The prevalence and significance of renal perfusion defects in early kidney transplants quantified using 3D contrast enhanced ultrasound (CEUS)

Objectives - Vascular complications are one of the most common causes of early kidney transplant dysfunction. Contrast enhanced ultrasound increases sensitivity to tiny vascular changes.. The aim was to assess the prevalence and size of vascular abnormalities in renal transplantation patients following surgery using 3D CEUS to determine the significance of perfusion defects on renal function. Methods - Ninety nine renal transplant patients underwent 3D CEUS after surgery to quantify perfusion defects as percentage total renal volume (TRV). Serum creatinine and estimated glomerular filtration rate (eGFR) were recorded up to three months post-surgery. Results - In the 99 patients, 20 had perfusion defects (0.2 – 43% TRV). There was a meaningful difference in patients with perfusion defects in eGFR at 1 month (90% CI 2.7 to 19.2 ml/min/1.73m2) and 3 months (90% CI 1.9 to 19.6 ml/min/1.73m2) and in Creatinine at 3 months (90% CI -56 to -8 μmol/L) using a predetermined clinical threshold. Perfusion defect size correlated well with both serum creatinine and eGFR at 3 months (R= 0.80 (p ≤ 0.000) and 0.58 (p= 0.038)). No correlation seen prior to 3 months. Conclusions - Perfusion defects in kidney transplants were more common than expected and were highly likely to reduce renal function at 1-3 months and the size of the defect affected the degree of functional change at 3 months.