Accessory Renal Artery Stenosis – A Cause For Drug Refractory Hypertension

Author: M. Auron, M.D, Department of Hospital Medicine, Cleveland Clinic
Reviewer: V. Dimov, M.D., Department of Hospital Medicine, Cleveland Clinic

78 yo AAF, with long standing HTN ( for more than 30yrs), obesity (BMI higher than 35), hypercholesterolemia, peripheral vascular disease, aortic sclerosis, chronic renal insufficiency (GFR 35-40 cc/min/m2), and a history of chewing tobacco presented to the Internal Medicine clinic with uncontrolled HTN and deterioration of renal function over a 12 months period.

Despite aggressive medical therapy and modification of lifestyle factors there was no improvement in her kidney function and blood pressure control.

- Decreased GFR: 35 to 25 ml/min/1.73 m²
- Increased Cr: 1.6 to 2.4 mg/dL
- Kidney U/S: normal

Lisinopril 40 mg daily, Norvasc 10 mg daily, Furosemide 80 mg bid, Doxazosin 8 mg daily. Clonidine 0.3 mg po tid, Atorvastatin 80 mg daily and Ezetimibe 10 mg daily.

Physical examination:
Well appearing and in no distress. Fundoscopy showed increased arteriolar brightness with no papilledema. No carotid bruits were appreciated. Heart auscultation revealed S4 with soft 2/6 systolic murmur (previously documented). Chest showed normal respiratory sounds with no crackles. Abdominal exam was benign. No bruits appreciated. Peripheral pulses were decreased in both lower extremities.

What is the most likely diagnosis?
Refractory hypertension, most probably secondary to renovascular causes. As patient did not have paroxysmal episodes, pheochromocytoma would be a remote possibility.

What tests would you order?
Chest X-Ray to evaluate cardiac size; echocardiogram to assess valves and ejection fraction as well as LVH; bloodwork includes a basic chemistry to asses for electrolytes and creatinine; 24 hours fractionated urinary metanephrines and cathecolamines; renal ultrasound; nuclear imaging of kidneys with Lasix to assess renal function; MRA of renal arteries as a non invasive approach to renovascular hypertension.

Laboratory results:
- Echocardiogram showed EF 60%, stage 1 diastolic dysfunction and aortic sclerosis.
- 24 h urinary metanephrines and cathecolamines were normal.
- Nuclear imaging of the kidneys showed symmetric kidney function (49% vs. 51%).
- MRA of the renal arteries showed high grade stenosis of an inferior accessory right renal artery with mild narrowing of the superior right renal artery (Fig. 1). Traditional angiography showed severe narrowing of the accessory renal artery at the origin (Fig. 2).

What treatment would you start for this patient?
Stenting of the accessory renal artery was done. Post-procedure selective arteriography showed wide patency of the inferior accessory renal artery (Fig. 3) with increased kidney perfusion after the procedure (Fig. 4).

What happened?
After 18 months of follow-up, the patient has continued with the same antihypertensive regimen. Her BP is 125/72, Cr has decreased to 1.4 mg/dL and GFR has improved to 47 ml/min/1.73 m². See figure below – month 0 is the time that procedure was done.

Final diagnosis:
Refractory hypertension secondary to accessory renal artery stenosis with patent main renal arteries.

What did we learn from this case?
• Isolated accessory RAS even with patent main renal arteries can cause refractory HTN with progressive renal dysfunction.
• Endovascular intervention with renal artery angioplasty and stenting can significantly improve blood pressure management and stabilize renal function.
• The results of large randomized trials comparing medical management with percutaneous intervention in the treatment of RAS are awaited.
• The approach to the patient with renovascular hypertension should be addressed on an individual basis.

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Created: 01/21/2008
Updated: 02/04/2008

1 comment:

  1. It is important to state that gadolinium is not considered "safe" in renal patients. Indeed, it is associated with nephrogenic fibrosing dermopathy.

    It is preferred to hydrate the patient, give bicarbonate and n-acetylcysteine prior to a conventional angiography, as in fact, if it is suspected to have stenosis, the renal function should improve after revascularization.