Temporary Wound Coverage Research Articles

Development of a Vascularized Skin Construct Using Adipose-Derived Stem Cells from Debrided Burned Skin

Large body surface area burns pose significant therapeutic challenges. Clinically, the extent and depth of burn injury may mandate the use of allograft for temporary wound coverage while autografts are serially harvested from the same donor areas. The paucity of donor sites in patients with burns involving large surface areas highlights the need for better skin substitutes that can achieve early and complete coverage and retain normal skin durability with minimal donor requirements. We have isolated autologous stem cells from the adipose layer of surgically debrided burned skin (dsASCs), using a point-of-care stem cell isolation device. These cells, in a collagen—polyethylene glycol fibrin-based bilayer hydrogel, differentiate into an epithelial layer, a vascularized dermal layer, and a hypodermal layer. All-trans-retinoic acid and fenofibrate were used to differentiate dsASCs into epithelial-like cells. Immunocytochemical analysis showed a matrix- and time-dependent change in the expression of stromal, vascular, and epithelial cell markers. These results indicate that stem cells isolated from debrided skin can be used as a single autologous cell source to develop a vascularized skin construct without culture expansion or addition of exogenous growth factors. This technique may provide an alternative approach for cutaneous coverage after extensive burn injuries.

Early soft tissue coverage and negative pressure wound therapy optimises patient outcomes in lower limb trauma

BackgroundThe timing of soft tissue reconstruction for severe open lower limb trauma is critical to its successful outcome, particularly in the setting of exposed metalware and pre-existing wound infection. The use of negative pressure wound therapy (NPWT) may allow a delay in soft tissue coverage without adverse effects. This study evaluated the impact of delayed free-flap reconstruction, prolonged metalware exposure, pre-flap wound infection, and the efficacy of NPWT on the success of soft tissue coverage after open lower limb injury. MethodsRetrospective review of all free-flap reconstructions for lower limb trauma undertaken at a tertiary trauma centre between June 2002 and July 2009. Results103 patients underwent 105 free-flap reconstructions. Compared with patients who were reconstructed within 3 days of injury, the cohort with delayed reconstruction beyond 7 days had significantly increased rates of pre-flap wound infection, flap re-operation, deep metal infection and osteomyelitis. Pre-flap wound infection independently predicted adverse surgical outcomes. In the setting of exposed metalware, free-flap transfer beyond one day significantly increased the flap failure rate. These patients required more surgical procedures and a longer hospital stay. The use of NPWT significantly lowered the rate of flap re-operations and venous thrombosis, but did not allow a delay in reconstruction beyond 7 days from injury without a concomitant rise in skeletal and flap complications. ConclusionsFollowing open lower limb trauma, soft tissue coverage within 3 days of injury and immediately following fracture fixation with exposed metalware minimises pre-flap wound infection and optimises surgical outcomes. NPWT provides effective temporary wound coverage, but does not allow a delay in definitive free-flap reconstruction.

Klinische Manifestationen infusionsbedingter Extravasate und ihr therapeutisches Management

Extravasal application of chemo-therapeutic agents may cause necrosis of surrounding tissue. Often tendons, nerves and muscles are destroyed. In some cases a surgical excision with an additional coverage is indicated. In the last ten years we have treated 44 patients with necrosis after extravasation. The defects were mostly localised at the hand or distal forearm, but the cubital fossa and the thorax were affected, too. Excision of the infiltrated tissue was performed and the defect covered with local or free flaps, split skin graft or primary closure. In nearly all cases a stable coverage was achieved. An amputation of the hand was never necessary. Patients with immunosuppression or comorbidity sometimes had wound-healing difficulties that in some cases necessitated further operations. Serious complications were in one case a flap necrosis and another patient died 2 days after the operation because of his nephrotic syndrome. Chemotherapy extravasation is an important oncological complication that may cause permanent functional disability of the anatomic region. A variety of free and local flaps with tolerable donor site morbidity can be used for -coverage. We prefer a two-step procedure with radical resection of the area and conditioning of the wound with vacuum therapy or temporary wound coverage and in the next step the definitive wound closure. Conservative treatment is -often followed by a high rate of complications. Early radical debridement and coverage with an adequate flap offers a cure with good functional results.

