Meta-analysis shows colon capsule endoscopy is effective in detecting colorectal polyps

Choice of colon capsule or colonoscopy versus default colonoscopy in FIT positive patients in the Danish screening programme: a parallel group randomised controlled trial

BACKGROUND

Colonoscopy is among the standard tests for colorectal cancer (CRC) screening. However, uptake varies, and alternatives such as colon capsule endoscopy (CCE) are available. The uptake and detection rate of clinically significant neoplasia with CCE, compared with colonoscopy, remain unclear in this setting.

OBJECTIVE

The primary objective of this study was to compare the detection rates of advanced neoplasia between CCE and colonoscopy, using a pathway in which the study group could choose between the two procedures, while the control group was offered only colonoscopy.

DESIGN

A randomised, intention-to-treat trial was conducted among Danish CRC screening participants who tested positive with a faecal immunochemical test (FIT). The trial compared the detection rate of advanced neoplasia (primary outcome) and the uptake rate of both approaches between the two arms.

RESULTS

A total of 473 684 invitations were sent to 396 676 individuals, with 62.6% returning the test. Among them, 11 075 tests were positive (4.5%), with no significant differences between the two study groups. Among FIT-positive cases, the uptake for colonoscopy was 91.1% in the control arm and 91.7% in the study arm, where participants had a choice of methods. In the study arm, 45.8% preferred CCE, 11.4% preferred colonoscopy and 42.8% had no preference and underwent colonoscopy. Ultimately, 69.9% of patients who initially opted for CCE were later referred for colonoscopy. The rate of advanced neoplasia detection was similar between the groups: 0.67% in the study arm versus 0.64% in the control arm.

CONCLUSION

Offering CCE as an alternative to colonoscopy did not significantly alter the detection rate of advanced neoplasia, nor did it increase uptake in a screening programme with high adherence to colonoscopy following a positive FIT test. Instead, it led to a very high rate of secondary colonoscopies. Therefore, CCE cannot be recommended in this setting.

TRIAL REGISTRATION NUMBER

NCT04049357 (ClinicalTrials.gov).

A Head-to-Head Comparison of Computed Tomography Colonography, Optical Colonoscopy, and Colon Endoscopic Capsule for the Detection of Polyps After Partial Colectomy or Rectosigmoidectomy for Colorectal Cancer: A Pilot Study

Background and objective Optical colonoscopy is the gold standard method for the diagnosis of colorectal cancer (CRC) and it allows for biopsy and resection, as well as documentation of synchronous lesions. CT colonography (CTC) and colon endoscopic capsule (CEC) are also recommended as alternative minimally invasive or non-invasive procedures. Prospective studies comparing these three approaches are scarce in the current literature. In light of this, the aim of this pilot study was to compare the efficacy of polyp detection between these three methods in patients with a history of curative surgical resection of CRC. Methods Patients were consecutively recruited and all procedures were sequentially conducted on the same day. The primary endpoint was the detection rate of polyps, whereas secondary endpoints were the detection of polyps according to size and location, and the adverse events caused by these procedures. Results A total of 21 patients were consecutively included and all of them underwent all three interventions. No adverse events, local recurrences, or metachronous lesions were detected. In two cases with elevated carcinoembryonic antigen (CEA), CTC unveiled distant metastasis. Optical colonoscopy registered a mean of 0.4 polyp >6 mm and 1.3 polyps <6 mm per patient. CTC unveiled only 0.5 polyp >6 mm/patient and no smaller lesions were documented, whereas findings for the colon capsule comprised an average of 0.4 polyps >6 mm and 0.7 polyps <6 mm per patient. Statistical difference was not demonstrated, except for virtual colonoscopy in terms of the total number of polyps detected in comparison to optical colonoscopy. Conclusions Optical colonoscopy showed superior results in comparison to virtual colonoscopy while there was no statistical difference in comparison to colon capsule. Notwithstanding occasional difficulties, all three techniques were well tolerated. Hence, decisions concerning the use of each diagnostic method should be based on their availability, professional expertise, contraindications, and patient preferences.

Low Colon Capsule Endoscopy (CCE) False Negative Rate for Polyps Excluding Reader Error

BACKGROUND

CCE is a diagnostic tool lacking clinical data on false negative rates. We aimed to assess this rate and the reader/technical error breakdown.

METHODS

False negative CCEs were identified after comparing to a colonoscopy database. Missed pathology characteristics and study indications/quality were collated. Cases were re-read by experts and newly identified lesions/pathologies were verified by an expert panel and categorised as reader/technical errors.

RESULTS

Of 532 CCEs, 203 had an adequately reported comparative colonoscopy, 45 (22.2%) had missed polyps, and 26/45 (57.8%) reached the colonic section with missed pathology. Of the cases, 22 (84.6%) had adequate bowel preparation. Indications included 13 (50%) polyp surveillance, 12 (46%) GI symptoms, 1 (4%) polyp screening. CCE missed 18 (69.2%) diminutive polyps and 8 (30.8%) polyps ≥ 6 mm, 18/26 (69.2%) of these were adenomas. Excluding incomplete CCE correlates, colonoscopy total and significant polyp yield were 97/184 (52.7%) and 50/97 (51.5%), respectively. CCE total polyp and significant polyp false negative rate was 26.8% (26/97) and 16% (8/50), respectively. Following re-reading, reader and technical error was 20/26 (76.9%) and 6/26 (23.1%). Total and significant missed polyp rates were 20.6% (20/97) and 14% (7/50) for reader error, 6.2% (6/97) and 2% (1/50) for technical error.

CONCLUSIONS

False negative CCE rate is not insubstantial and should be factored into clinical decision making.

Colon Capsule Endoscopy in the Diagnosis of Colon Polyps: Who Needs a Colonoscopy?

Colon screening programs have reduced colon cancer mortality. Population screening should be minimally invasive, safe, acceptably sensitive, cost-effective, and scalable. The range of screening modalities include guaiac or immunochemical fecal occult blood testing and CT colonography and colonoscopy. A number of carefully controlled studies concur that second-generation capsule endoscopy has excellent sensitivity for polyp detection and a high negative predictive value. Colon capsules fulfill the screening expectation of safety, high sensitivity for polyp detection, and patient acceptance, and appear to straddle the divide between occult blood testing and colonoscopy. While meeting these criteria, there remains the challenges of scaling, capsule practitioner training, resource allocation, and implementing change of practice. Like CT colonography, capsule screening presents the clinician with a decision on the threshold for colonoscopy referral. Overall, colon capsules are an invaluable tool in polyp detection and colon screening and offer a filter that determines “who needs a colonoscopy?”.

Video Capsule Endoscopy in Gastroenterology

Video capsule endoscopy (VCE) is a wireless technology used by gastroenterologists for various indications in their clinical practice. There has been significant improvement in this technology since its start about two decades ago. Specific video capsules have been made to evaluate the small bowel, colon, and esophagus. Now pan-enteric video capsule is available to assess both the small bowel and colon. VCE is a non-invasive procedure that has been tremendously evaluated for various gastrointestinal disorders, particularly small intestinal bleeding. There are specific contraindications and complications of VCE. This procedure has the technical part and video reading part. Newer software programs will come to reduce the reading time. Artificial intelligence is also coming for quick and accurate diagnosis of any positive findings during VCE. VCE is an important diagnostic test in the field of gastroenterology. Although it is an addition to optical endoscopic procedures to visualize the gastrointestinal mucosa, it has advantages and disadvantages.

