Prospective multicenter performance evaluation of the second-generation colon capsule compared with colonoscopy

Experimental assessment of a novel robotically-driven endoscopic capsule compared to traditional colonoscopy

BACKGROUND

Despite colonoscopy represents the conventional diagnostic tool for colorectal pathology, its undeniable discomfort reduces compliance to screening programmes.

AIMS

To evaluate feasibility and accuracy of a novel robotically-driven magnetic capsule for colonoscopy as compared to the traditional technique.

METHODS

Eleven experts and eleven trainees performed complete colonoscopy by robotic magnetic capsule and by conventional colonoscope in a phantom ex vivo model (artificially clean swine bowel). Feasibility, overall accuracy to detect installed pins, procedure elapsed time and intuitiveness were measured for both techniques in both operator groups.

RESULTS

Complete colonoscopy was feasible in all cases with both techniques. Overall 544/672 pins (80.9%) were detected by experimental capsule procedure, while 591/689 pins (85.8%) were detected within conventional colonoscopy procedure (P=ns), thus establishing non-inferiority. With the experimental capsule procedure, experts detected 74.2% of pins vs. 87.6% detected by trainees (P<0.0001). Overall time to complete colon inspection by robotic capsule was significantly higher than by conventional colonoscopy (556±188s vs. 194±158s, respectively; P=0.0001).

CONCLUSION

With the limitations represented by an ex vivo setting (artificially clean swine bowel and the absence of peristalsis), colonoscopy by this novel robotically-driven capsule resulted feasible and showed adequate accuracy compared to conventional colonoscopy.

Clinical applications of small bowel capsule endoscopy

Video capsule endoscopy has revolutionized our ability to visualize the entire small bowel mucosa. This modality is established as a valuable tool for the diagnosis of obscure gastrointestinal bleeding, Crohn's disease, small bowel tumors, and other conditions involving the small bowel mucosa. This review includes an overview of the current and potential future clinical applications of small bowel video endoscopy.

Clinical applications of small bowel capsule endoscopy

Video capsule endoscopy has revolutionized our ability to visualize the entire small bowel mucosa. This modality is established as a valuable tool for the diagnosis of obscure gastrointestinal bleeding, Crohn’s disease, small bowel tumors, and other conditions involving the small bowel mucosa. This review includes an overview of the current and potential future clinical applications of small bowel video endoscopy.

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.

The future of capsule endoscopy

Small-bowel capsule endoscopy (SBCE) was introduced 11 years ago by Given Imaging and is becoming the gold standard for small-bowel examination. This major step in the field of digestive medicine has opened the possibility of promising non-invasive explorations of the esophagus, stomach, and colon. SBCE can be used to overcome the inherent limitations of enteroscopy, especially in the West, where the capsule has been available since 2001. Obscure gastrointestinal (GI) bleeding with normal findings on upper and lower endoscopy remains the most important indication, and suspected Crohn's disease is also a well-accepted indication. Findings from a capsule investigation may warrant therapeutic endoscopy, but in many cases, SBCE avoids this useful but time-consuming endoscopic procedure. The use of a colon capsule for colorectal cancer screening when traditional colonoscopy is contraindicated or impossible is undergoing clinical trials. Early results seem promising, but control of colonic motility is still cumbersome, and patient preparation remains the most important drawback. We performed the first clinical trial in humans of a magnetically guided gastric capsule that offers the possibility of investigation with a capsule that can be controlled spatially. To date, we have carried out procedures in more than 400 patients and volunteers, with impressive results compared with high-definition gastroscopy. Even though endoscopy remains the most important tool in the GI field, capsules offer promising new possibilities.

Video capsule endoscopy of the small bowel

PURPOSE OF REVIEW

Small bowel capsule endoscopy (SBCE) was introduced 13 years ago by Given Imaging (Yokneam, Israel). It has become one of the most important investigational tools of the small bowel. The capsule is swallowed with water after a 12 h fast, propelled via peristalsis through the gastrointestinal tract and excreted naturally. A nonvideo patency capsule was developed to confirm functional patency of the gastrointestinal tract.

RECENT FINDINGS

Four additional companies have introduced competitive small bowel video capsules, some of which are Food and Drug Admistration (FDA) approved. Due to the easiness of the procedure, SBCE has become a first-line tool to detect small bowel abnormalities. The main indications for SBCE include obscure gastrointestinal bleeding, suspected Crohn's disease, small bowel tumors and practically any abnormal small bowel imaging. New indications are emerging like small bowel motility and monitoring of drug therapy and mucosal healing. The present review will describe the available capsules in the market, the procedure itself, present indications and future expectations. It will focus on the PillCam SB of Given Imaging as it is the one on which most of the literature is written.

