Clogging of mesenteric arteries

[pablo20995]

---

Members don't see this ad.

On last years Radio Anatomy of the Organs one of the questions was: How would the colon be vascularised if both the superior and inferior mesenteric arteries were clogged?

Looking through my atlas and on the web I couldn't find an answer. The only conclusion is, that it couldn't. Or would the pancreaticoduodenal artery be able to do it?

 

[Anti-PD1]

The only way I can think of is if the gastroduodenal collaterals could make an eventual anastomosis with the marginal artery of Drummond. I'm not sure, but this illustration suggests it. My guess would be this connection doesn't exist in everyone:

 

[AnatomyGrey12]

Artherosclerosis of the mesenteric arteries leads to ischemic bowel (Anki card for the win). Some people might have small collaterals that would anastomose and slightly vascularize areas like mentioned above but with regards to the question you asked if it were on my test I would go with it simply not being vascularized.

 

[pablo20995]

Could there be an anastomosis of the inferior and middle rectal arteries with the superior rectal artery, that would provide (very limited) vascularisation of the colon through the colic arteries? Maybe that this, in combination with the pancreaticoduodenals (gastroduodenal collaterals) anastomosing with the marginal artery of Drummond, could be enough.

 

[The Knife & Gun Club]

Gun to my head personally I’d say it could not be done, at least in practice.

But that said the SMA and IMA have a lot of branches and depending on where along the path it is occluded, maybe some collaterals could survive. For gastroduodenal collaterals (which vary from person to person) alone to supply that amount of blood just seems kind of absurd practically.

Interesting question though, we should have more of this (and less mid level fear-mongering) happening on here!

 

[libertyyne]

Could there be an anastomosis of the inferior and middle rectal arteries with the superior rectal artery, that would provide (very limited) vascularisation of the colon through the colic arteries? Maybe that this, in combination with the pancreaticoduodenals (gastroduodenal collaterals) anastomosing with the marginal artery of Drummond, could be enough.

i dont think the inferior and superior rectal arteries anastomose(IIRC). I do think the anterior and posterior superior Pancreaticoduadenals would have to flow retrograde through the inferior PDs to end up in the SMA as I dont think there is anastamoses between the PD and drummond. Apparently Occlusion of IMA is very common and is usually asymptomatic because of SMA flow.

 

[The Knife & Gun Club]

Also, just practically if you’re getting to the point where you occlude off BOTH of those giant arteries I’d have to imagine you’re gonna have “Case report worthy” atherosclerosis of...like...every other important artery in your body.

The stroke/renal crisis/MI/other weird pathology will probably get you first.

 

[AnatomyGrey12]

Also, just practically if you’re getting to the point where you occlude off BOTH of those giant arteries I’d have to imagine you’re gonna have “Case report worthy” atherosclerosis of...like...every other important artery in your body.

The stroke/renal crisis/MI/other weird pathology will probably get you first.

Yeah if it’s that bad you’re probably already dead and had Familial Hypercholesterolemia

 

[Anti-PD1]

I have too much time on my hands #MS4

 

[bananafish94]

If it were occluded at the pedicle of the SMA and IMA it would be hard. I don't know if that would be possible. A little bit distal on either of them and there would be considerably more wiggle room. Also, the mesenteric vasculature is surprisingly inconsistent. There are all sorts of anastomoses (i.e. Arc of Riolan, superior LCA, etc.) that could potentially do the job in some patients.


Sent from my iPhone using SDN mobile

 

[libertyyne]

If it were occluded at the pedicle of the SMA and IMA it would be hard. I don't know if that would be possible. A little bit distal on either of them and there would be considerably more wiggle room. Also, the mesenteric vasculature is surprisingly inconsistent. There are all sorts of anastomoses (i.e. Arc of Riolan, superior LCA, etc.) that could potentially do the job in some patients.


Sent from my iPhone using SDN mobile

There used to be a page in netters with multiple examples of variability.

 

[AnatomyGrey12]

I have too much time on my hands #MS4

Take advantage my friend, come July 1 that NS residency you're going to land will own your soul #RIP

 

[Anti-PD1]

Take advantage my friend, come July 1 that NS residency you're going to land will own your soul #RIP

I have no soul.

 

[mimelim]

Gun to my head personally I’d say it could not be done, at least in practice.

But that said the SMA and IMA have a lot of branches and depending on where along the path it is occluded, maybe some collaterals could survive. For gastroduodenal collaterals (which vary from person to person) alone to supply that amount of blood just seems kind of absurd practically.

