Preparation

Dissection of the aortic and pulmonary roots, mitral valves and/or arteries as well as all steps of the processing are performed by appropriately trained medical and paramedical staff inside a vertical laminar flow clean-room Class A, background Class B/C. After macroscopic examination, competence testing and measurements, the tissues are decontaminated in a low temperature, low concentrated antibiotic cocktail during 40-48 hours.

Cryopreservation

Following decontamination, the tissues are cryopreserved using the dimethyl-sulfoxide (DMSO) as cryoprotecting solution. The pouches with the tissues are frozen in liquid nitrogen vapors according to a specific computer monitored program.

Quality control involves

• Microbiology (before and after decontamination) :
  • Aerobic and anaerobic bacteria
  • Mycoses and yeasts
  • Mycobacterium Tuberculosis (by indication)
• Serology : Screening of the donor for transmissible diseases
• Hepatitis B & C, AIDS, HTLV, Syphilis
• Q- Fever (by indication), Coxsackie viruses  (by indication)
• Histology : Pieces of the cardiac muscle (myocardium), aortic and mitral wall and mitral valve (hearts) and pieces of the arterial tissue are systematically tested histologically for exclusion of any infection or malignancy, as well as to detect any malformation of the valve/vascular tissue.

Curve of cryopreservation

Each tissue must have the registered cryopreservation curve, as to be able to document the requested quality.

Final validation

The manager of human body material (Medical Doctor), after having obtained all necessary tests, controls them for conformity with the regulation and quality requirements and validates the allografts for clinical application.