HISTORY:
A. Prior to 1980’s, very few active tissue banks existed.

Apart from corneas, storage of human tissue was not common

Tissues for transplantation were scarce

No professional standards and government control meant that
effectiveness were uncertain
B.
Introduction of Immunosuppressant drugs in the 1980’s led to:

Successful organ transplants

Public support and effective organ donation programs

Paved the way for use of cadaver tissue donations.

Increased availability of tissue allografts

Tissue banks combined with organ and tissue procurement agencies
(COPA, UNOS)
C.
D.
Early Tissue banking

Originally managed by surgeons, had many quality control problems

Poor stored tissue quality

Very little disease testing

Poor tracking of tissue sources.
TMS involvement improved quality of work

ABO, Rh Typing

Improvements in Source Tracking

Better quality storage equipment

Reputation of Blood Banking improved community relations and donor
pool.
E.
Government Regulation of Tissue Banks

In 1993, an Interim Rule was implemented by the FDA

Allowed FDA inspection of tissue banks, ability to recall and destroy
unsuitable tissues

FDA requirements focused on assuring safety of tissue for transplant,
accuracy of medical history and records, proper processing and storage of
tissue.
F.
Increasing surgical demands for allografts

Demand for bone in hip replacements, femoral head allografts, mending
acetabular and femoral defects.

Demands for cadaver skin in burn patients exceeds supply in US, skin
imported from Europe to meet demand
APPLICATIONS:
A.
B.
Apart from blood, banked tissues include:

Bone, frozen, freeze dried, and demineralized

Corneas

Heart Valves

Tendons

Skin

Hematopoetic tissues, including cord blood

Dura mater, cartilage, and ear ossicles
Growth in Tissue Transplantation

300,000 bone allografts made annually

40,000 corneas transplanted annually

20,000 cadaveric organs transplanted annually

50,000-100,000 vials of powdered bone allografts used in dental practice
annually
C.
Common Clinical Uses of Banked Tissues

Bone allografts used in spinal fusion surgery

Tendon allografts for knee ligament replacement

Heart valves for treatment of congenital heart defect in children

Viable and non-viable skin dressing for burn patients

Powdered bone used in dental repairs

Hematopoetic stem cells and marrow used to replace bone marrow

Cornea transplants
STANDARDS
A.
Process required for Safe Tissue Transplantation

Careful, thorough review of donor’s medical and social history – next of
kin, physicians, hospital records

Donor blood microbiological testing – serologic and PCR

Physical examination of cadavers – tattoos, needle marks, other
indications of risky lifestyle

Review of post-mortem autopsy exam results – cause of death, time of
death, etc

B.
Aseptic tissue retrieval from donor.
Donor Selection and Testing

National Blood Service require that HIV 1 & 2, Hepatitis B & C, and
serologic testing for syphilis be performed on all potential donors

Other tests may be performed by individual labs, including CMV,
Hepatitis G, and HTLV I & II
C.
Various Testing Methods Used to Detect Viruses

Hepatitis B testing for surface antigens

HIV and Hepatitis C detect presence of antibodies to virus

ELISA used for HIV, may not detect donors in seroconversion

PCR used to detect HIV viral nucleotide without depending on antibody
response – more sensitive and specific
PROCEDURES
A.
ABO and HLA Typing

Major ABO mismatching can cause rapid graft rejection due to damage by
ABO antibodies, causing endothelial damage and thrombosis

ABO matching is important to the success of all vascular tissue grafts –
liver, kidneys, heart, lungs, and pancreas
B.
C.
D.
ABO matching not important in other tissue grafts

Fascia

Bone

Heart Valves

Skin

Cornea

Tissues not vascular, do not have problems with thrombosis
HLA A, B, and Dr are cross-matched for:

Kidneys and some other soft organs when time permits

Bone Marrow

Peripheral blood stem cells

Second cornea grafts
HLA donor-recipient matching not done on connective tissues that are not
considered viable
E.

