We're talking about three different procedures, two of which CGTK is involved with.
1. CABG
2. Peripheral bypass
3. AV Grafts for Hemodialysis
Shared characteristics;
The use of a graft designed for low pressure flow in a high pressure system. That is, using a vein where nature intended an artery.
The development of intimal hyperplasia as a response to being subject to high pressure.
The subsequent development of occlusion, either from the hyperplasia itself, or more likely from the risk it confers for atheromatous plaques.
Important Difference;
In 3, the purpose is to facilitate hemodialysis. This entails creating a high pressure system (so that the blood flows freely into the hemodialysis machine) and joining it to the venous system. In bypass and cabg, your graft is merely a bridge from artery to artery.
"I don't understand the market; are shunts preferable to grafts or fistulae (some patients not suited for one or the other; infection; or?)? In other words, if one solved the problem in grafts, would anybody bother with shunts anymore?"
Synthetic grafts (gortex, etc) are second best to veins. They are used only when venous quality is poor to begin with.
I brought up the hemodialysis idea because AV grafts are notorious sob's (or a vascular surgeons bread and butter, depending on how you look at it). If a vein could be transfected in vivo, that would be huge. In the current procedure, the cephalic vein is anastamosed to the radial artery. The vein is just mobilized a bit - it never leaves the body. |
