title: Transplant renal artery stenosis in children: risk factors and outcome after endovascular treatment.
abstract: BACKGROUND
  Transplant renal artery stenosis (TRAS) is an increasingly recognised cause of post-transplant hypertension.
  
  
  METHODS
  We retrospectively analysed 216 paediatric renal recipients transplanted between 2001 and 2011 to assess TRAS prevalence and percutaneous transluminal angioplasty (PTA) efficacy. To assess risk factors, we compared children with TRAS with a propensity score-matched cohort of recipients without TRAS.
  
  
  RESULTS
  Of the 216 paediatric patients who were transplanted in the study period, 44 were hypertensive (prevalence 20.3 %) and ten presented with TRAS (prevalence 4.6 %, median age at transplantation 14 years, range 6.78-17.36 years). Hypertensive patients without TRAS were prescribed one to two anti-hypertensive agents, whereas patients with TRAS required one to five medications. In the TRAS group, one recipient presented with vascular complications during surgery, and in three patients the graft had vascular abnormalities. TRAS was detected by Doppler ultrasonography (US) performed due to hypertension in nine of the patients with TRAS, but in the tenth case the TRAS was clinically silent and detected by routine Doppler-US screening. TRAS diagnosis was refined using angio-computed tomography or angio-magnetic resonance imaging. All patients underwent PTA without complications. Significant improvement after PTA was observed in the standard deviation scores for blood pressure [3.2 ± 1.4 (pre-PTA) vs. 1.04 ± 0.8 (post-PTA); p = 0.0006) and graft function [creatinine clearance: 69 ± 17.08 (pre-PTA) vs. 80.7 ± 21.5 ml/min/1.73 m(2) (post-PTA); p = 0.006] We observed no significant differences between the two cohorts for cold ischaemia time, recipient/donor weight ratio, delayed graft function, cytomegalovirus infections and acute rejection episodes.
  
  
  CONCLUSIONS
  Our study reports a low but significant TRAS prevalence among the paediatric patients who were transplanted at our centre in the study period and confirms that PTA is an effective and safe therapeutic option in paediatric renal transplant recipients. Known risk factors do not appear to be related to the development of TRAS.
authors.affiliation: Pediatric Nephrology, Dialysis and Transplant Unit, Department of Pediatrics, University Hospital of Padua, Via Giustiniani 2, 35128, Padova, Italy, giulia.ghirardo@unipd.it.
authors.forename: Giulia
authors.initials: G
authors.lastname: Ghirardo
authors.forename: Marco
authors.initials: M
authors.lastname: De Franceschi
authors.forename: Enrico
authors.initials: E
authors.lastname: Vidal
authors.forename: Alessandro
authors.initials: A
authors.lastname: Vidoni
authors.forename: Gaetano
authors.initials: G
authors.lastname: Ramondo
authors.forename: Elisa
authors.initials: E
authors.lastname: Benetti
authors.forename: Raffaella
authors.initials: R
authors.lastname: Motta
authors.forename: Alberto
authors.initials: A
authors.lastname: Ferraro
authors.forename: Giovanni Franco
authors.initials: GF
authors.lastname: Zanon
authors.forename: Diego
authors.initials: D
authors.lastname: Miotto
authors.forename: Luisa
authors.initials: L
authors.lastname: Murer
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000800:Angioplasty, Balloon; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure; D002648:Child; D004359:Drug Therapy, Combination; D006801:Humans; D006978:Hypertension, Renovascular / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D007558:Italy / Q000453:epidemiology; D016030:Kidney Transplantation / Q000009:adverse effects*; D018810:Magnetic Resonance Angiography; D015995:Prevalence; D012078:Renal Artery Obstruction / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler
chemical_list: D000959:Antihypertensive Agents