PillCam ESO versus esophagogastroduodenoscopy in esophageal variceal screening: A decision analysis

Current status and future developments of upper gastrointestinal tract capsule endoscopy

Capsule endoscopy has been widely used for the diagnosis of small bowel diseases due to its safety, noninvasiveness, and acceptability. Despite the potential benefits of capsule endoscopy, there are obvious challenges to capsule endoscopy application in the upper gastrointestinal tract, due to the fast transit speed in the esophagus and large space of the gastric cavity. With the development of innovative technologies, such as magnetic navigation and tethered capsule endoscopy, the indications for capsule endoscopy have recently been expanded. Various capsule endoscopes have been applied to clinical practice, and several state-of-the-art research-oriented designs and devices provide hope for further use in the diagnosis of upper gastrointestinal diseases. In this review, we will summarize the current status and future developments of upper gastrointestinal tract capsule endoscopy.

Diagnostic yield of esophagogastroduodenoscopy in France

BACKGROUND AND STUDY AIMS

Large scale data on esophagogastroduodenoscopy (EGD) in Western countries are scarce. We conducted a prospective study on the diagnostic yield of upper gastrointestinal endoscopy in France.

PATIENTS AND METHODS

An online questionnaire was sent to all French gastroenterologists practicing endoscopy. Data from EGDs performed during one week were collected. A statistical extrapolation of the results to a whole year was performed.

RESULTS

342 gastrointestinal endoscopists, representative of the population of French gastroenterologists, provided data on 2735 EGDs, corresponding to 1 006 316 (95%CI=937 080-1 075 552) procedures for the entire year. 1770 (64.7%) EGDs were performed under sedation or general anesthesia, and 930 (34%) were associated with a colonoscopy. 896 (32.8%) EGDs were normal. Hiatal hernia and esophagitis were the most frequent esophageal diagnoses, in 496 (18.1%) and 374 (13.7%) cases, respectively. Barrett's esophagus was diagnosed in 109 (4%) patients. Among gastric lesions, endoscopic gastritis was reported in 572 (20.9%) patients; ulcer, polyps, and suspected malignancy in 78 (2.9%), 62 (2.3%), and 19 (0.7%), respectively. 1597 (58.4%) EGDs included mucosal biopsies, and 141 (5.1%) were associated with a therapeutic procedure.

CONCLUSIONS

We report nationwide prospective data on upper gastrointestinal endoscopy practice in France. Our data suggest that about 300 000 normal EGDs each year in France could potentially be avoided by a diagnostic strategy relying on upper GI capsule endoscopy, providing significant relief on healthcare practitioners.

The detection of oesophageal varices using a novel, disposable, probe-based transnasal endoscope: a prospective diagnostic pilot study

BACKGROUND & AIMS

Screening for oesophageal varices (OV) using conventional oesophagogastroduodenoscopy (C-OGD) is invasive and requires costly monitoring, recovery, and decontamination facilities. We aimed to evaluate the technical feasibility, acceptability and accuracy of a novel, portable and disposable office-based transnasal endoscope (EG Scan™ ) compared to C-OGD as the reference standard.

METHODS

This was a prospective cohort study. Consecutive adult patients with cirrhosis were invited to participate. All subjects underwent the two procedures on the same day performed by two endoscopists in a blinded design. Patients completed preference and validated tolerability (10-point visual analogue scale (VAS)) questionnaires on day 0 and day 14 post procedures.

RESULTS

Forty-five of 50 patients (90%) completed both interventions. Mean age was 59 years and OV prevalence was 49%. Patients reported higher preference (percentage) and better experience (mean VAS) with EG Scan compared to C-OGD on day 0 (76.5% vs. 23.5%, P < 0.001; 7.8 vs. 6.8, P = 0.058, respectively) and day 14 (77.8% vs. 22.2%, P < 0.001; 7.0 vs. 5.5, P = 0.0013 respectively). Sensitivity and specificity of the EG Scan for the diagnosis of any size OV were 0.82 (95% confidence interval (CI) 0.60-0.95), and 0.78 (95% CI 0.56-0.93) respectively. Corresponding values for the diagnosis of clinically significant (medium/large) OV were 0.92 (95% CI 0.62-1.0), 0.97 (95% CI 0.84-1.0) respectively. No serious adverse events occurred.

