Protocol of Cardiovascular Tissues Banking

According to the requirements of the EU Directives, to the Belgian legislation and to the recommendations of the EATB, the Medical Director has responsibility for the whole process of tissue banking.

The EHB protocols are based on:

• Belgian Standards for cardiovascular allografts (1993, revised in 2000, 2006)
• Directive 2004/23CE of the European Parliament and Commission from
  March 31st 2004 concerning the establishment of the standards of the quality and security for the donation, achievement, control, processing, preservation and storage of the human tissues and cells
• Directive 2006/17/CE from the Commission from February 8th 2006 containing the application of the Directive 2004/23/CE from the European Parliament and Commission from March 31st 2004, concerning certain technical requirements related to donation, procurement and control of the tissues and cells of human origin
• Directive 2006/86/CE from the Commission from October 24th 2006, containing application of the Directive 2004/23/CE from the European Parliament and Commission from March 31st 2004, concerning the technical requirements of traceability and notification of the reactions and side-effects and certain technical requirements related to the processing, preservation, storage and distribution of the human tissues and cells
• Guide to safety and quality assurance for organs, tissues and cells (2nd edition), Council of Europe (2004)
• EATB General Standards (2003) and European Standards for Cardiovascular Tissue Banking (2004)
  

Procurement of Heart and Arteries

A. EXCLUSION CRITERIA

MEDICAL HISTORY OF THE DONOR

1. Death of unknown cause (or diseases of unknown etiology)

2. Infections:

• History, presence or suspicion (jaundice of unknown etiology) of a viral
  B hepatitis (except for the cases with known acquired immunization) and
  C hepatitis
• History, presence or suspicion (based on the clinical signs or laboratory evidence) of the HIV I/II or the HTLV
• Septicemia, viral infection, active tuberculosis, systemic mycosis or established parasitic diseases, malaria and other protozoan infections
  (Q- fever, Brucellosis,…) at the moment of donation
• Viral myocarditis

3. Malignant diseases

• History or presence of malignant tumors, excluding:
  • primary basocellular skin carcinoma
  • various primary tumors of the central nervous system
• History or presence of oncogene hemopathies or Hodgkin’s disease

4. Risk of transmission of the prion diseases:

• Suspicion of the Creutzfeldt-Jakob or the variants of the Creutzfeldt-Jakob disease
• Family history of Creutzfeldt-Jakob disease
• Progressive dementia with a rapid evolution or neurological diseases of unknown origin
• Treatment with the growth-hormone, obtained from extracts of human pituitary gland
• Implantation of an allograft of dura mater or the cornea
• History of non-documented neurosurgical intervention

5. Risk behavior

• The donors, whose life-style contains the arguments of the risky behavior in relationship with HIV and/or parasite hepatitis (travel to the endemic region, established homosexuality, recent imprisonment, drug abuse, chronic alcohol abuse, …)

6. Other general exclusion criteria:

• Donor with altered immune competence or having been under long-term corticosteroid treatment (during 4 years with a daily dose of 10 mg or during 1 year of 20 mg)
• Being transplanted with a xenograft
• History of vaccination with an alleviated virus
• Ingestion of the toxic substances (cyanide, mercury, lead etc.) with a toxic dose for the donor
• History of auto-immune or collagen diseases with a specific invasion of the concerning tissues and cells
• Children, younger than 18 months, from the infected mothers with HIV, HTLV, Hepatitis B or C, who received breast-feeding during the last
  12 months before the procurement
• Pregnancy and breast-feeding in case of the living donors
  

MACROSCOPIC ASPECTS OF THE TISSUES

• Dilation of the aortic and pulmonary roots
• Important morphological lesions of the valves and proximal parts of the coronary arteries
• Important fat deposition on the valve and large fenestration particularly at the commissural areas
• Atheromatosis (atheromas/calcifications) of the arterial wall
  

B. AGE LIMITS

Donor Blood Sampling

Blood of the donor must be collected in three 10 ml tubes - 1 EDTA + 2 dry tubes- before dilution of the blood and must be sent to EHB together with the procured tissues.

