Esophageal Capsule Endoscopy for Screening Esophageal Varices among Japanese Patients with Liver Cirrhosis. Gastroenterol Res Pract. 2012;2012:946169. [PMID: 22190914 PMCID: PMC3235577 DOI: 10.1155/2012/946169]

Detachable string magnetically controlled capsule endoscopy for detecting high-risk varices in compensated advanced chronic liver disease (CHESS1801): A prospective multicenter study

BACKGROUND

Gastroesophageal varices is a serious complication of compensated advanced chronic liver disease (cACLD). Primary prophylaxis to reduce the risk of variceal hemorrhage is recommended if high-risk varices (HRV) are detected. We performed this study to compare the accuracy, patients' satisfaction and safety of detection of HRV by detachable string magnetically controlled capsule endoscopy (DS-MCCE) with esophagogastroduodenoscopy (EGD) as the reference.

METHODS

We prospectively recruited participants with cACLD from 12 university hospitals (11 in China and one in the United Kingdom) between November 2018 and December 2019 (ClinicalTrials.gov, NCT03749954). All participants underwent DS-MCCE, followed by EGD within a week in a blinded fashion. Following endoscopy, and on the same day, participants were asked to fill in a satisfaction questionnaire regarding their experience.

FINDINGS

A total of 105 eligible participants were enrolled. With EGD as the reference standard, the concordance index, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio of DS-MCCE in diagnosis of HRV were 0•90 (95% confidence interval [CI]: 0•83-0•95), 92% (95% CI: 78-98%), 88% (95% CI: 78-95%), 80% (95% CI: 70-92%), 95% (95% CI: 90-100%), 7•91 (95% CI: 4•10-15•30), and 0•09 (95% CI: 0•03-0•30), respectively. The kappa score of 0•78 (95% CI: 0•65-0•90) suggested substantial agreement between DS-MCCE and EGD. Moreover, in participants undergoing EGD without sedation, the satisfaction of DS-MCCE was significantly better than that of EGD (p < 0•0001, d = 1•15 [95%CI: 0•88-1•42]). All participants confirmed the excretion of the capsule, and no adverse events occurred.

INTERPRETATION

DS-MCCE is an accurate alternative to EGD for detecting HRV in cACLD, which is safe and associated with better satisfaction.

FUNDING

A full list of funding can be found in the Funding Support section.

Current and Future Use of Esophageal Capsule Endoscopy

Capsule endoscopy can be a diagnostic option for patients with esophageal diseases who cannot tolerate esophagogastroduodenoscopy.Functional modifications of the capsule allow for thorough examination of the esophagus. Esophageal capsule endoscopy has so farfailed to show sufficient performance to justify the replacement of traditional endoscopy for the diagnosis of esophageal diseasesbecause the esophagus has a short transit time and common pathologies appear near the esophagogastric junction. However,technological improvements are being introduced to overcome the limitations of capsule endoscopy, which is expected to become agood alternative to conventional endoscopy.

Use of Wireless Capsule Endoscopy for the Diagnosis and Grading of Esophageal Varices in Patients With Portal Hypertension: A Systematic Review and Meta-Analysis

INTRODUCTION

Esophageal variceal bleeding is a severe complication of portal hypertension with significant morbidity and mortality. Although traditional screening and grading of esophageal varices has been performed by endogastroduodenoscopy (EGD), wireless video capsule endoscopy provides a minimally invasive alternative that may improve screening and surveillance compliance.

AIM OF THE STUDY

The aim of the study was to perform a systematic review and structured meta-analysis of all eligible studies to evaluate the efficacy of wireless capsule endoscopy for screening and diagnosis of esophageal varices among patients with portal hypertension.

METHODS

Searches of PubMed, EMBASE, Web of Science, and the Cochrane Library databases were performed through December 2015. Bivariate and hierarchical models were used to compute the pooled sensitivity and specificity, and to plot the summary receiver operating characteristics curve with summary point and corresponding 95% confidence region. Bias of included studies was assessed using the quality assessment of diagnostic accuracy studies-2.