CONCLUSIONS

EG Scan accuracy was higher for the diagnosis of medium/large OV compared to any size OV. Patients' preference and overall experience of the EG Scan was favourable compared to C-OGD 14 days after procedures.

Multidetector computed tomography versus platelet/spleen diameter ratio as methods for the detection of gastroesophageal varices

BACKGROUND

All patients with liver cirrhosis should undergo screening endoscopy, but there are limitations and this approach places a heavy burden upon endoscopy units. The aim of this study was to compare multidetector computed tomography (MDCT) and the platelet/spleen diameter ratio as non-invasive methods for the detection of gastroesophageal varices.

METHODS

The study included 38 cirrhotics who underwent upper gastrointestinal (GI) endoscopy and MDCT within one month. Two radiologists reviewed the scans, in order to determine the presence and the size of varices. Blood tests and measurement of the spleen maximum diameter were also carried out and the platelet/spleen diameter ratio was calculated. Endoscopy was considered the gold standard and the results of the two methods were compared to it.

RESULTS

Varices were detected by upper GI endoscopy in 24 of 38 patients. The mean sensitivity and specificity of MDCT for the two observers was 86.1% and 57.1% respectively. In patients with large varices (>5 mm), the sensitivity was 100% (4/4). Using 909 as a cut-off value of the platelet/spleen diameter ratio this method yielded a sensitivity of 56.5% and a specificity of 35.7%. The difference in sensitivity and specificity between the two methods was statistically significant P<0.05.

CONCLUSION

MDCT was accurate for the detection of gastroesophageal varices, especially those with clinically significant size (>5 mm), and superior to platelet/spleen diameter ratio. MDCT could replace, in selected patients, upper GI endoscopy as a method for detecting gastroesophageal varices in cirrhotic patients.

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.

Oesophageal capsule endoscopy versus oesophago-gastroduodenoscopy for the diagnosis of recurrent varices: a prospective multicentre study

BACKGROUND

Oesophago-gastroduodenoscopy is the standard method for the diagnosis of recurrent oesophago-gastric varices after endoscopic treatment and eradication. The aim of this study was to evaluate the PillCam Eso capsule endoscopy in this setting.

METHODS

Prospective, multicentre study in which patients with history of oesophageal varices treated by band ligation underwent PillCam Eso capsule and oesophago-gastroduodenoscopy. Capsule recordings were blindly read by two endoscopists. Indication for a new prophylactic treatment and patient satisfaction were determined for both procedures.

RESULTS

80 patients (80% males, mean age: 57±12 years) were included, after a median delay of 16 months from last endoscopic treatment. Recurrent oesophageal varices requiring a new prophylactic treatment were detected in 26 patients (32.5%). The mean oesophageal transit time of the capsule was 153 s (range 2-930 s). Capsule sensitivity, specificity, negative and positive predictive values for indication of new prophylactic treatments were 65%, 83%, 83%, and 65%, respectively. Capsule adequately classified 77.5% of the patients for prophylaxis indication. Inter-observer concordance for capsule readings was 88% for the prophylaxis indication.

CONCLUSION

This study demonstrates that accuracy of PillCam Eso capsule for the diagnosis of recurrent oesophageal varices after endoscopic eradication is suboptimal. PillCam Eso capsule might therefore be proposed in patients unable or unwilling to undergo oesophago-gastroduodenoscopy.

Towards noninvasive detection of oesophageal varices

Current guidelines recommend that all cirrhotic patients should undergo screening endoscopy at diagnosis to identify patients with varices at high risk of bleeding who will benefit from primary prophylaxis. This approach places a heavy burden upon endoscopy units and the repeated testing over time may have a detrimental effect on patient compliance. Noninvasive identification of patients at highest risk for oesophageal varices would limit investigation to those most likely to benefit. Upper GI endoscopy is deemed to be the gold standard against which all other tests are compared, but is not without its limitations. Multiple studies have been performed assessing clinical signs and variables relating to liver function, variables relating to liver fibrosis, and also to portal hypertension and hypersplenism. Whilst some tests are clearly preferable to patients, none appear to be as accurate as upper GI endoscopy in the diagnosis of oesophageal varices. The search for noninvasive tests continues.