SUMMARY

Over the past 10 years, SBCE has become a routine, first-line investigational tool of many small bowel pathologies.

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.

Advanced endoscopic technologies for colorectal cancer screening

Colorectal cancer is the third most common cancer in men and the second most common cancer in women worldwide. Diagnosing colorectal has been increasingly successful due to advances in technology. Flexible endoscopy is considered to be an effective method for early diagnosis and treatment of gastrointestinal cancer, making it a popular choice for screening programs. However, millions of people who may benefit from endoscopic colorectal cancer screening fail to have the procedure performed. Main reasons include psychological barriers due to the indignity of the procedure, fear of procedure related pain, bowel preparation discomfort, and potential need for sedation. Therefore, an urgent need for new technologies addressing these issues clearly exists. In this review, we discuss a set of advanced endoscopic technologies for colorectal cancer screening that are either already available or close to clinical trial. In particular, we focus on visual-inspection-only advanced flexible colonoscopes, interventional colonoscopes with alternative propulsion mechanisms, wireless capsule colonoscopy, and technologies for intraprocedural bowel cleansing. Many of these devices have the potential to reduce exam related patient discomfort, obviate the need for sedation, increase diagnostic yield, reduce learning curves, improve access to screening, and possibly avert the need for a bowel preparation.

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.

What we have learned and what to expect from capsule endoscopy

Capsule endoscopy was conceived by Gabriel Iddan and Paul Swain independently two decades ago. These applications include but are not limited to Crohn’s disease of the small bowel, occult gastrointestinal bleeding, non steroidal anti inflammatory drug induced small bowel disease, carcinoid tumors of the small bowel, gastro intestinal stromal tumors of the small bowel and other disease affecting the small bowel. Capsule endoscopy has been compared to traditional small bowel series, computerized tomography studies and push enteroscopy. The diagnostic yield of capsule endoscopy has consistently been superior in the diagnosis of small bowel disease compared to the competing methods (small bowel series, computerized tomography, push enteroscopy) of diagnosis. For this reason capsule endoscopy has enjoyed a meteoric success. Image quality has been improved with increased number of pixels, automatic light exposure adaptation and wider angle of view. Further applications of capsule endoscopy of other areas of the digestive tract are being explored. The increased transmission rate of images per second has made capsule endoscopy of the esophagus a realistic possibility. Technological advances that include a double imager capsule with a nearly panoramic view of the colon and a variable frame rate adjusted to the movement of the capsule in the colon have made capsule endoscopy of the colon feasible. The diagnostic rate for the identification of patients with polyps equal to or larger than 6 mm is high. Future advances in technology and biotechnology will lead to further progress. Capsule endoscopy is following the successful modern trend in medicine that replaces invasive tests with less invasive methodology.

Feasibility and safety of magnetic-controlled capsule endoscopy system in examination of human stomach: a pilot study in healthy volunteers

OBJECTIVE

To assess the feasibility and safety of magnetic-controlled capsule endoscopy (MCE) system for examination of human stomach.

METHODS

This pilot study enrolled 34 healthy volunteers. All subjects swallowed the MCE and gas-producing powder for gastric distention. An external robot was used to generate magnetic field to manipulate MCE inside the stomach. The primary measurements included safety, gastric preparation, maneuverability and visualization of gastric mucosa.

RESULTS

Gastric preparation and examination was well accepted by subjects and there were no adverse events. The examination in the stomach takes 43.8±10.0min (27-60). The cleanliness was evaluated as good in the 30 (88.2%) subjects and as moderate in 4 (11.8%) subjects. The distention of gastric cavity was evaluated as good in the 29 (85.3%) subjects and moderate in 5 (14.7%) subjects. Maneuverability of the MCE to movements of the guidance magnet robot was graded as good in 29 (85.3%) subjects and moderate in 5 (14.7%) subjects. More than 75% gastric mucosa was visualized in 27 (79.4%) subjects and 50% to 75% in 7 (20.6%) subjects. Visualization of the gastric cardia, fundus, body, angulus, antrum and pylorus was subjectively assessed as complete in 82.4%, 85.3%, 100.0%, 100.0%, 100.0% and 100.0%, respectively. Polyp and erosive lesions were found in 7 subjects.

CONCLUSION

Magnetic-controlled capsule endoscopy used for examination of the human stomach is feasible and safe.

A survey of potential adherence to capsule colonoscopy in patients who have accepted or declined conventional colonoscopy

BACKGROUND

Capsule colonoscopy might improve adherence to colorectal cancer screening.

OBJECTIVE

Measure attractiveness of capsule colonoscopy in patients who have declined conventional colonoscopy, using patients who have undergone colonoscopy as a control group.

DESIGN

Internet-based survey.

SETTING

United States.

