Cardiovascular mojo. Wow, 6.5 cm is pretty scary. I'm glad he's a candidate for this procedure.
There are no accidents in life. Your knowledge of this option may give him a far greater chance of a longer, healthier life.
If by chance you run into problems with that hospital, I have a cousin who is a vice president at HCA in Dallas (and formerly with Methodist Health System), plus her MD step dad who invented several dialysis systems is well connected with the Houston Methodist DeBakey Heart & Vascular Center.
Keep us posted and feel free to vent.