The Diagnostic Value of Contrast-Enhanced Ultrasound for Monitoring Complications After Kidney Transplantation—A Systematic Review and Meta-Analysis

Abstract

Contrast-enhanced ultrasound (CEUS) has increasingly gained acceptance in the postoperative evaluation of kidney-transplantation recipients. Our meta-analysis aims to evaluate the diagnostic accuracy of CEUS in identifying post-transplantation complications. PubMed, Scopus, Ovid Medline, and Cochrane databases were searched from their inception until February 28, 2020, for diagnostic test accuracy studies comparing CEUS to a reference standard for monitoring complications after kidney transplantation. A meta-analysis was conducted to calculate the pooled sensitivity, specificity, accuracy, and diagnostic odds ratio using a bivariate random effects model. Sensitivity analysis was performed using R software by stratifying the studies based on study design, sample size, age, and origin of the study to evaluate the influence of these factors on the overall effect. Two independent reviewers analyzed 285 publications, out of which 29 were determined directly relevant and 12 (with a total of 542 cases) contained all required data for the meta-analysis. The overall sensitivity of included studies was estimated to be 0.86 (95% confidential interval (CI); 0.78--0.92). Similarly, the overall specificity was estimated to be 0.90 (95% CI; 0.82-0.94). Log diagnostic odds ratio was 4.25 (95% CI; 3.43-5.07), and the area under the curve of the pooled receiver operating characteristic was 0.94. Stratified sensitivity analyses showed study design, sample size, age group, and origin of the study had no significant impact on the overall diagnostic value of CEUS. Evidence suggests that CEUS is a potentially effective and accurate method to evaluate a variety of complications such as rejection, vascular complications, and malignancies after kidney transplantation.