Colon capsule endoscopy in colorectal cancer screening: a systematic review

INTRODUCTION

Primary colonoscopy and fecal immunochemical test (FIT) are the most commonly used colorectal cancer (CRC) screening modalities. Colon capsule endoscopy (CCE) might be an alternative. Data on the performance of CCE as a CRC screening tool in a screening population remain scarce. This is the first systematic review to provide an overview of the applicability of CCE as a CRC screening tool.

METHODS

A systematic search was conducted of literature published up to September 2020. Studies reporting on CRC screening by second-generation CCE in an average-risk screening population were included.

RESULTS

582 studies were identified and 13 were included, comprising 2485 patients. Eight studies used CCE as a filter test after a positive FIT result and five studies used CCE for primary screening. The polyp detection rate of CCE was 24 % - 74 %. For polyps > 6 mm, sensitivity of CCE was 79 % - 96 % and specificity was 66 % - 97 %. For polyps ≥ 10 mm, sensitivity of CCE was 84 % - 97 %, which was superior to computed tomographic colonography (CTC). The CRC detection rate for completed CCEs was 93 % (25/27). Bowel preparation was adequate in 70 % - 92 % of examinations, and completion rates varied from 57 % to 92 %, depending on the booster used. No CCE-related complications were described.

CONCLUSION

CCE appeared to be a safe and effective tool for the detection of CRC and polyps in a screening setting. Accuracy was comparable to colonoscopy and superior to CTC, making CCE a good alternative to colonoscopy in CRC screening programs, although completion rates require improvement.

Feasibility of a second-generation colon capsule in visualization of the upper gastrointestinal tract

BACKGROUND

Capsule endoscopy for visualization of the entire gastrointestinal tract is a challenge. A second-generation colon capsule endoscopy system (CCE-2) performed well in the colon and small intestine, but its utility in the upper gastrointestinal duct is not clear. We evaluated the use of the CCE-2 in the visualization of the upper gastrointestinal tract.

METHODS

We performed a retrospective study and further evaluated CCE-2 images using the typical landmarks of esophagus and stomach. The two imagers located at each end of the CCE-2 system were defined as imager1 (green) and imager2 (yellow). Two endoscopists read the images, and they were blinded to the other reader's results. All of the images from the two imagers were separately reviewed.

RESULTS

Images from 127 subjects were analyzed. This study demonstrated the comprehensive visualization of 71.7% of esophageal landmarks and 89.8% of gastric landmarks using the CCE-2. The two CCE-2 imagers were not identical, and the lighter imager (imager2, yellow) was superior to the heavier imager (imager1, green) (78% vs. 33.1%) in the stomach. Compared with the use of one imager, the use of two imagers was superior (two-imager vs. imager1, 89.8% vs. 33.1%; two-imager vs. imager2, 89.8% vs. 78%) in the stomach. Two-imager combination analysis detected a total of 160 positive findings. In contrast, single-imager analysis with imager1 and imager2 detected 133 and 137 findings, respectively. Two-imager combination analysis provided 20.3% and 16.8% more findings than imager1 and imager2, respectively. The two imagers complemented each other to detect more lesions.

CONCLUSIONS

The CCE-2 system is feasible for use in the upper gastrointestinal tract and may be considered an optional tool for upper gastrointestinal imaging. This system may represent a good choice for complete gastrointestinal duct screening. Compared with the use of one imager, the two-imager combination provided improved upper gastrointestinal tract mucosal visualization.

Colon capsule endoscopy versus CT colonography after incomplete colonoscopy. Application of artificial intelligence algorithms to identify complete colonic investigations

BACKGROUND

Guidelines suggest computed tomography colonography (CTC) following incomplete optical colonoscopy (OC). Colon capsule endoscopies (CCE) have been suggested as an alternative, although completion rates have been unsatisfactory. Introduction of artificial intelligence (AI)-based localization algorithms of the camera capsules may enable identification of incomplete CCE investigations overlapping with incomplete OCs.

OBJECTIVE

The study aims to investigate relative sensitivity of CCE compared with CTC following incomplete OC, investigate the completion rate when combining results from the incomplete OC and CCE, and develop a forward-tracking algorithm ensuring a safe completeness of combined investigations.

METHODS

In this prospective paired study, patients with indication for CTC following incomplete OC were included for CCE and CTC. Location of CCE abortion and OC abortion were registered to identify complete combined investigations. AI-based algorithm for localization of capsules were developed reconstructing the passage of the colon.

RESULTS

In 237 individuals with CTC indication; 105 were included, of which 97 underwent both a CCE and CTC. CCE was complete in 66 (68%). Including CCEs which reached most oral point of incomplete OC, 73 (75%) had complete colonic investigations; 78 (80%) had conclusive investigations. Relative sensitivity of CCE compared with CTC was 2.67 (95% confidence interval (CI) 1.76;4.04) for polyps >5 mm and 1.91 (95% CI 1.18;3.09) for polyps >9 mm. An AI-based algorithm was developed.

CONCLUSION

Sensitivity of CCE following incomplete OC was superior to CTC. Introducing and improving algorithm-based localization of capsule abortion may increase identification of overall complete investigation rates following incomplete OC.ClinicalTrials.gov identifier: NCT02826993.

Accuracy of colon capsule endoscopy for advanced neoplasia

BACKGROUND AND AIMS

Second-generation colon capsule endoscopy (CCE-2) has shown promising accuracy for the diagnosis of overall neoplasia. Advanced neoplasia (AN) represents the main target of colorectal cancer screening programs. Our aim was to assess the diagnostic accuracy of CCE-2 for the detection of AN in patients with a positive result for the fecal immunochemical test (FIT) who are undergoing screening.

METHODS

Patients aged 50 to 69 years with a positive result for the FIT in 4 population screening programs in Italy and Spain were enrolled. Screenees were asked to undergo CCE-2, followed by traditional colonoscopy (TC). TC was performed the same day or the following morning. Bowel preparation included a split-dose polyethylene glycol-based regimen, with sodium phosphate (NaP) with gastrografin as boosters. The CCE-2 video was read by an endoscopist blinded to the results of TC. The main outcomes were CCE-2 accuracy in terms of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for AN when using 2 different size thresholds for TC referral (ie, polyps ≥6 mm and ≥10 mm).

RESULTS

Two hundred twenty-two patients were enrolled, and 178 patients completed both CCE-2 and TC (87.7%). Overall, 59 cases of AN were detected at TC. CCE-2 sensitivity was 90%, specificity was 66.1%, PPV was 57.4%, and NPV was 92.9% for AN when using a 6-mm cut-off (TC referral rate, 52.8%) and 76.7%, 90.7%, 80.7%, and 88.4% when using a 10-mm cut-off (TC referral rate, 32%), respectively. CCE-2 detected that 8 of 9 already developed colorectal cancers. Among the 41 false positives at the 6-mm cut-off, 34 (82.9%) presented with a nonadvanced adenoma at TC. Mean transit time was 4 hours and 4 minutes, and ≥70% of patients excreted the capsule within 5 hours.

CONCLUSIONS

In an enriched disease setting, we showed the high sensitivity of CCE-2 for the diagnosis of AN at a 6-mm cut-off. The apparently low CCE-2 specificity is related to the choice of AN as the main outcome. (Clinical trial registration number: ISRCTN 62158762.).

