Frequency, clinical significance and impact on therapy of duplex sonographic vascular findings in renal allograft dysfunction

Abstract

Objective: The aim of this study was to establish the frequency of vascular findings by color-coded duplex sonography in renal allografts with dysfunction. Furthermore, we estimated the clinical significance of these findings and their impact on therapy. Methods: A total of 184 duplex scans were performed in 119 patients (68 male, 51 female) with insufficient or declining diuresis and/or rising creatinine. Color-coded duplex sonography was used to examine the entire length of the iliac vessels as well as the central and peripheral renal arteries and veins. Results: A total of 45 abnormal vascular findings were identified in 37 patients (31%, including 21 transplant artery stenoses (7 > 50%), 5 iliac stenoses, 11 AV fistulas and 8 venous stenoses. Of all vascular findings, 4 were determined to be responsible for functional deterioration, including 2 high grade kinking stenoses of the transplant artery in the early post-operative period, 1 transplant artery stenosis in the middle segment and 1 high-grade iliac artery stenosis. The other abnormal vascular findings did not appear to cause renal dysfunction. Biopsy results did not explain the functional deterioration in 1.6% of patients without vascular findings but in 13% of patients with vascular findings. Conclusions: Abnormal duplex sonographic vascular findings occur frequently in renal allografts but only a few of them are responsible for deterioration of graft function. Histologic findings insufficient to explain renal dysfunction possibly indicate a potential vascular cause. Due to its non-invasiveness, color-coded duplex sonography is a useful diagnostic tool but all findings need to be interpreted strictly in a clinical context.