The most common aneurysm site in the circle of Willis

[MudPhud20XX]

is where the anterior communicating artery joins an anterior cerebral artery according to Kaplan Neuroanatomy.

I remember that there was a particular reason from my neuroanatomy class, but I forgot. Can anyone explain this?

Many thanks in advance.

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[ChessMaster3000]

is where the anterior communicating artery joins an anterior cerebral artery according to Kaplan Neuroanatomy.

I remember that there was a particular reason from my neuroanatomy class, but I forgot. Can anyone explain this?

Many thanks in advance.

Basically there is some weakness in the media at the bifurcation there, and therefore the intima/adventitia can puff out a little bit. The big thing is medial weakness. I think I learned that in pathoma. If we were ever to be asked on a question on that, it would be WEAKNESS of the MEDIA.

 

[Ionian]

Just be careful with what the question asks. ACA is overall the most common.

I remember getting a haines questions asking the most common aneurysm of the posterior circulation (from vertebral arteries) a detail I overlooked, lazily scanning the question, and the answer is an aneurysm at the basilar tip.

 

[ChessMaster3000]

Just be careful with what the question asks. ACA is overall the most common.

I remember getting a haines questions asking the most common aneurysm of the posterior circulation (from vertebral arteries) a detail I overlooked, lazily scanning the question, and the answer is an aneurysm at the basilar tip.

Is PCOM not considered posterior circulation?

 

[Ionian]

Is PCOM not considered posterior circulation?

Look.

Ill definitely hunt down the question for you later and post it, with the explanation, just so its clear i didnt make it up 😛 you can argue with hanes and not me after that haha.

 

[ChessMaster3000]

Look.

Ill definitely hunt down the question for you later and post it, with the explanation, just so its clear i didnt make it up 😛 you can argue with hanes and not me after that haha.

Its just a matter of what is considered posterior circulation. I guess for testing purposes, PCOM is not.

 

[Ionian]

Its just a matter of what is considered posterior circulation. I guess for testing purposes, PCOM is not.

Did you check out the image?

I know FA says "Pcomm is a common site for aneurysm". But haines atlas has the aneurysm on the Internal Carotid at the level of the pcom, but not on it.

I doubt a question asking about the posterior circulation would have both Basilar tip/pcomm as answer choice, as I bet both are used to explain the same thing, cause the basilar tip is where pcomm starts.

Just think posterior Basilartip/pcomm.

 

[ChessMaster3000]

Did you check out the image?

I know FA says "Pcomm is a common site for aneurysm". But haines atlas has the aneurysm on the Internal Carotid at the level of the pcom, but not on it.

I doubt a question asking about the posterior circulation would have both Basilar tip/pcomm as answer choice, as I bet both are used to explain the same thing, cause the basilar tip is where pcomm starts.

Just think posterior Basilartip/pcomm.

Yeah that makes sense. It will be at the INTERSECTION of two arteries, not actually on any specific artery. The basilar tip sort of implies an intersection, so that works out.

 

[Donald Juan]

Did you check out the image?

I know FA says "Pcomm is a common site for aneurysm". But haines atlas has the aneurysm on the Internal Carotid at the level of the pcom, but not on it.

I doubt a question asking about the posterior circulation would have both Basilar tip/pcomm as answer choice, as I bet both are used to explain the same thing, cause the basilar tip is where pcomm starts.

Just think posterior Basilartip/pcomm.

The basilar tip is that part of the image that says 4%, where the PCAs bifurcate, not at the PCOM/ICA junction that says 20%. I think chestmasters first post was right, that the question is not considering PCOM to be posterior circulation (which I wouldn't really either).