SUBJECTS

A total of 308 geographically diverse, high school or higher educated, middle to upper income, insured internet users who had been offered colonoscopy previously.

INTERVENTIONS

Survey.

MAIN OUTCOME MEASUREMENTS

Preferences for colonoscopy, capsule colonoscopy, fecal occult blood test, or no screening.

RESULTS

After a description of capsule technology features relative to colonoscopy, including "no need for a ride," "no time off work," "approximately 5% less accurate," "booster preparation needed," and "follow-up colonoscopy needed in 20% of patients," preference for capsule colonoscopy was shown by 24% of those who had undergone colonoscopy and 49% of those who had not. "No need for a ride" and "no time off work" were considered positive features of capsule colonoscopy. The potential to undergo capsule colonoscopy during the weekend was also considered attractive.

LIMITATIONS

Restricted population.

CONCLUSIONS

The availability of capsule colonoscopy could potentially increase colorectal cancer screening adherence rates among patients who decline screening colonoscopy.

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.

Capsule colonoscopy increases uptake of colorectal cancer screening

BACKGROUND

Screening colonoscopy effectiveness is hampered by limited adherence by the general population. The present prospective study was performed to evaluate whether adding capsule colonoscopy to the endoscopic screening options increases uptake.

METHODS

Invitation letters were sent to 2150 persons above the age of 55 insured with a German medical insurance company in the area of Rinteln, Lower Saxony with a baseline spontaneous annual screening colonoscopy uptake of 1 %. Both capsule or conventional colonoscopy were offered. Interested persons were given information about the two screening options by four local gastroenterologists and examinations were then performed according to screenees' final choice.

RESULTS

154 persons sought further information, and 34 and 90 underwent conventional and capsule colonoscopy, respectively. Colonoscopy uptake was thus increased by the invitation process by 60 % (1.6 % vs. 1 %; p = 0.075), while the option of capsule endoscopy led to a fourfold increase of screening uptake (4.2 % vs. 1 %, p < 0.001). Despite similar age distribution in both sex groups, uptake in men was significantly higher (5.6 % vs. 2.8 %, p = 002). However, overall adenoma yield was not different in both groups.

CONCLUSIONS

The present study suggests that offering the option of capsule colonoscopy increases uptake of endoscopic colorectal cancer screening. However, capsule endoscopy sensitivity for adenoma detection needs to be improved.

Can we shorten the small-bowel capsule reading time with the "Quick-view" image detection system?

BACKGROUND

The mean small-bowel capsule reading time is about 60 min, and shortening this reading time is a major aim.

AIM

To evaluate the efficiency of the "Quick-view" detection algorithm.

METHODS

Multicentre prospective comparative study. One hundred and six small bowel capsule films from 12 centres reviewed in Quick-view mode by 12 experienced readers. Reading time, image relevance, and comparison of Quick-view reading results to results of initial reading. Review of discordant result by 3 experts.

RESULTS

The mean reading time in Quick-view mode was of 11.6 min (2-27). Concordant negative results were obtained in 41 cases (38.6%) and concordant positive results in 35 cases (33.0%). A discordant result was obtained in 30 (28.3%) cases: 21 false positive cases (initial reading 12 cases, Quick-view reading 9 cases), 14 false negative cases (initial reading 7, Quick-view 7). Four out of 7 lesions missed at Quick-view reading were not present on the Quick-view film (theoretical sensitivity 93.5%).

CONCLUSION

The Quick-view informatic algorithm detected nearly 94% of significant lesions, and Quick-view reading was as efficient as the initial reading and much shorter. These results are to be confirmed by further studies, but suggest an excellent sensitivity for the Quick-view algorithm.

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.

New reduced volume preparation regimen in colon capsule endoscopy

AIM: To evaluate the effectiveness of our proposed bowel preparation method for colon capsule endoscopy.

METHODS: A pilot, multicenter, randomized controlled trial compared our proposed “reduced volume method” (group A) with the “conventional volume method” (group B) preparation regimens. Group A did not drink polyethylene glycol electrolyte lavage solution (PEG-ELS) the day before the capsule procedure, while group B drank 2 L. During the procedure day, groups A and B drank 2 L and 1 L of PEG-ELS, respectively, and swallowed the colon capsule (PillCam COLON^® capsule). Two hours later the first booster of 100 g magnesium citrate mixed with 900 mL water was administered to both groups, and the second booster was administered six hours post capsule ingestion as long as the capsule had not been excreted by that time. Capsule videos were reviewed for grading of cleansing level.

