The 82 year old women described by Dr Ship had an atherosclerotic
renal stenosis, but no clinical problems related to renovascular disease
(RVD), like renal failure, malignant or uncontrolled hypertension, nor
heart failure or flash pulmonary edema. Hypertension, which a very common
finding in elderly individuals, is well controlled by antihypertensive agents
in this patient. She has anatomical RVD, but not a clinical RVD. Stent
placement is the best procedure to revascularize kidneys with
atherosclerotic renal stenosis (1). This procedure was found to improve
the control of hypertension in patients with refractory hypertension (2)
and to stabilize or even improve renal function in patients with renal
failure related to RVD (3,4). Stenting also seems to improve the symptoms
of patients with heart failure related to RVD (5).
But is renal artery
stenting appropriate in the present case?
Since the patient had no clinical problem related to RVD, no immediate
benefit can be expected from the procedure. Long term benefits of renal
stenting consist of reducing the risk of occlusion or atherosclerotic
progression of the vessel. How this results in prevention of clinically
relevant issues in uncomplicated RVD is unknown. It should be taken into
account that the progression of RVD does not always result in clinical
disease. In the population-based Cardiovascular Health Study, 834
participants (mean age 77.2 + 4.9 years) underwent renal duplex sonography
(RDS) at entry, and 137 of them had a second RDS 8.0 + 0.8 years later
(6). None of the individuals with renal stenosis at entry developed renal
artery occlusion. Clinically significant RVD occurred in 4% of the
participants, indicating a very low incidence of complications related to RVD.
In the present case, there is a large accessory renal artery vascularizing
the lower pole suggesting that a large part of left kidney is protected
against ischemia. Overall, that indicates that the expected benefit of
kidney revascularisation is minimal in this patient.
Stent placement in the renal artery might create immediate
complications related to the procedure. Major complications occurred in 2%
of cases (0.6% to 4.0% according to studies) (1). In addition, restenosis
was found to occur 16% of cases and a second procedure was required in
about 12% of cases. Few cases of death or acute renal failure requiring
dialysis have been described as complications of stenting (1).
My conclusion is that the risks related to renal stenting overtake the
benefits in this patient, and thus the procedure is not appropriate for her. Her medical
therapy, which includes aspirin and a statin, is appropriate for
atherosclerotic renal artery stenosis. Even though the risk of occurrence of a
clinically revelant RVD disease in the future is low (6), I would propose
that she have her blood pressure and serum creatinine checked periodically, perhaps every 3
months. Renal artery stenting should discussed again
only if RVD appears to be responsible for clinical problems like
uncontrolled hypertension, renal function worsening and/or flash pulmonary
edema.
REFERENCES
1. White CJ. Catheter-based therapy for atherosclerotic renal artery
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2. Leertouwer TC, Gussenhoven EJ, Bosch JL, van Jaarsveld BC, van Dijk LC,
Deinum J, et al. Stent placement for renal arterial stenosis: where do we
stand? A meta-analysis. Radiology. 2000; 216: 78–85.
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Predictors of improved renal function after percutaneous stent-supported
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decline in renal function reflects reversibility and predicts the outcome
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of renal artery stent implantation in patients with renovascular
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Am J Cardiol. 1997; 80: 363–366.
6; Pearce JD, Craven BL, Craven TE, Piercy KT, Stafford JM, Edwards MS, et
al. Progression of atherosclerotic renovascular disease: A prospective
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