Skin substitutes for burn wound healing: current and future approaches

Partial-thickness burn wounds can heal spontaneously, but full-thickness burns require skin grafting for definitive wound closure. Historically, the gold standard for closure of excised full-thickness burns is split-thickness skin autograft. Patients with very large burns have limited donor sites for harvesting of autograft and may benefit from the use of skin substitutes. Engineered skin substitutes that may provide temporary wound coverage until donor sites are ready to be reharvested for autograft, or if they contain autologous cells, may provide permanent wound closure. Relatively few permanent skin substitutes are currently available, but developments in tissue engineering of human skin are expected to soon provide improved models for increased availability and enhanced healing of burn wounds

Soft Tissue Management in Open Fractures of the Lower Leg: The Role of Vacuum Therapy.

The management of severe open fractures of the lower leg continues to challenge the treating surgeon. Major difficulties include high infection rates as well as adequate temporary soft tissue coverage. In the past, these injuries were commonly associated with loss of the extremity. Today, vacuum therapy provides not only safe temporary wound coverage but also conditioning of the soft tissues until definitive wound closure. Amongst other advantages, bacterial clearance and increased formation of granulation tissue are attributed to vacuum therapy, making it an extremely attractive tool in the field of wound healing. However, despite its clinical significance, which is underlined by a constantly increasing range of indications, there is a substantial lack of basic research and well-designed studies documenting the superiority of vacuum therapy compared to alternative wound dressings. Vacuum therapy has been approved as an adjunct in the treatment of severe open fractures of the lower leg, complementing repeated surgical debridement and soft tissue coverage by microvascular flaps, which are still crucial in the treatment of these limb-threatening injuries. Vacuum therapy has in general proven useful in the management of soft tissue injuries and, since it is generally well tolerated and has low complication rates, it is fast becoming the gold standard for temporary wound coverage in the treatment of severe open fractures of the lower leg.

Der Einsatz der Vakuumversiegelung zur Konditionierung von Weichteildefekten

Acute or chronic wounds requiring temporary wound coverage and closure. Soft-tissue defects unsuitable for any type of wound closure. Soft-tissue defects associated with infection. Temporary or definite wound closure according to a general concept for treatment of acute or chronic wounds. Support of wound healing through enhanced cell proliferation and formation of granulation tissue. Improvement of local blood circulation and eradication of infection. Surgical debridement. Temporary wound closure with vacuum-assisted closure therapy. Second look with change of vacuum-assisted closure systems, irrigation and debridement procedures. Definitive wound closure through - vacuum-aided wound reduction and secondary suture or - mesh grafting or - debridement and flap coverage. Embedded in the general concept of treatment algorithm for acute or chronic wounds, vacuum-assisted wound closure is part of the therapy. Vacuum therapy facilitates direct wound closure or improves wound conditioning to assist further surgical procedures.

Staged Reconstruction for Resection Wounds in Sarcoma Patients Treated With Brachytherapy

Adjuvant brachytherapy reduces local recurrences following wide local excision of large, high-grade sarcomas, but its use with immediate flap reconstruction is associated with a high wound complication rate following previous radiotherapy. To avoid flap irradiation and reduce wound-healing morbidity, a treatment strategy using negative-pressure wound therapy (NPWT) for temporary wound coverage during brachytherapy followed by delayed flap reconstruction was used in 3 previously irradiated sarcoma patients. NPWT was continued after brachytherapy catheter removal to stimulate vascularization, granulation, and wound contraction. Flap reconstructions were performed after the adequacy of the resection margins was pathologically confirmed and the wound bed appeared grossly vascularized. Prior to reconstruction, 2 patients required additional excision of positive or close permanent-section surgical margins. There were no major wound-healing complications during 9-18 months' follow-up. Staged closure using this approach may have advantages over immediate flap reconstruction in some sarcoma patients. Potential advantages include avoiding flap irradiation, reducing wound size and magnitude of the reconstructive procedure, and ensuring tumor-free surgical margins before definitive reconstruction.