RESULTS: Sixty-four subjects were enrolled, with results from 60 analyzed. Groups A and B included 31 and 29 subjects, respectively. Twenty-nine (94%) subjects in group A and 25 (86%) subjects in group B had adequate bowel preparation (ns). Twenty-two (71%) of the 31 subjects in group A excreted the capsule within its battery life compared to 16 (55%) of the 29 subjects in group B (ns). Of the remaining 22 subjects whose capsules were not excreted within the battery life, all of the capsules reached the left side colon before they stopped functioning. A single adverse event was reported in one subject who had mild symptoms of nausea and vomiting one hour after starting to drink PEG-ELS, due to ingesting the PEG-ELS faster than recommended.

CONCLUSION: Our proposed reduced volume bowel preparation method for colon capsule without PEG-ELS during the days before the procedure was as effective as the conventional volume method.

Accuracy and safety of second-generation PillCam COLON capsule for colorectal polyp detection

PillCam COLON capsule endoscopy (CCE) (Given Imaging Ltd, Yoqneam, Israel) is one of the most recent diagnostic, endoscopic technologies designed to explore the colon. CCE is a noninvasive, patient-friendly technique that is able to explore the colon without requiring sedation and air insufflation. The first generation of CCE was released onto the market in 2006 and although it generated great enthusiasm, it showed suboptimal accuracy. Recently, a second-generation system (PillCam COLON 2) (CCE-2) has been developed to increase sensitivity for colorectal polyp detection. In this review, accuracy and safety data for CCE-2 are analyzed.

Colon capsule endoscopy: Advantages, limitations and expectations. Which novelties?

Since the first reports almost ten years ago, wireless capsule endoscopy has gained new fields of application. Colon capsule endoscopy represents a new diagnostic technology for colonic exploration. Clinical trials have shown that colon capsule endoscopy is feasible, accurate and safe in patients suffering from colonic diseases and might be a valid alternative to conventional colonoscopy in selected cases such as patients refusing conventional colonoscopy or with contraindications to colonoscopy or when colonoscopy is incomplete. Despite the enthusiasm surrounding this new technique, few clinical and randomized controlled trials are to be found in the current literature, leading to heterogeneous or controversial results. Upcoming studies are needed to prove the substantial utility of colon capsule endoscopy for colon cancer screening, especially in a low prevalence of disease population, and for other indications such as inflammatory bowel disease. Possible perspectives are critically analysed and reported in this paper.

Progress and challenges in colorectal cancer screening

Although faecal and endoscopic tests appear to be effective in reducing colorectal cancer incidence and mortality, further technological and organizational advances are expected to improve the performance and acceptability of these tests. Several attempts to improve endoscopic technology have been made in order to improve the detection rate of neoplasia, especially in the proximal colon. Based on the latest evidence on the long-term efficacy of screening tests, new strategies including endoscopic and faecal modalities have also been proposed in order to improve participation and the diagnostic yield of programmatic screening. Overall, several factors in terms of both efficacy and costs of screening strategies, including the high cost of biological therapy for advanced colorectal cancer, are likely to affect the cost-effectiveness of CRC screening in the future.

Mucosal region detection and 3D reconstruction in wireless capsule endoscopy videos using active contours

Wireless capsule endoscopy (WCE) provides an inner view of the human digestive system. The inner tubular like structure of the intestinal tract consists of two major regions: lumen - intermediate region where the capsule moves, mucosa - membrane lining the lumen cavities. We study the use of the Split Bregman version of the extended active contour model of Chan and Vese for segmenting mucosal regions in WCE videos. Utilizing this segmentation we obtain a 3D reconstruction of the mucosal tissues using a near source perspective shape-from-shading (SfS) technique. Numerical results indicate that the active contour based segmentation provides better segmentations compared to previous methods and in turn gives better 3D reconstructions of mucosal regions.

Magnetic air capsule robotic system: proof of concept of a novel approach for painless colonoscopy

BACKGROUND

Despite being considered the most effective method for colorectal cancer diagnosis, colonoscopy take-up as a mass-screening procedure is limited mainly due to invasiveness, patient discomfort, fear of pain, and the need for sedation. In an effort to mitigate some of the disadvantages associated with colonoscopy, this work provides a preliminary assessment of a novel endoscopic device consisting in a softly tethered capsule for painless colonoscopy under robotic magnetic steering.

METHODS

The proposed platform consists of the endoscopic device, a robotic unit, and a control box. In contrast to the traditional insertion method (i.e., pushing from behind), a "front-wheel" propulsion approach is proposed. A compliant tether connecting the device to an external box is used to provide insufflation, passing a flexible operative tool, enabling lens cleaning, and operating the vision module. To assess the diagnostic and treatment ability of the platform, 12 users were asked to find and remove artificially implanted beads as polyp surrogates in an ex vivo model. In vivo testing consisted of a qualitative study of the platform in pigs, focusing on active locomotion, diagnostic and therapeutic capabilities, safety, and usability.

