Significance of elevated transplant renal artery velocities in the postoperative renal transplant patient

Introduction Non-invasive imaging studies can provide visualization of allograft perfusion in the postoperative evaluation of newly transplanted renal allografts. Aim The purpose of our study was to evaluate the significance of elevated renal artery velocities in the immediate postoperative period. Methods Peak systolic velocities (PSVs) were obtained in the transplanted renal artery of 128 patients immediately after transplantation. Repeat allograft Doppler ultrasonography was performed on patients with elevated values. Results Of the 128 patients, 57 (44.5%) had severely elevated Doppler velocities >400 cm/s on the initial studies. Three patients within this category had persistently elevated values of >400 cm/s, warranting angiographic visualization of the renal vessels. Stent placement within the transplanted renal artery was required in two of these patients. There was normalization of the PSV in the remaining patients. Conclusions Routine allograft Doppler ultrasonography in the immediate postoperative period allows for visualization of allograft perfusion. Elevated renal artery velocities in the immediate postoperative period do not necessarily represent stenosis requiring intervention. Failure of the PSV to normalize may require further intervention, and angiography continues to be the gold standard.