Bone

Tendon

Cartilage

Fascia

Epidermal dressing
Collection Procedures: Bone

Fresh, autologous bone taken from illiac crest, reduces risk of disease
transmission

Allograft bone also collected when conditions make autologous collection
in impractical

Can be frozen or freeze-dried, and stored at room temperature for five
years

Freeze dried bone is processed to remove marrow and blood, treated with
alcohol, and irradiated, resulting in decreased risk of disease transmission

Demineralizing bone makes proteins and growth factors readily available,
promoting healing
F.
Collection Procedures: Skin

Allograft skin used as dressing in deep burn patients

Layers of skin 0.015 inch thick are removed

Skin can be stored at 2-8 OC for up to 14 days, in a nutrient and antibiotic
broth media

Skin frozen and stored in liquid nitrogen freezer, or at –70 OC.

Tissue stored using Dimethylsulfoxide, 15% Glycerol, or Phosphate
Buffered Saline and another Cryoprotective Agent

Thawing depends on freezing media used, some have cytotoxic effects at
higher temperatures
Many Factors affect quality of Skin retrieved:

Delay in collection after death reduces viability of tissue

Autolytic and enzymatic degradation of tissue allows for increasing
bacterial load
Second are of concern in retrieval is surface contamination

Primarily collected in mortuary or funeral home, not the most aseptic
environment
Proper Aseptic Retrieval includes

Use of sterile drapes

Decontamination of skin using disinfectants

Operating room techniques

Staff should be scrubbed, gloved, masked and gowned

Collection should take place in sterile environment

Use of sterile instruments for collection, and sterile storage after collection
Skin normally carries both residual and transient normal flora

Reduced by transport at low temperatures in sealed containers

Also reduces drying of skin during transport to tissue bank.

Placed in an antibiotic transport solution
Transport solution similar to medium used to grow tissue cultures, helps
maintain viability of graft
G.
Collection Procedures: Heart Valves

Allografts do not require anticoagulation therapy like mechanical grafts.

Whole Heart aseptically collected in Operating Room or at autopsy.

Aortic and pulmonary valves removed, stored in DMSO, and frozen in
liquid nitrogen
H.
I.
Disease Transmission by Tissue Transplants

Viruses, bacteria, and fungi

HIV transmitted by bone and solid organ transplants

Hepatitis transmitted by bone, bone marrow, and other organs

Tuberculosis transmitted by bone and heart valves

Prion diseases transmitted by corneas and dura mater

Rabies has been transmitted by corneas
Incidents of fungal, bacterial and viral agents reportedly due to tissue grafts

Occasionally of donor origin

More commonly, acquired during tissue procurement, processing, or
storage.
J.
Sterilization of Banked Tissue

Antimicrobial mixtures used must be effective against bacterial and fungal
contamination

Ohio Valley Tissue and Skin Center – 0.4 mM L-glutamine, 100 units
penicillin, 100 g streptomycin, 200 g kanamycin, 8 mg gentamycin, and
100 g nystatin.

“Reina Sofia” Cordoba Spain – 50 g/ml tobramycin, 50 g/ml co-
trimoxazole, 50 g/ml vancomycin, 50 g/ml amphotericin B

In clinical trials, both mixtures were 100% effective against normal flora
gram-positive bacteria and had varying degrees of effectiveness against gramnegative and drug resistant gram-positive bacteria.

Against Candida sp., the Reina Sofia mixture was 100% effective, while
the OVTSC mixture was shown to be ineffective on all trials.
K.
Procedures At UNC Hospitals
Frozen Skin at UNC:

UNC Hospitals use tissue banked by OVTSC for skin allograft

Tissues ordered and distributed by the Transfusion Medicine Services

Tissue stored in -70 Degree Celsius Freezer for 1 year

Collected in 2x8 and 3x8 strips, ordered by square foot
ABO, Rh, HLA at UNC

UNC requires ABO/Rh type match on all tissues and organs

HLA match done pre-transplant on kidneys only

HLA match done post-transplant on heart, liver, lungs, and other organs,
due to need for rapid transplant of these organs only

HLA match done post-transplant on heart, liver, lungs, and other organs,
due to need for rapid transplant of these organs