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

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.

A Prototype Therapeutic Capsule Endoscope for Ultrasound-Mediated Targeted Drug Delivery

The prevalence of gastrointestinal (GI) diseases such as Crohn’s disease, which is chronic and incurable, are increasing worldwide. Treatment often involves potent drugs with unwanted side effects. The technological–pharmacological combination of capsule endoscopy with ultrasound-mediated targeted drug delivery (UmTDD) described in this paper carries new potential for treatment of these diseases throughout the GI tract. We describe a proof-of-concept UmTDD capsule and present preliminary results to demonstrate its promise as an autonomous tool to treat GI diseases.

Diagnostic Role of Colon Capsule Endoscopy in Patients with Optimal Colon Cleaning

Background. Colon capsule endoscopy (CCE) is a diagnostic test with relatively rare usage. In this study, we aimed to evaluate both the optimal cleaning regimen for CCE and the diagnostic value of test in the study group. Methods. A total of 62 patients were enrolled in this study. In the first step, 3 different colon preparing regimens were given to 30 patients [Group A: 3 days of liquid diet, sodium phosphate (NaP) (90 mL), and NaP enema; Group B: 3 days of liquid diet, 4 L of polyethylene glycol (PEG), and metoclopramide; Group C: 3 days of liquid diet, 4 L of PEG, NaP (45 mL), and bisacodyl after capsule ingestion] (10 patients in each group). The other consecutive 32 patients were cleaned with the best regimen which was NaP + PEG and CCE was performed. The results of CCE were controlled with colonoscopy in 28 patients. Results. Group C had the highest cleaning score, compared with the other groups (2.2 ± 0.4 versus 2.7 ± 0.4 versus 3.7 ± 0.4, p value = 0.000). The CCE findings were as follows in 28 patients who were also examined with colonoscopy: polyp (range: 5–10 mm) in 6 patients, internal hemorrhoids in 3 patients, angiodysplasia in 1 patient, diverticula in 1 patient, and ulcerative colitis in 1 patient. The sensitivity, specificity, PPV, and NPV of CCE were 100%, 92%, 93%, and 100%, respectively. Conclusions. Low dosage NaP combined with PEG provides optimal bowel preparation for CCE. CCE appears to be a highly sensitive diagnostic modality for detecting colonic pathologies.

Increased Detection of Colorectal Polyps in Screening Colonoscopy Using High Definition i-SCAN Compared with Standard White Light

Background/Aims:

The aim of this study was to evaluate the efficacy of high definition (HD) i-SCAN for colorectal polyp detection in screening colonoscopy.

Methods:

We retrospectively analyzed the records of 501 patients who had undergone screening colonoscopy performed by three endoscopists with either HD i-SCAN (n=149) or standard white light (n=352) from January 2, 2014 through June 30, 2014. Patient information and inter-endoscopist variation as well as polyp number, endoscopic findings, and pathologic characteristics were reviewed.

Results:

The detection rates of colorectal and neoplastic polyps were significantly higher using HD i-SCAN than standard white light colonoscopy (52% vs. 38.1%, p=0.004 for colorectal polyps; and 37.2% vs. 27.9%, p=0.041 for neoplastic polyps). Analysis of endoscopic findings revealed no difference in detected polyp size between HD i-SCAN and standard white light colonoscopy (4.59±2.35 mm vs. 4.82±2.81 mm, p=0.739), but non-protruding polyps were more commonly detected by i-SCAN than by standard white light colonoscopy (24.6% vs. 13.5%, p=0.007).

Conclusions:

Colonoscopy using HD i-SCAN had a significantly higher detection rate of colorectal polyps, including neoplastic polyps, because of improved sensitivity for detecting non-protruding lesions.