Repeatability of small bowel transit time in capsule endoscopy in healthy subjects

BACKGROUND

There are no reports to prove the repeatability of gastric transit time (GTT) and small bowel transit time (SBTT) in capsule endoscopy (CE).

OBJECTIVE

To clarify the repeatability and factors that affect GTT/SBTT in CE.

METHODS

We analyzed the data of 150 healthy subjects from our previous randomized controlled trial that compared small intestinal injuries between two 14-day treatment groups: 1) celecoxib and 2) loxoprofen + lansoprazole. Correlation of GTT/SBTT with pre- and post-treatment CE was analyzed. In addition, the associations of pre-treatment CE SBTT with physical factors, post-treatment CE SBTT and the presence of small intestinal mucosal injuries were analyzed.

RESULTS

Analyses of 148 subjects pre-treatment CE and 146 subjects post-treatment CE were performed. There were no significant differences between mean GTT and SBTT before and after treatment. Both GTT (𝜌 = 0.22, p < 0.01) and SBTT (𝜌 = 0.47, p < 0.0001) showed positive correlations between pre- and post-treatment CE. In pre-treatment CE, physical factors and the presence of small intestinal mucosal injury had no associations with SBTT.

CONCLUSIONS

Moderate correlation in SBTT and slight correlation in GTT were shown on repeated CE. The factors affecting SBTT were not clarified in this analysis.

PillCamColon2 after incomplete colonoscopy - A prospective multicenter study

AIM

To evaluate the ability of PillCamColon2 to visualize colonic segments missed by incomplete optical colonoscopy (OC) and to assess the diagnostic yield.

METHODS

This prospective multicentre study included 81 patients from nine centres who underwent second-generation colon capsule endoscopy (CCE) following incomplete OC performed by an experienced gastroenterologist (> 1000 colonoscopies). Patients with stenosis were excluded. According to patient preferences, CCE was performed the following day (protocol A) after staying on clear liquids and 0.75 L Moviprep in the morning or within 30 d after new split-dose Moviprep (protocol B). Boosts consisted of 0.75 L and 0.25 L Moviprep, and phospho-soda was given as a rescue if the capsule was not excreted after seven hours.

RESULTS

Seventy-four patients were analysed (51% of them in group A; 49% in group B). Bowel cleansing was adequate in 67% of cases, and CCE could visualize colonic segments missed by incomplete colonoscopy in 90% of patients under protocol A and 97% of patients under protocol B (P = 0.35, n.s.). Significant polyps including adenocarcinoma were detected in 24% of cases. Detection rates for all polyps and significant polyps per patient were similar in both protocols. Polyps were found predominantly in the right colon (86%) in segments that were not reached by OC. Extracolonic findings - such as reflux esophagitis, suspected Barrett esophagus, upper GI-bleeding, gastric polyps, gastric erosions and angiectasia - were detected in eight patients. PillCamColon2 capsule was retained in the ileum of one patient (1.4%) without symptoms and removed during an uneventful resection for unknown Crohn’s disease that was diagnosed as the cause of anemia, which was the indication for colonoscopy. CCE was well tolerated. One patient suffered from self-limiting vomiting after consuming the phospho-soda.

CONCLUSION

Second-generation CCE using a low-volume preparation is useful after incomplete OC, and it allows for the detection of additional relevant findings, but cleansing efficiency could be improved.

Recent Advance in Colon Capsule Endoscopy: What's New?

Colon capsule endoscopy (CCE) is a relatively new diagnostic procedure for patients with suspected colonic diseases. This convenient,noninvasive method enables the physician to explore the entire colon without significant discomfort to the patient. However, while CCEcan be performed painlessly without bowel air insufflation, the need for vigorous bowel preparation and other technical limitationsexist. Due to such limitations, CCE has not replaced conventional colonoscopy. In this review, we discuss historical and recentadvances in CCE including technical issues, ideal bowel preparation, indications and contraindications and highlight further technicaladvancements and clinical studies which are needed to develop CCE as a potential diagnostic tool.

Applications of Colon Capsule Endoscopy

PURPOSE OF REVIEW

This is a review of colon capsule endoscopy (CCE) with a focus on its recent developments, technological improvements, and current and potential future indications.

RECENT FINDINGS

Based on the current literature, CCE II demonstrates comparable polyp detection rates as optical colonoscopy and CT colonography, and improved cost-effectiveness. The main limitation to patient acceptance is the requirement of a rigorous bowel preparation. Preliminary studies show good correlation between CCE and optical colonoscopy for assessment of colonic disease activity in inflammatory bowel disease (IBD). CCE II is currently FDA, approved as an adjunctive test in patients with prior incomplete colonoscopy, and in the evaluation of patients with suspected lower gastrointestinal bleeding. The test is approved in Europe as one of the options for average-risk colorectal cancer screening, and high-risk screening in patients with contraindications or unwilling to undergo colonoscopy. CCE has a potential role in the evaluation and monitoring of colonic disease activity in IBD. Future technological advances should focus on minimizing bowel preparation, improvement in reading times, and development of therapeutic capabilities. • With technological improvements, the second-generation colon capsule has a significantly higher sensitivity than the first-generation capsule for detection of colon polyps. • Colon capsule endoscopy has been approved in Europe as an option for average-risk colorectal cancer screening, and high-risk screening in patients with contraindications or unwilling to undergo colonoscopy. • Colon capsule endoscopy has received FDA approval as an option for colorectal cancer screening in patients with prior incomplete colonoscopy, and in evaluation of patients with suspected lower gastrointestinal bleeding. • Colon capsule endoscopy may have a role in evaluation and monitoring of inflammatory bowel disease. • Colon capsule endoscopy currently requires a bowel preparation that is more rigorous than colonoscopy.

Colorectal Cancer Screening-Who, How, and When?

Colorectal cancer (CRC) is the third most common cancer worldwide. It is amenable to screening as it occurs in premalignant, latent, early, and curable stages. PubMed, Cochrane Database of Systematic Reviews, and national and international CRC screening guidelines were searched for CRC screening methods, populations, and timing. CRC screening can use direct or indirect tests, delivered opportunistically or via organized programs. Most CRCs are diagnosed after 60 years of age; most screening programs apply to individuals 50-75 years of age. Screening may reduce disease-specific mortality by detecting CRC in earlier stages, and CRC incidence by detecting premalignant polyps, which can subsequently be removed. In randomized controlled trials (RCTs) guaiac fecal occult blood testing (gFOBt) was found to reduce CRC mortality by 13%-33%. Fecal immunochemical testing (FIT) has no RCT data comparing it to no screening, but is superior to gFOBt. Flexible sigmoidoscopy (FS) trials demonstrated an 18% reduction in CRC incidence and a 28% reduction in CRC mortality. Currently, RCT evidence for colonoscopy screening is scarce. Although not yet corroborated by RCTs, it is likely that colonoscopy is the best screening modality for an individual. From a population perspective, organized programs are superior to opportunistic screening. However, no nation can offer organized population-wide colonoscopy screening. Thus, organized programs using cheaper modalities, such as FS/FIT, can be tailored to budget and capacity.

Accuracy of Colon Capsule Endoscopy in Detecting Colorectal Polyps in Individuals with Familial Colorectal Cancer: Could We Avoid Colonoscopies?

