39-Year-Old With New Onset Resistant Hypertension
A 39-year-old Caucasian female was referred to cardiology clinic for evaluation of new onset hypertension. She had no significant past medical history but had two ER visits within the preceding month for hypertensive urgency prompting initiation of three anti-hypertensive medications: carvedilol 25mg BID, amlodipine 10mg daily and hydrochlorothiazide 25mg daily. She reported symptoms of intermittent headaches and pulsatile tinnitus. She had no family history of hypertension. On physical exam, blood pressure was 202/112 mmHg, and the remainder of her exam was normal. Initial laboratory evaluation showed normal creatinine, erythrocyte sedimentation rate (ESR) and C-reactive protein. Further laboratory testing for hyperthyroidism, hyperaldosteronism and pheochromocytoma were all negative. Renal artery duplex ultrasound showed normal sized kidneys, but there were elevated Doppler velocities in the left renal artery concerning for left renal artery stenosis. Thus, the patient was referred for renal angiogram. The notable findings are seen in Figure 1.
Figure 1: Renal Angiogram
Which of the following is the most likely etiology for this patient's left renal artery abnormalities?