Weichteildefekte an der Streckseite der Hand durch Paravasate im Rahmen systemischer Chemotherapien - chirurgische Therapieoptionen

Systemic treatment with chemotherapeutic agents is often applied by infusions over peripheral vein cannulae located on the hands and lower arms. Dislocation of the cannulae or vein perforation causes an extravasation of the cytostatic agent. This complication occurs in approximately 0.1 - 6 % of intravenous treatments and is rarely noticed before administration of greater volumes. Depending on the tissue toxicity of the administered substances, the extravasation results in tissue damage of different extents. In a few cases, only conservative therapy is required. The majority of patients, however, needs immediate surgical therapy. The reason for this is the severe tissue damage caused by the chemotherapeutic agent that accumulates in the subcutaneous fat where it destroys the connective and fat tissue, nerves, vessels, tendons and muscles, impairing the functionality of the entire hand and arm. In very severe cases, partial or complete amputation of the extremity is the only treatment. The application of antidotes has been discussed controversially and is not a standard procedure. In the past 11 years, 18 patients with extravasations of chemotherapeutics on the dorsum of the hand were admitted to our department. After radical debridement no primary closure of the resulting defect was advisable in the first operation. In all cases we could later perform a stable wound closure. In our opinion, this two-step procedure with primary radical debridement, temporary wound coverage and later wound closure should be performed regularly.

Actual Strategies in the Treatment of Severe Burns - Considering Modern Skin Substitutes

Early wound closure enables a better prognosis with regard to survival and outcome in severe burn injuries. Even so, the treatment of extended 2nd degree thermal traumas is well discussed. A conservative procedure with daily changes of dressings and application of topical antimicrobial creams is uncomfortable for patients and staff. In addition, there is a higher risk of severe infection. Meanwhile, early debridement and temporary wound coverage is established as state of the art also in 2nd degree burns. Many biological and textile materials are already in use. The newly designed resorbable polylactide-membrane Suprathel® seems to be a good alternative material. We have proved that Suprathel® significantly reduces pain. The handling of Suprathel® is very easy. This retrospective study of our patients with severe thermal injuries shows that primarily the majority of burn victims were treated with Suprathel®. Only few patients required an additional grafting even in cases with extended burn areas. The frequency of grafting procedures could be reduced considerably. But also patients with extended 3rd degree burn areas requiring an early skin grafting had a benefit from the application of Suprathel® on donor sites and all tangential necrotic areas. Encouraged by this success, we established a new two-step concept for the treatment of severe thermal injuries. This strategy seems to be suitable also for burn centres with low financial resources, because expensive tissue engineering therapies are reduced to a minimum by this concept.

What are the Differences? - Treatment of Burns in Children Compared to Treatment in Adults

Burns in children are very common. In this article we would like to focus on those aspects of wound care and surgical treatment in burns which are special in the paediatric population. Especially in small children it is crucial to correctly estimate a burned area and to delay appropriate fluid resuscitation. Pain management in children is very important, we therefore recommend standing pain orders managed by the nursing team. Wound care should be as little stressful as possible and enable an excellent evaluation of the wound. Surgical coverage is needed in less than 40% of all scald paediatric injuries and should be done with unmeshed split thickness skin from the scalp. In major and massive burns in children one should opt for an aggressive excision of all deep burned areas within the first 4 to 5 days and for a temporary wound coverage before replacing it with meshed autologous skin transplantations and/or keratinocyte sheet grafts. Finally, rehabilitation is very important, it starts at the day of trauma and needs a multidisciplinary approach. Parents have to be involved early, need to be well taught and well trained to guarantee excellent long-term results in a growing child.

Komplexes Fußtrauma

The so-called “complex foot injury” is defined as a foot injury with more than 5 points in the additive scale of Zwipp. These injuries are uncommon, but they present difficult treatment challenges. The use of a standardized protocol is necessary to achieve an optimal result in the treatment of crush injuries of the foot. In the case of a complex trauma of the foot, primary amputation in the multiply-injured patient can be indicated. Limb salvage depends on the intraoperative aspect during the second look with the Debridement has to be radical, the selection of amputation level should be at the most distal point compatible with tissue viability and wound healing. If there is a compartment syndrome, an immediate dermatofas-ciotomy is essential. Open fractures are reduced following radical debridement and irrigation, temporarily stabilized with K-wires and tibiometatarsal trans-fixation with an external fixator and temporary wound coverage. Complex foot injuries require early and durable soft tissue coverage to reduce infection rates. The choice of definitive treatment depends on the severity of the soft-tissue lesion. The goal is the anatomic reduction of the joint facets and the restoration of the geometrical shape and alignement of the foot followed by early mobilization. Therefore, minimum invasive surgical techniques have been developed, modifications of the standard approaches and percutaneous screw fixation, the use of interlocking mini-plates which contribute to improve the prognosis of this complex trauma of the foot. In the multiply-injured patient the ultimate goal remains the same as for all significant foot injuries: the restoration of a painless, stable and plantigrade foot to avoid corrective procedures with moderate results.

