clinical question..

[marly]

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This 40 something yr old guy developed acute leg ischemia, had angiogram which showed total occlusion of external iliac artery on the right side. ABI on the right side was 0.1 on the opposite side 0.9

The question is what is the eatiology of this occlusion. His background include mild elevation of LDL in the 120's very low HDL 19 and very high triglycerides 400's and he is on HAART for HIV. He stopped smoking about 10 yrs ago, has no hx of claudication etc.

I believe the reason for the occlusion is not atherosclerosis, and therefore the reason has to be looked for. Some of my collegues think it is dyslipidemia and peripheral vascular disease.

Anyone with experience with similar presentations ..? thanks..

 

[imtiaz]

did you check an EKG? is he currently in atrial fibrillation?

if not that, then does he have an AAA that you dont know about with a thrombus?

if not, how about a hypercoag workup?

 

[gerickson03m]

This 40 something yr old guy developed acute leg ischemia, had angiogram which showed total occlusion of external iliac artery on the right side. ABI on the right side was 0.1 on the opposite side 0.9

The question is what is the eatiology of this occlusion. His background include mild elevation of LDL in the 120's very low HDL 19 and very high triglycerides 400's and he is on HAART for HIV. He stopped smoking about 10 yrs ago, has no hx of claudication etc.

I believe the reason for the occlusion is not atherosclerosis, and therefore the reason has to be looked for. Some of my collegues think it is dyslipidemia and peripheral vascular disease.

Anyone with experience with similar presentations ..? thanks..

Need a little more history here. Did he have claudication prior to his acute symptoms? On exam is there evidence of severe disease? If the answer is yes, it is likely that his problems come from atherosclerosis and plaque rupture (though its usually not bilateral acutely). The above poster questioned embolization from a-fib. This usually gives u "trash foot" and you get occlusion at artery junctions. Also he would have a high chance of stroke and ischemia to the bowels. Remember that PVD/Atherosclerosis is a progressive disease, even once the patient quites smoking. Once endothelial damage has happened, the result of inflamation causes foam cells and plaque build up to be progressive. This can even happen to non smokers who have trauma to the arteries.

 

[marly]

Never had intermittent claudication/ rest pain. EKG shows sinus rhythm...

And the opposite does not have severe peripheral vascular disease going by the ABI( of 0.9).

thanks.

 

[gerickson03m]

cool, sounds like teh patient needs a Ct to check for AAA and a cardiac echo to check for Thrombus/Septal problems.

 

[Skylizard]

Is he shooting dope in his leg? I have seen a similar picture in other extremities...either a miss or a vein gives way and an infitrate.

 

[Skialta]

two words: Cardiac Myxoma, actually saw a case that presented similarly, but he has a crappy lipid profile.

 

[Whisker Barrel Cortex]

Good case. HIV patients, especially on HAART therapy, have been shown to have increased risk of acute arterial thrombosis as well as chronic peripheral and coronary artery disease (look up cardiovascular disease and HIV and you will find articles on this). Given the age of this patient and his clinical history, this seems a likely etiology. HIV can also be associated with antiphospholipid antibody syndrome which predisposes to thrombosis.

As for the aortic aneurysm, the angiogram would have picked this up since they most certainly did an aortagram as well. The lack of significant contralateral disease, age of the patient, and lack of other significant risk factors makes routine PVD less likely.

Although atrial myxomas could do this, given the patients HIV, I still think this is a more likely cause. However, an echocardiogram is certainly indicated to rule out myxoma/thrombus.

 

[gerickson03m]

Totally disagree that angiogram will pick up an AAA, I have had many cases where the thrombus in the aneurysm makes the aorta look normal or even narrow. Also it will constantly underestimate the size.

 

[Whisker Barrel Cortex]

Totally disagree that angiogram will pick up an AAA, I have had many cases where the thrombus in the aneurysm makes the aorta look normal or even narrow. Also it will constantly underestimate the size.

I agree that aortagram may not show the true nature of the aneurysm. Of course it underestimates size, many aneurysms are partially thrombosed. However, in my experience, you do not usually see a completely normal looking aorta, especially if this is due to atherosclerotic disease. Although the size may measure normal, the contour usually at least hints at it. It seems that in this 40 year old man with other risk factors for thrombosis (as I mentioned above) and not extreme risk factors for atherosclerosis, this is a less likely etiology.

 

[johnny_blaze]

I just came back from a course on techniques in thoracic aortic surgery. During the case discussion there was a case quite similar to this. The patient was young with no real risk factors for emboli who developed acute limb ischaemia. Long story short, the cause of the acute ischemia was a intimal flap secondary to asymptomatic type b aortic dissection. The patient was later found to have a connective tissue disorder (me thinks).
Investigations - CT
Tx - percutaneous fenestration and stent placement. Femoral-Femoral cross-over graft (the other iliac artery was patient)

 

[popbirch]

Here is a link to some of the HAART induced dyslipidemia problems. I would second that this is the likely cause of clot formation.

http://www.hivmedicine.com/textbook/ls.htm

Lipodystrophy Syndrome

"Hyperlipidemias are a frequently observed side effect of antiretroviral therapy, especially in combinations that include protease inhibitors."
"In contrast, ritonavir (Norvir™) often leads to hypertriglyceridemia correlating to the drug levels."

 

[gerickson03m]

Totally agree with Tired, I have spent 9 months during my residency on vascular surgery and have seen this problem quite a few times. Non of the patients had HIV. I will not totally discount the dx but the term " hearing hooves and thinking of zebras comes to mind".

 

[Whisker Barrel Cortex]

Good discussion. I agree that things like dissection and aneurysm are important to rule out. And I also agree that an aortagram doesn't entirely exlcude an aneurysm or dissection (especially if only peformed of the abdominal aorta). CTA and echo are both prudent in this case.

Turns out there is some evidence that HIV predisposes to a variety of cardiovascular diseases ranging from thrombosis (antiphospholipid, Protein S, unknown cause) to aneurysm to dilated cardiomyopathy (also a possible source of embo in the patient). Here is a good review article (from a radiology journal):

http://radiographics.rsnajnls.org/cgi/content/full/26/1/213

 

[SocialistMD]

two words: Cardiac Myxoma, actually saw a case that presented similarly, but he has a crappy lipid profile.

I've seen the same thing, 6 months s/p resection of the myxoma.

I really agree with the hypercoag w/u and the ECHO. Equivocal about the AAA w/u in a 40 y/o guy (unless he has Marfan's), as something should have been seen on the aortogram that was likely done at the same time as the angio.