title: Detection of transplant renal artery stenosis: determining normal velocities at the renal artery anastomosis.
abstract: Renal artery anastomosis peak systolic velocity (RAA PSV) exceeding 250 cm/s and a ratio of the renal artery to the adjacent external iliac artery (RAA:EIA) exceeding 1.8 historically suggest significant transplant renal artery stenosis (TRAS). However, the range of RAA PSV in transplants without TRAS has not been established.
  
  
  
  A retrospective review of renal transplants at a single institution over 5 years was performed identifying patients without graft dysfunction, failure, or refractory hypertension. RAA PSV obtained during interval postoperative sonograms was recorded.
  
  
  
  Of 1141 patients, 844 met the inclusion criteria. Mean RAA PSV for 377 patients evaluated within 2 days of transplant measured 195 cm/s; RAA PSV exceeded 250 cm/s in 97 patients (26%). Mean RAA PSV for 820 patients evaluated 1-month post-transplant measured 206 cm/s; RAA PSV exceeded 250 cm/s in 224 patients (27%). Mean RAA PSV for 785 patients evaluated 4-month post-transplant measured 203 cm/s; RAA PSV exceeded 250 cm/s in 201 patients (26%). Mean RAA PSV for 766 patients evaluated 1-year post-transplant measured 189 cm/s; RAA PSV exceeded 250 cm/s in 141 patients (18%). At each of the given time points, 24%-34% of normal patients had RAA-to-EIA ratios greater than 1.8.
  
  
  
  Approximately, 26% of patients without TRAS have RAA PSV > 250 cm/s in the first 9 months, and 18% do at 1 year. Similar findings also occurred with regards to the RAA-to-EIA ratio threshold of 1.8. In isolation, a PSV over 250 cm/s or 1.8 ratio threshold for suspicion of TRAS will lead to a large number of false-positive assessments.
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic Hospital, 5777 East Mayo Blvd, Phoenix, AZ, 85054, USA. Robinson.Kristin2@mayo.edu.
authors.forename: Kristin A
authors.initials: KA
authors.lastname: Robinson
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic Hospital, 5777 East Mayo Blvd, Phoenix, AZ, 85054, USA.
authors.forename: J Scott
authors.initials: JS
authors.lastname: Kriegshauser
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic Hospital, 5777 East Mayo Blvd, Phoenix, AZ, 85054, USA.
authors.forename: Nirvikar
authors.initials: N
authors.lastname: Dahiya
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic Hospital, 5777 East Mayo Blvd, Phoenix, AZ, 85054, USA.
authors.forename: Scott W
authors.initials: SW
authors.lastname: Young
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic Hospital, 5777 East Mayo Blvd, Phoenix, AZ, 85054, USA.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Czaplicki
authors.affiliation: Department of Diagnostic Radiology, Mayo Clinic Hospital, 5777 East Mayo Blvd, Phoenix, AZ, 85054, USA.
authors.forename: Maitray D
authors.initials: MD
authors.lastname: Patel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000714:Anastomosis, Surgical; D001783:Blood Flow Velocity; D005260:Female; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging*; D012189:Retrospective Studies
keywords: Normal transplant renal artery velocities; Transplant renal artery peak systolic velocity; Transplant renal artery stenosis