Interesting question though, we should have more of this (and less mid level fear-mongering) happening on here!

Also, just practically if you’re getting to the point where you occlude off BOTH of those giant arteries I’d have to imagine you’re gonna have “Case report worthy” atherosclerosis of...like...every other important artery in your body.

The stroke/renal crisis/MI/other weird pathology will probably get you first.

If it were occluded at the pedicle of the SMA and IMA it would be hard. I don't know if that would be possible. A little bit distal on either of them and there would be considerably more wiggle room. Also, the mesenteric vasculature is surprisingly inconsistent. There are all sorts of anastomoses (i.e. Arc of Riolan, superior LCA, etc.) that could potentially do the job in some patients.


Sent from my iPhone using SDN mobile

It is not common, but it is certainly not unheard of to have occlusion of both your SMA/IMA. A couple of things ahead of time...

1) IMA occlusion is incredibly common in older patients, especially those with vascular disease. Probably 90%+ are occluded in those over 75 in my patient population. We don't even comment on it because it is assumed that it is closed off. We also depend on it to be closed off when we do most of our aortic work. Open aortic cases, we routinely ligate. EVAR, we don't actively close it off, but we assume/hope that it closes off, otherwise you get a type 2 endoleak which +/- needs fixing. The IMA is not a giant artery by any stretch of the imagination.
2) The MS3 level understanding of mesenteric disease should be about the THREE visceral vessels, ie. Celiac, SMA and IMA. While in practice things are a little different... The rule of thumb is that you need disease in 2 out of the 3 to get symptoms. More practically, the SMA is king. You can easily get symptoms from just your SMA being stenotic and as I mentioned before, the IMA is usually long gone by that point.

We routinely have patients with occluded aortas, SMAs, IMAs, etc. The key is the temporal component. Acute occlusion is deadly. Thrombus, embolus, doesn't matter what it is, if you lose blood flow quick, patients go down and they go down hard. But, there are plenty of people that take years to develop their stenosis/occlusion and develop robust collateral pathways. Be extremely careful about talking about the size of arteries. I've seen pelvic collaterals that were >1cm in diameter. Likewise, I've seen huge superior and inferior pancreaticoduodenal arteries, feeding the middle colic. If you give the body enough time, it will find a way to get blood flow, mostly off of your hypogastrics or the celiac access.

 

[libertyyne]

netters 4 gives a variant on the PD artery that gives off the 1st jujunal art. This would be a dick move if this was a question.

 

[Anti-PD1]

Interesting question though, we should have more of this (and less mid level fear-mongering) happening on here!

I agree, loving this insider knowledge, thanks @mimelim

 

[libertyyne]

It is not common, but it is certainly not unheard of to have occlusion of both your SMA/IMA. A couple of things ahead of time...

1) IMA occlusion is incredibly common in older patients, especially those with vascular disease. Probably 90%+ are occluded in those over 75 in my patient population. We don't even comment on it because it is assumed that it is closed off. We also depend on it to be closed off when we do most of our aortic work. Open aortic cases, we routinely ligate. EVAR, we don't actively close it off, but we assume/hope that it closes off, otherwise you get a type 2 endoleak which +/- needs fixing. The IMA is not a giant artery by any stretch of the imagination.
2) The MS3 level understanding of mesenteric disease should be about the THREE visceral vessels, ie. Celiac, SMA and IMA. While in practice things are a little different... The rule of thumb is that you need disease in 2 out of the 3 to get symptoms. More practically, the SMA is king. You can easily get symptoms from just your SMA being stenotic and as I mentioned before, the IMA is usually long gone by that point.

We routinely have patients with occluded aortas, SMAs, IMAs, etc. The key is the temporal component. Acute occlusion is deadly. Thrombus, embolus, doesn't matter what it is, if you lose blood flow quick, patients go down and they go down hard. But, there are plenty of people that take years to develop their stenosis/occlusion and develop robust collateral pathways. Be extremely careful about talking about the size of arteries. I've seen pelvic collaterals that were >1cm in diameter. Likewise, I've seen huge superior and inferior pancreaticoduodenal arteries, feeding the middle colic. If you give the body enough time, it will find a way to get blood flow, mostly off of your hypogastrics or the celiac access.

i was hoping you would chime in on this thread. Makes perfect sense considering the body can use the internal thoracics if there are aortic issues.