Renal Infarction:  is the formation of a coagulated, necrotic area in one or both kidneys that results from renal blood vessel occlusion.  The size and location of the infarct depend on the site of vascular occlusion.  Most often affects the renal cortex, but it can extend into the medulla.  Residual renal function after infarction depends on the extent of the damage.

Cause:  Most common caused - renal artery embolism secondary to  mitral stenosis.  Other causes includes infective endocarditis, atrial fibrillation, microthrombi in the left ventricle, rheumatic valvular disease, or recent myocardial infarction.
May also be caused by  atherosclerosis with or without thrombus formation, thrombus from flank trauma, sickle cell anemia, scleroderma, and arterionephrosclerosis.

Symptoms:

Patient can be asymptomatic. 

Upper abdominal pain or gnawing flank pain and tenderness, costovertebral tenderness

Fever

Anorexia

Nausea and or Vomiting

Treatment:

Surgical repair may be require.  Nephrectomy

Antihypertensives 

Low sodium diet

Intra arterial streptokinase (to lyse blood clots)

Catheter embolectomy