Carotid Endarterectomy indication after stroke

[docslytherin]

So I am reading First Aid for Step 2 CK and come across this for prevention and long term treatment of stroke:

"Carotid Endarterectomy: If stenosis >70% in symptomatic or >60% in asymptomatic patients"

Can someone please explain to me how this is true? It seems to me to be opposite. A 68% stenosed symptomatic guy can't get the CEA, but his asymptomatic neighbor with the same stenosis can get it...

So I started checking online and these statistics are legit. It really is correct in First Aid. I'm completely baffled...

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[Idiopathic]

I think it has to do with plaque stabilization, like in CAD, you wont get cathed until your artery is almost totally occluded. With the CEA, if you are symptomatic, it shows that your plaques are unstable, and you need more plaque for stabilization before you will do a CEA. Thats just my opinion, though.

 

[Bevo]

thought it was 80% in asymptomatic individuals.

http://www.aafp.org/afp/990501ap/2475.html

there is a bit about CEA at the bottom and this is what I had to write for a small homework assignment in my vasc. surgery elective.
Which is essentially ripped from Essentials of Gen Surgy and some other surgery book I can't remember the name of anymore

"- Indications for the treatment of Carotid Stenosis for Carotid Endarterectomy (CEA).

(1) Stenosis of the carotid artery of at least 70% with symptoms (TIA, amaurosis fugax, mild non-disabling stroke, etc.)

(2) Stenosis between 50% and 70% who (1) suffered neurological symptoms despite adequate medical therapy, (2) associated contralateral carotid occlusion, or (3) angiographic evidence of ulceration.

(3) Carotid Stenosis of at least 80% which is asymptomatic

- Contra-Indications include: TIA or stroke with stenosis less than 50%, not receiving anti-platelt therapy, CVA accident or an associated dense neurological deficit (i.e. multi-infarct dementia, alzheimer’s disease, senile dementia, recent myocardial infarction, etc.)
"

 

[DOC2KGILL]

herez what i think - a patient who is symptomatic is being managed with medicines unless he gets upto 70% block,and when his condition deteriorates endartirectomy can be done.but a patient who is asymptomatic (i.e he has a block in artery but his body is not showing any symptoms),is at greater risk coz if the block becomes bigger he wont percieve it n sudden death can occur,even if we try to give drugs to pts who r asymptomatic and diagnosed accidently we can never know when the danger bells ring coz there wont be any worsening of symptoms(coz there r no symptoms!)so i think its sort of precautionary measure.hope my guess is right

 

[DOC2KGILL]

but im not too sure,it would be gud if any1 can explain better please!

 

[dynx]

So I am reading First Aid for Step 2 CK and come across this for prevention and long term treatment of stroke:

"Carotid Endarterectomy: If stenosis >70% in symptomatic or >60% in asymptomatic patients"

Can someone please explain to me how this is true? It seems to me to be opposite. A 68% stenosed symptomatic guy can't get the CEA, but his asymptomatic neighbor with the same stenosis can get it...

So I started checking online and these statistics are legit. It really is correct in First Aid. I'm completely baffled...

This is the result of evidence based medicine. Two different trials on two different populations, symptomatic and asymptomatic. One showed a benefit in symptomatic people w/ 70% occlusion because that is who they were looking at...doesn't mean that the benefit isnt there at 50%, they just didnt analize the data that way. The other looked at asymp at 60% and showed a benefit. So these are the PROVEN values, as in the results you've seen in the studies you looked up. Acual practice is different but these numbers are a strict interpretation of what is published. Hope this helps, its a GREAT example of the failings (or at least faults) of evidence based medicine, you still need to use common sense to apply the data you see. I think comon practice is 50% symptomatic and 70% asymp, or at least that was what I was told.

btw...this isnt a guess, this is the real reason its writen that way, I have the names of the studies somewhere, or its in Larson's essentials of general surgery if you have it and beat me to editing this post.

 

[docslytherin]

This is the result of evidence based medicine. Two different trials on two different populations, symptomatic and asymptomatic. One showed a benefit in symptomatic people w/ 70% occlusion because that is who they were looking at...doesn't mean that the benefit isnt there at 50%, they just didnt analize the data that way. The other looked at asymp at 60% and showed a benefit. So these are the PROVEN values, as in the results you've seen in the studies you looked up. Acual practice is different but these numbers are a strict interpretation of what is published. Hope this helps, its a GREAT example of the failings (or at least faults) of evidence based medicine, you still need to use common sense to apply the data you see. I think comon practice is 50% symptomatic and 70% asymp, or at least that was what I was told.

btw...this isnt a guess, this is the real reason its writen that way, I have the names of the studies somewhere, or its in Larson's essentials of general surgery if you have it and beat me to editing this post.

i'm with you. it just seems so strange that you can't extrapolate from the findings of a study. if a 60% stenosed symptomatic patient will benefit, why wouldn't it be a preventative step to correct the asymptomatic 60% person? i understand the risk/benefit argument, but why the arbitrary line at 70%? isn't it better to treat an asymptomatic earlier than to wait for the possibilty of them becoming a 62% stenosed symptomatic patient?

after i read it i looked for (and found) the studies. it just seems counter-intuitive. (sort of like treating renal stones with increased calcium intake)

 

[seansoutherland]

 

[hale-bopp]

i'm with you. it just seems so strange that you can't extrapolate from the findings of a study. if a 60% stenosed symptomatic patient will benefit, why wouldn't it be a preventative step to correct the asymptomatic 60% person? i understand the risk/benefit argument, but why the arbitrary line at 70%? isn't it better to treat an asymptomatic earlier than to wait for the possibilty of them becoming a 62% stenosed symptomatic patient?

after i read it i looked for (and found) the studies. it just seems counter-intuitive. (sort of like treating renal stones with increased calcium intake)

the reason for the cutoffs is because one of the studies was done by Canadians and the other was done by Americans. seriously.

so one group picked 70% as their cutoff (and 50%-70% as another group, but that one did not show clear benefit) and the other group picked >60%.