Skin Bank Research Articles

Banking and use of glycerol preserved full-thickness skin allograft harvested from body contouring procedures

IntroductionThe use of glycerol preserved skin allograft (GPA) became a main stay in burn treatment. However, harvesting of cadaveric skin is not yet legalized in many countries including Egypt. ObjectivesTo estimate the feasibility of using skin harvested from body contouring procedures as a source of GPA and its clinical efficacy. Patients and methodsSkin harvested from body contouring procedures done in Al-Azhar university hospitals was preserved by glycerolization and used in management of burn and complicated wounds. ResultsIn the period between February 2012 and February 2013 skin was harvested from 24 abdomenoplasty cases, 6 bilateral breast reduction cases, and 1 case of thigh lift done in Al-Azhar university hospitals. This yielded about 22,000cm2 of skin preserved by glycerolization. This GPA was used in 15 excised burn wounds, in 9 cases of chronic burn wounds, and in 6 complicated wounds. Partial graft loss occurred in 3 cases and total graft loss occurred in 1 case. ConclusionThe glycerolized full-thickness skin harvested from body contouring procedures is clinically effective in burn and wound management. In the presence of regional coordination, it can serve as an abundant source for skin banking in where cadaveric skin use is not legalized.

The use of allodermis prepared from Euro skin bank to prepare autologous tissue engineered skin for clinical use

Over the past two decades a range of 3D models for human skin have been described. Some include native collagen and intrinsic basement membrane proteins and fibroblasts, others are based on xenogeneic collagen or synthetic supports often without fibroblasts. The aim of this study was to look at the influence of media calcium, basement membrane and fibroblasts on the quality of 3D tissue engineered skin produced using human de-epidermized acellular dermis. In this study we deliberately used Euro skin as the source of the donor dermis to examine to what extent this could provide an effective dermal substrate for producing 3D skin for clinical use. Keratinocytes were cultured in the presence and absence of fibroblasts and both with and without basement membrane on decellularized dermis at calcium concentrations ranging from 250μM to 1.6mM over a period of 14 days. Results showed the formation of a well attached epithelium with many of the features of normal skin in the presence of a basement membrane. This was largely independent of the presence of fibroblasts and not greatly influenced by the concentration of calcium in the media. However there was a clear requirement for physiological levels of calcium in the formation of a stratified epithelium in the absence of a basement membrane.

Traitement des nævi géants congénitaux de l’extrémité céphalique par expansion cutanée

Giant congenital pigmented nevi are benign melanocytic tumors. The lesion transformation to a malignant melanoma is a rare but severe condition. Treatment is complex and often difficult. The purpose of this study was to analyze the results and discuss the contribution of expansion technique in the treatment of giant nevi of the cephalic extremity. Six giant nevi (five children and one adult) were treated by skin expansion between 1993 and 2010. The nevus had a fronto-temporal region and vertex location (one case), and hemifacial in five cases. Subtotal resection of the nevus was performed in every case. The defect was filled by a double rotation flap of expanded scalp (one case), and an expanded total skin graft (five cases). Two complications were observed: a depression of the frontal bone in a 6-year-old child who had received a total prosthesis volume of 2000 mL; and migration of the valve under a prosthesis, which required repositioning. These complications did not alter the final results. The risk of evolution to a malignant melanoma is considerably decreased after exeresis of congenital nevi. Tissue expansion is a true skin bank. It allows treating giant congenital nevi of the scalp and face, with good esthetic results and less morbidity.

A Newly Developed Container for Safe, Easy, and Cost-effective Overnight Transportation of Tissues and Organs by Electrically Keeping Tissue or Organ Temperature at 3 to 6°C

