INTRODUCTION. Transplant renal artery stenosis (TRAS) is the most frequent post-transplant vascular complication. Its incidence varies among 1-23% in adult series. Poor data regarding TRAS incidence and no data regarding percutaneous treatment in pediatric series are available.

MATERIALS AND METHODS. Aim of our study was to analyze a population of paediatric kidney recipients in order to improve our understanding on TRAS prevalence, on its pathogenesis and medium-term effect of revascularization on graft function and blood pressure control.

Since 2001, 215 pediatric-kidney transplants were performed in our department. 10/215 developed TRAS, with a prevalence of 4.65%. 9/10 patients were male, mean age 11,8+6years. Median time before TRAS diagnosis was 19 months (2-69). In all cases diagnosis was made by eco-color-doppler and then completed with angio-CT (5/10) or angio-MR (4/10). All patients underwent percutaneous angioplasty (PTA) without complications. In order to compare populations affected by similar co-morbidities, 2 cohorts of 10 patients each (TRAS group and control group) were generated using Propensity Score Analysis (PSA). The 2 groups showed equally balanced baseline characteristics (age, sex, cause of renal disease, type and duration of dialysis, immunosuppressive regimen).

RESULTS. We observed no significant differences in recipient/donor body weight ratio, hot or cold ischemia time, incidence of DGF, CMV infections or rejection episodes between the two groups. Mean blood pressure Standard Deviation Score, calculated according to Cole and Green LMS method, significantly improved after angioplasty (3.28+1,47 vs 1,04+0,85, p=0.0006). 7/10 patients stopped antihypertensive therapy after PTA, while 3/10 reduced the number of antihypertensive drugs.

Graft function significantly improved after PTA (creatinine clearance 69+17,1ml/min/1,73m2 before PTA vs 80,7+21,5ml/min/1,73m2 after PTA, p=0.006)

CONCLUSIONS. Our results show high TRAS prevalence also in paediatric recipients, confirming the need to investigate all patients with arterial hypertension after kidney transplantation, starting with renal eco-color-doppler. PTA is an effective and safe therapeutic option, also in paediatric recipients with low body weight; it ensures excellent medium-term results for what concern graft function and blood pressure control.