 2b studies, four level 3b studies, two level 4 studies, and two level 5 studies. All relevant studies demonstrated that CTC had high or moderately high per patient and per polyp sensitivity and specificity compared to OC for clinically relevant polyps (>5 mm). The majority of evidence suggests that CTC is an acceptable alternative to OC, particularly in the group of patients who are either unwilling or unable to undergo OC. The results of the large, multicenter American College of Radiology Imaging Network study are pending. This trial presented preliminary results in 2007 suggesting that the sensitivity and specificity of CTC are high and comparable to those of OC.

Does the Use of a Wide Angle, High Definition Colonoscope Enable the Endoscopist to Detect More Significant Polyps or High Risk Adenoma Bearing Patients than the Use of a Conventional Colonoscope?

Does the Use of a Wide Angle, High Definition Colonoscope Enable the Endoscopist to Detect More Significant Polyps or High Risk Adenoma Bearing Patients than the Use of a Conventional Colonoscope?

Parallel imaging enhanced MR colonography using a phantom model

To compare various Array Spatial and Sensitivity Encoding Technique (ASSET)-enhanced T2W SSFSE (single shot fast spin echo) and T1-weighted (T1W) 3D SPGR (spoiled gradient recalled echo) sequences for polyp detection and image quality at MR colonography (MRC) in a phantom model. Limitations of MRC using standard 3D SPGR T1W imaging include the long breath-hold required to cover the entire colon within one acquisition and the relatively low spatial resolution due to the long acquisition time. Parallel imaging using ASSET-enhanced T2W SSFSE and 3D T1W SPGR imaging results in much shorter imaging times, which allows for increased spatial resolution. Using two porcine colon phantoms each with eight simulated 3-10-mm "polyps," baseline reference sequences acquired without ASSET (6-mm slices and readout bandwidth [BW] 62 kHz) were compared with 11 SSFSE and 8 SPGR sequences acquired with 2-fold ASSET acceleration. ASSET-enhanced SSFSE and SPGR sequences comprised BW/matrix combinations ranging from 20-62 kHz/256-352x256, respectively, with slice thicknesses adjusted from 3.0 to 4.5 mm to maintain a 23-26-second acquisition time and 30 cm slab thickness. Two experienced radiologists viewed the datasets in a randomized, blinded fashion. Compared to reference sequences, ASSET-enhanced SSFSE and SPGR sequences facilitated better polyp detection and had similar overall image quality and per-phantom specificity. The two best ASSET-enhanced SSFSE (3 and 4.5 mm slices, each with BW of 62.5 kHz and 352x256 matrices) and three best ASSET-enhanced SPGR BW/slice thickness/matrix combinations of 31 kHz/4.4 msec/192x256; 62/3.4/192x256; and 62/4.0/192x256, respectively, permitted detection of all polyps>or=5 mm. Parallel imaging using ASSET-enhanced T2W SSFSE and T1W 3D SPGR improves the ability to detect significant colon polyps in an MRC phantom model.

Complications of colonoscopy in a large public county hospital in Greece. A 10-year study

Information about the complications of colonoscopy in Southern Europe is limited, particularly in Greece where it is non-existent. Our study sought to determine the complications of colonoscopy in a large public county hospital in Greece over a 10-year period. All colonoscopy procedures from 1996 to 2006 were entered into a database. Data were analysed by both univariate and multivariate methods. Nine thousand six hundred forty-eight colonoscopies were entered into a database. The procedures were diagnostic in 79% and therapeutic in 21%. Overall bleeding complications occurred in 83 out of the 9648 patients (0.8%: 95% confidence interval [0.7%, 0.9%]). Perforation occurred in four female patients (0.04%: 95% confidence interval [0.01%, 0.07%]) in the sigmoid colon. Multivariate stepwise logistic regression analysis in the therapeutic colonoscopies revealed that presence of significant polyps (odds ratio 4.7, confidence interval [2.9-7.6]), the male sex (odds ratio 2, 95% confidence interval [1.2-3.3]) and the time period of the procedure (the first 5 years) (odds ratio 1.7, 95% confidence interval [1.01-3]), are significant predictors of a post-colonoscopy bleeding episode. This historical cohort study, the first in Greece on this subject, shows that colonoscopy is a rather safe procedure and that the rate of complications in this study was low.

A Fully Automatic CAD-CTC System Based on Curvature Analysis for Standard and Low-Dose CT Data

Computed tomography colonography (CTC) is a rapidly evolving noninvasive medical investigation that is viewed by radiologists as a potential screening technique for the detection of colorectal polyps. Due to the technical advances in CT system design, the volume of data required to be processed by radiologists has increased significantly, and as a consequence the manual analysis of this information has become an increasingly time consuming process whose results can be affected by inter- and intrauser variability. The aim of this paper is to detail the implementation of a fully integrated CAD-CTC system that is able to robustly identify the clinically significant polyps in the CT data. The CAD-CTC system described in this paper is a multistage implementation whose main system components are: 1) automatic colon segmentation; 2) candidate surface extraction; 3) feature extraction; and 4) classification. Our CAD-CTC system performs at 100% sensitivity for polyps larger than 10 mm, 92% sensitivity for polyps in the range 5 to 10 mm, and 57.14% sensitivity for polyps smaller than 5 mm with an average of 3.38 false positives per dataset. The developed system has been evaluated on synthetic and real patient CT data acquired with standard and low-dose radiation levels.

An Elevated Rate of Adenoma Detection in an Urban Latin American Population Undergoing Colorectal Cancer Screening

Purpose: Colorectal cancer is the second leading cause of cancer death in the United States. African Americans (AA) are known to have an elevated rate of colonic neoplasms compared to the general population. There is limited data on Latin Americans (LA) undergoing screening colonoscopies with respect to the incidence and location of neoplasms. We retrospectively reviewed screening colonoscopies performed at an inner city university hospital that serves a predominately minority population to detail colon polyp size, distribution, and pathology with respect to ethnicity. Methods: There were a total of 2,698 colonoscopies performed at the University Hospital in Newark, NJ from 2005–2006. Of these, 756 were screening colonoscopies performed on patients who were asymptomatic. These cases were analyzed for presence, location, size, and pathology of polyps with respect to patient ethnicity. Results: Of the 756 screening colonoscopies, 287 (38%) were performed in LA and 331 (44%) in AA. In LA, 112 patients (39%) were found to have at least one polyp. This was not significantly different from AA (145 patients; 44%). Additionally, 56 (19%) LA were found to have a right-sided lesion (proximal to the splenic flexure), which was comparable to AA (64 patients; 19%). Significant pathology was defined as adenomatous change (AD), tubular adenoma (TA), tubulovillous adenoma (TVA), villous adenoma, or carcinoma (CA). Of the AA patients screened, 67 (46%) had pathologically significant lesions (5 AD, 53 TA, 6 TVA, and 3 CA). LA had a similar incidence (54 patients; 48%) and distribution of pathologically significant lesions (2 AD, 47 TA, 5 TVA, 0 CA). The percentage of pathologically significant right-sided polyps were similar in AA (40 patients, 62%) and LA (32 patients, 57%). Of note, AA were significantly more likely to have a large (> 1 cm) polyp than LA (8.5% vs. 3.1%, P < .01), and were more likely to have a large right sided colonic polyp (4.6% vs. 1.7%, P= .07). Conclusion: This study provides evidence that LA undergoing screening colonoscopy have a higher than expected incidence of colonic polyps, pathologically significant lesions, and pathologically significant right-sided lesions. These findings were similar to those of AA, a known high-risk group. Our study suggests that screening guidelines for LA should reflect those for AA and warrants further prospective trials.