Use of wireless capsule endoscopy for the diagnosis and grading of esophageal varices in patients with portal hypertension: A systematic review and meta-analysis

Abstract

Background:: Esophageal varices are a life-threatening complication of portal hypertension, necessitating timely screening for optimal patient outcomes. While esophagogastroduodenoscopy (EGD) remains the gold standard for diagnosis, its invasiveness poses challenges for patient compliance. Wireless capsule endoscopy has emerged as a potential noninvasive alternative. This meta-analysis evaluates the diagnostic accuracy of wireless capsule endoscopy in screening and diagnosing esophageal varices compared to EGD.

Methods:: A comprehensive literature search was conducted across PubMed, Embase, Web of Science, and Cochrane Library database from 1995 to 2024. Studies assessing the sensitivity, specificity, and overall diagnostic efficacy of wireless capsule endoscopy for esophageal varices were included. The QUADAS-2 tool was employed to assess the risk of bias. Sensitivity and specificity were analyzed using a 95% confidence interval (CI), and heterogeneity among studies was evaluated using the I² statistic.

Results:: A total of 20 studies met the inclusion criteria, comprising 3350 unique records screened. Pooled analysis demonstrated that wireless capsule endoscopy had a sensitivity of 81.2% (95% CI: 78.5–83.7) and a specificity of 86.2% (95% CI: 82.7–89.1) for detecting esophageal varices. Minimal heterogeneity was observed (I² = 0%), reinforcing the robustness of the findings. Wireless capsule endoscopy was particularly effective in identifying high-risk varices, with some studies reporting sensitivity and specificity exceeding 95%. Additionally, patient tolerance and satisfaction with wireless capsule endoscopy were higher compared to EGD.

Conclusion:: Wireless capsule endoscopy demonstrates substantial diagnostic accuracy for esophageal varices, offering a noninvasive, well-tolerated alternative to EGD. Its role in clinical practice warrants further investigation.

Keywords: Esophageal varices; portal hypertension; wireless capsule endoscopy.

Figure 1

PRISMA flow diagram illustrating the study selection process for the meta-analysis

Figure 2

Forest plots summarizing pooled sensitivity and specificity of WCE for detecting esophageal varices

Figure 3

SROC curve showing overall diagnostic accuracy of WCE for detecting esophageal varices

Figure 4

Forest plots showing pooled sensitivity and specificity of WCE for grading medium to large varices

Figure 5

SROC curve demonstrating diagnostic accuracy of WCE for grading medium to large esophageal varices

Figure 6

Risk of bias summary across included studies using the QUADAS-2 tool

Figure 7

Risk of bias graph showing proportion of studies with low, high, or unclear risk in each QUADAS-2 domain