Comparison of esophageal capsule endoscopy and esophagogastroduodenoscopy for diagnosis of esophageal varices

Applications of Artificial Intelligence-Based Systems in the Management of Esophageal Varices

BACKGROUND

Esophageal varices, dilated submucosal veins in the lower esophagus, are commonly associated with portal hypertension, particularly due to liver cirrhosis. The high morbidity and mortality linked to variceal hemorrhage underscore the need for accurate diagnosis and effective management. The traditional method of assessing esophageal varices is esophagogastroduodenoscopy (EGD), which, despite its diagnostic and therapeutic capabilities, presents limitations such as interobserver variability and invasiveness. This review aims to explore the role of artificial intelligence (AI) in enhancing the management of esophageal varices, focusing on its applications in diagnosis, risk stratification, and treatment optimization.

METHODS

This systematic review focuses on the capabilities of AI algorithms to analyze clinical scores, laboratory data, endoscopic images, and imaging modalities like CT scans.

RESULTS

AI-based systems, particularly machine learning (ML) and deep learning (DL) algorithms, have demonstrated the ability to improve risk stratification and diagnosis of esophageal varices, analyzing vast amounts of data, identifying patterns, and providing individualized recommendations. However, despite these advancements, clinical scores based on laboratory data still show low specificity for esophageal varices, often requiring confirmatory endoscopic or imaging studies.

CONCLUSIONS

AI integration in managing esophageal varices offers significant potential for advancing diagnosis, risk assessment, and treatment strategies. While promising, AI systems should complement rather than replace traditional methods, ensuring comprehensive patient evaluation. Further research is needed to refine these technologies and validate their efficacy in clinical practice.

Upper gastrointestinal video capsule endoscopy: The state of the art

BACKGROUND

Video capsule can illuminate the entire gastrointestinal mucosa. Upper gastrointestinal capsule endoscopy (UGICE) has the potential to survey for oesophageal, gastric and duodenal pathology and determine whether biopsy or intervention is indicated.

AIMS

This review traces the evolution of foregut video capsule endoscopy.

METHODS

A broad literature research was performed independently by two investigators. Extracted articles were organized and evaluated to interpret all current data.

RESULTS

In contrast to small bowel capsule, UGICE required sequential innovations to deal with rapid oesophageal transit, the irregular shape of the stomach and unpredictable gastric peristalsis. Oesophageal capsule endoscopy required the development of a two-camera device operating at a high frame rate, and postural change was developed to improve image capture, especially at the level of the Z-line, thus providing good imaging of Barrett's oesophagus, erosive oesophagitis and oesophageal varices, with optimal patients' tolerance. UGICE in patients presenting to the emergency room with acute bleeding has demonstrated accuracy when deciding on the need for emergency intervention. The latest development of a high frame rate UGICE, designed to image the oesophagus, stomach and duodenum has overtaken dedicated oesophageal capsule development. Capsule control is possible by exposing a magnetised capsule to an external magnetic field, and early reports indicate high accuracy in the oesophagus and stomach with high levels of patient acceptability. There is little information on cost-benefit.

CONCLUSIONS

Capsule endoscopy offers gastroenterologists a new device to investigate the upper gastrointestinal tract with promising future potential.

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.

Diagnosis of Barrett's esophagus and esophageal varices using a magnetically assisted capsule endoscopy system

BACKGROUND AND AIMS

Magnetically assisted capsule endoscopy (MACE) potentially offers a comfortable, patient friendly, and community-based alternative to gastroscopy (EGD). This pilot study aims to explore whether this approach can be used to accurately diagnose Barrett's esophagus (BE) and esophageal varices.

METHOD

The MiroCam Navi capsule system was used to examine the upper GI tract in patients due to undergo a clinically indicated EGD. A total of 50 participants were enrolled: 34 had known pathology (17 BE, 17 esophageal varices [EV]) and 16 controls. Patients underwent the MACE procedure with the operator blinded to the indication and any previous endoscopic diagnoses. The subsequent EGD was performed by an endoscopist blinded to the MACE findings. Diagnostic yield, comfort, and patient preference between the 2 modalities were compared.

