Does peak systolic velocity correlate with renal artery stenosis in a pediatric renal transplant population?

PSV of renal transplant vessels, calculated during allograft ultrasonography, has previously been shown to correlate with TRAS. Controversy exists regarding the threshold PSV value (adult range: 1.5-3.0 ms), which should prompt further, more invasive investigations to confirm the diagnosis of TRAS. Furthermore, there is a paucity of literature regarding PSV values in the pediatric renal transplant population. In a group of pediatric renal transplant patients, we correlated post-operative renal transplant PSV values with BP, renal function (serum creatinine) and TRAS. All patients who underwent cadaveric or living-related renal transplantation at the HSC between 2001 and 2004 with at least 6 months of follow-up were reviewed through the HSC multi-organ transplant database. Post-operative allograft Doppler ultrasonography was performed during routine follow-up. PSV values obtained were correlated with BP and serum creatinine performed concomitantly. Finally, we correlated PSV in those patients who underwent more intensive investigations, including magnetic resonance and conventional angiography. Fifty-three patients underwent transplantation during the study period. Complete data available for 50/53 demonstrated a mean PSV of 2.13 m/s (range: 0.9-6.1 m/s) for all patients. Of six patients who underwent MRA for suspicion of TRAS, two (with mean PSV values of 1.93 m/s) were found to have clinically significant stenoses. Four of six without angiographic evidence of TRAS had mean PSV values of 2.22 m/s. Patients suspected of having TRAS demonstrated elevated median serum creatinine values compared with those without clinical suspicion of TRAS. However, both mean PSV and BP were not found to be statistically different in both patient subgroups. Furthermore, there was no correlation identified between PSV and serum creatinine and BP in these patient populations. Despite the utility of PSV for monitoring adult renal transplant patients, we did not find that PSV correlated with BP, nadir creatinine or identify those patients who, through subsequent investigations, were found to have TRAS in this pediatric population. Maintaining cognizance in conjunction with close clinical follow-up may identify patients at risk for this rare but potentially morbid complication of transplantation.