Vascular rejection in renal transplant: Diagnostic value of contrast-enhanced ultrasound (CEUS) compared to biopsy

Issue title: Special Issue in Honour of the Editor-in-Chief Prof. Dr. Ing. Friedrich Jung on his 70th Birthday

Article type: Research Article

Authors: Mueller-Peltzer, K.^{a; *} | Negrão de Figueiredo, G.^a | Fischereder, M.^b | Habicht, A.^b | Rübenthaler, J.^a | Clevert, D.-A.^a

Affiliations: [a] Department of Radiology, Ludwig-Maximilians-University Munich – Grosshadern Campus, Munich, Germany | [b] Department of Internal Medicine IV, Ludwig-Maximilians-University Munich – Grosshadern Campus, Munich, Germany

Correspondence: [*] Corresponding author: Katharina Mueller-Peltzer, M.D., Department of Radiology, Interdisciplinary Ultrasound Center, Ludwig-Maximilians-University Munich – Grosshadern Campus, Marchioninistr. 15, 81377 Munich, Germany. Tel.: +49 89 4400 73627; Fax: +49 89 4400 78832; E-mail: [email protected].

Abstract: BACKGROUND:Despite of the more potent immunosuppressive medication, vascular rejection is still a major issue after renal transplantation. Renal biopsy is the gold standard diagnostic to evaluate acute and chronic allograft rejection. As it is an invasive diagnostic there is the risk of complications like haematoma, arteriovenous fistulas, active bleeding or infection. Contrast-enhanced ultrasound is a non-invasive imaging modality that allows visualising renal transplant perfusion. OBJECTIVE:To analyse the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) compared to biopsy as gold standard in diagnosing vascular rejection in renal transplant patients. METHODS:A total of 57 renal transplant recipients with poor renal allograft function with initial diagnostic imaging between 2006 and 2017 were included in the study. Clinical data and imaging studies were analysed retrospectively. The diagnostic accuracy of CEUS in diagnosing vascular rejection of the renal transplant was compared to renal biopsy as gold standard. Out of 57 patients 7 patients showed signs of vascular rejection in biopsy. In 6 out of these 7 patients CEUS described irregularities in renal perfusion suspicious of vascular rejection. RESULTS:CEUS showed a sensitivity of 85.7%, a specificity of 100%, a positive predictive value (PPV) of 100%, and a negative predictive value (NPV) of 98.0%. CONCLUSIONS:CEUS is a safe, non-nephrotoxic imaging modality for the initial imaging of renal transplant recipients with elevated kidney function parameters suspicious of vascular rejection. Compared to renal biopsy as gold standard CEUS shows a high specificity and PPV in detecting signs of vascular rejection. Since sub-types of vascular rejection with cellular and humoral components with greater risk for allograft loss have been described renal biopsy is inevitable in these cases.

Keywords: Contrast-enhanced ultrasound, CEUS, biopsy, renal transplant, vascular complications

DOI: 10.3233/CH-189115

Journal: Clinical Hemorheology and Microcirculation, vol. 69, no. 1-2, pp. 77-82, 2018