RESULTS

The mean age of the participants was 61 years, the male/female ratio was 2.1:1, the mean body mass index was 29.5 kg/m2, and the average chest measurement was 105.3 cm. Forty-seven patients underwent both procedures; 3 patients were unable to swallow the capsule. With the use of the magnet, it was possible to hold the capsule within the esophagus for a mean duration of 190 seconds and up to a maximum of 634 seconds. A correct real-time MACE diagnosis was made in 11 of 15 patients with EV (sensitivity 73.3% [95% confidence interval (CI), 44.9%-92.2%] and specificity 100% [95% CI, 89.1%-100%]) and 15 of 16 patients with BE (sensitivity 93.8% [95% CI, 69.8%-99.8%] and specificity of 100% [95% CI, 88.8%-100%]). MACE was considered more comfortable than conventional endoscopy (P < .0001); the mean score was 9.2 for MACE compared with 6.7 for EGD when assessed on a 10-point scale. No MACE- or EGD-related adverse events occurred.

CONCLUSION

This pilot study demonstrates that MACE is both safe and well tolerated by patients. Accuracy for the diagnosis of BE was high, and therefore MACE may have a role in screening for this condition. (Clinical trial registration number: NCT02852161.).

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.

Νon-invasive screening for esophageal varices in patients with liver cirrhosis

Esophageal varices are one of the main complications of liver cirrhosis. Upper gastrointestinal endoscopy is the gold standard for the detection of esophageal varices. Many less invasive methods for screening of varices have been investigated and the most recent Baveno VI guidelines suggest that endoscopy is not necessary in patients with liver stiffness <20 kPa and platelets >150,000/μL. A critical review of the literature was performed concerning non-invasive or minimally invasive methods of screening for esophageal varices. Liver and spleen elastography, imaging methods including computed tomography, magnetic resonance imaging and ultrasound, laboratory tests and capsule endoscopy are discussed. The accuracy of each method, and its advantages and limitations compared to endoscopy are analyzed. There are data to support the Baveno VI guidelines, but there is still a lack of large prospective studies and low specificity has been reported for the liver stiffness and platelet count combination. Spleen elastography has shown promising results, as there are data to support its superiority to liver elastography, but it needs further assessment. Computed tomography has shown high diagnostic accuracy and can be part of the diagnostic work up of cirrhotic patients in the future, including screening for varices.

Ultrathin disposable gastroscope for screening and surveillance of gastroesophageal varices in patients with liver cirrhosis: a prospective comparative study

BACKGROUND AND AIMS

This study aims to evaluate the role of unsedated, ultrathin disposable gastroscopy (TDG) against conventional gastroscopy (CG) in the screening and surveillance of gastroesophageal varices (GEVs) in patients with liver cirrhosis.

METHOD

Forty-eight patients (56.4 ± 1.3 years; 38 male, 10 female) with liver cirrhosis referred for screening (n = 12) or surveillance (n = 36) of GEVs were prospectively enrolled. Unsedated gastroscopy was initially performed with TDG, followed by CG with conscious sedation. The 2 gastroscopies were performed by different endoscopists blinded to the results of the previous examination. Video recordings of both gastroscopies were validated by an independent investigator in a random, blinded fashion. Endpoints were accuracy and interobserver agreement of detecting GEVs, safety, and potential cost saving.

RESULTS

CG identified GEVs in 26 (54%) patients, 10 of whom (21%) had high-risk esophageal varices (HREV). Compared with CG, TDG had an accuracy of 92% for the detection of all GEVs, which increased to 100% for high-risk GEVs. The interobserver agreement for detecting all GEVs on TDG was 88% (κ = 0.74). This increased to 94% (κ = 0.82) for high-risk GEVs. There were no serious adverse events.

CONCLUSIONS

Unsedated TDG is safe and has high diagnostic accuracy and interobserver reliability for the detection of GEVs. The use of clinic-based TDG would allow immediate determination of a follow-up plan, making it attractive for variceal screening and surveillance programs. (Clinical trial (ANZCTR) registration number: ACTRN12616001103459.).

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.

Esophageal capsule endoscopy is not the optimal technique to determine the need for primary prophylaxis in patients with cirrhosis

INTRODUCTION

Capsule endoscopy has been suggested as a potential alternative to endoscopy for detection of esophagogastric varices and severe portal hypertensive gastropathy (PHG). The aim of the study was to determine whether PillCam esophageal capsule endoscopy could replace endoscopy for screening purposes.