BackgroundAs there is only one skin procurement organization in Japan the Japan Skin Bank Network (JSBN), all skin grafts procured in Japan are sent by a commercialized delivery system. Preliminarily, bottles containing saline were transported in a cardboard box using a so-called “cooled home delivery service” using a truck with a refrigerated cargo container. During transportation the temperature in the cardboard box increased to 18°C in summer and decreased to −5°C in winter. For these reasons, we investigated whether a newly developed container “Medi Cube” would be useful to transport skin grafts. ObjectivesFour bottles with a capacity of 300 mL containing 150 mL of saline in a Medi Cube container were transported from Osaka to the JSBN in Tokyo between 4 PM and 10 AM using a commercialized cooled home delivery service. Two bottles were transported in a Medi Cube container without phase change materials (PCM) in winter and summer, respectively. Another two bottles were transported in the Medi Cube with PCMs in winter. The temperatures inside saline, inside a transportation container, and outside the container, and air temperature were monitored continuously with a recordable thermometer. ResultsThe temperatures inside saline and inside a Medi Cube container were maintained between 3 and 6°C, even when the temperature outside the container increased during parking. The temperature inside a Medi Cube container without PCM decreased to −3°C when the inside of the cargo container was overcooled in winter. However, the temperatures inside saline and inside a Medi Cube container with PCM were between 3 and 6°C, even when the temperature outside the container decreased to below 0°C in winter. ConclusionA Medi Cube container with PCM provided a safe, easy, and cost-effective method for overnight transportation of skin grafts.

Homograft banking in Singapore: two years of cardiovascular tissue banking in Southeast Asia.

Established in 2008, the National Cardiovascular Homograft Bank (NCHB) has been instrumental in creating an available supply of cardiovascular tissues for implantation in Singapore. This article introduces its collaboration with Singapore General Hospital Skin Bank Unit. The procedure of homograft recovery, processing, cryopreservation and quality assurance are presented. Since its establishment, the NCHB has followed the guidelines set by the Ministry of Health Singapore and the American Association of Tissue Banks. A total of 57 homografts had been recovered and 40 homografts were determined to be suitable for clinical use. The most significant reasons for non-clinical use are positive microbiological culture or unsuitable graft condition. Crucial findings prompted reviews and implementation of new procedures to improve the safety of homograft recipients. These include (1) a change in antibiotic decontamination regime from penicillin and streptomycin to amikacin and vancomycin after a review and (2) mandating histopathogical examination since the discovery of cardiac sarcoidosis in a previously undiagnosed donor. Further, the NCHB also routinely performs dengue virus screening, for donors suspected of dengue infection. Cultural factors which affect the donation rate are also briefly explored. By 2010, 31 homografts had been implanted into recipients with congenital or acquired heart valve conditions. More than half of these recipients were children. Post-operative outcomes had been encouraging, with no report of adverse events attributed to implanted homografts.

Experience with the use of close-relative allograft for the management of extensive thermal injury in local national casualties during Operation Iraqi Freedom

The care of host nation burn victims in Iraq and Afghanistan has been a significant challenge to US military healthcare providers. To provide burn care in an austere environment is more challenging by limitations in resources such as inadequate medical supplies, infection control issues, and a lack of blood or tissue banking capabilities. Large full thickness burns pose a significant obstacle due to limitations in the casualties' available donor skin, which can be used to achieve wound coverage. In US burn centers, allograft stored in skin banks provides temporary coverage during donor site healing in the management of large total body surface area burns. This report is a study of two severely burned Iraqi children with inadequate donor site surface area to achieve wound coverage that were managed with close-relative allograft harvested from their fathers to achieve temporary wound closure. A brief literature review and future recommendations are included.

Evaluation of a microbiological screening and acceptance procedure for cryopreserved skin allografts based on 14 day cultures

Viable donor skin is still considered the gold standard for the temporary covering of burns. Since 1985, the Brussels military skin bank supplies cryopreserved viable cadaveric skin for therapeutic use. Unfortunately, viable skin can not be sterilised, which increases the risk of disease transmission. On the other hand, every effort should be made to ensure that the largest possible part of the donated skin is processed into high-performance grafts. Cryopreserved skin allografts that fail bacterial or fungal screening are reworked into ‘sterile’ non-viable glycerolised skin allografts. The transposition of the European Human Cell and Tissue Directives into Belgian Law has prompted us to install a pragmatic microbiological screening and acceptance procedure, which is based on 14 day enrichment broth cultures of finished product samples and treats the complex issues of ‘acceptable bioburden’ and ‘absence of objectionable organisms’. In this paper we evaluate this procedure applied on 148 skin donations. An incubation time of 14 days allowed for the detection of an additional 16.9% (25/148) of contaminated skin compared to our classic 3 day incubation protocol and consequently increased the share of non-viable glycerolised skin with 8.4%. Importantly, 24% of these slow-growing microorganisms were considered to be potentially pathogenic. In addition, we raise the issue of ‘representative sampling’ of heterogeneously contaminated skin. In summary, we feel that our present microbiological testing and acceptance procedure assures adequate patient safety and skin availability. The question remains, however, whether the supposed increased safety of our skin grafts outweighs the reduced overall clinical performance and the increase in work load and costs.

