title: Increased peak systolic velocity in the renal artery of paediatric kidneys transplanted to adult recipients.
abstract: BACKGROUND
  Paediatric kidneys transplanted to adult recipients increase in size after transplantation. It is unknown if the renal artery diameter increases concomitantly with the kidney. This study was performed to assess if peak systolic velocity (PSV) in the renal arteries of paediatric kidneys transplanted to adult recipients is comparable to PSV in the renal arteries of adult kidneys transplanted to adult recipients. Subjects and methods. Fifteen adult patients with paediatric renal transplants were examined with ultrasound Doppler and compared with a control group of adult recipients with adult transplants. MR angiography (MRA) or intra-arterial angiography (IA) was performed in patients with elevated PSV. MRA renal diameters of the paediatric transplants were compared with adult transplants.
  
  
  RESULTS
  The mean maximum PSV of the paediatric kidneys was 2.0 m/s (0.9-3.8), almost twice compared with the adult grafts transplanted to adult recipients, 1.1 m/s (0.7-1.6), P < 0.001. Seven paediatric transplants had a PSV >1.8 m/s, but only two had significant stenosis on MRA/IA. All patients had excellent blood pressure and renal function. The mean diameter of the paediatric renal arteries was 4.1 mm (3.4-6.0), whereas the mean for the adult renal arteries was 5.6 mm (4.8-6.9), P = 0.02.
  
  
  CONCLUSIONS
  Adult recipients of paediatric kidneys have significantly higher maximum PSV in the renal artery compared to adult recipients of adult grafts. The significantly smaller renal artery diameter might explain the high PSV. A PSV >1.8 m/s by itself does not necessarily indicate transplant renal artery stenosis in paediatric kidneys transplanted to adult recipients, but should be related to clinical findings.
authors.affiliation: Department of Radiology, Rikshospitalet University Hospital, N-0027 Oslo, Norway. anne.gunther@rikshospitalet.no
authors.forename: Anne
authors.initials: A
authors.lastname: Gunther
authors.forename: Aksel
authors.initials: A
authors.lastname: Foss
authors.forename: Hallvard
authors.initials: H
authors.lastname: Holdaas
authors.forename: Knut
authors.initials: K
authors.lastname: Brabrand
authors.forename: Anders
authors.initials: A
authors.lastname: Hartmann
authors.forename: Paal-Dag
authors.initials: PD
authors.lastname: Line
authors.forename: Karsten
authors.initials: K
authors.lastname: Midtvedt
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D016030:Kidney Transplantation / Q000009:adverse effects / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012078:Renal Artery Obstruction / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology; D013599:Systole; D014019:Tissue Donors; D055815:Young Adult