Clot formation in renal vein

Unilateral > bilateral

Kidney enlarged acutely in 75% cases

Renal vein dilated acutely

Possible inferior vena cava (IVC) thrombus extension

Altered renalarteryspectral waveforms

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  ↑ systolic pulsatility (narrow, sharp systolic peaks)

  
  
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  Persistent retrograde diastolic flow

Nephrotic syndrome: Most common cause of renal vein thrombosis in adults

Hypovolemia/renal hypoperfusion: Most common cause of renal vein thrombosis in children

Risk in neonates is associated with fetal distress, perinatal asphyxia, diabetic mothers, and volume contraction

Outcome depends on cause, time to diagnosis, duration of occlusion, recanalization, collateralization

Prognosis overall good; frequent spontaneous recovery

Anticoagulation: Heparin then Coumadin or low-molecular-weight heparin for maintenance

Thrombolysis/surgical thrombectomy: Heroic measure for life-threatening situations

Suprarenal caval filter (IVC thrombus)

Renal vein can be scanned from flank or epigastric window; flank window is more frequently used because it is less affected by body habitus and has fewer surrounding vessels

Do not mistake splenic vein for left renal vein (when using epigastric window)

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  Splenic vein anterior to superior mesenteric artery

  
  
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  Left renal vein posterior to superior mesenteric artery