Cadaveric skin for extensive burns

1. Department of Plastic and
Reconstructive Surgery
Sheri Kashmir Institute of Medical
Sciences
Topic :Skin Banking

2. Department of Plastic and
Reconstructive Surgery
Sheri Kashmir Institute of Medical
Sciences
• Presenter : Dr Junaid Khurshid
• Moderator : Dr Haroon Rashid Zargar

3. Definitions
Biorepository
• A biorepository is a biological materials repository
that collects, processes, stores, and
distributes biospecimens to support future
scientific investigationBiorepositories can contain
or manage specimens from animals, including
humans, and many other living organisms

4. Biorepository

5. BIOBANKS
• A biobank is a type of biorepository that stores
biological samples that are usually human for
research. Biobanks are an important resource for
medical research as it helps support various types
of contemporary research.

6. BIOBANKS

7. TYPES OF BIOBANKS
• Population-based biobanks
• Hospital or academic based biobanks
• Disease-oriented biobanks
• Non-profit organizations or commercial companies

8. Tissue Banking
• Tissue banking is the activity of harvesting,
processing, storage and distribution of
transplantable human tissues.
• Tissues retrieved from the human body are used to
repair and or replace the diseased or lost tissues of
living human body can save many lives.

9. Contd.
• The common tissues being harvested and used are
cornea, skin, bones, cartilage, joints, heart valves,
fascia, tendons, and duramater from human
cadaver.
• Biobanking of normal and tumor cells, stem cells
from bone marrow, umbilical cord, and adipose
tissue, are increasingly used by pathologist to
maintain cell lines and bioengineering.

10. • Newer applications of autologus banked tissues for
future use are being regularly reported in literature
viz., blood vessels, testicular tissue, ovarian tissue,
nipple areola complex, sperm, penile skin, cord
blood placenta
• Practically any human tissue can be harvested and
banked for clinical use and research.

11. Skin Bank
• A skin bank was defined as an
organization having sufficient structure,
equipment, laboratories and know-how
to ensure safety and efficacy of the
entire tissue banking process

12. SKIN BANKING

13. Burn wounds
• Burn wound is probably the most devastating of all
the wounds – physically, psychologically, socially
and economically.
• Early, expedious burn wound closure is crucial for
survival of patients with large burn wounds.

14. CONTD.
• After successful initial management, burn wound
infection leading to systemic sepsis is the single
most major cause of death in burn patients –
especially in developing countries

15. BURN WOUND CAUSES
• Loss of barrier to bacterial invasion.
• Hyper metabolism with consumption of body
proteins leading to severe catabolic state
• Immuno-suppresion, which is directly proportional
to the extent of burn.
• Disturbance of temperature regulation.
• Possibility of deformities and disfigurement.

16. Partial Thickness Burn
• The natural process of wound healing can be aided
and / or expedited with appropriate use of several
biological wound covers (e.g. collagen, amnion,
banana leaf dressing, etc.)
• Or interactive wound dressings (e.g. Acticoat)
• And topical agents (e.g. antimicrobial creams, E G F
containing preparations, etc.) The healing usually
takes about 10-20 days.

17. Full Thickness Burn Wound
• Split thickness skin grafting is the only way of
obtaining wound closure.
• Patients with burn size upto 40-50% Total Body
Surface Area (TBSA) can usually be provided
permanent closure of such wounds with skin
autografts obtained from the unburnt areas of the
patient.

18. Factors Precludeing Autograft
• Poor general condition of patient.
• Paucity of autograft donor sites.
• Risk of increase in the size of wound due to
addition of donor site wound to the extent of burn
wound and its consequences.
• Risk of loss of autografts due to sub optimal
recipient bed and general status.
• Duration needed (usually 3 weeks) for reharvesting
skin graft from same donor sites.

19. In these situations, the only way of
salvaging such patients is using
substitutes for skin autografts
• Xenografts (from other species e.g. pig-skin)
• Allografts (from another human being)
• Biosynthetic skin substitutes (Artificial Skin)

20. NOTE
• These skin substitutes provide
temporary but long term wound
closure, with potential to save life of
a patient with large burn.

21. Other Demands
• As the median age of the population increases, the
number of people with hard-to-heal wounds, such
as posttraumatic wounds in patients with diabetes
or on long-term therapy with high-dose
corticosteroids, chronic venous and pressure ulcers,
is increasing

22. Why Allografts
• Xenografts are not commercially available in India.
• Biosynthetic skin substitutes are extremely
expensive and unaffordable for most of the burnt
patients in our country. The availability is also
uncertain.
• Then the only alternative available is Skin Allografts
obtained from a human donor.

23. Skin Allografts
• The efficacy of skin allografts in the management
of burn wound was realized in 1881.These have
also been shown to be the most effective of the
alternatives. In Western countries, besides better
facilities and resources, one of the main reasons for
salvage of patients with very large burn (e.g. 95%
of TBSA) is availability of skin homografts.

24. Skin Allograft Donors can be
• 1. Living
•
2. Cadaver

25. Living Allografts
• For procurement of Skin grafts, the living donor
needs to undergo a battery of investigations for
preoperative evaluation
• Followed by a surgical procedure under suitable
anesthesia, hospitalization for atleast 2-3 days,
• Donor site healing time of about 10 days and
postoperative wound site pain.

26. Contd.
• Maximum body surface area that can be safety
utilized for harvesting of skin grafts is 15 to 20% at a
time.
• To avoid vested interests and commercial angles – it
is advisable to use only close relatives as living
donors.

27. Why Challanging
• In the present age of nuclear families availability of
such a relative is obviously very rare and
inconvenient too.
• In reality, majority of our patients are young
females from poor socioeconomic strata with
compromised nutritional status and have large
burn size (average extent more than 50% TBSA)
with most of the area bearing full thickness burn
wound.
• So the problem is obviously challenging.

