Hemoperfusion (British English: haemoperfusion) First introduced in the 1940s, the technique was refined during 1950 to 1970, and then introduced clinically for the treatment of poisoning in the 1970s and 1980s. Despite its availability, this technique is only infrequently utilized as a medical process used to remove toxic substances from a patient's blood. During hemoperfusion, the blood passes through a column with absorptive properties aiming at removing specific toxic substances from the patient’s blood. It especially targets small- to medium-sized molecules that tend to be more difficult to remove by conventional hemodialysis. The adsorbent substance most commonly used in hemoperfusion are resins and activated carbon. Hemoperfusion is an extracorporeal form of treatment because the blood is pumped through a device outside the patient's body.
Its major uses include removing drugs or poisons from the blood in emergency situations, removing waste products from the blood in patients with renal failure, and as a supportive treatment for patients before and after liver transplantation. 
^Rahman MH, Haqqie SS, McGoldrick MD (2006). "Acute hemolysis with acute renal failure in a patient with valproic acid poisoning treated with charcoal hemoperfusion". Hemodialysis international. International Symposium on Home Hemodialysis10 (3): 256–9. doi:10.1111/j.1542-4758.2006.00105.x. PMID16805886.