A previously healthy 27–year–old Caucasian male presented with acute onset of right sided flank pain, nausea, vomiting and mild fever for approximately 5 days. He denied any abnormal urinary symptoms and has no prior history of nephrolithiasis. He was afebrile and normotensive at presentation; WBC 11,900, BUN 9 and creatinine 0.9. Urinalysis was negative for RBC, pyuria, nitrites or leukocyte esterase. A CT scan revealed a peripheral defect in the middle and inferior right renal pole, with pyelonephritis, lobar nephronia and renal infarction as likely differentials. He was admitted and started on antibiotics and IV fluids. Over the next few days, his symptoms remained unchanged while he also developed new onset hypertension. A renal arterial doppler ultrasound showed evidence of right renal artery occlusion, making the CT findings most suggestive of a renal infarction. A vasculitis panel was essentially negative, lower extremity doppler ultrasound was negative for DVT while an agitated saline contrast echocardiogram failed to show a PFO, ruling out the possibility of paradoxical embolism. A hypercoagulable panel obtained was negative as well. Finally, a renal artery arteriogram was performed which revealed focal dissection of the main right renal artery beginning in its mid portion and causing occlusion of the anterior and inferior segmental branches. No evidence of fibromuscular dysplasia, polyarteritis nodosa or atherosclerosis was seen on the angiogram, thereby resulting in a diagnosis of a spontaneous renal artery dissection (SRAD). The patient’s renal function fortunately remained normal. He was started on lisinopril, as well as aspirin and plavix. His course remained uneventful until his discharge.
Renal artery dissection (RAD) is an occlusive lesion of the renal artery resulting in ischemia and infarction of the affected kidney. Associated conditions include atherosclerotic disease, FMD and CT disorders. The spontaneous form of RAD is a relatively rare condition with the few cases reported seen in young healthy males. Flank pain and new onset hypertension are the commonest clinical presentations. There may be fever and moderate leucocytosis, while creatinine elevation suggests accompanying renal infarct. The treatment options include medical management, endovascular stenting or open vascular surgery. Treatment decision is often based on patient’s renal function. ACE inhibitors are the drug of choice because these patients have high renin levels. The use of anticoagulation is controversial. Most notably, invasive treatments have not demonstrated superior efficacy over medical management. Nephrectomy is indicated for severely damaged kidneys identified with isotope renography.
Delay in the diagnosis of SRAD because of its rarity can potentially lead to unfavourable outcomes. Long term renal outcomes remain unclear, even in patients with preserved renal function at the time of diagnosis and continued follow up of these patients remains vital.