Colon capsule endoscopy compared with conventional colonoscopy for the detection of colorectal neoplasms

Colon capsule endoscopy to screen for colorectal neoplasia in those with family histories of colorectal cancer

BACKGROUND AND AIMS

Colon capsule endoscopy (CCE) has been recognized as an alternative for colorectal cancer (CRC) screening in average-risk people. Our aim was to prospectively assess the accuracy of CCE as a screening tool in first-degree relatives (FDRs) of people with CRC by using optical colonoscopy (OC) with segmental unblinding as the reference standard.

METHODS

Consecutive patients admitted with a CRC diagnosis (index cases) were prospectively evaluated and invited to contact their FDRs. Available FDRs were invited to undergo CCE and OC on the following day, with segmental unblinding of CCE results. Sensitivity, specificity, and predictive values/negative predictive values (PPV/NPV) of CCE were assessed for detecting patients with any polyp ≥6 mm and ≥10 mm.

RESULTS

A total of 177 FDRs (median age 57.0 years, 54.8% female) identified from 211 index cases were included. Both CCE and OC were completed in all the included FDRs. Overall, CCE identified 51 of 56 FDRs with polyps ≥6 mm (sensitivity 91%; 95% CI, 81-96) and correctly classified as negative 107 of 121 participants without lesions ≥6 mm (specificity 88%; 95% CI, 81-93). Per-patient positive and negative predictive values for ≥6 mm lesions were 78% (95% CI, 67-87) and 95% (95% CI, 90-98), respectively. CCE detected 24 of 27 patients with polyps ≥10 mm and correctly classified as negative 142 of 150 patients, corresponding to 89% sensitivity and 95% specificity. Post-CCE referral rates to colonoscopy were 37% and 18%, respectively.

CONCLUSIONS

CCE is an accurate method to screen FDRs of patients with CRC and could be offered as an alternative to those who decline or are unfit for colonoscopy screening. (Clinical trial registration number: NCT01184781.).

Overview of technical solutions and assessment of clinical usefulness of capsule endoscopy

The paper presents an overview of endoscopic capsules with particular emphasis on technical aspects. It indicates common problems in capsule endoscopy such as: (1) limited wireless communication (2) the use of capsule endoscopy in the case of partial patency of the gastrointestinal tract, (3) limited imaging area, (4) external capsule control limitations. It also presents the prospects of capsule endoscopy, the most recent technical solutions for biopsy and the mobility of the capsule in the gastrointestinal tract. The paper shows the possibilities of increasing clinical usefulness of capsule endoscopy resulting from technological limitations. Attention has also been paid to the current role of capsule endoscopy in screening tests and the limitations of its effectiveness. The paper includes the author's recommendations concerning the direction of further research and the possibility of enhancing the scope of capsule endoscopy.

Overview of technical solutions and assessment of clinical usefulness of capsule endoscopy

The paper presents an overview of endoscopic capsules with particular emphasis on technical aspects. It indicates common problems in capsule endoscopy such as: (1) limited wireless communication (2) the use of capsule endoscopy in the case of partial patency of the gastrointestinal tract, (3) limited imaging area, (4) external capsule control limitations. It also presents the prospects of capsule endoscopy, the most recent technical solutions for biopsy and the mobility of the capsule in the gastrointestinal tract. The paper shows the possibilities of increasing clinical usefulness of capsule endoscopy resulting from technological limitations. Attention has also been paid to the current role of capsule endoscopy in screening tests and the limitations of its effectiveness. The paper includes the author's recommendations concerning the direction of further research and the possibility of enhancing the scope of capsule endoscopy.

Design of wormlike automated robotic endoscope: dynamic interaction between endoscopic balloon and surrounding tissues

BACKGROUND

The current design of capsule endoscope is limited by the inability to control the motion within gastrointestinal tract. The rising incidence of gastrointestinal cancers urged improvement in the method of screening endoscopy.

OBJECTIVES

This preclinical study aimed to design and develop a novel locomotive module for capsule endoscope. We investigated the feasibility and physical properties of this newly designed caterpillar-like capsule endoscope with a view to enhancing screening endoscopy.

DESIGN

This study consisted of preclinical design and experimental testing on the feasibility of automated locomotion for a prototype caterpillar endoscope. The movement was examined first in the PVC tube and then in porcine intestine. The image captured was transmitted to handheld device to confirm the control of movement. The balloon pressure and volume as well as the contact force between the balloon and surroundings were measured when the balloon was inflated inside (1) a hard PVC tube, (2) a soft PVC tube, (3) muscular sites of porcine colons and (4) less muscular sites of porcine colons.

RESULTS

The prototype caterpillar endoscope was able to move inward and backward within the PVC tubing and porcine intestine. Images were able to be captured from the capsule endoscope attached and being observed with a handheld device. Using the onset of a contact force as indication of the buildup of the gripping force between the balloon and the lumen walls, it is concluded from the results of this study that the rate of change in balloon pressure and volume is two good estimators to optimize the inflation of the balloon.

CONCLUSION

The results of this study will facilitate further refinement in the design of caterpillar robotic endoscope to move inside the GI tract.

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.

Public preferences for colorectal cancer screening tests: a review of conjoint analysis studies

A wide range of screening technologies is available for colorectal cancer screening. There is demand to discover public preferences for these tests on the rationale that tailoring screening to preferences may improve uptake. This review describes a type of study (conjoint analysis) used to assess people's preferences for colorectal cancer screening tests and critically evaluates research quality using a recently published set of guidelines. Most primary studies assessed preferences for colonoscopy and fecal occult blood testing but newer technologies (e.g., capsule endoscopy) have not yet been evaluated. Although studies often adhered to guidelines, there was limited correspondence between stated preferences and actual screening behavior. Future research should investigate how studies can go beyond the guidelines in order to improve this and also explore how test preferences may differ by important population subgroups.

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.

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.

Towards universal screening for colon cancer: a cheap, reliable, noninvasive test using gene expression analysis of rectal swabs

Though colon cancer is the second leading cause of cancer deaths in the US, it is entirely preventable through early screening to detect and remove adenomatous polyps. Colonoscopy has long been regarded as the "gold standard" but is expensive, invasive, and uncomfortable, and only about half those considered at risk for colon cancer currently submit to colonoscopy or to less reliable alternatives such as fecal occult blood test. Here we describe the use of gene expression analysis to detect altered expression of certain genes associated with not only colon cancer but also polyps. The analysis can be performed on rectal swabs, with specimens provided in a routine doctor's office visit. The existence of this cheap and simple test, together with an active program to encourage individuals to submit to screening, could help eradicate colon cancer.