Background. Individuals with a family history of colorectal cancer (CRC) have an increased risk of CRC. We evaluated the diagnostic yield of CCE in the detection of lesions and also two different colon preparations. Methods. A prospective multicenter study was designed to assess CCE diagnostic yield in a cohort of asymptomatic individuals with a family history of CRC. CCE and colonoscopy were performed on the same day by 2 endoscopists who were blinded to the results of the other procedure. Results. Fifty-three participants were enrolled. The sensitivity, specificity, PPV, and NPV of CCE for detecting advanced adenomas were 100%, 98%, 67%, and 100%. Sensitivity, specificity, PPV, and NPV of CCE for the diagnosis of individuals with polyps were 87%, 97%, 93%, and 88%, respectively. CCE identify 100% of individuals with significant or advanced lesions. Overall cleanliness was adequate by 60.7% of them. The PEG-ascorbic boost seems to improve colon cleanliness, with similar colonic transit time. Conclusion. CCE is a promising tool, but it has to be considered as an alternative technique in this population in order to reduce the number of colonoscopies performed. More studies are needed to understand appropriate screening follow-up intervals and optimize the bowel preparation regimen.

Clinical Practice Guidelines for the Use of Video Capsule Endoscopy

BACKGROUND & AIMS

Video capsule endoscopy (CE) provides a noninvasive option to assess the small intestine, but its use with respect to endoscopic procedures and cross-sectional imaging varies widely. The aim of this consensus was to provide guidance on the appropriate use of CE in clinical practice.

METHODS

A systematic literature search identified studies on the use of CE in patients with Crohn's disease, celiac disease, gastrointestinal bleeding, and anemia. The quality of evidence and strength of recommendations were rated using the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

The consensus includes 21 statements focused on the use of small-bowel CE and colon capsule endoscopy. CE was recommended for patients with suspected, known, or relapsed Crohn's disease when ileocolonoscopy and imaging studies were negative if it was imperative to know whether active Crohn's disease was present in the small bowel. It was not recommended in patients with chronic abdominal pain or diarrhea, in whom there was no evidence of abnormal biomarkers typically associated with Crohn's disease. CE was recommended to assess patients with celiac disease who have unexplained symptoms despite appropriate treatment, but not to make the diagnosis. In patients with overt gastrointestinal bleeding, and negative findings on esophagogastroduodenoscopy and colonoscopy, CE should be performed as soon as possible. CE was recommended only in selected patients with unexplained, mild, chronic iron-deficiency anemia. CE was suggested for surveillance in patients with polyposis syndromes or other small-bowel cancers, who required small-bowel studies. Colon capsule endoscopy should not be substituted routinely for colonoscopy. Patients should be made aware of the potential risks of CE including a failed procedure, capsule retention, or a missed lesion. Finally, standardized criteria for training and reporting in CE should be defined.

CONCLUSIONS

CE generally should be considered a complementary test in patients with gastrointestinal bleeding, Crohn's disease, or celiac disease, who have had negative or inconclusive endoscopic or imaging studies.

Polyp Detection and Segmentation from Video Capsule Endoscopy: A Review

Video capsule endoscopy (VCE) is used widely nowadays for visualizing the gastrointestinal (GI) tract. Capsule endoscopy exams are prescribed usually as an additional monitoring mechanism and can help in identifying polyps, bleeding, etc. To analyze the large scale video data produced by VCE exams, automatic image processing, computer vision, and learning algorithms are required. Recently, automatic polyp detection algorithms have been proposed with various degrees of success. Though polyp detection in colonoscopy and other traditional endoscopy procedure based images is becoming a mature field, due to its unique imaging characteristics, detecting polyps automatically in VCE is a hard problem. We review different polyp detection approaches for VCE imagery and provide systematic analysis with challenges faced by standard image processing and computer vision methods.

Accuracy of First- and Second-Generation Colon Capsules in Endoscopic Detection of Colorectal Polyps: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Colon capsule endoscopy (CCE) is a noninvasive technique used to explore the colon without sedation or air insufflation. A second-generation capsule was recently developed to improve accuracy of detection, and clinical use has expanded globally. We performed a systematic review and meta-analysis to assess the accuracy of CCE in detecting colorectal polyps.

METHODS

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and other databases from 1966 through 2015 for studies that compared accuracy of colonoscopy with histologic evaluation with CCE. The risk of bias within each study was ascertained according to Quality Assessment of Diagnostic Accuracy in Systematic Reviews recommendations. Per-patient accuracy values were calculated for polyps, overall and for first-generation (CCE-1) and second-generation (CCE-2) capsules. We analyzed data by using forest plots, the I² statistic to calculate heterogeneity, and meta-regression analyses.

RESULTS

Fourteen studies provided data from 2420 patients (1128 for CCE-1 and 1292 for CCE-2). CCE-2 and CCE-1 detected polyps >6 mm with 86% sensitivity (95% confidence interval [CI], 82%-89%) and 58% sensitivity (95% CI, 44%-70%), respectively, and 88.1% specificity (95% CI, 74.2%-95.0%) and 85.7% specificity (95% CI, 80.2%-90.0%), respectively. CCE-2 and CCE-1 detected polyps >10 mm with 87% sensitivity (95% CI, 81%-91%) and 54% sensitivity (95% CI, 29%-77%), respectively, and 95.3% specificity (95% CI, 91.5%-97.5%) and 97.4% specificity (95% CI, 96.0%-98.3%), respectively. CCE-2 identified all 11 invasive cancers detected by colonoscopy.

CONCLUSIONS

The sensitivity in detection of polyps >6 mm and >10 mm increased substantially between development of first-generation and second-generation colon capsules. High specificity values for detection of polyps by CCE-2 seem to be achievable with a 10-mm cutoff and in a screening setting.

Colon Capsule Endoscopy: Review and Perspectives

Colon capsule endoscopy utilizing PillCam COLON 2 capsule allows for visualization potentially of the entire colon and is currently approved for patients who cannot withstand the rigors of traditional optical colonoscopy (OC) and associated sedation as well as those that had an OC that was incomplete for technical reasons other than a poor preparation. We will then describe the prior experience and current status of colon capsule endoscopy.

Current status and future perspectives of capsule endoscopy

Small bowel capsule endoscopy (CE) was first introduced 15 years ago, and a large amount of literature has since been produced, focused on its indication, diagnostic yields, and safety. Guidelines that have made CE the primary diagnostic tool for small bowel disease have been created. Since its initial use in the small bowel, CE has been used for the esophagus, stomach, and colon. The primary indications for small bowel CE are obscure gastrointestinal bleeding, unexplained iron deficiency anemia, suspected Crohn's disease, small bowel tumors, nonsteroidal anti-inflammatory drug enteropathy, portal hypertensive enteropathy, celiac disease, etc. Colon CE provides an alternative to conventional colonoscopy, with possible use in colorectal cancer screening. Guidelines for optimal bowel preparation of CE have been suggested. The main challenges in CE are the development of new devices with the ability to provide therapy, air inflation for better visualization of the small bowel, biopsy sampling systems attached to the capsule, and the possibility of guiding and moving the capsule by an external motion controller. We review the current status and future directions of CE, and address all aspects of clinical practice, including the role of CE and long-term clinical outcomes.