MATERIAL AND METHODS

Sixty-two patients with cirrhosis with no previous variceal bleeding had PillCam capsule endoscopy and video endoscopy performed on the same day. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of capsule endoscopy were compared to endoscopy for the presence and severity of esophageal and gastric varices, PHG and the need for primary prophylaxis. Patients' preference was assessed by a questionnaire.

RESULTS

Four (6%) patients were unable to swallow the capsule. Sensitivity, specificity, PPV and NPV of capsule endoscopy for detecting any esophageal varices (92%, 50%, 92%, 50%), large varices (55%, 91%, 75%, 80%), variceal red signs (58%, 87%, 69%, 80%), PHG (95%, 50%, 95%, 50%), and the need for primary prophylaxis (91%, 57%, 78%, 80%) were not optimal, with only moderate agreement (κ) between capsule and upper GI endoscopy. Had only a capsule endoscopy been performed, 12 (21.4%) patients would have received inappropriate treatment. Capsule endoscopy also failed to detect (0/13) gastric varices. The majority of patients ranked capsule endoscopy as more convenient (69%) and their preferred (61%) method.

CONCLUSIONS

Despite the preference expressed by patients for capsule endoscopy, we believe that upper GI endoscopy should remain the preferred screening method for primary prophylaxis.

Portal hypertensive gastropathy: A systematic review of the pathophysiology, clinical presentation, natural history and therapy

AIM

To describe the pathophysiology, clinical presentation, natural history, and therapy of portal hypertensive gastropathy (PHG) based on a systematic literature review.

METHODS

Computerized search of the literature was performed via PubMed using the following medical subject headings or keywords: "portal" and "gastropathy"; or "portal" and "hypertensive"; or "congestive" and "gastropathy"; or "congestive" and "gastroenteropathy". The following criteria were applied for study inclusion: Publication in peer-reviewed journals, and publication since 1980. Articles were independently evaluated by each author and selected for inclusion by consensus after discussion based on the following criteria: Well-designed, prospective trials; recent studies; large study populations; and study emphasis on PHG.

RESULTS

PHG is diagnosed by characteristic endoscopic findings of small polygonal areas of variable erythema surrounded by a pale, reticular border in a mosaic pattern in the gastric fundus/body in a patient with cirrhotic or non-cirrhotic portal hypertension. Histologic findings include capillary and venule dilatation, congestion, and tortuosity, without vascular fibrin thrombi or inflammatory cells in gastric submucosa. PHG is differentiated from gastric antral vascular ectasia by a different endoscopic appearance. The etiology of PHG is inadequately understood. Portal hypertension is necessary but insufficient to develop PHG because many patients have portal hypertension without PHG. PHG increases in frequency with more severe portal hypertension, advanced liver disease, longer liver disease duration, presence of esophageal varices, and endoscopic variceal obliteration. PHG pathogenesis is related to a hyperdynamic circulation, induced by portal hypertension, characterized by increased intrahepatic resistance to flow, increased splanchnic flow, increased total gastric flow, and most likely decreased gastric mucosal flow. Gastric mucosa in PHG shows increased susceptibility to gastrotoxic chemicals and poor wound healing. Nitrous oxide, free radicals, tumor necrosis factor-alpha, and glucagon may contribute to PHG development. Acute and chronic gastrointestinal bleeding are the only clinical complications. Bleeding is typically mild-to-moderate. Endoscopic therapy is rarely useful because the bleeding is typically diffuse. Acute bleeding is primarily treated with octreotide, often with concomitant proton pump inhibitor therapy, or secondarily treated with vasopressin or terlipressin. Nonselective β-adrenergic receptor antagonists, particularly propranolol, are used to prevent bleeding after an acute episode or for chronic bleeding. Iron deficiency anemia from chronic bleeding may require iron replacement therapy. Transjugular-intrahepatic-portosystemic-shunt and liver transplantation are highly successful ultimate therapies because they reduce the underlying portal hypertension.

CONCLUSION

PHG is important to recognize in patients with cirrhotic or non-cirrhotic portal hypertension because it can cause acute or chronic GI bleeding that often requires pharmacologic therapy.

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--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.