Moderatorsʼ Summary: Wound Management (Session II)

Moderatorsʼ Summary: Wound Management (Session II)

The ABC’s of Thoracic Trauma Imaging

Temporary coverage of severely burned patients with cadaver allograft skin represents an important component of burn care, but is limited by availability and cost. Porcine skin shares many physical properties with human skin, but is susceptible to hyperacute rejection due to preformed antibodies to α-1,3-galactose (Gal), a carbohydrate on all porcine cells. Our preliminary studies have suggested that skin grafts from α-1,3-galactosyltransferase knock out (GalT-KO) miniature swine might provide temporary wound coverage comparable to allografts, since GalT-KO swine lack this carbohydrate. To further evaluate this possibility, eight non-human primates received primary autologous, allogeneic, GalT-KO, and GalT + xenogeneic skin grafts. Additionally, secondary grafts were placed to assess whether sensitization would affect the rejection time course of identical-type grafts. We demonstrate that both GalT-KO xenografts and allografts provide temporary coverage of partial- and full-thickness wounds for up to 11 days. In contrast, GalT + xenografts displayed hyperacute rejection, with no signs of vascularization and rapid avulsion from wounds. Furthermore, secondary GalT-KO transplants failed to vascularize, demonstrating that primary graft rejection sensitizes the recipient. We conclude that GalT-KO xenografts may provide temporary coverage of wounds for a duration equivalent to allografts, and thus, could serve as a readily available alternative treatment of severe burns.

Die Vakuumtherapie als temporäre Deckung an der „Problemzone Hand”

Vacuum therapy of hand defect problematic due to the interdigital folds and in particular due to the small surface. As a temporary cover in staged procedures, e. g. following excision of tumor-suspicious skin alterations at the hand, and/or at the fingers, the application of vacuum therapy results not only in a sterile, temporary cover of the wound, furthermore it promotes wound conditioning and reduction of the wound area as well as lymph and edema reduction. A 75 year old female patient presented herself with a skin alteration at the right dorsal ring finger and the tentative diagnosis of a Morbus Bowen like lesion was raised. Due to the unclear histological status, a staged procedure with excision of the tumour and temporary defect coverage by means of vacuum therapy until final histological evaluation was indicated. We accomplished the radical excision of the unclear skin tumour at the proximal phalanx under preservation of the synovial sheath of the tendon. Subsequently, the wound was temporarily closed with vacuum therapy. Histological examination revealed the complete removal of a solar keratosis. Finally, after 7 days of vacuum therapy as a sterile dressing, with obvious reduction of wound area and simultaneous decrease of edema, the defect was finally covered with a reversed cross finger flap from the adjacent middle finger. The donor site was covered with a full thickness skin graft harvested from the right forearm. The further course was without complication after flap dissection and complete healing. Vacuum therapy represents a usefull procedure for temporary wound coverage. Especially at hand defects, when nerves, tendons or bones following trauma or staged procedures are exposed, vacuum therapy can be successfully applied utilizing the special surgical "hand glove" technique.

Delayed Reverse Sural Flap for Staged Reconstruction of the Foot and Lower Leg

Soft-tissue defects of the foot and lower leg caused by traumatic injury, tumor ablation, or infection associated with osteomyelitis often require coverage by flaps. One excellent option for reconstruction of these defects is the distally based neurofasciocutaneous sural flap. It allows rapid and reliable coverage of defects from the distal third of the lower leg to the forefoot without significant functional donor-site morbidity. However, the maximal size of the flap is limited by the delicate perfusion of the arterial network associated with the superficial sensory nerve. Delay procedures may increase the reliability of large sural flaps. The authors successfully used delayed sural flaps based on a two-step procedure for the treatment of 11 patients (three women and eight men, age 50.1 +/- 20.0 years) with osteomyelitis (n = 3), melanoma (n = 3), sarcoma (n = 1), squamous cell carcinoma (n = 1), posttraumatic defects (n = 2), and recurrent gouty ulcer (n = 1). The delay period ranged from 7 to 15 days (9.7 +/- 3.1), the length of the flap was from 9 to 19 (14.8 +/- 3.0) cm, and the width of the flap from 7 to 12 (9.2 +/- 1.3) cm. Temporary wound coverage was achieved by vacuum-assisted closure during the delay period. All defects were covered successfully without major complications. The delay procedure positively affects the viability of large sural neurofasciocutaneous flaps. The authors recommend this modification for patients with large defects at the distal third of the lower leg or foot, requiring a two-step surgical approach due to the underlying disease.