RESULTS

The mean percentage of beads identified by each user during ex vivo trials was 85 ± 11%. All the identified beads were removed successfully using the polypectomy loop. The mean completion time for accomplishing the entire procedure was 678 ± 179 s. No immediate mucosal damage, acute complications such as perforation, or delayed adverse consequences were observed following application of the proposed method in vivo.

CONCLUSIONS

Use of the proposed platform in ex vivo and preliminary animal studies indicates that it is safe and operates effectively in a manner similar to a standard colonoscope. These studies served to demonstrate the platform's added advantages of reduced size, front-wheel drive strategy, and robotic control over locomotion and orientation.

Screening for colorectal cancer

March is national colorectal cancer awareness month. It is estimated that as many as 60% of colorectal cancer deaths could be prevented if all men and women aged 50 years or older were screened routinely. In 2000, Katie Couric's televised colonoscopy led to a 20% increase in screening colonoscopies across America, a stunning rise called the "Katie Couric Effect". This event demonstrated how celebrity endorsement affects health behavior. Currently, discussion is ongoing about the optimal strategy for CRC screening, particularly the costs of screening colonoscopy. The current CRC screening guidelines are summarized in Table 2. Debates over the optimum CRC screening test continue in the face of evidence that 22 million Americans aged 50 to 75 years are not screened for CRC by any modality and 25,000 of those lives may have been saved if they had been screened for CRC. It is clear that improving screening rates and reducing disparities in underscreened communities and population subgroups could further reduce colorectal cancer morbidity and mortality. National Institutes of Health consensus identified the following priority areas to enhance the use and quality of colorectal cancer screening: Eliminate financial barriers to colorectal cancer screening and appropriate follow-up of positive results of colorectal cancer screening. Develop systems to ensure the high quality of colorectal cancer screening programs. Conduct studies to determine the comparative effectiveness of the various colorectal cancer screening methods in usual practice settings. Encouraging population adherence to screening tests and allowing patients to select the tests they prefer may do more good (as long as they choose something) than whatever procedure is chosen by the medical profession as the preferred test.

Second-generation colon capsule endoscopy compared with colonoscopy

BACKGROUND

Colon capsule endoscopy (CCE) represents a noninvasive technology that allows visualization of the colon without requiring sedation and air insufflation. A second-generation colon capsule endoscopy system (PillCam Colon 2) (CCE-2) was developed to increase sensitivity for colorectal polyp detection compared with the first-generation system.

OBJECTIVE

To assess the feasibility, accuracy, and safety of CCE-2 in a head-to-head comparison with colonoscopy.

DESIGN AND SETTING

Prospective, multicenter trial including 8 European sites.

PATIENTS

This study involved 117 patients (mean age 60 years). Data from 109 patients were analyzed.

INTERVENTION

CCE-2 was prospectively compared with conventional colonoscopy as the criterion standard for the detection of colorectal polyps that are ≥6 mm or masses in a cohort of patients at average or increased risk of colorectal neoplasia. Colonoscopy was independently performed within 10 hours after capsule ingestion or on the next day.

MAIN OUTCOME MEASUREMENTS

CCE-2 sensitivity and specificity for detecting patients with polyps ≥6 mm and ≥10 mm were assessed. Capsule-positive but colonoscopy-negative cases were counted as false positive. Capsule excretion rate, level of bowel preparation, and rate of adverse events also were assessed.

RESULTS

Per-patient CCE-2 sensitivity for polyps ≥6 mm and ≥10 mm was 84% and 88%, with specificities of 64% and 95%, respectively. All 3 invasive carcinomas were detected by CCE-2. The capsule excretion rate was 88% within 10 hours. Overall colon cleanliness for CCE-2 was adequate in 81% of patients.

LIMITATIONS

Not unblinding the CCE-2 results at colonoscopy; heterogenous patient population; nonconsecutive patients.

CONCLUSION

In this European, multicenter study, CCE-2 appeared to have a high sensitivity for the detection of clinically relevant polypoid lesions, and it might be considered an adequate tool for colorectal imaging.

Evolving techniques in colonoscopy

PURPOSE OF REVIEW

This review summarizes recent clinical studies of colonoscopy technique and new technologies.

RECENT FINDINGS

Water immersion reduces pain and sedation doses in unsedated and lightly sedated colonoscopy. Cap-fitted colonoscopy makes insertion faster and improves detection of lesions behind folds, but the latter effect is operator-dependent. A single controlled trial showed improved detection with the Third Eye Retroscope, but the two arms of the study were not controlled for withdrawal time. Chromoendoscopy increases detection of diminutive adenomas, but adds time to the colonoscopy procedure. Electronic chromoendoscopy methods (narrow band imaging, Fujinon Intelligent ChromoEndoscopy, i-scan, and autofluorescence) have been either unsuccessful in improving detection or require more study. However, these methods and several other methods (chromoendoscopy with magnification, confocal laser microscopy, and endocytoscopy) allow accurate real time determination of polyp histology.

