Necessity of apheresis
Apheresis is often necessary if there is a fat metabolism disorder with increased LDL cholesterol or lipoprotein (a). Although appropriate medication is taken in a maximum tolerated dosage and the individual risk factors such as diabetes, high blood pressure or nicotine consumption are minimised, vasoconstriction and increasing vascular deposits can occur as a result of the lipid metabolism disorder.
Definition
Apheresis is derived from the Greek and means to take away or separate. In the broadest sense, it means that certain substances are removed from the blood, in this case cholesterol or lipoprotein (a). But there are also other dieseases, for example neurological ones, where "unwanted" or harmful substances are removed.
Technically, various processes are suitable for this. In all of them, the blood is passed through a filter or over a membrane in which the substance to be separated remains suspended and the thus purified blood is then returned. The treatments usually last 2-3 hours and are generally well tolerated.
Realisation
We use three different techniques to perform apheresis:
- Lipid adsorption: by means of physical interactions, the fats remain suspended in an adsorber cartridge
- Lipid filtration: a filter membrane retains the fats due to their molecular size
- Heparin-induced extracorporeal LDL precipitation: several chemical and physical processes in succession complex the fats and filter them from the blood.
As cholesterol is constantly being produced by the body, it is necessary to repeat the treatments regularly, usually once a week. The body's own veins are often suitable for vascular access. But sometimes it is necessary to create a connection between an artery and a vein (the so-called AV shunt), similar to dialysis treatment.