Colorectal cancer

Colorectal cancer had a low incidence several decades ago. However, it has become a predominant cancer and now accounts for approximately 10% of cancer-related mortality in western countries. The 'rise' of colorectal cancer in developed countries can be attributed to the increasingly ageing population, unfavourable modern dietary habits and an increase in risk factors, such as smoking, low physical exercise and obesity. New treatments for primary and metastatic colorectal cancer have emerged, providing additional options for patients; these treatments include laparoscopic surgery for primary disease, more-aggressive resection of metastatic disease (such as liver and pulmonary metastases), radiotherapy for rectal cancer, and neoadjuvant and palliative chemotherapies. However, these new treatment options have had limited impact on cure rates and long-term survival. For these reasons, and the recognition that colorectal cancer is long preceded by a polypoid precursor, screening programmes have gained momentum. This Primer provides an overview of the current state of the art of knowledge on the epidemiology and mechanisms of colorectal cancer, as well as on diagnosis and treatment.

Controversies in colorectal cancer screening

BACKGROUND

Colorectal cancer (CRC) is one of the most common cancers worldwide and a good candidate for screening programmes. However, there is controversy concerning which of the available screening tests should be used.

SUMMARY

There is general agreement that screening for CRC in the asymptomatic population should begin at the age of 50. Several different screening methods are available which can be separated into those that mainly detect cancers: faecal occult blood tests [guaiac (FOBT) and immunochemical (FIT)], genetic stool tests, blood tests and the M2-pyruvate kinase (M2-PK) test. Methods that detect cancers and polyps are colonoscopy, sigmoidoscopy, CT-colonography (CT-C) and colon capsule endoscopy. The only tests for which a reduction in CRC mortality compared to no screening have been proven in randomized trials are FOBT and sigmoidoscopy. Several trials suggest that FIT are superior to FOBT in terms of detection rates of cancers and advanced adenomas and possibly compliance. There is indirect evidence suggesting efficacy of colonoscopy as a screening test. The role of CT-C is controversial. There is data suggesting a good sensitivity for neoplasia >9 mm with a lower sensitivity for smaller neoplasia. However, radiation exposure is considered a major limitation in some countries. Unresolved questions include the lesion cut-off for referral to colonoscopy and work-up of extracolonic findings. For other methods, like genetic stool testing using newer markers, blood tests, capsule endoscopy and M2-PK, there is currently insufficient data on screening of the asymptomatic population. Key Messages: Colorectal screening is recommended and should be performed in the form of an organized programme. If detection of early-stage cancers is the aim of a screening programme, FIT seem to be superior to FOBT. If detection and removal of adenomas is the aim of a screening programme, endoscopic methods seem to be good alternatives. Sigmoidoscopy is easier to perform but will likely only have an effect on distal cancers. Colonoscopy is more invasive but enables inspection of the whole colon. The role of CT-C, capsule endoscopy, genetic stool tests, blood tests and M2-PK is currently unknown.

Update on colon cancer screening: recent advances and observations in colorectal cancer screening

There have been many recent advances and observations regarding colorectal cancer (CRC) screening. New CRC surveillance guidelines have been published to help endoscopists with the management of important clinical issues such as serrated polyps. There have been several important large studies examining the impact of endoscopic process measures such as bowel prep, withdrawal time, and adenoma detection rate on CRC screening. In addition, there have been technical advances in CT colonography including the development of exams that do not require a bowel preparation. Other new technology such as colon capsule endoscopy may aid endoscopists in the challenge of completing the evaluation of the colon in those patients with an incomplete colonoscopy. Finally, there have been large studies which examine the performance characteristics of the so-called non-invasive CRC screening tests such as fecal immunochemical test (FIT) and fecal DNA.

Recent trends in diagnostic techniques for inflammatory bowel disease

Although ileocolonoscopy is the gold standard for diagnosis of inflammatory bowel disease and is useful for assessing the disease severity in the colon and terminal ileum, several alternative diagnostic techniques have been developed recently. For ulcerative colitis (UC), magnification colonoscopy, endocytoscopy, and confocal laser endomicroscopy enable assessment of histological inflammation without the need for biopsy. Capsule endoscopy is useful for detection of small intestinal and colonic lesions in both female and male patients. For UC, capsule endoscopy may be useful for evaluating colonic inflammation in patients with a previous poor colonoscopy experience, while it should be used only in Crohn's disease (CD) patients with unexplained symptoms when other examinations are negative. Magnetic resonance enterography (MRE) is particularly useful for detecting transmural inflammation, stenosis, and extraintestinal lesions, including abscesses and fistulas. MRE is also useful when evaluating small and large intestinal lesions, even in cases with severe strictures in which full evaluation of the small bowel would be virtually impossible using other devices. Therefore, the appropriate diagnostic devices for detecting CD lesions in the small and large intestine should be used.

Capsule endoscopy--not just for the small bowel: a review

Video capsule endoscopy is being increasingly used to investigate the esophagus and colon as well as the small bowel. With the advancement of technology used in capsule endoscopy there have been marked improvements in diagnostic rates for colon capsule endoscopy in the detection of colonic polyps and colorectal cancer. It is also being increasingly used in the field if inflammatory bowel disease to investigate for mucosal inflammation and could potentially be used to assess mucosal healing. It also has role in completing the evaluation of colonic pathology in those in whom colonoscopy is incomplete. Esophageal capsule is preferred by patients over esophagogastroduodenoscopy (EGD) but as yet does not rival EGD in terms of diagnostic accuracy however the advent of magnetically steerable capsules may improve this. This review covers advances in the field of colon and esophageal capsule endoscopy; it covers diagnostic capabilities of these 2 tools as well as technical aspects of both procedures and preparation.

The role of capsule endoscopy in assessing mucosal inflammation in ulcerative colitis

Assessment of mucosal inflammation is important in the management of patients with ulcerative colitis (UC). Colon capsule endoscopy (CCE) has recently been shown to be effective in colorectal polyp detection. However, its role in the evaluation of mucosal inflammation in UC is unclear. This systematic review aims to clarify the state of the art with an evidence-based summary of current studies on the utility of CCE in UC. The overall results show that the accuracy of CCE for assessment of mucosal inflammation in UC appeared to be comparable with that of colonoscopy. Long-term follow-up studies with larger sample size are needed to further validate the utility of CCE in the management of UC subjects in clinical practice.

Is there a role for colon capsule endoscopy beyond colorectal cancer screening? A literature review

Colon capsule endoscopy is recommended in Europe alternatively to colonoscopy for colorectal cancer screening in average risk individuals. The procedure has also been proposed to complete colon examination in cases of incomplete colonoscopy or when colonoscopy is contraindicated or refused by the patient. As tissue samples cannot be obtained with the current capsule device, colon capsule endoscopy has no place in diagnosing ulcerative colitis or in dysplasia surveillance. Nevertheless, data are accumulating regarding its feasibility to examine ulcerative colitis disease extent and to monitor disease activity and mucosal healing, even though reported results on the capsule's performance in this field vary greatly. In this review we present the currently available evidence for the use of colon capsule endoscopy to complement colonoscopy failure to reach the cecum and its use to evaluate ulcerative colitis disease activity and extent. Moreover, we provide an outlook on issues requiring further investigation before the capsule becomes a mainstream alternative to colonoscopy in such cases.

Modified bowel preparation regimen for use in second-generation colon capsule endoscopy in patients with ulcerative colitis

BACKGROUND AND AIM

We have reported that second-generation colon capsule endoscopy (CCE-2) might be feasible for assessing the severity of mucosal inflammation in ulcerative colitis (UC). However, because of the low rate (69%) of complete evaluation of the colon and owing to inadequate cleansing. We believe that the method of bowel preparation could be improved by reducing volume. In the present study, we attempted to improve the colon-cleansing regimen in order to optimize the usefulness of CCE-2 in the management of UC patients.