Advances in Capsule Endoscopy

Wireless video capsule endoscopy (VCE) is a minimally invasive technology that has revolutionized the approach to small intestinal disease investigation and management. Designed primarily to provide diagnostic imaging of the small intestine, VCE is used predominantly for obscure gastrointestinal bleeding and suspected Crohn's disease; however, numerous other indications have been established, including the assessment of celiac disease, investigation of small bowel tumors, and surveillance of hereditary polyposis syndromes. Since the introduction of small bowel VCE in 2000, more than 1600 articles have been published describing the evolution of this technology. The main adverse outcome is capsule retention, which can potentially be avoided by careful patient selection or by using a patency capsule. Despite the numerous advances in the past 15 years, limitations such as incomplete VCE studies, missed lesions, and time-consuming reporting remain. The inability to control capsule movement for the application of targeted therapy or the acquisition of tissue for histologic analysis remains among the greatest challenges in the further development of capsule technology. This article outlines the recent technological and clinical advances in VCE and the future directions of research in this field.

Assessment of mucosal healing in inflammatory bowel disease: review

BACKGROUND AND AIMS

Mucosal healing is an important treatment end-point in inflammatory bowel disease, and achieving mucosal healing has been demonstrated to improve disease-related outcomes. Considerable uncertainty exists, however, regarding the optimal approach for the assessment of mucosal healing.

AIMS

To compare currently available diagnostic tools for the assessment of mucosal healing and outline the ideal approach to integrating these tools into clinical trials and clinical practice.

METHODS

Review article.

RESULTS

Endoscopy represents the criterion standard for the assessment of mucosal healing, and frequent endoscopic assessment is associated with a higher rate of achieving mucosal healing. The use of mucosal biopsy allows for the identification of persistent histologic disease activity, but the incremental clinical benefit of achieving histologic healing is yet to be determined. Magnetic resonance enterography has a high sensitivity for ulcer healing in endoscopically inaccessible disease activity. However, the presence of mucosal lesions cannot be reliably excluded based on this modality alone, and further small-bowel endoscopy should be considered in symptomatic patients. Video capsule endoscopy or device-assisted enteroscopy can be used, with device-assisted enteroscopy being preferred in stricturing Crohn's disease because of the risk of capsule retention or in patients in whom small-bowel malignancy is a possibility.

CONCLUSIONS

Endoscopy remains the criterion standard for the assessment of mucosal healing. Several alternative diagnostic modalities have become available that can be of value in specific clinical circumstances, particularly in patients with small-bowel involvement.

Colon Capsule Endoscopy for the Detection of Colorectal Polyps: An Evidence-Based Analysis

BACKGROUND

Colorectal cancer, a leading cause of mortality and morbidity in Ontario, can be prevented through early diagnosis and removal of precancerous polyps. Colon capsule endoscopy is a relatively new, minimally invasive test for detecting colorectal polyps.

OBJECTIVE

The objectives of this analysis were to evaluate the diagnostic accuracy and safety of colon capsule endoscopy for the detection of colorectal polyps among adult patients with signs or symptoms of colorectal cancer or with increased risk of colorectal cancer, and to compare colon capsule endoscopy with alternative procedures.

REVIEW METHODS

A literature search was performed using Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid EMBASE, the Wiley Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published between 2006 and 2014. Data on diagnostic accuracy and safety were abstracted from included studies. Quality of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

RESULTS

The search yielded 2,189 citations. Five studies, all of which evaluated PillCam COLON 2 (PCC2), met the inclusion criteria. The per-patient sensitivity and specificity for detecting colorectal polyps were meta-analyzed. Colon capsule endoscopy, using PCC2, had a pooled sensitivity and specificity of 87% (95% confidence interval [CI] 77%-93%) and 76% (95% CI 60%-87%), respectively, for the detection of a colorectal polyp at least 6 mm in size (GRADE: very low). PCC2 had a pooled sensitivity and specificity of 89% (95% CI 77%-95%) and 91% (95% CI 86%-95%), respectively, for the detection of a colorectal polyp at least 10 mm in size (GRADE: low). One study directly compared PCC2 with computed tomographic (CT) colonography and found no statistically significant difference in accuracy (GRADE: low). Few adverse events were reported with PCC2; 3.9% of patients (95% CI 2.4%-6.5%) experienced adverse effects related to bowel preparation. Capsule retention was the most serious adverse event and occurred in 0.8% of patients (95% CI 0.2%-2.4%) (GRADE: very low).