Current status of capsule endoscopy through a whole digestive tract

More than a decade has passed since small-bowel capsule endoscopy (CE) was first reported. Small-bowel CE is a non-invasive tool that allows visualization of the entire small-intestinal mucosa and facilitates detection of small-intestinal abnormalities. Several studies have shown benefit of small-bowel CE for certain disorders. Because it is non-invasive, CE has been applied to other organs including the esophagus, stomach, and colon. The main indications for esophageal CE (ECE) are screening for gastroesophageal reflux disease/Barrett's esophagus, and esophageal varices. However, the clinical benefit of ECE is unconfirmed. Magnetically guided CE (MGCE) was developed to visualize the gastric mucosa. MGCE is a new concept with room for improvement of capsule navigation and the preparation protocol. Recently, two new small-bowel CE tools were released. First-generation colon CE (CCE-1) has moderate sensitivity and specificity compared with colonoscopy for colorectal neoplasia surveillance. To obtain higher accuracy, a second-generation CCE (CCE-2) was developed with a high sensitivity for detecting clinically relevant polypoid lesions. A possible application of CCE is for inflammatory bowel disease. In the near future, CE may include diagnostic and therapeutic functions such as magnifying endoscopy systems, targeted biopsy forceps, and drug delivery systems.

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.

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.

Wireless capsule endoscopy

Over the last decade, WCE has established itself as a valuable test for imaging the small intestine. It is a safe and relatively easy procedure to perform that can provide valuable information in the diagnosis of small-bowel conditions. Its applications still remain limited within the esophagus and colon. Future developments may include improving visualization within the esophagus and developing technologies that may allow manipulation of the capsule within the GI tract and biopsy capabilities.

Multidetector CT oesophagography: an alternative screening method for endoscopic diagnosis of oesophageal varices and bleeding risk

BACKGROUND AND STUDY AIMS

Variceal bleeding is a frequent and life-threatening complication of portal hypertension. The aim of this study was to evaluate multidetector computed tomographic (MDCT) oesophagography as an alternative to endoscopy for screening oesophageal varices (EVs) and predicting bleeding risk.

PATIENTS AND METHODS

A total of 137 cirrhotic patients underwent MDCT followed by endoscopy and EVs were graded independently. The screening ability of CT for EV was evaluated by comparing the grades of EV at CT and at endoscopy. Prediction of bleeding risk by CT was determined by correlating the CT variceal grades, diameters and palisade vein dilatation with the endoscopic red colour (RC) sign. Extra-oesophageal findings were assessed by CT. Patients' acceptance for both examinations were compared.

RESULTS

At endoscopy, 47 (34%) patients had grade 0 EV, 52 (38%) patients had grade 1 EV, 29 (21%) patients had grade 2 EV and nine (7%) patients had grade 3 EV. The sensitivity, specificity, positive and negative predictive values and accuracy of CT oesophagography for defining EV in all grades were 99%, 98%, 99%, 98% and 99%, respectively. The MDCT variceal grades, diameters and palisade vein dilatation were correlated with the severity of the RC sign. Important extra-oesophageal findings were determined by CT only. The acceptance of patients for CT oesophagography was significantly more than that for endoscopy (p<0.001).

CONCLUSION

MDCT is a reliable, preliminary or adjunctive method that can be used for routine screening for EVs and the prediction of variceal bleeding.

Capsule endoscopy is not as accurate as esophagogastroduodenoscopy in screening cirrhotic patients for varices

BACKGROUND & AIMS

Esophagogastroduodenoscopy (EGD) is the standard technique for screening cirrhotic patients for high-risk varices and other significant upper gastrointestinal lesions (HRVLs). We investigated whether esophageal capsule endoscopy (ECE) is as convenient and accurate as EGD for the detection of HRVLs.

METHODS

We analyzed data from 65 cirrhotic patients without prior upper gastrointestinal bleeding who were examined for varices and HRVLs by ECE and EGD (both procedures were performed on the same day). EGD was performed by 2 physicians (75% of patients were unsedated) who used standard grading for esophageal and gastric varices, portal hypertensive gastropathy, and HRVLs. Coded capsule tracings were read by 2 investigators, blinded to the EGD findings, using standard grading.

RESULTS

The median procedure time for EGD (with or without biopsy collection) was 3 minutes, compared with 20 minutes for ECE. The overall accuracy for diagnosis of esophageal varices was 63.2% ± 5.9%; for detection of esophageal varices red marks was 68.8% ± 5.4%; and for diagnosis of other HRVLs was 51.5% ± 4.2%. The interobserver agreement in the diagnosis of esophageal varices was 90.8%; in the detection of esophageal varices red marks was 86.2%; and in the diagnosis of other HRVLs was 7.3%.

