Dear Pauline:
I am sorry, but to be honest, I have no experience with dialysis of a patient with PCT or PPCT.
HDF does improve solute clearance - and this includes larger molecular solutes - but whether it would make sufficient difference … I do not know for sure.
There are some high porosity membranes available now (such as the high cut-off membranes we are now using for the removal of light chains in multiple myeloma) but I am not aware of these being used as yet for the treatment of such rare conditions as PCT or PPCT.
Peritoneal dialysis also permits much larger solute clearance and has been used (with a mixed bag of outcomes) in PCT but again, I do not have any personal experience here.
I will, when I get a moment, try to sift the literature a little to see if there are any pointers to better outcomes with such things as HDF, high cut-off membranes and/or PD … and ask around among some of my colleagues. If I find anything that might be useful, I will re-post here.
Sorry to have been such a dead loss to you on this one.