The application of new biosynthetic artificial skin for long-term temporary wound coverage

Temporary dressings protect wounds from desiccation and infection. In our previous study, we used meshed acellular porcine dermis (APD) to enhance wound healing and decrease wound contraction; however, the wounds showed meshed scar [Wang HJ, Chen TM, Cheng TY. Use of a porcine dermis template to enhance widely expanded mesh autologous split-thickness skin graft growth: preliminary report. J Trauma 1997;42(2):177–82]. In this study, we produced an artificial skin composed of a cross-linked silicon sheet on the surface of APD which we have called silicone acellular porcine dermis (SAPD). This new artificial skin can protect the wound long enough to promote wound healing either by second intention or covered long enough until cultured epithelium autograft (CEA) or autologous skin graft can be harvested for permanent coverage. We delivered 4 cm × 5 cm full-thickness wound on the back of 350 g Sprague–Dawley rats. Thirty-six rats were divided into two groups. Eighteen rats had SAPD and the other 18 were covered with Biobrane. The wounds were first examined 2 weeks after grafting and followed weekly for an additional 4 weeks to evaluate the wound and study pathological changes by using H.E. and Masson's stains. Wound size was calculated by ruler and analyzed by Student's t-test. At the 2-week inspection, both SAPD and Biobrane showed tight adherence to the wound with no change of wound size. Both the SAPD and Biobrane dermal templates were pink. In the Biobrane-covered group, the wounds contracted soon after the tie-over dressing was removed. Its dermal layer is a layer of thin porcine dermal substance, which was promptly digested by tissue hyaluronidase and provides no real dermal template. In the SAPD-covered group however, the wound size was maintained significantly from third to sixth week after grafting ( p < 0.001). SAPD was designed with thick epidermal silicone and a well-organized porcine dermis so that it incorporates into the recipient wound. Clinically the silicone layer of SAPD dislodged from APD about 6–7 weeks after grafting and was followed by dermal matrix exposure and infection. In pathological examination, much like a human skin graft, new vessels were found in APD about 1 week after grafting with minimal inflammatory cells infiltrated in the graft and wound. Six weeks after grafting, the collagen of APD incorporated into the wound, showing palisade arrangement and no sign of rejection. In the Biobrane group however, the wounds showed severe inflammation, the porcine dermal matrix was digested and disappeared 3 weeks after coverage. In conclusion, SAPD is a thick biosynthetic artificial skin, which protects the rat wound significantly longer than Biobrane and prevents contraction. We expect that using of SAPD for temporary wound coverage will provide enough time to grow autologous-cultured epithelium or to reharvest skin grafts.

