Friday, June 26, 2009

DOING MORE DOES NOT MEAN BETTER; DOES RENAL ARERY STENTING HELP ATHEROSCLEROTIC RENAL ARTERY STENOSIS

It is not uncommon for me to be asked at professional ( Interventional ) meetings on whether I thought that renal artery stenting help improved BP control and renal function, in patients with atherosclerotic renal artery stenosis and deteriorating renal function. Does renal artery stenting help improve renal function.
I have often held the view that the answer is no. Renal artery interventionist ( probably because of the oculo-stenotic reflex ) often considered that any stenosis, if relieved, will help the patient, and that stents ( and nowadays drug-eluting stents ) will help.
The 16th June issue of Annals of Internal Medicine, carried a study by Dutch aorkwers led by Dr Liesbeth Bax, on 140 patients comparing medical therapy with renal artery stenting, in patients with artherosclerotic renal artery stenosis, and poor renal functions. The results showed that whether you had just good medical therapy and renal artery stenting + medications, there was no difference in outcome as far as renal function is concerned. Good medical therapy was just as good as intervention + medication. Again, the oculo-stenotic reflex should be severely controlled by interventionist ( and dare I say, by young, aggressive interventionist ). Not as far as evidence based medicine is concerned. Not to say that renal artery intervention does carry some risk. I note from Dr Bax study that there were two deaths in about 40 odd patients who received renal artery intervention ( something like 4% ). That is high.
This study by Dr Bax also looks like a renal, mirror image of the "COURAGE TRIAL " for management of coronary artery disease. Coronary artery interventions in assympotomatic CAD ( as one would find in mass public MSCT screening of CAD ), does no better than intensive medical therapy. Of course, that is not to mention the financial angle.
I was concerned because 2 weeks ago, a patient was refered to me for renal artery artery intervention with hypertension. This patient also had significant CAD. In fact, I ended up stenting his important coronary disease, but also took a quick angiographic look at the renals, and found them to me normal.
Now I know that medical therapy for hypertension and renal failure is still very good therapy, as good as interventional therapy.
Stated in another way, doing less may be as good as doing more.

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