Skin banking: Treatment option for native skin necrosis following skin‐sparing mastectomy and previous breast irradiation

Skin flap necrosis, as well as positive resection margins in the context of skin-sparing mastectomy and immediate breast reconstruction, may require reoperation, potentially associated with tissue loss, and thereby impair the aesthetic result. Skin banking has recently been described as a method for handling skin flaps of uncertain viability. Here, we describe the advantages of skin banking in previously irradiated patients with breast cancer recurrence, which underwent skin-sparing mastectomy and immediate breast reconstruction. Aside from its utility in the management of skin necrosis, we present this method as an option to conserve the native breast shape in patients with questionable total resection during surgery.

Letter: Some Caveats in Skin Bank Practices from the Perspectives of Fungal Skin Flora

Editor I read the review by Linford et al.1 regarding the use of allograft skin and its microbiological safety. In the retrospective findings, Linford et al. has provided only a grim overview of the fungal agents. As described by authors, among the yeast the genus Candida are encountered frequently as skin colonisers. However, the role of diverse fungal skin flora other than Candida and potential safety issues owing to their presence need to be highlighted. A wider spectrum of fungal skin flora needs to be screened as part of the skin bank microbiology evaluation practices. The role of potentially pathogenic fungi like Malassezia, Rhodotorula, Trichosporon, Dermatophytes seems to be undermined and not documented in the review. In Table 2, culture results ‘candida’ is misspelt as ‘Candica’. Recently, novel fungal agents like Coniosporium epidermidis have been recovered from human skin which emphasise the concern in this regard 2. The processing of allograft skin described in the article using 85% glycerol and antibiotics like G-Penicillin and Streptomycin is inadequate to completely eradicate the fungal agents. Moreover, it can be speculated that the glycerolisation process might potentially favour the growth of lipid-dependent Malassezia found on humans jeopardizing the skin grafting. The resident skin fungal flora can initiate degradation process damaging the integrity of the allograft skin. Thus, there is a need for thorough screening for fungal skin flora and development of robust processing protocols to ensure increased success rate in skin grafting. Prakash Yegneswaran Peralam 1

Deceased donor skin allograft banking: Response and utilization

ABSTRACT Background: In the absence of xenograft and biosynthetic skin substitutes, deceased donor skin allografts is a feasible option for saving life of patient with extensive burn injury in our country. Aims: The first deceased donor skin allograft bank in India became functional at Lokmanya Tilak Municipal (LTM) medical college and hospital on 24th April 2000. The response of Indian society to this new concept of skin donation after death and the pattern of utilization of banked allografts from 2000 to 2010 has been presented in this study. Settings and Design: This allograft skin bank was established by the department of surgery. The departments of surgery and microbiology share the responsibility of smooth functioning of the bank. Materials and Methods: The response in terms of number of donations and the profile of donors was analyzed from records. Pattern and outcome of allograft utilization was studied from specially designed forms. Results: During these ten years, 262 deceased donor skin allograft donations were received. The response showed significant improvement after counselling was extended to the community. Majority of the donors were above 70 years of age and procurement was done at home for most. Skin allografts from 249 donors were used for 165 patients in ten years. The outcome was encouraging with seven deaths in 151 recipients with burn injuries. Conclusions: Our experience shows that the Indian society is ready to accept the concept of skin donation after death. Use of skin allografts is life saving for large burns. We need to prepare guidelines for the establishment of more skin banks in the country.

Present Status of Kinki Area Skin Bank

Present Status of Kinki Area Skin Bank

Skin bank development and critical incident response

The Donor Tissue Bank of Victoria (DTBV), situated in Melbourne, Australia developed a skin banking program in 1994. It remains Australia's only operational skin bank, processing cryopreserved human cadaveric skin for the treatment of burns. The demand for allograft skin in Australia has steadily increased since the development of the program. The bank has been involved in the provision of skin for a number of critical incidences or disasters both in Australia and overseas. Demand always exceeds supply, and in the absence of other local skin banks, the DTBV has needed to develop strategies to enable increased provision of allograft skin nationally.

