renal infarct / infarction

see also:

• renal masses and cysts
• renal abscesses and perinephric abscesses
• acute pyelonephritis

• embolic (~60%)
  • over 80% of these are due to atrial fibrillation - renal infarction may be the 1st presentation of AF
  • cardiomyopathy
  • artificial heart valve thrombi
  • septic emboli - infective endocarditis (including SBE)
• renal artery trauma (~8%)
  • physical trauma
  • iatrogenic trauma from angiography
  • dissection
  • Marfan's syndrome, Ehlers-Danlos syndrome, fibromuscular dysplasia
  • polyarteritis nodosa (PAN)
• renal artery vasculitis
  • see vasculitis
• hypercoagulable states
• abdominal aortic aneurysm (AAA)
• COVID-19 coronavirus (2019-nCoV / SARS-CoV-2)
  • can even occur in asymptomatic infections although presumably rarely so
  • DDimer usually normal but CRP is elevated
• idiopathic

• may present as renal colic or pyelonephritis with flank pain but neither of these will have an elevated LDH
• 10% will have a fever
• almost 20% have bilateral involvement
• suspicion of renal infarct is usually after renal USS raises the possibility
• many will develop transient hypertension in the 1st week

• FBE, U&E, CRP, LFTs, LDH
  • in patients with flank pain, an elevated serum LDH (usually > 2-4x the upper limit of normal) with little or no rise in serum aminotransferases is strongly suggestive of renal infarction
    • other DDx of raised LDH with normal transaminases: late AMI, haemolysis, renal transplant rejection
  • WCC and CRP may be mildly raised
• MSU m/c/s
  • 1/3rd will have haematuria
• ECG to exclude AF

• consider percutaneous endovascular therapy
  • best results are in the early stages of renal artery ambolism
• consider angioplasty with stent placement for dissection
• consider anticoagulation for atrial fibrillation