METHODS

Twenty patients with histologically confirmed UC were enrolled. Patients took a maximum 2.2 L lavage solution (polyethylene glycol solution and magnesium citrate) in two or three divided doses. To assess the effectiveness of the modified bowel preparation regimen, we evaluated the rate of total colonobservation, the effectiveness of bowel cleansing, andinterobserver agreement in assessing UC disease activity. We used a four-point grading scale (poor, fair, good, and excellent) for evaluating the quality of bowel cleansing. Matts' endoscopic score was used to evaluate disease activity.

RESULTS

The rate of total colon observation was 85%, and 15 patients (75%) excreted the CCE-2 within 8 h. The proportion of excellent plus good cleansing was approximately 60%. There was a substantial interobserver agreement (κ = 0.777) in assessment of overall cleansing, which was still substantial at the fair cleansing level (κ = 0.700).

CONCLUSION

Using CCE-2, the modified bowel preparation regimen, with reduced volume has the potential to succeed in the evaluation of mucosal severity in UC.

Automated polyp detection in colon capsule endoscopy

Colorectal polyps are important precursors to colon cancer, a major health problem. Colon capsule endoscopy is a safe and minimally invasive examination procedure, in which the images of the intestine are obtained via digital cameras on board of a small capsule ingested by a patient. The video sequence is then analyzed for the presence of polyps. We propose an algorithm that relieves the labor of a human operator analyzing the frames in the video sequence. The algorithm acts as a binary classifier, which labels the frame as either containing polyps or not, based on the geometrical analysis and the texture content of the frame.We assume that the polyps are characterized as protrusions that are mostly round in shape. Thus, a best fit ball radius is used as a decision parameter of the classifier. We present a statistical performance evaluation of our approach on a data set containing over 18 900 frames from the endoscopic video sequences of five adult patients. The algorithm achieves 47% sensitivity per frame and 81% sensitivity per polyp at a specificity level of 90%. On average, with a video sequence length of 3747 frames, only 367 false positive frames need to be inspected by an operator.

Capsule endoscopy in patients refusing conventional endoscopy

Capsule endoscopy is nowadays the diagnostic technique of choice in the study of small bowel pathologies, allowing the non-invasive study of the entire mucosa. This has led, together with new technical advances, to the creation of two new models (PillCam ESO and PillCam Colon) for the study of esophageal and colonic diseases. These two new capsules offer an interesting alternative to conventional endoscopy in the study of the upper and lower digestive tracts, because traditional endoscopy is often unpleasant and uncomfortable for the patient, can be painful, often requires moderate or deep sedation and is not without complications (hemorrhage, perforation, etc.). PillCam Colon is particularly important for its usefulness in the diagnosis of colonic polyps, and is a potentially useful tool in cases of incomplete colonoscopy or in colorectal cancer screening, even more when most patients are reluctant to undergo screening programs due to the said disadvantages of conventional colonoscopy. This article discusses the advantages of capsule endoscopy over conventional endoscopy, its current application possibilities and indications in routine clinical practice. In the various sections of the work, we assess the application of endoscopic capsule in different sections of the digestive tract (esophagus, stomach, and colon) and finally the potential role of panendoscopy with PillCam Colon.

Bowel preparation regimens for colon capsule endoscopy: a review

Colon capsule endoscopy (CCE) is being actively evaluated as an emerging complementary or alternative procedure for evaluation of the colon. The yield of CCE is significantly dependent on the quality of bowel preparation. In addition to achieving a stool-free colon the bowel preparation protocols need to decrease bubble effect and aid propulsion of the capsule. An extensive English literature search was done using PubMed with search terms of colon capsule endoscopy, PillCam and bowel preparation. Full-length articles which met the criteria were included for review. A total of 12 studies including 1149 patients were reviewed. There was significant variability in the type of bowel preparation regimens. Large-volume (3-4 liters) polyethylene glycol (PEG) was the most widely used laxative. Lower volumes of PEG showed comparable results but larger studies are needed to determine efficacy. Sodium phosphate was used as an effective booster in most studies. Magnesium citrate and ascorbic acid are emerging as promising boosters to replace sodium phosphate when it is contraindicated. The potential benefit of prokinetics needs further evaluation. Over the past decade there has been significant improvement in the bowel preparation regimens for CCE. Further experience and studies are likely to standardize the bowel preparation regimens before CCE is adopted into routine clinical practice.

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.

Colon capsule endoscopy is feasible to perform after incomplete colonoscopy and guides further workup in clinical practice

BACKGROUND

Colon capsule endoscopy (CCE) could be an option to examine the colon after incomplete colonoscopy.

OBJECTIVE

To investigate the extent that CCE complements incomplete colonoscopy and guides further workup.

DESIGN

Prospective, follow-up study.

SETTING

Three tertiary-care centers.

PATIENTS

Consecutive outpatients after colonoscopy failure; 1-year study period.

INTERVENTION

Patients underwent CCE either immediately after colonoscopy or were rescheduled. Further investigations were guided by the results of CCE. Patients were followed as long as 2 years.

RESULTS

We studied 75 outpatients; 39 had a screening colonoscopy. One third of the patients underwent CCE immediately after colonoscopy. Overall, CCE reached or went beyond the colon segment at which colonoscopy stopped in 68 patients (91%). CCE technically complemented difficult colonoscopy independently of whether same-day CCE was performed (24 [96%]) or was not performed (44 [88%]). CCE detected additional significant findings in 36% of the same-day CCE cases and in 48% of the rescheduled ones. Two patients in the same-day group and 13 in the rescheduled CCE group underwent further colon examination that revealed additional significant findings in 3 of them. Ten percent of the patients reported mild adverse events (AE). If needed, 63 participants (84%) were willing to repeat CCE. Follow-up has not identified symptomatic missed colon cancers.

LIMITATIONS

Selected patient population, first-generation colon capsule, old preparation scheme.

CONCLUSION

CCE performed immediately or at a scheduled date after colonoscopy failure is feasible and safe. CCE after incomplete colonoscopy appears to yield significant findings, guide further workup, and has high patient acceptance.

Colon capsule endoscopy: detection of colonic polyps compared with conventional colonoscopy and visualization of extracolonic pathologies

BACKGROUND

Conventional colonoscopy (CC) is the gold standard for diagnostic examination of the colon. However, the overall acceptance of this procedure is low due to patient fears of complications or embarrassment. Colon capsule endoscopy (CCE) represents a minimally invasive, patient-friendly procedure that offers complete visualization of the entire intestine.

OBJECTIVE

To assess the PillCam Colon 2 (Given Imaging Ltd, Israel) capsule with regard to feasibility, sensitivity and specificity for the detection of colonic pathologies and additional recorded extracolonic findings.

METHODS

CCE was performed before CC in patients indicated for CC for known or suspected colonic disease. The results of both techniques were compared with regard to polyp detection. Additionally, bowel preparation and extracolonic pathologies were analyzed.

RESULTS

Twenty-four patients (mean age 51.1 years) were included in the analysis. Visualization of the colon was complete in 23 CCs and 17 CCEs. No adverse events or major technical failures occurred. CC detected 47 polyps and CCE detected 43 polyps of any size (per-finding sensitivity 90.9%, specificity 67.6%). The accuracy of CCE in detecting polyp carriers was 81.5% (per-patient analysis). On average, the colon was adequately cleansed in 90.1% of patients. CCE identified esophageal, gastric and small bowel pathologies in seven (24%), nine (38%) and 14 (58%) patients, respectively.