Evolving practice of the Helsinki Skin Bank

The purpose of this study is to review the management and running of the Helsinki Skin Bank between the years 2001 and 2008. Further aims were to assess the microbiological safety of the glycerol-preserved allograft skin and analyse its clinical use. The files of the Helsinki Skin Bank were reviewed for allograft skin harvested from organ donors between 2001 and 2008. Data on harvested skin area and microbiological culture results were collected. The patients receiving allograft were also identified and operation indications analysed. Allograft skin was collected from 115 donors, with a mean of 44,335 cm(2) per year. No skin batches were discarded. Microbiological cultures of the allograft skin batches were negative in 86 (75%) cases. Thirty-five donor skin batches were used in 69 operations. The most common indication was 'Biological dressing on partial-thickness burns', comprising 52% of cases. The cost per cm(2) was 0.81euro. The use of allograft skin in the Helsinki Skin Bank is microbiologically safe and continues to provide a versatile and useful treatment modality in many major burn cases with few observed complications. As compared with synthetically produced temporary dressings currently available, our allograft skin is also more economical.

Potential release of aluminum and other metals by food-grade aluminum foil used for skin allograft cryo preservation

Since 1991, the skin bank of the Queen Astrid Military Hospital uses food-grade aluminum foil as a primary support for storing cryo preserved human donor skin (511 donors). The possible release of heavy metals into the cryo preservation media (30% (v/v) glycerol in physiological water) and the possible impact this release could have on the quality of the cryo preserved donor skin was evaluated. Aluminum was the principal detection target. Possible contaminants of the aluminum foil as such (arsenic, cadmium, chromium and lead) were also investigated. The evaluation was set up after a Belgian Competent Authority inspection remark. Aluminum was detected at a concentration of 1.4 mg/l, arsenic and lead were not detected, while cadmium and chromium were detected in trace element quantities. An histological analysis revealed no differences between cryo preserved and fresh donor skin. No adverse reactions in patients, related to the presence of aluminum or heavy metal traces, were reported since the introduction of the cryo preserved donor skin in our burn wound centre.

Tissue Procurement System in Japan: The Role of a Tissue Bank in Medical Center for Translational Research, Osaka University Hospital

Although organ procurement has been regulated by The Organ Transplantation Law (brain-dead donors since 1997, donors after cardiac death since 1979), there has been no law or governmental procurement network (except for cornea) in Japan. Since the late 1980s, some university hospitals have developed original banks. Finally, in 2001 guidelines for tissue procurement were established by The Japanese Society of Tissue Transplantation and Japan Tissue Transplant Network (JTTN) to coordinate tissue harvesting. Five tissue banks were joined to the tissue transplant network (skin in one, heart valves in two, and bone in two). As the number of tissue banks is small, each bank cooperates on procurement, but cannot cover the entire country. With regard to skin transplantation, only one skin bank—The Japan Skin Bank Network (JSBN), which is located in Tokyo—has organized skin procurement. Therefore, it has been difficult to procure skin in areas distant from Tokyo, especially around Osaka. In order to improve such a situation, a tissue bank collaborating with the JSBN was established at The Medical Center for Translational Research (MTR), Osaka University Hospital in April 2008. The bank has played a role in skin procurement center in western Japan and supported procurement and preservation at the time of the skin procurement. Between April 2008 and September 2009, the bank participated in eight tissue procurements in the western area. In the future, the bank is planning to procure and preserve pancreatic islets and bones. Moreover, there is a plan to set up an induced pluripotent stem cells center and stem cell bank in MTR. This tissue bank may play a role to increase tissue procurement in Japan, especially in the western area.

Deceased donor skin allograft banking: Response and utilization

Background:In the absence of xenograft and biosynthetic skin substitutes, deceased donor skin allografts is a feasible option for saving life of patient with extensive burn injury in our country.Aims:The first deceased donor skin allograft bank in India became functional at Lokmanya Tilak Municipal (LTM) medical college and hospital on 24th April 2000. The response of Indian society to this new concept of skin donation after death and the pattern of utilization of banked allografts from 2000 to 2010 has been presented in this study.Settings and Design:This allograft skin bank was established by the department of surgery. The departments of surgery and microbiology share the responsibility of smooth functioning of the bank. Materials and Methods: The response in terms of number of donations and the profile of donors was analyzed from records. Pattern and outcome of allograft utilization was studied from specially designed forms.Results:During these ten years, 262 deceased donor skin allograft donations were received. The response showed significant improvement after counselling was extended to the community. Majority of the donors were above 70 years of age and procurement was done at home for most. Skin allografts from 249 donors were used for 165 patients in ten years. The outcome was encouraging with seven deaths in 151 recipients with burn injuries.Conclusions:Our experience shows that the Indian society is ready to accept the concept of skin donation after death. Use of skin allografts is life saving for large burns. We need to prepare guidelines for the establishment of more skin banks in the country.