OPEN FRACTURES OF THE CALCANEUS

Studies of open calcaneal fractures have been limited and have not analyzed results according to wound location, severity of soft-tissue disruption, fracture type, or treatment method. In this study, results were evaluated on the basis of the hypothesis that early surgical intervention was indicated. Between 1989 and 1997, 503 calcaneal fractures were treated at our institution, and forty-three of these fractures, in forty-two patients, were open (8.5%). According to the Gustilo classification there were nine type-I, eight type-II, twelve type-IIIA, and thirteen type-IIIB open fractures as well as one type-IIIC open fracture. All fractures were treated according to the same protocol, consisting of intravenous administration of antibiotics chosen on the basis of the wound type, irrigation and débridement in the operating room, temporary wound coverage, and initial stabilization of the limb. Definitive final fixation was performed after the wound was clean, and soft-tissue swelling was minimal. The final follow-up examinations were performed at a minimum of two years after treatment. Clinical results were graded with use of the AOFAS (American Orthopaedic Foot and Ankle Society) score. An infection developed at the sites of 37% of the forty-three fractures, with osteomyelitis developing at the sites of 19%. Seven of the nine type-I open fractures were treated with open reduction and internal fixation or with primary fusion, with no major complications and a good-to-excellent short-term result. Three of the eight type-II open fractures were complicated by an infection. Three of the twelve type-IIIA open fractures and ten of the thirteen type-IIIB open fractures were complicated by an infection. Six of the infections associated with a type-IIIB open fracture progressed to osteomyelitis, and three of those cases led to an amputation. Overall, thirteen (50%) of the twenty-six type-III open fractures were complicated by an infection, with osteomyelitis occurring in seven (27%). Thirty-three patients with a total of thirty-four open calcaneal fractures were available for follow-up at a minimum of two years, and an average of fifty-five months. The average AOFAS hindfoot score for the twenty-seven patients who had not undergone amputation was 71 points. Open calcaneal fractures have a high propensity for deep infection despite the use of an aggressive treatment protocol to prevent it. It appears that type-I and type-II open fractures associated with a medial wound can be treated with open reduction and internal fixation. Type-II fractures associated with a wound in another location should be treated with limited or no internal fixation. Type-III open fractures, and especially type-IIIB open fractures, require extensive débridement and prompt soft-tissue coverage as soon as possible. Early internal fixation should be avoided in this subgroup because of the high rates of osteomyelitis and subsequent amputation.

Advances of Wound Coverage - Dermal Template Transplantation

The function and appearance of grafted skin over the recipient wound is depended upon the thickness of the donor skin. In extensive burn injury, the donor skin is not always available in the acute stage and usually patient needs a temporary skin substitute to cover the wound, the better long enough until the surgeon has chances to reharvest the same donor site. To use very thin skin for grafting can ensure successful skin graft take and permit faster donor site healing but leave recipient wound contraction. The harvest thick skin for grafting will produce deep wound over donor site and induce infection, scarring, blistering, and pigmentation. During the wound coverage, if we can support additional dermal template other than the autologous dermis may promote prompt and perfect quality healing for recipient wound. In 1995 Alloderm (Life Cell Inc., the Woodland, Texas) was successfully applied to cover full-thickness burn wound with applied a piece of meshed thin split-thickness skin autograft. Since then, the Alloderm had been utilized as a substitute to cover full-thickness burn wound, release scar, repair the nasal septum and for lip agumentation. Our personal experiences also confirm with same result except the meshed skin mark is always unacceptable by most of the patients. Since 1980, Yannas and Burke began to design a bilayer artificial skin, finally named as ‘Integra’, composed of a temporary silastic epidermis and a porous collagen-chondroitin 6-sulfate fibrillar dermis and applied it to cover extensive burn wound. The neodermis was then covered by a piece of ultra thin split-thickness skin after the silastic epidermis was removed. In 1988, Heimbach had reported a multi-center clinical trial by using Integra to cover extensive burn wound and showed that the Integra could provide a vascularized dermal template to take ultra thin split-thickness autologous skin graft. Their long term follow up study also showed that the grafted wound demonstrated minimal scar contraction with rare complications. In 1998, Pandya had provided that Integra can provide a stable environment to support cultured epidermal keratinocytes growth for 1 year firmly (18). Decontaminated pig skin had been used as a biological dressing for burn wound coverage since 1966. In 1984, the porcine dermis had been utilized as a dura substitute, urinary bladder sling, to repair orbit defects and inguinal hernias with acceptable biocompatibility. In 1995, Livesey investigated the potential use of acellular porcine dermis as an allograft combine with a meshed split-thickness autograft can successfully to cover a full-thickness skin wounds in pig model. In 1995 we used meshed porcine dermis combined with a widely expanded mesh autologous thin split-thickness skin (ASTS) graft for a rat wound. Wounds were studied by clinical inspection for texture and contraction, and by histological and immuno-fluorescent techniques. The results showed that the integrity of this complex skin graft was maintained for 4 months with acceptable wound contraction. The cultured epidermal autograft (CEA) was first described in 1984 for cover extensive bum wounds. Unfortunately the CEA showed poor adhesion to recipient wound due to inadequate formation of rete ridges between neoepidermis and wound bed. Evidences had indicated that the formation of rete ridge from CEA needs a recipient wound with dermal-like matrix, such as collagen-glycosaminoglycan (C-GAG), allodermis, autodermis or, must apply fibrin glue to create tight interface integration. In the recent 20 years, because of shortage of the allogenic skin substitute, we had produced 4 generations of pig skin to help for high quality wound healing, they are: 1. Regular porcine skin, 12-15/1000 inches, epidermis / dermis, for temporary wound coverage. It is usually be removed or sloughed by 7-10 days after tansplantation.2. Acellular porcine dermis, 20/1000 inches, when transplantation, it usually combined with a sheet of autologous thin skin overlay. It is a permanent graft.3. Silicon-Acellular Porcine Dermis (SAPD), need 2-stage procedures a. Thin SAPD - temporary / 4-6 weeksb. Thick SAPD - permanent, need autologous STSG / CEA for wound coverage in the second procedure at day 10-14. The safety of using the porcine products had been discussed in the past. In 1993, there is an occasion to developed lymphocytic meningitis with culture negative y using of a porcine dermis implant to repair an operative dura defect, which was considered a hypersensitivity reaction to the porcine dermal implant. The existence of the porcine endogenous retorovirus (PERV) DNA during transplantation of porcine products had been always be raised, and will be discussed.

