Dr. Sclafani, I was wondering how high you think the risk of thrombosis is post-angioplasty, considering that other doctors are not prescribing anticoagulants after the procedure unless stents are involved. I am considering if the risk is high enough if I should request it anyway, even though its not part of their protocol. What are your thoughts and what regimen do you prescribe after the angioplasty?
Injury to blood vessels occurs when one performs angioplasty/venoplasty: when you stretch the vessel wall it has some tears. otherwise it cant get larger. When you expose the inner part of the blood vessel, the collagen) to circulating blood products, the body, that magnificent highly developed instrument, recognizes that the wall is injured and a variety of mechanisms act to prevent blood loss.
When the platelets contact chemicals in the wall of the vein or other clotting factors in the area, they are activated and become sticky and clump together. They change shapes forming leglike extensions and they excrete chemicals into the surrounding blood.
Activated platelets will adhere to the collagen that is exposed by the tears in the inner lining of the blood vessel. Aggregation and adhesion act together to form the platelet plug. Myosin and actin filaments in platelets are stimulated to contract during aggregation, further reinforcing the plug. On this plug other clotting elements adhere as well.
Thus the body has sealed the breach.
However that clot causes turbulent flow and in some cases that leads to progressive clotting of the blood vessel. To much leads to thrombosis. that is not what we are trying to do when we balloon dilate a blood vessel.
So this delicate balance between clotting and nonclotting has to be managed. We certainly dont want bleeding and just as much we dont want the vein to clot off.
Some physicians do not use anticoagulation when there is a high flow state to keep things from getting too turbulent.
So better living through chemistry...with thanks to Big Pharma
We can inhibit the platelets so that they do not cause too much platelet aggregation....aspirin, plavix, ibuprofen, and others
We can reduce the amount of clot that forms.....coumadin, heparin, lovenox, fondaparinux
Many regimens exist, each has value and risk.
Personally, I was very affected by my first impression during liberation on my first patient who had an incomplete duplication of the jugular vein. Angioplasty seemed to work really well. As she was my first patient, she was kept in the hospital overnight. On the next morning without any change in her condition, a extracranial ultrasound (ECU) was done and it showed that the vein had occluded.
So we resorted to another class of drugs, thrombolytic agents, that dissolve clot. After a few hours, the clot did dissolve. Unfortunately by the next morning, clot had reformed. A second round of thrombolysis failed.
So,,,,do i use drug therapy to prevent clot formation. DAMN STRAIGHT.
I started by treating with a rapid acting anticoagulant like lovenox or fondaparinux and then converted to coumadin for two months.
But patients didnt like it, so i have backed off, using only the short acting drugs that are injectable for 2-3 weeks. I have stopped using coumadin because of its longer acting effects that are not as easily reversed and the short acting ones.
I hope that helps