RESULTS

Seventeen studies from 2005 to 2015 were included in this meta-analysis (n=1328). The diagnostic accuracy of wireless capsule endoscopy in the diagnosis of esophageal varices was 90% [95% confidence interval (CI), 0.88-0.93]. The diagnostic pooled sensitivity and specificity were 83% (95% CI, 0.76-0.89) and 85% (95% CI, 0.75-0.91), respectively. The diagnostic accuracy of wireless capsule endoscopy for the grading of medium to large varices was 92% (95% CI, 0.90-0.94). The pooled sensitivity and specificity were 72% (95% CI, 0.54-0.85) and 91% (95% CI, 0.86-0.94), respectively, for the grading of medium to large varices. The use of capsule demonstrated only mild adverse events. A sensitivity analysis limited to only high quality studies revealed similar results.

DISCUSSION

Wireless esophageal capsule endoscopy is well tolerated and safe in patients with liver cirrhosis and suspicion of portal hypertension. The sensitivity of capsule endoscopy is not currently sufficient to replace EGD as a first exploration in these patients, but given its high accuracy, it may have a role in cases of refusal or contraindication to EGD.

A pilot study of capsule endoscopy after a standard meal for the detection and grading of oesophageal varices in cirrhotic patients

BACKGROUND

Capsule endoscopy has been proposed as an alternative to fibreoptic endoscopy for oesophageal varices evaluation in cirrhotics. However, it shows only moderate sensitivity compared to fibreoptic endoscopy.

AIM

To compare post-meal capsule endoscopy to fibreoptic endoscopy, based on the hypothesis that meal-induced increase of portal pressure can enhance its sensitivity.

METHODS

Twenty-five patients were submitted to fibreoptic endoscopy and, after a standard meal, capsule endoscopy.

RESULTS

Post-meal capsule endoscopy detected varices in the 18 patients in whom fibreoptic endoscopy detected varices plus 3 more subjects (sensitivity 100%, specificity 70%); large varices in the 4 patients in whom fibreoptic endoscopy graded varices as large, plus 5 more subjects; red markers in the 5 patients in whom fibreoptic endoscopy detected red markers, plus 3 more subjects. High-risk varices were identified in 11 patients by post-meal capsule endoscopy and in 10 by fibreoptic endoscopy (sensitivity 100%, specificity 93.8%).

CONCLUSIONS

Post-meal capsule endoscopy identified more varices, large varices and red markers than fibreoptic endoscopy. The two methods detected similar proportions of high-risk varices. These data suggest that a standard meal can enhance the sensitivity of capsule endoscopy in the detection and grading of oesophageal varices in cirrhotics.

Capsule endoscopy for the diagnosis of oesophageal varices in people with chronic liver disease or portal vein thrombosis

BACKGROUND

Current guidelines recommend performance of oesophago-gastro-duodenoscopy at the time of diagnosis of hepatic cirrhosis to screen for oesophageal varices. These guidelines require people to undergo an unpleasant invasive procedure repeatedly with its attendant risks, despite the fact that half of the people do not have identifiable oesophageal varices 10 years after the initial diagnosis of cirrhosis. Video capsule endoscopy is a non-invasive test proposed as an alternative method for the diagnosis of oesophageal varices.

OBJECTIVES

To determine the diagnostic accuracy of capsule endoscopy for the diagnosis of oesophageal varices in children or adults with chronic liver disease or portal vein thrombosis, irrespective of the aetiology. To investigate the accuracy of capsule endoscopy as triage or replacement of oesophago-gastro-duodenoscopy.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Diagnostic Test Accuracy Studies Register (October 2013), MEDLINE (Ovid SP) (1950 to October 2013), EMBASE (Ovid SP) (1980 to October 2013), ACP Journal Club (Ovid SP) (1991 to October 2013), Database of Abstracts of Reviews of Effects (DARE) (Ovid SP) (third quarter), Health Technology Assessment (HTA) (Ovid SP) (third quarter), NHS Economic Evaluation Database (NHSEED) (Ovid SP) (third quarter), and Science Citation Index Expanded (SCI-EXPANDED) (ISI Web of Knowledge) (1955 to October 2013). We applied no language or document type restrictions.

SELECTION CRITERIA

Studies that evaluated the diagnostic accuracy of capsule endoscopy for the diagnosis of oesophageal varices using oesophago-gastro-duodenoscopy as the reference standard in children or adults of any age, with chronic liver disease or portal vein thrombosis.

DATA COLLECTION AND ANALYSIS

We followed the available guidelines provided in the Cochrane Handbook for Diagnostic Test of Accuracy Reviews. We calculated the pooled estimates of sensitivity and specificity using the bivariate model due to the absence of a negative correlation in the receiver operating characteristic (ROC) space and of a threshold effect.

