Single-Center Retrospective Study on the Efficacy of Contrast-Enhanced Ultrasound for Detection of Endoleak After Endovascular Aortic Repair

Abstract

Introduction: Surveillance for endoleak after endovascular aortic aneurysm repair with computed tomography angiography has the associated risks of radiation exposure and nephrotoxic contrast agents. The purpose of this study was to evaluate the performance of contrast-enhanced ultrasound in the detection of endoleak post–endovascular aortic aneurysm repair. Methods: A single-center retrospective cohort study was performed evaluating patients with abdominal aortic aneurysm treated with endovascular aortic aneurysm repair between October 29, 2017 and April 21, 2021 and follow-up imaging with both computed tomography angiography and contrast-enhanced ultrasound. The sample included 35 imaging combinations in 28 patients. Positive and negative results for detection of endoleak by contrast-enhanced ultrasound were tabulated as true positive, false positive, true negative, and false negative compared to computed tomography angiography and conventional angiography. Sensitivity, specificity, positive predictive value, and negative predictive value of contrast-enhanced ultrasound were calculated. Results: Out of 35 imaging combinations, endoleak was detected in 24 cases by computed tomography angiography and in 23 cases by contrast-enhanced ultrasound. Using computed tomography angiography as the reference standard, contrast-enhanced ultrasound yielded 96% sensitivity, 100% specificity, 100% positive predictive value, and 92% negative predictive value for endoleak detection. In the 23 cases of endoleak detection by both contrast-enhanced ultrasound and computed tomography angiography, contrast-enhanced ultrasound discerned the correct endoleak type in all 23 cases, while computed tomography angiography identified the correct endoleak type in 20 cases ( P = .2333). Discussion: Endoleak detection by contrast-enhanced ultrasound appears at least equivalent to computed tomography angiography. Some of the advantages of contrast-enhanced ultrasound in the surveillance of endoleak after endovascular aortic aneurysm repair include an avoidance of radiation, elimination of nephrotoxic contrast agents, reduction in costs, real-time imaging, discerning flow directionality, and visualizing endoleaks in regions previously embolized with coils/plugs/liquid embolic agents. Limitations include operator dependence and variables that obscure the visual field including obese body habitus. With these advantages and excellent comparison data, contrast-enhanced ultrasound should be considered as a first-line imaging modality for long-term surveillance of endoleaks after endovascular aortic aneurysm repair. Conclusion: Contrast-enhanced ultrasound is a safe and viable option for long-term surveillance post–endovascular aortic aneurysm repair.