Quantified power Doppler as a predictor of delayed graft function after renal transplantation

Abstract

Purpose: No safe ultrasound (US) parameters have been established to differentiate the causes of graft dysfunction.

Objectives: To define US parameters and identify the predictors of normal graft evolution, delayed graft function (DGF), and rejection at the early period after kidney transplantation.

Methods: Between June 2012 and August 2013, 79 renal transplant recipients underwent US examination 1-3 days posttransplantation. Resistive index (RI), power Doppler (PD), and RI + PD (quantified PD) were assessed. Patients were allocated into three groups: normal graft evolution, DGF, and rejection.

Results: Resistive index of upper and middle segments and PD were higher in the DGF group than in the normal group. ROC curve analysis revealed that RI + PD was the index that best correlated with DGF (cutoff = 0.84). In the high RI + PD group, time to renal function recovery (6.33 ± 6.5 days) and number of dialysis sessions (2.81 ± 2.8) were greater than in the low RI + PD group (2.11 ± 5.3 days and 0.69 ± 1.5 sessions, respectively), p = 0.0001. Multivariate analysis showed that high donor final creatinine with a relative risk (RR) of 19.7 (2.01-184.7, p = 0.009) and older donor age (RR = 1.17 (1.04-1.32), p = 0.007) correlated with risk DGF.

Conclusions: Quantified PD (RI + PD) was the best DGF predictor. PD quantification has not been previously reported.