SUMMARY

Water immersion is a clear advance in unsedated colonoscopy. Cap-fitted colonoscopy is a promising method for both practical and effective visualization of the proximal sides of haustral folds. Electronic chromoendoscopy has been largely ineffective at improving polyp detection, but is effective (as are confocal laser microscopy and endocytoscopy) for diagnosis of polyp histology.

PillCam COLON capsule endoscopy: recent advances and new insights

Capsule endoscopy for the colon was introduced to allow an alternative screening method to the invasive classic colonoscopy. The results of initial studies have shown inferior detection rates of colonic polyps by the colon capsule. In this paper we aim to review and summarize the recent advances in wireless capsule endoscopy of the colon. Publications regarding the use of colon capsule with new technology, as well as personal experience, were reviewed. Since the introduction of the first generation of the colon capsule, many improvements have been made to create a better capsule endoscope. These include a wider angle of view, a faster adaptable frame rate and a new data recorder which is able to control the capsule activity during the transit through the bowel. Recent studies show these improvements had a direct effect on the colon capsule performance, leading to a better diagnostic yield. Recent advancements in the technology of the wireless colon capsule endoscope offer the option to screen patients for colonic polyps noninvasively. Colon capsule endoscopy may become relevant for assessment of extent of inflammatory bowel disease.

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

Given the low compliance with screening colonoscopy in countries with a national colorectal cancer screening program, noninvasive methods with an acceptable high rate of sensitivity and specificity are welcome to enlarge the array of screening tools. Colon capsule endoscopy seems to be a safe and effective method of visualizing the colonic mucosa without the need for sedation or insufflation of air. Bowel cleansing for colon capsule endoscopy is more rigorous as only excellent or good results can be accepted in order to obtain an adequate sensitivity. This restricts its application on persons who are able to drink 4 l of polyethylene glycol plus laxatives. The sensitivity of colon capsule endoscopy to detect polyps, advanced adenomas and cancer is lower compared with optical colonoscopy. It still seems to be an adequate alternative for patients reluctant to undergo colonoscopy. Conventional colonoscopy is still established as the gold standard in colorectal cancer screening and is used to evaluate positive screening tests of all programs. It is the only method with the ability to remove detected polyps and obtain biopsy specimens.

High cecal intubation rates with a new computer-assisted colonoscope: a feasibility study

OBJECTIVES

The acceptability of colonoscopy as a screening test is limited by several factors including patient discomfort. A new self-propelled colonoscope, the Invendo SC20 (Invendo Medical GmbH), may be helpful in reducing sedation. It consists of a sheathed endoscope contained within an "inverted sleeve," and having an instrument channel and an electrohydraulic bendable tip; it is steered using a handheld device and propelled by a motorized drive unit. This study assessed the safety and efficacy of this new endoscope in volunteers undergoing colorectal cancer (CRC) screening.

METHODS

Paid healthy volunteers aged 50-70 years and eligible for screening colonoscopy were included. Total colonoscopy using carbon dioxide insufflation or water instillation on demand was attempted, with all procedures being started without sedation. The main outcome parameters were safety and the cecal intubation rate.

RESULTS

A total of 61 volunteers participated (34 men and 27 women; mean age 57.5 years). The cecum was reached in 60 volunteers (cecal intubation rate of 98.4%). The median time to reach the cecum was 15 min (range 7-53.5). Sedation was given in three individuals (4.9%). On withdrawal (median time 15 min), the material for histological evaluation was obtained from 33 polyps (mean size 4.8 mm) in 23 people by biopsy forceps or snare. No device-related complications were encountered.

CONCLUSIONS

A new computer-assisted colonoscope, controlled using a handheld device, showed excellent cecal intubation rates during screening examinations, with sedation required in only ~ 5% of screenees. Further clinical and comparative studies are warranted.

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.

[The new generation of the Pillcam Colon Capsule: a non-invasive alternative in colorectal cancer screening?]

The Pillcam colon capsule was first introduced in 2006 for the study of the colon. Colon capsule endoscopy is a new diagnostic technology to visualize the colorectal mucosa without sedation, intubation or insufflation and appears to be a safe and attractive alternative to colonoscopy. Since the introduction of this technology, numerous studies have been published on its diagnostic sensitivity and the regimen of colon preparation for better evaluation of the colon. Recently, a new generation of the capsule, Pillcam Colon 2, has been presented, with important innovations.