Transport

All excised tissues - hearts, arterial roots or arteries – and blood samples are transported to EHB in ice-cold sterile transport medium. So far the transport medium has not been standardized and varies according to the procurement centers. Saline, Ringer, Euro-Collins as well as Tissue Culture Medium 199 HEPES (TCM) have been used.

Processing and quality control of the Homografts

PREPARATION :

Dissection of the aortic and pulmonary roots, mitral valves and/or arteries as well as all steps of the processing are performed by medical staff members inside a vertical laminar flow clean-room (grade EEC C /class US 10.000) with two workstations (grade EEC A /class US 100) - clean-room BASAN ® - located in a regular operating room (grade EEC D/class US 100.000). After macroscopic examination (involving an endoscopic examination in valvular conduits and in arteries), competence testing and measurements, the tissues are decontaminated in a low temperature, low concentrated antibiotic cocktail.

CRYOPRESERVATION :

Following decontamination, the tissues are rinsed with the pure TCM and transferred to an ice-cold cryoprotection solution consisting of 10% dimethylsulfoxide (DMSO) in TCM. The total volume is sealed in a double sterile bag and kept at +4°C during 40 to 60 min, in order to allow the DMSO to penetrate completely into the tissues.
The pouches with the tissues are frozen in liquid nitrogen vapors according to an electronic monitored programme, together with a pouch containing a control tissue of approximately the same type and size, and temperature probe. The freezing is achieved at the rate of -1°C/min down to –40°C and at –5°C/min down to –100°C.

QUALITY CONTROL involves :

FINAL VALIDATION

The medical director checks all the data, writes himself the Standardized Description Sheet and signs the document for definitive validation of each prepared tissue.

PRESERVATION & STORAGE OF THE HOMOGRAFTS :

Cryopreserved cardiovascular homografts are stored in storage containers at the temperature of -140°C/-150°C in the vapor phase of liquid nitrogen (they are never submerged in liquid nitrogen).
The manufacturer of these tanks and supplier of liquid nitrogen (AIR LIQUID MEDICAL) is in charge of the effective monitoring programme & for the permanent (24Hrs/24Hrs) control by an electronic system to continuously ensure the compliance with the storage conditions & temperature and to ensure the avoidance of temperature fluctuations.

Expiration Date: A maximum storage period with an expiration date is assigned for
5 years. At the expiration date, the non-implanted homograft is discarded and destroyed.

A short-term storage at –80°C is acceptable for MAX 1 month.

DISTRIBUTION

Homografts are ordered by phone, fax and/or e-mail and allocated on the basis of clinical diagnosis and patient’s age, normally after a dialogue between the surgeon and the director of the bank or his delegate. This dialogue is essential since the homograft bank is responsible for the distribution of human tissues. Priority indications for valves are prosthetic and native endocarditis, congenital heart diseases and valve replacement in young adults and/or when the anticoagulation is contraindicated. The vascular homografts are used mainly in cases of the prosthetic graft infection, infected and/or mycotic aneurysms as well as the critical limb ischemia with non-healing ulcers. The description sheet of the homograft is sent to the demanding surgeon by fax for approval before the homograft allocation. The surgeon signs it and sends it back (by fax) for acceptance.

FOLLOW-UP OF IMPLANTED HOMOGRAFTS

The surgeons are requested to provide operative and postoperative information on the implanted valve or artery. They do so by filling in the special forms (traceability sheet) provided by EHB. At the discharge, they need to fill in the discharge form (prepared and sent by the EHB) and send it to EHB. In some cases they provide the own documents (discharge form).

The explanted homografts recovered by EHB are submitted to a pathology study including at least macroscopy and histology. In selected cases several other studies can also be performed: X-Ray, immune-histochemistry and/or electron-microscopy.