Beyond dialysis: current and emerging blood purification techniques

Extracorporeal blood purification using various techniques and hardware is a major part of the modern day practice of clinical nephrology. Although the various modalities of hemodialysis and hemofiltration are the most commonly used extracorporeal therapies in clinical nephrology, blood purification using other techniques have become necessary to remove pathogenic, toxic, or waste substances not easily cleared by hemodialysis or hemofiltration due to factors such as molecular size, protein binding, and lipid solubility. The following review is an up to date summary of extracorporeal therapies, beyond hemodialysis and hemofiltration, in current clinical use as practiced by nephrologists and others in the United States and beyond. This comprises therapeutic apheresis (plasma exchange and cytapheresis), plasma adsorption, hemoperfusion, and the bio-artificial devices.