CONCLUSIONS

In adult patients with signs, symptoms, or increased risk of colorectal cancer, there is low-quality evidence that colon capsule endoscopy using the PCC2 device has good sensitivity and specificity for detecting colorectal polyps. Low-quality evidence does not show a difference in accuracy between colon capsule endoscopy and CT colonography. There is very low-quality evidence that PCC2 has a good safety profile with few adverse events; capsule retention is the most serious complication.

PillCam COLON 2© in Crohn’s disease: A new concept of pan-enteric mucosal healing assessment

AIM: To evaluate mucosal healing in patients with small bowel plus colonic Crohn’s disease (CD) with a single non-invasive examination, by using PillCam COLON 2^© (PCC2).

METHODS: Patients with non-stricturing nonpenetrating small bowel plus colonic CD in sustained corticosteroid-free remission were included. At diagnosis, patients had undergone ileocolonoscopy to identify active CD lesions, such as ulcers and erosions, and small bowel capsule endoscopy to assess the Lewis Score (LS). After ≥ 1 year of follow-up, patients underwent entire gastrointestinal tract evaluation with PCC2. The primary endpoint was assessment of CD mucosal healing, defined as no active colonic CD lesions and LS < 135.

RESULTS: Twelve patients were included (7 male; mean age: 32 years), and mean follow-up was 38 mo. The majority of patients (83.3%) received immunosuppressive therapy. Three patients (25%) achieved mucosal healing in both the small bowel and the colon, while disease activity was limited to either the small bowel or the colon in 5 patients (42%). It was possible to observe the entire gastrointestinal tract in 10 of the 12 patients (83%) who underwent PCC2.

CONCLUSION: Only three patients in sustained corticosteroid-free clinical remission achieved mucosal healing in both the small bowel and the colon, highlighting the limitations of clinical assessment when stratifying disease activity, and the need for pan-enteric endoscopy to guide therapeutic modification.

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.

Emerging Issues and Future Developments in Capsule Endoscopy

Capsule endoscopy (CE) has transformed from a research venture into a widely used clinical tool and the primary means for diagnosing small bowel pathology. These orally administered capsules traverse passively through the gastrointestinal tract via peristalsis and are used in the esophagus, stomach, small bowel, and colon. The primary focus of CE research in recent years has been enabling active CE manipulation and extension of the technology to therapeutic functionality; thus, widening the scope of the procedure. This review outlines clinical standards of the technology as well as recent advances in CE research. Clinical capsule applications are discussed with respect to each portion of the gastrointestinal tract. Promising research efforts are presented with an emphasis on enabling active capsule locomotion. The presented studies suggest, in particular, that the most viable solution for active capsule manipulation is actuation of a capsule via exterior permanent magnet held by a robot. Developing capsule procedures adhering to current healthcare standards, such as enabling a tool channel or irrigation in a therapeutic device, is a vital phase in the adaptation of CE in the clinical setting.

Colorectal cancer screening: tests, strategies, and perspectives

Screening has a central role in colorectal cancer (CRC) control. Different screening tests are effective in reducing CRC-specific mortality. Influence on cancer incidence depends on test sensitivity for pre-malignant lesions, ranging from almost no influence for guaiac-based fecal occult blood testing (gFOBT) to an estimated reduction of 66–90% for colonoscopy. Screening tests detect lesions indirectly in the stool [gFOBT, fecal immunochemical testing (FIT), and fecal DNA] or directly by colonic inspection [flexible sigmoidoscopy, colonoscopy, CT colonography (CTC), and capsule endoscopy]. CRC screening is cost-effective compared to no screening but no screening strategy is clearly better than the others. Stool tests are the most widely used in worldwide screening interventions. FIT will soon replace gFOBT. The use of colonoscopy as a screening test is increasing and this strategy has superseded all alternatives in the US and Germany. Despite its undisputed importance, CRC screening is under-used and participation rarely reaches 70% of target population. Strategies to increase participation include ensuring recommendation by physicians, introducing organized screening and developing new, more acceptable tests. Available evidence for DNA fecal testing, CTC, and capsule endoscopy is reviewed.