Capsule endoscopy in patients with cardiac pacemakers, implantable cardioverter defibrillators, and left heart devices: a review of the current literature

Background and Study Aims. Capsule endoscopy is an established tool for investigation of the small intestine. Because of limited clinical experience in patients with cardiac devices, the Food and Drug Administration and the manufacturer recommended not to use capsule endoscopy in these patients. The vast majority of investigations did not reveal any interference between capsule endoscopy and cardiac devices. Methods. Studies investigating interference between CE and cardiac devices were analysed. For the review we considered studies published in English or German and indexed in Medline, as well as highly relevant abstracts. Results. In vitro and in vivo studies mainly revealed no interference between capsule endoscopy and cardiac devices. Technical data of capsule endoscopy (Given Imaging) reveal that interference with cardiac pacemakers and implantable cardioverter defibrillator is impossible. Telemetry can interfere with CE video. Conclusion. The clinical use of capsule endoscopy (Given Imaging) is unproblematic in patients with cardiac pacemakers.

A new regimen of bowel preparation for PillCam colon capsule endoscopy: a pilot study

BACKGROUND

Colon capsule endoscopy (CCE) represents a new diagnostic, endoscopic technology for colonic exploration. Current protocols of preparation led to discordant rates of adequate cleansing level or CCE excretion.

AIM

To evaluate the effect of a new regimen of bowel preparation for CCE on colon cleansing levels and on rate of capsule excretion.

STUDY

60 patients were prospectively enrolled. The new regimen of preparation consisted of a split regimen of PEG administration and of a 45 mL dose of sodium phosphate (NaP). Four senna tablets and a low-residue diet were also included. CCE excretion rate, colon cleansing, and accuracy were assessed.

RESULTS

Forty-six patients were included in the final analysis, 13 patients (22%) being excluded because of preparation protocol deviations and one due to CCE technical failure (2%). At CCE, bowel preparation was rated as good in 78% of patients, fair in 20% and poor in 2%. CCE excretion rate occurred in 83% of patients. CCE sensitivity and specificity for significant findings was 100% and 95%, respectively.

CONCLUSIONS

The combination of a split-dose of PEG solution with a low dose of NaP boosters resulted in high rates of adequate cleansing level and CCE excretion.

Literature review and recommendations for clinical application of Colon Capsule Endoscopy

Colon Capsule Endoscopy represents a new diagnostic technology for colonic exploration. Despite the great enthusiasm around this new technique, only few studies are available in the literature, and reported results are still controversial and non-homogeneous. Current preparation protocols have led to discordant results. In January 2010, the first Italian Meeting on Colon Capsule Endoscopy was held. Aim of this Meeting was to critically evaluate the available results obtained by Colon Capsule Endoscopy in clinical studies, in order to identify the proper test indications, to propose a shared preparation protocol and Colon Capsule Endoscopy procedure. Studies published in literature were extensively reviewed and analysed during the Meeting. The available evidence served to propose recommendations for preparation protocols, proper test indications and Colon Capsule Endoscopy procedure. Possible perspectives were also critically analysed and are reported in this paper.

Automatic polyp detection in pillcam colon 2 capsule images and videos: preliminary feasibility report

Background. The aim of this work is to present an automatic colorectal polyp detection scheme for capsule endoscopy. Methods. PillCam COLON2 capsule-based images and videos were used in our study. The database consists of full exam videos from five patients. The algorithm is based on the assumption that the polyps show up as a protrusion in the captured images and is expressed by means of a P-value, defined by geometrical features. Results. Seventeen PillCam COLON2 capsule videos are included, containing frames with polyps, flat lesions, diverticula, bubbles, and trash liquids. Polyps larger than 1 cm express a P-value higher than 2000, and 80% of the polyps show a P-value higher than 500. Diverticula, bubbles, trash liquids, and flat lesions were correctly interpreted by the algorithm as nonprotruding images. Conclusions. These preliminary results suggest that the proposed geometry-based polyp detection scheme works well, not only by allowing the detection of polyps but also by differentiating them from nonprotruding images found in the films.

Video capsule endoscopy: what is the future?

Video capsule endoscopy (VCE) that was launched 10 years ago has become a first-line procedure for examining the small bowel, especially in the case of obscure gastrointestinal bleeding. Other major indications include Crohn disease (CD), celiac disease, and intestinal polyposis syndrome. In the case of small bowel diseases, the use of VCE must be integrated in a global diagnostic and therapeutic approach. More recently, wireless endoscopy has been adapted for examining the colon, opening up larger perspectives for colorectal cancer screening or colon examination. Technologic modifications of the second-generation colon capsule increase the sensitivity of this method for detecting polyps. Other new developments, including remote magnetic manipulation, power management, drug delivery capsule, microbiopsy capsule, and adaptation of technologies such as chromoendoscopy, are sure to enhance the capabilities of wireless endoscopy in gastrointestinal disorders.

