Blood purification by dialysis is a nephrology cornerstone. However, despite its success, dialysis has not systematically moved to the treatment of other conditions, such as liver failure, intoxication with protein-bound toxins or drugs, poisoning with non–water-soluble toxins, and hyperinflammatory states. In these conditions, hemoadsorption (HA) may provide a possible therapy.

The Technology of HA

HA implies direct contact of blood or plasma with a sorbent. For this to occur safely, a sufficient level of biocompatibility is needed. Earlier technology from approximately 40 years ago used zeolites and charcoal with low biocompatibility and was marred by serious complications. Consequently, the clinical application of HA waned.¹

However, evolving sorbent coating science and better materials have made HA potentially relevant again. Trials of endotoxin removal by polymyxin-bound cartridges have provided some impetus in this field. Finally, sorbent-based biocompatible synthetic porous polymers (styrene or acrylic acid based) have become commercially available, thus enabling the expansion of clinical experience.

Large polymers of cross-linked networks of divinylbenzene can be structured into beads and made more biocompatible with polysulfone coating. They deliver an adsorptive surface area >1000 m²/g in cartridges containing 200–300 g and can bind multiple substances by van der Waals forces, strong hydrophobic bonds, and weak ionic bonds. Because of the above technological changes, adverse reactions have become relatively uncommon and can be further prevented by plasma separation, thus avoiding contact of cells with the sorbent.