What is new in burn care?

A burn injury is not limited to the skin but is associated with the dysfunction of almost every cell in the body and various organs leading to alterations, not only in cellular functions but also in cellular signaling pathways. The current thought that alterations and new treatments of these pathways may restore cellular function and productivity, which in turn may lead to an improved energy metabolism, cell survival, morbidity, and mortality is perhaps the most cutting-edge research in burn care. Hypermetabolism is associated with cell deaths (apoptosis) in skeletal muscles, fat, liver, kidney, lung, heart and gut. These detrimental cellular events are also associated with dysfunction of the cellular organelles such as the mitochondria or the endoplasmic reticulum, thus making burn a truly systemic disease. The areas of advancement in burn care that have improved results of both acute injuries as well as long-term outcome include acute care, burn wound treatment, control of the hypermetabolic responses, and control of life-threatening infections. Both the mortality as well as the length of hospital stay of burned patients have been greatly reduced because of improvement in acute care, such as resuscitation and management of inhalation injuries, early excision and grafting, the control of infections and improving the immune system, improvements in provision of metabolic and nutritional requirements, evolution of effective skin banks, infection control, and alternative wound-closure materials and strategies. Gene therapy is another emerging technique to alter dermal and epidermal regeneration and to improve wound healing. Non-viral constructs have been shown to effectively change the cells into a productive and active cell that releases growth factors and other signaling factors to improve dermal and epidermal regeneration. Liposomal gene constructs have been shown to transfect dermal stem cells increasing the therapeutic possibilities of this futuristic technology! Skin substitutes are creating a revolution and it is now possible to construct an artificial skin, which is called cultured skin substitute (CSS). CSS is the patients own skin (epithelium) in combination with a dermal substitute (Integra) that represents a full-skin substitute including both dermis as well as epidermis. The use of bilayer artificial skin has improved the survival and cosmetic results of early eschar excision in patients with massive full-thickness burns. This technique is helping both, in the acute stage to cover large raw areas as well as in reducing the amount of donor sites taken from the patient and improving cosmesis associated with an improved quality of life in severely burned patients. The challenge that remains is to make this science economically viable for those who need it most. The scope of surgery too has changed from covering chronic burn wounds and treating disfiguring deformities to management of the acute burn wound. Thus escharectomy, tangential excision, meshed skin grafting, micro-skin grafting, and meek grafting are all invaluable arsenals of our armamentarium. Softened freeze-dried glutaraldehyde-preserved skin, chlorhexidine-alcohol refrigerated porcine skin, and frozen amniotic membrane are all effective as burn dressings. The reconstruction in the burn patient is often a long process requiring multiple procedures and stages. It demands a stepwise and prioritized approach, aiming at both maximum function as well as optimal appearance. With better anaesthetic and critical care support surgeons do not hesitate to climb up the reconstructive ladder and microsurgical reconstructions for the sake of better function and cosmesis are becoming more and more common. Rehabilitation of burn patients to effectively reintegrate them in the society as productive members has been a Herculean task, which is still ongoing. Vocational training has rendered these patients the skills and developmental improvements that are truly outstanding, leading to their return as useful and productive members of their family. The devastating effects of burns are long lasting at both an individual and societal level. These impacts are compounded in resource-poor settings, where the human and material resources necessary to deal with this complex public health problem are thinly distributed over a large population base. A structured and comprehensive approach to burn care must be applied to these resource-poor settings in order to improve outcomes. A combination of improved management and prevention strategies has resulted in important declines in morbidity and mortality in the developed world. Unfortunately, without adequate resources in first-aid, acute surgical management and rehabilitation facilities, patients that do survive their burn injuries in developing countries often have poor, disfiguring and disabling long-term outcomes. Burn care truly deserves a helping hand from both governmental and non-governmental sources and philanthropists should come up with a modestly funded burn care strategy for the developing world.