Guidelines for colorectal cancer screening--a puzzle of tests and strategies

Colorectal cancer (CRC) is a leading cause of cancer death around the World. An effective way to reduce colorectal cancer mortality is to screen for it and its precursor, the adenoma. In industrialized countries the mortality related to CRC is decreasing probably due to better screening programmes in average-risk individuals as well as changes in risk factors. Screening procedures are various including faecal screening tests--which primarily detect colon cancer--and structural tests (endoscopy--flexible sigmoidoscopy or colonoscopy--, Barium enema, Computed Tomography Colonography) that may detect not only cancer but also its precursors. Video-colon capsule is a new tool for exploring the colon but needs further studies before becoming a screening test. The choice of a screening test includes several factors as cost, invasiveness, acceptability, adherence to repeat testing and acceptance referral for colonoscopy for positive tests as well as local financial resources. Every screening programme has advantages and limitations. Enhancing use and quality of CRC screening programmes is mandatory.

Colon capsule endoscopy vs. colonoscopy in patients at average or increased risk of colorectal cancer

BACKGROUND

Colon capsule endoscopy (CCE) is a new, non-invasive technology.

AIM

To conduct a prospective, multicentre trial to compare CCE and colonoscopy in asymptomatic subjects enrolled in screening or surveillance programmes for the detection of colorectal neoplasia.

METHODS

Patients underwent CCE on day one and colonoscopy (gold standard) on day two. CCE and colonoscopy were performed by independent endoscopists.

RESULTS

A total of 545 patients were recruited. CCE was safe and well-tolerated. Colon cleanliness was excellent or good in 52% of cases at CCE. Five patients with cancer were detected by colonoscopy, of whom two were missed by CCE. CCE accuracy for the detection of polyps ≥ 6 mm was 39% (95% CI 30-48) for sensitivity, 88% (95% CI 85-91) for specificity, 47% (95% CI 37-57) for positive predictive value and 85% (95% CI 82-88) for negative predictive value. CCE accuracy was better for the detection of advanced adenoma, in patients with good or excellent cleanliness and after re-interpretation of the CCE videos by an independent expert panel.

CONCLUSIONS

Although well-tolerated, CCE cannot replace colonoscopy as a first line investigation for screening and surveillance of patients at risk of cancer. Further studies should pay attention to colonic preparation (Clinicaltrial.gov number NCT00436514).

Performance improvements of imaging-based screening tests

Endoscopic and radiologic tests appear to be more accurate than stool-tests in detecting advanced neoplasia because of direct visualisation of colorectal mucosa. Further technological advances are expected to improve the performance and acceptability of these tests. Several attempts at increasing the adenoma detection rate of colonoscopy have been tested, and in vivo histologic differentiation between neoplastic and hyperplastic polyps may lead to substantial saving in economic and medical resources. Low-volume and non-cathartic bowel preparations may improve CT colonography acceptability, whilst computer-aided detection and low-dose protocols may result in a higher accuracy and safety of this procedure. Despite the lack of ionising radiation, significant drawbacks will likely to limit the role of MR colonography in screening programs. Colon capsule endoscopy appears to be a safe and technically feasible procedure. The suboptimal accuracy of the first generation seems to be substantially improved by the second generation of this device.

New endoscopy devices to improve population adherence to colorectal cancer prevention programs

Despite recent advances in medicine, colorectal cancer (CRC) remains one of the greatest hazards for public health worldwide and especially the industrialized world. It has been well documented with concrete data that regular screening colonoscopy aimed at early detection of precancerous polyps can help decrease the incidence of CRC. However, the adherence of the general population to such screening programs has been shown to be lower than that expected, thus allowing CRC to remain a major threat for public health. Various reasons have been suggested to explain the disappointing compliance of the population to CRC screening programs, some of them associated with colonoscopy per se, which is viewed by many people as an unpleasant examination. Governments, medical societies, individual gastroenterologists, as well as the medical industry are working in order to improve endoscopic devices and/or to improve standard colonoscopy. The aim is to improve the acceptance of the population for this method of CRC screening, by providing a painless and reliable examination of the colon. This review focuses on some of the latest improvements in this field.

The PillCam™ Colon Capsule for Colon Cancer Screening: Comparison Between the First- and Second-Generation Capsules

Population-based screening for colorectal cancer is widely recommended, with conventional colonoscopy (CC) being considered the preferred modality. However, compliance with colonoscopy screening is low, ranging between 20% and 50%, and manpower capacity for performing CC is limited. Therefore, a new, minimally invasive diagnostic tool, the PillCam™ Colon Capsule Endoscope (PCCE) was developed to become a desirable, patient-friendly, alternative strategy. This article will review the data regarding the 2 available generations of the PCCE.