28. • The other alternative is to procure
split thickness skin grafts from a
cadaver donor and preserve them for
use in future.

29. Cadaver Donor
• The concept of skin donation after death is not
new and the first skin bank was established in USA
around 1950. The chief benefits of use of allografts
on excised full thickness burn wounds are
• Effective control of protein and fluid loss from
wounds.
• Reversal of hypermetabolic state with
improvement in nutritional status.

30. Contd.
• Augmentation of immunological response.
• Control of wound infection and improvement in the
wound bed making it ready for acceptance of
precious skin autografts.
• Immediate pain relief and general feeling of well
being.
• Excellent biological wound cover till the autograft
donor sites become ready for reharvesting.

31. Why Unique
• The skin allograft transplant differs from organ
transplantation as the skin grafts are used to
provide temporary long term protection and are not
expected to survive in the recipient permanently as
transplanted organ.
• This means that neither ABO blood group nor HLA
matching is required for allograft skin
transplantation.
• So, any human being can be a donor for anyone
else.

32. Why problem not perceved
• The need for skin allografts is not likely to be
perceived unless the burn center is a high
volume unit with ability to salvage most of the
patients with upto 50% TBSA burns.

33. WHY BANK
• The largest organ of the body is skin.
• A person can survive with more than 60% damage
to other organs, such as liver and kidney, but loss
of 40% of the skin may be fatal, unless the tissue is
replaced.
• The skin in a major burn patient is deficient even
after meshing of skin graft.
• In such situation, cadaveric skin graft may be the
major source of the skin.

34. Problem Statement
• In India approximately 1 million people get burnt
every year and most of them are from the lower or
middle income strata.
• It is obligatory to find out an economic way of
treatment for the affected populace.
• Since use of human skin allograft is the gold
standard for the treatment of burn wound, in-
house skin banking for a burn unit hospital is
prerequisite to make the treatment procedure
affordable.

35. Brief History
• The first tissue bank in Europe, the Yorkshire Regional
Tissue Bank, was established in England in 1960
• The Dutch National Skin Bank in The Netherlands
followed this, in October 1976.
• With the further evolution of techniques to preserve
skin, the Euro Skin Bank was opened in 1992.
•

36. Initiatives
• There was one skin bank at India till 2009, but it
was difficult for a single bank to cover the entire
country’s need.
• Looking at the necessities, National Burns Centre
(a tertiary burn care centre) along with Rotary
International and Euro Skin Bank collaborated and
developed an effective cadaveric skin banking
model in Mumbai, Maharashtra in 2009. Initial
two to three years were formation phase; by the
year 2013 the entire system was organized and
started running full fledged

37. How to apply
• In case of deficient donor skin, immediate early
excision and cover can be done with allograft. This
is done to protect the excised area and to prepare
the wound for future autograft take.
• Allograft can be used for coverage of wound or it
can be used with autograft as “sandwich
technique.”

39. Protocol
• Skin grafts are harvested from a cadaveric donor
and stored (banked) for future use.
• The skin from a donor is generally harvested within
6 h of death, stored in glycerol, and then taken to a
skin bank.
• It undergoes processing, and is stored in skin bank,
where after processing it is stored in skin bank.

40. Graft storage
• If serology and microbiology reports are
satisfactory, the grafts are shifted to -70 0 C. with
15% Glycerol as cryo-protectant. The grafts can be
preserved upto 6 months at this temperature.

41. Liquid Nitrogen technology
• Liquid Nitrogen technology permits preservation
upto 3 years.
• But the present mismatch between availability and
requirement does not necessitate the need for
methods for prolonged storage.
• The grafts are thawed to room temperature before
use and once thawed, restorage is not
recommended.

42. Glycerol preservation
• Involves incubation in increasing concentrations of
glycerol solution in order to fix free water in intra-
and extracellular spaces.
• GPAs are maintained at a temperature of +2°C to
+10°C in concentrated glycerol solution.
• It is recommended to expose allografts to 98%
glycerol for at least 4 weeks before clinical use to
increase their safety.

43. • Glycero-preserved skin allografts are nonviable grafts
• Glycero-preservation has some advantages as GPAs
have a certain degree of antibacterial and antiviral
activities as well as reduced immunogenicity
• Processing is simpler than for cryopreservation
• Grafts are easily distributed at refrigerated
temperature.
• GPAs are widely used in clinical practice all over the
world as temporary dressing, alone or combined with
CSAs, for difficult, posttraumatic and surgical wounds,
and deep loss of substance (e.g., tendon coverage).

44. Gamma-irradiation
• Sterilizing tissue grafts offer a clear advantage in terms
of safety
• Gamma-irradiation is the process of exposure to
gamma rays from radionuclide isotopes 60Co and
137Cs.
• According to the International Atomic Energy Agency, a
radiation dose of 25 kGy is defined as the reference
dose for the sterilization of the tissue grafts,
• Some authors reported toxic or architectural alterations
such as increased tissue stiffness induced by free
radicals cross-linking collagen fibers

45. Lyophilization/freeze-drying
• A dehydration process involving two consecutive
steps: a freezing phase and a sublimation phase, in
which low pressure allows frozen water to
sublimate directly from a solid to a gaseous state
• Skin is de-epidermized and processed for
decellularization, which commonly consists of
physical, biological (enzymatic) and chemical
methods, variously combined.

46. • Such freeze-dried acellular dermis lacks
immunogenic potential and is sterile, and can
therefore be used as a dermal scaffold that
integrates into the host tissue or closed wounds.
• It is easily stored and distributed, and is used
when required after re-hydration (for 30−60 min at
+37°C in sterile saline in the case of lyophilized
dermis