title: Reversed diastolic flow in the renal transplant: perioperative implications versus transplants older than 1 month.
abstract: OBJECTIVE
  The purpose of our study was to evaluate the causes, waveform morphology, and clinical outcomes of high-resistance reversed diastolic flow in transplanted kidneys.
  
  
  METHODS
  To identify patients with reversed diastolic flow, we performed a review of 5,089 renal transplant Doppler sonograms obtained over a 10-year period. Waveform morphology was correlated with surgical-histologic findings and clinical outcomes.
  
  
  RESULTS
  Fifty-nine patients (33 male, 26 female; age range, 14-69 years) with reversed diastolic flow fell into three chronologic groups: acute group (six patients), transplant < 24 hours; perioperative group (34 patients), transplant < or = 30 days; and long-term group (19 patients), transplant > 30 days. Acute reversed diastolic flow was associated with higher likelihood of graft survival (p = 0.001, Fisher's exact test) compared with reversed diastolic flow discovered in the perioperative or long-term group. In the acute group, hematoma, acute tubular necrosis, renal vein thrombosis, and vascular kink produced reversed diastolic flow. The causes of reversed diastolic flow for the perioperative group were acute tubular necrosis, rejection, and renal vein thrombosis; for the long-term group, reasons for diastolic reversal were rejection, glomerulosclerosis, low cardiac output, and diabetic nephrosclerosis. The causes of reversed diastolic flow were not differentiated by waveform morphology.
  
  
  CONCLUSIONS
  The causes of reversed diastolic flow cannot be distinguished by waveform morphology. Patients with reversed diastolic flow < 24 hours after transplantation warrant emergent exploration because correction of treatable causes may lead to recovered function. Long-standing renal transplants with reversed diastolic flow are not likely salvageable.
authors.affiliation: Department of Radiology, University of Alabama at Birmingham, 619 19th St. S, Birmingham, AL 35249, USA. mlockhart@uabmc.edu
authors.forename: Mark E
authors.initials: ME
authors.lastname: Lockhart
authors.forename: Charles G
authors.initials: CG
authors.lastname: Wells
authors.forename: Desiree E
authors.initials: DE
authors.lastname: Morgan
authors.forename: Naomi S
authors.initials: NS
authors.lastname: Fineberg
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Robbin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006085:Graft Survival / Q000502:physiology*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D012079:Renal Circulation / Q000502:physiology*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance / Q000502:physiology*