I use plasmapheresis very successfully. Did the problems with the catheter keep you from finishing a full set of treatments? If they did, let me encourage you to try it again. There are very types of catheters and it may be worth trying them again. Let me encourage you that they can work and not be too much of a burden. I have had my catheter nearly 3.5 years, with no infections and no significant clotting.
Godspeed in finding a truly effective treatment,