MAIN RESULTS

The search identified 16 eligible studies, in which only adults with cirrhosis were included. In one study, people with portal thrombosis were also included. We classified most of the studies at high risk of bias for the 'Participants selection' and the 'Flow and timing' domains. One study assessed the accuracy of capsule endoscopy for the diagnosis of large (high-risk) oesophageal varices. In the remaining15 studies that assessed the accuracy of capsule endoscopy for the diagnosis of oesophageal varices of any size in people with cirrhosis, 936 participants were included; the pooled estimate of sensitivity was 84.8% (95% confidence interval (CI) 77.3% to 90.2%) and of specificity 84.3% (95% CI 73.1% to 91.4%). Eight of these studies included people with suspected varices or people with already diagnosed or even treated varices, or both, introducing a selection bias. Seven studies including only people with suspected but unknown varices were at low risk of bias; the pooled estimate of sensitivity was 79.7% (95% CI 73.1% to 85.0%) and of specificity 86.1% (95% CI 64.5% to 95.5%). Six studies assessed the diagnostic accuracy of capsule endoscopy for the diagnosis of large oesophageal varices, associated with a higher risk of bleeding; the pooled sensitivity was 73.7% (95% CI 52.4% to 87.7%) and of specificity 90.5% (95% CI 84.1% to 94.4%). Two studies also evaluated the presence of red marks, which are another marker of high risk of bleeding; the estimates of sensitivity and specificity varied widely. Two studies obtained similar results with the use of a modified device as index test (string capsule). Due to the absence of data, we could not perform all planned subgroup analyses. Interobserver agreement in the interpretation of capsule endoscopy results and any adverse event attributable to capsule endoscopy were poorly assessed and reported. Only four studies evaluated the interobserver agreement in the interpretation of capsule endoscopy results: the concordance was moderate. The participants' preferences for capsule endoscopy or oesophago-gastro-duodenoscopy were reported differently but seemed in favour of capsule endoscopy in nine of 10 studies. In 10 studies, participants reported some minor discomfort on swallowing the capsule. Only one study identified other significant adverse events, including impaction of the capsule due to previously unidentified oesophageal strictures in two participants. No adverse events were reported as a consequence of the reference standard.

AUTHORS' CONCLUSIONS

We cannot support the use of capsule endoscopy as a triage test in adults with cirrhosis, administered before oesophago-gastro-duodenoscopy, despite the low incidence of adverse events and participant reports of being better tolerated. Thus, we cannot conclude that oesophago-gastro-duodenoscopy can be replaced by capsule endoscopy for the detection of oesophageal varices in adults with cirrhosis. We found no data assessing capsule endoscopy in children and in people with portal thrombosis.

Capsule endoscopy: Present status and future expectation

Video capsule endoscopy (CE) since its introduction 13 years back, has revolutionized our approach to small intestinal diseases. Obscure gastrointestinal bleed (OGIB) continues to be the most important indication for CE with a high sensitivity, specificity as well as positive and negative predictive values. It is best performed during ongoing bleed or immediately thereafter. Overt OGIB has a higher diagnostic yield than occult OGIB. However, even in iron deficiency anemia, CE is emerging as important investigation after initial negative work up. In suspected Crohn’s disease (CD), CE has been shown superior to traditional imaging and endoscopic technique and should be considered after a negative ileocolonoscopy. Although CE has also been used for evaluating established CD, a high capsule retention rate precludes its use ahead of cross-sectional imaging. Celiac disease, particularly where gastro-duodenoscopy cannot be performed or is normal, can also be investigated by CE. Small bowel tumor, hereditary polyposis syndrome, and non-steroidal anti-inflammatory drugs induced intestinal damage are other indications for CE. Capsule retention is the only significant adverse outcome of CE and occurs mostly in presence of intestinal obstruction. This can be prevented by use of Patency capsule prior to CE examination. Presence of cardiac pacemaker and intracardiac devices continue to be relative contraindications for CE, though data do not suggest interference of CE with these devices. Major limitations of CE today include failure to control its movement from outside, inability of CE to acquire tissue for diagnosis, and lack of therapeutic help. With ongoing interesting and exciting developments taking place in these areas, these issues would be solved in all probability in near future. CE has the potential to become one of the most important tools in diagnostic and possibly in the therapeutic field of gastrointestinal disorder.

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.