CONCLUSIONS

ECE is not as accurate as EGD in the diagnosis of esophageal varices and red markings or in grading esophageal varices. Moreover, ECE had poor accuracy in grading portal hypertensive gastropathy and detecting ulcers, gastric varices, and other significant upper gastrointestinal lesions. It took significantly longer to perform ECE and interpret the results than for EGD. These findings do not support ECE as a preferred tool for screening esophageal varices and HRVLs.

Influence of operator experience and reporting time on the accuracy of esophageal capsule endoscopy screening for varices

Conflicting data exist concerning the accuracy of esophageal capsule endoscopy (ECE) for the screening of varices. No study has examined the influence of operator factors on the accuracy of ECE reporting. The primary aims of this study were, therefore, to examine how operator experience with esophagogastroduodenoscopy (EGD) and operator reporting times of capsule videos influenced test accuracy. Twelve cirrhotic patients presenting for EGD had same-day ECE performed. The gold standard for variceal grade was determined using a panel of experienced endoscopists. Six novice capsule endoscopists, blinded to results of EGD, subsequently reported capsule videos for each of the 12 patients.Novice capsule endoscopists accurately identified high-risk varices. The mean area under the receiver operating characteristic curve for identifying high-risk varices for the six operators was 0.88 ±/-0.14. The mean sensitivity, specificity, positive, and negative predictive values for identifying high-risk varices for the six operators were 83%, 93%, 82%, and 97%, respectively. Years of prior EGD experience were not associated with accuracy of capsule reporting (OR = 0.9, 95% CI [0.74, 1.08]; p = .26). Time spent reporting capsule videos was associated with accuracy of capsule reporting for high-risk varices using British Society of Gastroenterology criteria (OR = 1.33, 95% CI [1.05, 1.08]; p = .018). Novice capsule endoscopists are able to accurately identify high-risk esophageal varices. Time taken to report capsule videos, but not amount of prior EGD experience, influenced capsule report accuracy. These findings may have implications for the design of further trials and the cost-effectiveness of ECE screening of varices.

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.

Esophageal Capsule Endoscopy for Screening Esophageal Varices among Japanese Patients with Liver Cirrhosis

Purpose. Although esophageal capsule endoscopy (ECE) is reportedly useful in the diagnosis of esophageal varices (EV), few reports have described the benefits of this technique in Asian countries. The present paper evaluates the usefulness of ECE for diagnosing EV in Japanese patients with cirrhosis. Methods. We examined 29 patients with cirrhosis (20 males and 9 females; mean age 60 years; Child-Pugh classification A/B/C; 14/14/1) using ECE followed by esophagogastroduodenoscopy (EGD). High-risk EV were defined as F2 and/or RC2 and above. Results. The sensitivity and specificity of ECE for the diagnosis of high-risk EV were 92% and 80%, respectively. Conclusions. The findings showed that ECE is a highly sensitive method of diagnosing high-risk EV that requires endoscopic or pharmacological therapy. Thus, ECE might be a useful method for the screening and followup of EV in patients with cirrhosis.

Defining the threshold: new data on the ability of capsule endoscopy to discriminate the size of esophageal varices

BACKGROUND

Endoscopy (esophagogastroduodenoscopy, EGD) to screen for esophageal varices (EV) is recommended in patients with portal hypertension. Reports indicate that capsule endoscopy (CE) is capable of identifying large/medium varices (L/MV) when the varix comprises more than 25% of the circumference of the field of view.

AIMS

We evaluated the ability of CE to discriminate the size of EV using this grading scale.

METHODS

Patients underwent CE and EGD on the same day. A blinded investigator interpreted capsule findings. CE labeled EV as L/MV if ≥25% of the lumen circumference was occupied, and small/none for <25%.

RESULTS

A total of 37 patients were enrolled in this prospective, observational study at a single tertiary-care academic center. Three CE were excluded due to rapid esophageal transit time or technical malfunction. Using a 25% threshold, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for EC to discriminate L/MV were 23.5%, 88.2%, 66.7%, and 53.6%, respectively (κ=0.12). Reducing the threshold to 12.5% resulted in sensitivity, specificity, PPV, and NPV of 88.2%, 64.7%, 71.4%, and 84.6%, respectively (κ=0.53). A receiver-operator characteristic (ROC) curve showed a 15% threshold to be optimal in discriminating EV size using CE, resulting in sensitivity, specificity, PPV, and NPV of 76.5%, 82.4%, 81.3%, and 77.8%, respectively (κ=0.59).