Colorectal cancer screening: 20 years of development and recent progress

Colorectal cancer (CRC) is the second most common cancer in Europe and its incidence is steadily increasing. This trend could be reversed through timely secondary prevention (screening). In the last twenty years, CRC screening programs across Europe have experienced considerable improvements (fecal occult blood testing; transition from opportunistic to population based program settings). The Czech Republic is a typical example of a country with a long history of nationwide CRC screening programs in the face of very high CRC incidence and mortality rates. Each year, approximately 8000 people are diagnosed with CRC and some 4000 die from this malignancy. Twenty years ago, the first pilot studies on CRC screening led to the introduction of the opportunistic Czech National Colorectal Cancer Screening Program in 2000. Originally, this program was based on the guaiac fecal occult blood test (FOBT) offered by general practitioners, followed by colonoscopy in cases of FOBT positivity. The program has continuously evolved, namely with the implementation of immunochemical FOBTs and screening colonoscopy, as well as the involvement of gynecologists. Since the establishment of the Czech CRC Screening Registry in 2006, 2405850 FOBTs have been performed and 104565 preventive colonoscopies recorded within the screening program. The overall program expanded to cover 25.0% of the target population by 2011. However, stagnation in the annual number of performed FOBTs lately has led to switching to the option of a population-based program with personal invitation, which is currently being prepared.

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.

Percutaneous closure of catheter enterotomy: feasibility determination in vivo

AIM

To determine whether a catheter enterotomy can be percutaneously sealed with a commercially available vascular closure implant.

MATERIAL AND METHODS

The study was performed using a porcine model of small intestinal obstruction. Preliminary experiments were performed to allow an informed choice between two of the most promising commercially available alternatives: A multipronged metal clip (StarClose®) and a resorbable anchored polymer plate (FemoSeal®). Thereafter closure of seven enterotomies was attempted with the most suitable implant. The deployment procedure was subjectively analyzed. The sealed enterotomies were visually evaluated and hydrostatically tested.

RESULTS

StarClose was rejected for formal assessment because it was both difficult to deploy and could not ensure a watertight seal. The conventional method for deploying FemoSeal was found to be inappropriate for percutaneously closing enterotomies. However an improvised accessory allowed all seven enterotomies to be successfully sealed with the implant using a modified procedure that involved only one additional step. After closure, six of the seven enterotomies tolerated intraluminal pressure up to 65 mm Hg.

CONCLUSION

FemoSeal has the potential to serve as an implant for percutaneous closure of catheter enterotomies if the deployment tool can be appropriately modified.

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.

Wireless insufflation of the gastrointestinal tract

Despite clear patient experience advantages, low specificity rates have thus far prevented swallowable capsule endoscopes from replacing traditional endoscopy for diagnosis of colon disease. One explanation for this is that capsule endoscopes lack the ability to provide insufflation, which traditional endoscopes use to distend the intestine for a clear view of the internal wall. To provide a means of insufflation from a wireless capsule platform, in this paper we use biocompatible effervescent chemical reactions to convert liquids and powders carried onboard a capsule into gas. We experimentally evaluate the quantity of gas needed to enhance capsule visualization and locomotion, and determine how much gas can be generated from a given volume of reactants. These experiments motivate the design of a wireless insufflation capsule, which is evaluated in ex vivo experiments. These experiments illustrate the feasibility of enhancing visualization and locomotion of endoscopic capsules through wireless insufflation.

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.