PEE6: COST-EFFECTIVENESS OF ARTIFICIAL SKIN SUBSTITUTE VS ALLOGRAFT FOR BURN PATIENTS

INTRODUCTION: Healing after a burn injury requires a temporary wound cover until the skin epithelium heals. Traditional wound covering, human cadaver allograft (HCA), is expensive, and limited by availability. OBJECTIVE: To determine if artificial skin substitute (Transcyte) wound cover is cost-effective for temporary wound coverage in patients with major total body surface (TBSA) burns. METHODS: Incremental cost per quality adjusted life year (QALY) in 2000 US dollars is estimated assuming a base case adult patient who has 40% TBSA burn with no inhalation injury, complications, or facial burn followed for one year after HCA or Transcyte procedure. A societal perspective is used. Utilities were surveyed from burn-unit hospital employees. Other variables are taken from literature. RESULTS: Under the base case, Transcyte saves $3600 over HCA, and adds 0.04 QALYs. Quality of life was significantly greater in the Transcyte group (0.54, 95% CI = 0.48–0.59) vs. HCA group (0.65, 95% CI = 0.57–0.74, p = 0.04) while in the hospital, but not significantly different while recovering at home, after recovery, and at work. The incremental QALY of Transcyte minus HCA must be <−0.07 in order for the ICER to reach a threshold of $50,000. Sensitivity analysis shows that a 33% increase in Transcyte price will reach the threshold ICER of $50,000. In addition, this model is highly sensitive to utility at work; a 22% decrease of at-work utility with Transcyte will result in an ICER greater than $50,000. CONCLUSIONS: The results show that use of Transcyte as a temporary wound covering for 40% TBSA burns is a dominant strategy relative to standard HCA. Use of this artificial skin results in cost savings, due to faster healing and less operation room time. A gain in QALYs is seen with Transcyte, due to less scarring and pain during the healing process.

Early and late treatment of iatrogenic injection damage

Extravasation injuries can result in extensive soft-tissue defects. On the cellular level there are five different pathophysiological mechanisms. Early treatment (surgical removal of the extravasated material within 24 h) and late treatment (debridement and coverage) are different. Thirty-two patients who suffered a significant extravasation were treated surgically by the Department of Plastic Surgery between 1989 and 1997. In 8 patients, referred within the first 24 h, the extravasated material could be removed by saline flushout. None of these patients developed soft-tissue defects or skin necrosis. The other 24 patients were referred late (mean 19 days after the injury). Patients with defects of the dorsum of the hand or cubital fossa area who underwent debridement, temporary wound coverage and skin grafting (n = 11) presented complete healing 52 days after the referral. Defects of the same regions covered by a flap after debridement (n = 6) healed within 14 days. The healing time of defects of the forearm (n = 2) and dorsum of the foot (n = 5) was a mean of 15 days after skin grafting. Cytotoxic and osmotically active substances should be removed by saline flushout within 24 h. In defects of the dorsum of the hand and cubital fossa, early debridement and coverage with an adequate flap should be performed.