Subclavian artery pseudoaneurysm - Forum

[Alalo]

35 yo WF 4 wks s/p severe head injury as a result of an MVA, she also suffered pelvic and Lt radial fx. Pt is still poorly functioning mentally and physically, with tracheostomy, on Neurosurgery service. Yesterday, she was accidentally (by the relative) found to have a right supraclavicular pulsatile mass. Duplex revealed 1.5x2 cm Rt subclavian artery pseudoaneurysm. There is no appreciable neurodeficit or venous stasis in RUE. We are going to obtain an angiogram today and thinking about a stented endoluminal prosthesis placement.

Brief MEDLINE search did not reveal any natural history studies on subclavian pseudoaneurysms. There are multiple case reports regarding diagnosis and treatment, mostly endovascular.

My questions are:
1) what would you do
2) can be results on femoral pseudoneurysms extrapolated to subclavian aneurysm (re: size, observation etc)
3) has anybody ran into a subclavian artery pseudoaneurysm natural history study

[Doctor Green]

We treated a post-traumatic right subclavian pseudoaneurysm a few months ago. The patient was a construction worker who was struck with an I beam to the right neck and upper chest. CXR showed a widened mediastinum and Angio revealed an injury and associated pseudoaneurysm in the proximal right subclavian. We treated this with a covered stent (Palmaz stent mounted on a ePTFE graft) inserted via a right axillary cutdown. This was done in the OR with the chest prepped and ready for sternotomy should things go wrong.

Observation would not be recommended as this type of pseudoaneurysm generally represents a disruption of the artery as compared to those following catheterization. It is also conceivable that your patient's pseudoaneurysm could represent a complication of an attempted central line insertion. Was this done ? Does your Duplex show a pseudoaneurysm distinct from the artery and having a neck ? If so, we would treat this type of pseudoaneurysm with thrombin injection under duplex guidance. If not, your angio should clarify this.

[Hans]

Like all such injuries they only get bigger and just from personal experience they will take out the brachial plexus quite fast if left, and recovery can be very slow. In fact arm weakness seems a common presentation. Their late presentation like you mention is not untypical. Your suggestion of an endoprosthesis sounds very interesting, and I would like to hear what you decide and how it goes. I would repair it open with a vein graft.

[Alalo]

Both causes of the pseudoaneurysm in my patient can be true. She was involved in the MVA, had lung contusion, and your case confirms the fact that it could be a result of blunt injury to the artery. She also had a right IJ vein introducer placement which allegedely was uncomplicated. Duplex revealed a pseudoaneurysm with a distinct neck. Angio confirmed it. Pseudoaneurysm was located about 4 cm distal to the vertebral artery takeoff. This location would rather be attributed to a catheterization mishap.

Right after I posted the case, my intern who continued a MEDLINE search ran into a following reference:

Treatment of iatrogenic femoral artery pseudoaneurysm with percutaneous thrombin injection

Chiau-Suong Liau, MD, Feng-Ming Ho, MD, Ming-Fong Chen, MD, PhD, and Yuan-Teh Lee, MD, Taipei and Tau-Yuen, Taiwan

And that was what we did. Patient was still on the angio table. Interventional radiologist occluded Rt subclavian artery with a balloon at the pseudoaneurysm neck, Doppler confirmed no flow in the aneurysm. Under U/S guidance, we catheterized aneurysm and injected Thrombin. Minutes later, there was no Doppler detectable flow within the pseudoaneurysmal sack and angio confirmed that with good patency of the arm vessels.

[Surgeon]

We have been treating pseudoaneurysms with thrombin injection at Loyola for about two years with excellent results. Our technique is a bit simpler in that it is done without adjunctive balloon occlusion.

[Arizona]

James Yeo MD from Chicago has quite a series of subclavian artery pseudoaneuysms in baseball pitchers.

[Billroth]

The traumatic aneurysms I see are usually related to stabs and GSW's - the artery frequently transected or nearly so - so embolisation techniques wouldn't help. I think it must be rare to get such aneurysms without penetrating trauma.

What sort of catheter in your case do you think was the cause? I have never seen this in our institution (the biggest CV line we use is about 14g, and all are put in via Seldinger method. We do occasionally use an 8F if we can't get a big peripheral line. - we don't have radiologists or cardiologists sticking in huge catheters here).

I was thinking about prosthetic endoprostheses in these usually young patients. Elegant but is it a good idea if long term graft survival is unknown. The patency rates for other prostheses in PVD probably aren't relevant. All I know is that we don't seem to see any of these patients back again - prosthetic or vein repair.

[Stent]

>What sort of catheter in your case do you think was the cause?

The catheter in blame would be a 7.5F introducer for the Swan-Gans catheter. Again, it has never been confirmed cause of pseudoaneurysm in my patient. As I mentioned before, we entertained this option as well as possibility of the blunt trauma to the artery during an MVA.

>I was thinking about prosthetic endoprostheses in these usually young
>patients. Elegant but is it a good idea if long term graft survival is
>unknown.

This is a good thought. As we have gained some experience with endoluminal prosthesis we'll have more follow up and will have better idea about their longevity.

[Hans]

Regarding the need for scanners, we recently had a very good rendition of an ERCP taken by digital camera, which can also be used for clinical photos - hence much more versatile than a scanner and less expensive too.