CONCLUSIONS

CCE proved to be technically feasible and safe. Acceptable sensitivity and moderate specificity levels in polyp detection were recorded. Bowel preparation was adequate in most patients. Because extracolonic pathologies were effectively visualized, new indications for the PillCam Colon 2 may be defined.

Wireless capsule endoscopy

Over the last decade, WCE has established itself as a valuable test for imaging the small intestine. It is a safe and relatively easy procedure to perform that can provide valuable information in the diagnosis of small-bowel conditions. Its applications still remain limited within the esophagus and colon. Future developments may include improving visualization within the esophagus and developing technologies that may allow manipulation of the capsule within the GI tract and biopsy capabilities.

New optical method for enhanced detection of colon cancer by capsule endoscopy

PillCam®COLON capsule endoscopy (CE), a non-invasive diagnostic tool of the digestive tract, has dramatically changed the diagnostic approach and has become an attractive alternative to the conventional colonoscopy for early detection of colorectal cancer. However, despite the significant progress and non-invasive detection capability, studies have shown that its sensitivity and specificity is lower than that of conventional colonoscopy. This work presents a new optical detection method, specifically tailored to colon cancer detection and based on the well-known optical properties of immune-conjugated gold nanorods (GNRs). We show, on a colon cancer model implanted in a chick chorioallantoic membrane (CAM), that this detection method enables conclusive differentiation between cancerous and normal tissues, where neither the distance between the light source and the intestinal wall, nor the background signal, affects the monitored signal. This optical method, which can easily be integrated in CE, is expected to reduce false positive and false negative results and improve identification of tumors and micro metastases.

Second-generation colon capsule endoscopy is feasible in the out-of-clinic setting

BACKGROUND

No colorectal imaging test may be performed on an out-of-clinic basis. This represents a major drawback compared with fecal tests. Because colon capsule endoscopy (CCE) automatically detects small bowel mucosa, it has the potential to become the first colorectal imaging test to be performed out-of-clinic. This study aimed to evaluate the feasibility and efficiency of CCE when offered as an out-of-clinic procedure.

METHODS

Patients with known or suspected colonic diseases who had up to 40 min of travel time from clinic to home were offered CCE as an out-of-clinic procedure. These patients were provided with four numbered vials (1 with metoclopramide, 2 with sodium phosphate, 1 with bisacodyl) and detailed instructions on how to interact with data-recorder automatic signaling. Patient compliance with data-recorder instructions, CCE excretion, and detection rates were prospectively assessed.

RESULTS

The study enrolled 41 patients (29 men) with a mean age of 57 years. According to data recorder DR3-registered alerts, 14 patients (34 %) required a single booster only, 27 patients (66 %) required two boosters, and 13 patients (32 %) required a suppository. Comparison of the DR3 alerts with the returned vials showed that patient compliance to DR3 alerts was 100 %. During the procedure, 16 patients (39 %) called the physician/clinic from home. In 85 % of the cases, the CCE was excreted within the battery operating time. Lesions size 6 mm or larger were detected in 10 (24 %) of the 41 patients.

CONCLUSIONS

As an out-of-clinic procedure, CCE is feasible and easily performed. A home-based procedure may be associated with better acceptability and potentially with increased adherence to Colorectal cancer screening.

New platforms and devices in colonoscopy

Gastrointestinal endoscopy is a rapidly evolving field. Techniques in endoscopy continue to become more sophisticated, as do the devices and platforms, particularly in colonoscopy and endoscopic resection. This article reviews new platforms for endoscopic imaging of the colon, and discusses new endoscopic accessories and developments in endoscopic resection.

Applicability of second-generation colon capsule endoscope to ulcerative colitis: a clinical feasibility study

BACKGROUND AND AIM

Colon capsule endoscopy has already been used for colon visualization and detection of polyps but its applicability to inflammatory bowel disease is still unconfirmed. The aim of this study was to assess the feasibility of evaluating the severity of mucosal inflammation in patients with ulcerative colitis (UC) using a second-generation colon capsule endoscope (CCE-2).

METHODS

Forty patients with histological confirmed diagnosis of UC were enrolled. Low-volume (2 L) polyethylene glycol solution with prokinetics (mosapride citrate and metoclopramide) regimen was used for the bowel preparation. In Phase 1, consisting of 10 patients, to confirm appropriate CCE-2 bowel preparation for UC. In Phase 2, consisting of 30 patients, CCE-2 was performed with a fixed bowel preparation regimen. CCE-2 findings were recorded for 8 h starting from capsule ingestion and conventional colonoscopy was subsequently performed on the same day. CCE-2 procedure completion rate and the colon cleansing level with a 4-point grading scale (poor, fair, good, and excellent) were evaluated in Phase 2. Correlations between Matts endoscopic scores as judged by CCE-2 and conventional colonoscopy were calculated.

RESULTS

CCE-2 procedure was completed within 8 h in 69% of the patients. The proportion of patients with good or excellent cleansing level was below 50%. However, Matts endoscopic scores determined by CCE-2 showed a strong correlation with scores obtained by conventional colonoscopy (average ρ = 0.797).

CONCLUSIONS

Although modifications in bowel preparation are needed, CCE-2 might be feasible for assessing the severity of mucosal inflammation in patients with UC.

Effects of colon capsule endoscopy on medical decision making in patients with incomplete colonoscopies

BACKGROUND & AIMS

Colon capsule endoscopy (CCE) is an orally ingested colon imaging tool used to evaluate patients with colonic disease. We evaluated the efficacy of CCE in helping physicians make decisions about patients with incomplete conventional colonoscopies (ICCs).

METHODS

In a prospective study, we analyzed data from 34 patients with nonocclusive ICC who were eligible for CCE between May 2010 and April 2011; patients with colectomy, occlusive lesions, or inadequate bowel cleansing for the colonoscopy were excluded. Two experienced observers who were blinded to colonoscopy findings analyzed the CCE data. Four months later, medical records were reviewed to determine the effects of CCE on medical decision making. CCE was considered conclusive when the findings facilitated a medical decision.

RESULTS

Bowel cleanliness was good or excellent for 22 patients (64.7%). CCE exceeded the most proximal point reached by conventional colonoscopy in 29 patients (85.3%). CCE findings allowed formulation of a specific medical plan for 20 patients (58.8%); 12 (35.2%) had irrelevant or no lesions, so the study was concluded; 7 (20.5%) underwent polypectomy or surgery for advanced colorectal neoplasia; and 1 (3%) was treated for Crohn's disease. Inconclusive CCEs resulted from poor preparation of the bowel (n = 12) and excessively slow (n = 1) or rapid (n = 1) capsule transit.

CONCLUSIONS

CCE might be an alternative procedure to complete colon examination in patients with nonocclusive ICC.