Two-Phase Flow in Volatile Oil Reservoir Using Two-Phase Pseudo-Pressure Well Test Method

Abstract When the bottomhole pressure (BHP) of volatile oil reservoirs falls below the bubblepoint pressure, two phases are created in the region around the wellbore, and a single phase (oil) appears in regions away from the well. The oil relative permeability reduces towards the near-wellbore region due to increasing gas saturation. This behaviour is quite similar to a gas-condensate reservoir below the dew-point, where the gas relative permeability is reduced due to the existence of a liquid bank around the wellbore. There are numerous publications in the literature concerning the behaviour diagnostic and well deliverability calculation in the case of gas-condensate reservoirs. However, the behaviour of volatile oil reservoirs is not well understood. This paper aims at understanding the behaviour of volatile oil reservoirs. We used reservoir compositional simulations to predict the fluid behaviour below the bubblepoint, and then exported the flowing bottomhole pressure to a well test package to diagnose the existence of different mobility regions. In this study, the applicability of the two-phase pseudo-pressure method on volatile and highly volatile oil reservoirs was investigated, and it was found that this method is a very powerful tool for the prediction of true permeability and mechanical skin. Also, this method is capable of distinguishing between mechanical skin and condensate bank skin, which can be very helpful for designing after-drilling well treatment and IOR process designs. Introduction In gas-condensate reservoirs, retrograde condensation occurs when the flowing bottomhole pressure declines below the dew-point pressure, creating four regions in the reservoir with different liquid saturations. Away from the well, an outer region has the initial liquid and gas saturation. Next, nearer the well, there is a rapid increase in liquid saturation and a decrease in the gas mobility where the liquid still is immobile. Closer to the well, an inner region is formed where liquid saturation is higher than the critical condensate saturation and both oil and gas phases are mobile. Finally, in the immediate vicinity of the well, there is a region with a lower liquid saturation due to capillary number (the ratio of viscous to capillary forces) effects. Such a region has been inferred from a number of experimental core studies at low interfacial tension and high flow rates. The existence of the fourth region is important because it counters the reduction in productivity caused by liquid drop-out. The various mobility zones described above can be identified by well test analysis, using a variety of analytical and numerical models(1–3). Well test analysis is now commonly used to identify and quantify near-wellbore effects, reservoir behaviour (i.e. zones of different mobilities and storativities) and reservoir boundaries. Finding all of this information from well tests in gas-condensate reservoirs, however, is challenging. This is due to changes in the composition of the original reservoir fluid and the impact of wellbore dynamics. Nonetheless, gas-condensate flow behaviour is now reasonably well understood.

Delayed Skin Grafting Utilizing Autologous Banked Tissue

In performing bowel flaps for voice reconstruction, it is common practice to delay skin grafting to allow for swelling and monitoring. Harvesting the skin graft at the time of reconstruction and banking it at its donor site allows for later transfer at bedside. Ten patients between January and July of 2006 had skin harvested from their thigh at the time of intestinal transfer and banked at the donor site. Transfer of the graft from donor to recipient site was carried out at bedside between the third and eighth postoperative day with sedation and analgesia. Elevation of the graft was well tolerated and take was over 95% in all cases without related complications. At follow-up between 5 and 12 months all grafts had healed. This is a reliable technique for skin storage in diverse clinical applications or when traditional skin banking cannot be performed because of tissue banking regulations.

Processing efficacy in relation to microbial contamination of skin allografts from 723 donors

The Siena Skin Bank, established in 2000, processes skin from more than 130 cadaveric donors per year (about 400,000 cm 2) and distributes it for transplants to treat burns and other types of skin loss. More than 1,500,000 cm 2 of homologous skin has been transplanted to date. At the Siena Skin Bank we conducted a retrospective study of our data to assess microbial contamination of skin specimens from 723 donors banked in the period 2000–2007. Our aim was to determine factors deleterious for skin quality, to optimize skin banking procedures and to reduce corrective actions. The factors analyzed were: type of donor (multi-organ, multi-tissue, live or cadaver), cause of death, time elapsing between death and procurement, different procurement centres and operator experience. Of the 723 donors considered, 26.55% (192/723) were positive for microbes, 22.68% (164) for bacteria and 5.39% (39) for mycetes. Of these 192 positives, 82 (42.70%) required corrective actions. The data obtained showed that the only variables significantly affecting microbial contamination of tissue were type of donor (live or cadaver) and type of processing (cryo- or glycerol preservation).