Severely elevated intrarenal arterial impedance and abnormal venous flow pattern in a normal functioning kidney graft

Impact of ultrasound examination shortly after kidney transplantation

Background

Ultrasound is routinely performed at our transplant unit within the first 48 h of kidney transplantation (KTX). The objective of this study was to evaluate the association of ultrasound results and, in particular, elevated resistance indices (RIs) with the occurrence of surgical complications and allograft outcomes.

Methods

The study included all kidney allograft recipients undergoing transplantation at our center between January 2010 and December 2011 (N = 329). Ultrasound examination was performed on 315 recipients (95.7%).

Results

Delayed graft function was more common in subjects with a high RI (≥0.7) than in patients with an RI < 0.7 (47.2 vs. 28.2%; p = 0.032). A lack of arterial signal was detected in eight patients (2.5%), of whom five had a vascular complication that required surgical therapy. In 12 patients (3.8%), RI was 1 without any other signs of vascular impairment. Even though such values can be a sign of venous thrombosis, no case was observed in any of these patients.

Conclusions

The results of our study suggest that ultrasound evaluation of the transplanted kidney shortly after transplantation is a valuable tool not only for detecting vascular complications but also as a predictor of graft outcome regarding delayed graft function.