Colorectal cancer screening--optimizing current strategies and new directions

The first evidence that screening for colorectal cancer (CRC) could effectively reduce mortality dates back 20 years. However, actual population screening has, in many countries, halted at the level of individual testing and discussions on differences between screening tests. With a wealth of new evidence from various community-based studies looking at test uptake, screening-programme organization and the importance of quality assurance, population screening for CRC is now moving into a new realm, promising better results in terms of reducing CRC-specific morbidity and mortality. Such a shift in the paradigm requires a change from opportunistic, individual testing towards organized population screening with comprehensive monitoring and full-programme quality assurance. To achieve this, a combination of factors--including test characteristics, uptake, screenee autonomy, costs and capacity--must be considered. Thus, evidence from randomized trials comparing different tests must be supplemented by studies of acceptance and uptake to obtain the full picture of the effectiveness (in terms of morbidity, mortality and cost) the different strategies have. In this Review, we discuss a range of screening modalities and describe the factors to be considered to achieve a truly effective population CRC screening programme.

Suture marker lesion detection in the colon by self-stabilizing and unmodified capsule endoscopes: pilot study in acute canine models

BACKGROUND

Capsule endoscopy is a noninvasive method for examining the small intestine. Recently, this method has been used to visualize the colon. However, the capsule often tumbles in the wider colon lumen, resulting in potentially missed pathology. In addition, the capsule does not have the ability to distend collapsed segments of the organ. Self-stabilizing capsule endoscopy is a new method of visualizing the colon without tumbling and with the ability to passively distend colon walls.

OBJECTIVE

To quantitatively compare the detection rate of intraluminal suture marker lesions for colonoscopy by using a custom-modified, self-stabilizing capsule endoscope (SCE); an unmodified capsule endoscope (CE) of the same brand; and a standard colonoscope.

DESIGN

Four mongrel dogs underwent laparotomy and the implantation of 5 to 8 suture markers to approximate colon lesions. Each dog had both capsule endoscopy and self-stabilizing capsule endoscopy, administered consecutively in random order. In each case, the capsule was inserted endoscopically into the proximal lumen of the colon followed by pharmacologically induced colon peristalsis to propel it distally through the colon. Blinded standard colonoscopy was performed by an experienced gastroenterologist after the capsule endoscopies.

SETTING

Experimental study in a live canine model.

SUBJECTS

Four dogs.

INTERVENTION

Laparotomy, capsule endoscopy, colonoscopy.

MAIN OUTCOME MEASUREMENTS

Comparison of the marker detection rate of the SCE to that of the unmodified MiroCam CE and a colonoscope.

RESULTS

The average percentages of the marker detection rate for unmodified capsule endoscopy, self-stabilizing capsule endoscopy, and colonoscopy, respectively, were 31.1%, 86%, and 100% (P < .01), with both self-stabilizing capsule endoscopy and colonoscopy performing significantly better than the unmodified capsule endoscopy.

LIMITATIONS

Acute canine model, suture markings poorly representative of epithelial polyps, limited number of animals.

CONCLUSION

The proposed self-stabilizing capsule endoscope delivered a significant improvement in detection rates of colon suture markings when compared with the unmodified capsule endoscope.

Accuracy of automatic detection of small-bowel mucosa by second-generation colon capsule endoscopy

BACKGROUND

Colon capsule endoscopy (CCE) is a noninvasive technique for the detection of colorectal lesions. However, for CCE to be offered as an out-of-clinic procedure, the system needs to automatically alert the patient when to ingest the laxative (booster).

OBJECTIVE

We tested the reliability of the automatic detection of the small-bowel (SB) mucosa and the subsequent alert for booster ingestion by the Data Recorder 3 (DR3) of the second-generation CCE (CCE-2).

DESIGN AND SETTING

Retrospective analysis.

PATIENTS AND INTERVENTION

Data from 120 consecutive cases of CCE-2 were analyzed for proper DR3 automatic detection of the capsule entering the SB to prompt the patient to ingest the laxative booster.

MAIN OUTCOME MEASUREMENTS

Accuracy of the DR3 for detecting the SB mucosa.

RESULTS

The DR3 correctly identified the proper time for ingestion of the laxative (booster) in 118 of 120 cases, corresponding to a sensitivity of 98.3% (95% CI, 97%-100%). The median time difference between DR3 automatic SB detection to the observed entrance of the capsule into the SB was 3 minutes 30 seconds (interquartile range 2 minutes 35 seconds to 5 minutes 57 seconds).

LIMITATION

Retrospective analysis.

CONCLUSIONS

The 98.3% sensitivity of the DR3 for automatic identification of the SB mucosa and subsequent alert for the first laxative (booster) ingestion paves the way for CCE-2 to be offered as an out-of-clinic procedure.

Advances in gastrointestinal endoscopy

Gastrointestinal endoscopy has undergone a remarkable expansion in its capabilities as a result of sophisticated technological advances in recent years. New imaging technologies, novel ablation and resection techniques, cutting-edge endoscope development and creative extraluminal applications have taken gastrointestinal endoscopy to an exciting new level. An update on some of these advances is presented for the physician audience.

The race for mainstream gastrointestinal endoscopy: frontrunners

In recent years, gastrointestinal endoscopy has evolved and branched out from a primary naked-eye diagnostic technique to a multitude of sophisticated investigative and therapeutic procedures. While many of the new endoscopic techniques are currently too complex or expensive to make it to mainstream clinical practice, others are already bringing major progress to the management of digestive diseases. In this review we will discuss a selected group of the emerging techniques and technologies used to increase the diagnostic yield in the colon and small intestine, including Third Eye® Retroscopes®, colon capsule endoscopy, spiral enteroscopy and confocal laser endomicroscopy. We will also discuss over-the-scope clip devices, a relatively simple and inexpensive tool potentially capable of noninvasive closing intestinal perforations and allowing the removal of infiltrating tumors.

Role of capsule endoscopy as a screening tool for colorectal cancer

SUMMARY Colon capsule endoscopy is currently under evaluation to become a noninvasive colorectal cancer screening test. The sensitivity and specificity of colon capsule endoscopy for colorectal polyps and cancer are improving with ongoing technical refinements to the capsule and recording device, with sensitivity as high as 84% for polyps greater than 1 mm in size. Specificity for smaller polyps, however, remains suboptimal. Colon capsule endoscopy requires extensive bowel preparation to ensure adequate colon cleansing and complete colonic evaluation. The complication rate for colon capsule endoscopy is unclear, but may be lower than that for small bowel capsule endoscopy. The role of colon capsule endoscopy in colorectal cancer screening has not been fully defined, as technical, logistical and implementation issues remain.

New vision in video capsule endoscopy: current status and future directions

Now, more than 10 years after the approval of video capsule endoscopy (VCE), the technology has become an essential component in the management of several clinical conditions. Currently, two capsules are approved in the USA for visualizing the small bowel mucosa, one capsule is authorized for oesophageal assessment and several others are in use or under evaluation worldwide. New investigations have focused on optical improvements, advances in intestinal cleansing and risk reduction strategies to optimize VCE methodologies in clinical care. Established indications diagnosed using VCE include unexplained gastrointestinal bleeding, small bowel Crohn's disease (in adults and children >10 years old), localization of small bowel tumours and a broad range of miscellaneous abnormalities. Investigations are ongoing to determine the utility of VCE in colon cancer screening, assessment of oesophageal disorders and diagnosis of coeliac disease. Active research is in progress into ways to improve the efficacy of VCE recording interpretation, prolong imaging time and further enhance optics and imaging methods. To expand the potential utility of VCE, novel devices that can manoeuvre within or insufflate the gut lumen, tag or biopsy suspect lesions, or target drug delivery to specific sites are in development. To facilitate these advances, consortia have been organized to promote innovative VCE technologies.