CONCLUSIONS

This study indicates that discriminating EV size by the current capsule scale is unreliable. Lowering the grading threshold improved the ability to discriminate EV size by CE. In the proper context, CE is an alternative to EGD to screen for EV.

Capsule endoscopy in portal hypertension

Since the introduction of small bowel capsule endoscopy, and more recently of esophageal capsule endoscopy, these diagnostic tools have become available for the evaluation of the consequences of portal hypertension in the esophagus, stomach, and small intestine. The main advantage of the esophageal and the small bowel capsule is the relatively less invasiveness that could potentially increase patients' adherence to endoscopic screening/surveillance programs. When esophageal capsule endoscopy was compared with traditional gastroscopy, it showed good sensitivity and specificity in recognizing the presence and the size of esophageal varices. However, the results are not consistent among studies, and more data are needed.

Current staging and diagnosis of gastroesophageal varices

Portal hypertension is defined as an increase in hepatic sinusoidal pressure to 6 mm Hg or higher. Cirrhosis is the most common cause of portal hypertension in the western world and results from increased resistance to blood flow at the hepatic sinusoidal level.

Utilization of platelet count spleen diameter ratio in predicting the presence of esophageal varices in patients with cirrhosis

GOALS

To assess whether the platelet count/spleen diameter ratio is a useful noninvasive predictor of esophageal varices.

BACKGROUND

Current guidelines recommend that all patients with cirrhosis undergo screening endoscopy for the presence of varices. Recent studies have focused on using noninvasive techniques to stratify cirrhotic patients according to their risk of having varices. One study examining the platelet count/spleen diameter ratio using a cut-off value of 909, yielded a negative predictive value of 100% for the presence of varices.

STUDY

A retrospective analysis of 137 patients with cirrhosis over the age of 18 that underwent screening endoscopy for varices between January 2003 and October 2005. The data collected were age, sex, etiology of cirrhosis, spleen diameter, prothrombin time/international normalized ratio, total bilirubin, platelet count, albumin, Child-Pugh score, and endoscopic findings.

RESULTS

There were 137 patients with 87 (63.5%) men and a mean age of 56 years. Seventy-six (55%) patients had esophageal varices. The mean age, sex, and etiology of cirrhosis were similar between those with and without varices. Using a platelet count/spleen diameter ratio with a cut-off value of 909, yielded a negative predictive value of only 73% and a positive predictive value of 74%.

CONCLUSIONS

The platelet count/spleen diameter ratio with a cut-off value of 909 may not be sufficiently accurate in predicting the presence of esophageal varices. Upper endoscopy remains the method of choice to screen for the presence of varices.

Capsule endoscopy of the esophagus

Video capsule endoscopy has acquired wide clinical acceptance since its the US Food and Drug Administration approval in 2001. Recently, the technology of video capsule endoscopy has been adapted to other organs in the gastrointestinal tract, including the esophagus and colon. In this review, we discuss esophageal capsule endoscopy (ECE)-the procedure, its indications, contraindications, safety, and future applications. ECE is a minimally invasive procedure that uses special video capsules with ability to acquire images from 2 cameras with high image storing speed of 14 to 18 frames per second. A special ingestion procedure allows for prolonged esophageal transit time and an optimized view of the gastroesophageal junction. ECE has been shown to have moderately high sensitivity and accuracy in the diagnosis and surveillance of Barrett esophagus in patients with gastroesophageal reflux disease but has not demonstrated superiority to esogastroduodenoscopy in cost-effectiveness models. In patients with portal hypertension, ECE has a sensitivity of 63% to 100% for screening of esophageal varices, but does not seem to be superior to esogastroduodenoscopy in its cost-effectiveness. No serious complications have been reported after ECE although a low rate of esophageal capsule retention (0.7% to 2.2%) has been reported, usually because of unsuspected esophageal strictures. Contraindications to capsule endoscopy include known or suspected gastrointestinal and esophageal obstruction, strictures, or fistulas, intestinal pseudoobstruction, and children under 10 years of age. It is expected that improvements in imaging technology will improve the accuracy of ECE with the development of immunological-based and chemical-based diagnostic capabilities.