title: Evaluation of severe transplant renal artery stenosis with Doppler sonography.
abstract: OBJECTIVE
  To evaluate and determine Doppler criteria for predicting a severe transplant renal artery stenosis (80%-99% diameter reduction) and to compare the Doppler findings in patients with end-to-end and end-to-side anastomosis.
  
  
  METHODS
  We performed Doppler sonography on 16 consecutive patients with transplant renal artery stenosis (TRAS) confirmed by digital subtraction arteriography (DSA). Fourteen patients had end-to-end anastomosis, and 2 had end-to-side anastomosis. Eleven patients were re-evaluated with color Doppler sonography within 4 days after intervention. Seven Doppler parameters, including the peak systolic velocity (PSV) in the renal, iliac and interlobar artery, Pre-PSV ratio (the ratio of the PSV in the renal artery to that in the iliac artery), Post-PSV ratio (the ratio of the PSV in the renal artery to that in the interlobar arteries, acceleration time and resistance index, were measured. In the patients with severe TRAS the measurements of these parameters were compared before and after successful intervention.
  
  
  RESULTS
  In the 16 patients with a single transplanted kidney, arteriography demonstrated 14 main renal arteries with severe stenosis, and 3 renal arteries with moderate stenosis. When using the cutoff values of Post-PSV ratio >13, renal artery PSV >4 m/sec, acceleration time >0.06 second, and resistance index <0.5 for the detection of all 14 severe stenoses, the sensitivities were 100%, 71%, 93%, and 50%, respectively. For assessing all 14 severe stenoses and 12 severe stenoses of end-to-end anastomosis, the cutoff value of Pre-PSV ratio >5 had sensitivities of 86% and 100%, respectively. Pre-PSV ratios in severe stenoses of end-to-end anastomosis (range, 5.1-11.5) were significantly greater than those recorded in severe stenoses of end-to-side anastomosis (range, 2.8-3.1). Statistically significant differences before and after successful intervention were found for all 7 Doppler parameters in the 7 patients with severe stenosis.
  
  
  CONCLUSIONS
  An 80%-99% diameter reduction of the renal artery can be diagnosed based on a Post-PSV ratio >13 for patients with either end-to-end or end-to-side anastomosis. A Pre-PSV ratio >5 for patients with end-to-end anastomosis and acceleration time >0.06 second are helpful in the diagnosis of severe TRAS.
authors.affiliation: Department of Ultrasound, Peking Union Medical College Hospital of the Chinese Academy of Medical Sciences, 1 Shuai Fu Yuan, Wang Fu Jing, Beijing 100730, China.
authors.forename: Jian-Chu
authors.initials: JC
authors.lastname: Li
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Ji
authors.forename: Sheng
authors.initials: S
authors.lastname: Cai
authors.forename: Yu-Xin
authors.initials: YX
authors.lastname: Jiang
authors.forename: Qing
authors.initials: Q
authors.lastname: Dai
authors.forename: Jin-Xi
authors.initials: JX
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction / Q000379:methods; D017130:Angioplasty / Q000379:methods; D001783:Blood Flow Velocity / Q000502:physiology; D005260:Female; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis; D011237:Predictive Value of Tests; D012077:Renal Artery / Q000000981:diagnostic imaging / Q000601:surgery; D012078:Renal Artery Obstruction / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D015607:Stents; D018615:Ultrasonography, Doppler, Color / Q000379:methods*