subclavian stenosis

My dad had a triple bypass a little more than a year and half ago, he is now back in the hospital with what they are saying is a severe subclavian stenosis on the left side......with a triple bypass aren't new veins put in place and if so then why the blockage again......and can this cause a heart attack.....and does this require surgery or can youlive with this....

[kenkeith]

There are two methods of bypassing a blocked coronary artery to increase the blood flow to the heart muscle. They are the Saphenous Vein Bypass and the Internal Mammary Bypass.

I assume the bypass was a mammary artery...it is larger,  more convenient, and it has a record of fewer restenosis than sapheneous vein that is harvested from the leg.  The usuasl procedure for a bypass occlusion is angioplasy and possibly a stent implant.

Yes, it can cause a heart attack as occluded vessels a vulnerable to smaller clots causing cardiac arrest.  The risk can be minimized with anti-platlette medication.

[maggiemag]

The subclavian artery is not a coronary artery.  Therefore a *blockage* in that will not cause a heart attack.  A heart attack (MI), is  heart muscle dying from lack of blood carrying oxygen, from blockages in coronary artery disease.  A severely stenotic subclavian *could* be from an entirely different disease process.  I am not a physician, however, and this would not be a common disorder and there may not be a simple solution either, sorry to say.

[kenkeith]

My response was based on an assumption of an internal mammary graft to the left anterior descending coronary artery (LAD). In about 90% of coronary bypass operations, this vessel is the best conduit available for surgical bypass to the major arteries of the heart. The by-pass IS TO the LAD and the left subclavian vein.  A blockage within this configuration can cause a heart attack.

[kenkeith]

Your response is somewhat confusing.  For clarification Internal Mammary Artery grafts are already attached at their origin from the main artery to the arm (the subclavian artery). Blood flowing through the IMA directly comes from the SUBCLAVIAN artery.

This differs from GSV (greater saphenous vein from the leg) grafts that are detached at both ends. After connecting one end of the vein to the coronary artery, the other end must then be connected to a source of red blood. "This is done by partially occluding a segment of the ascending aorta with a specialized, curved vascular clamp. Holes are created in the front wall of the aorta, and the veins are anchored to these openings with fine suture. After releasing this partially occluding clamp, the veins fill with red blood from the aorta and deliver this blood to the coronary arteries downstream". So it is obivous an internal mammary artery graft is more convenient, in addition it is often in superior condition and less apt to occlude in the future.  But it can and occasionally occludes and angioplasty and stent can be implanted.

If there is a clot, etc. in the lumen of subclavian artery, it can disrupt the blood flow to the CORONARY artery causing an MI (heart attack) due to ischemia (lack of blood flow).  

[maggiemag]

Please forgive me.  I was looking at the stenosis from a completely different perspective, as a congenital defect.  I, myself, have severe congenital subclavian issues that complicate things.  I was not giving a cabg a second thought, erroneously apparently.  I also got the impression that you thought the subclavian was part of the NATURAL coronary circulation.  Part of the role I assume on these boards is to make sure people have accurate information.  As a  master's prepared nurse, I do know some things.

[kenkeith]

The OP is not very clear so I made assumptions based on triple by-pass comment.  I do know the name of the 4 arteries that are subject to occlusion.

[kenkeith]

Precisely 4 coronary arteries! :)