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PubMed2001

[An experimental study on the recombinant composite skin graft consisting of human epithelium and acellular xeno-dermis].

OBJECTIVE: To observe the effects of the recombinant composite skin graft consisting of human epithelium and acellular xeno-dermis on full thickness skin loss wounds, so as to find a new wound covering material. METHODS: Forty-two nude mice with full thickness skin loss on the back were grafted with the composite skin (compound skin grafting group, G) and human keratinocyte sheet (control group, C), respectively. The wound healing conditions, such as wound healing rate and wound contraction rate, were observed at different time points after the operation. Simultaneously, wound tissue samples were harvested for histological examination. RESULTS: The wound healing rate in G group was much higher than that in C group. In contrast, the wound contraction rate in G group was obviously lower than that in C group (P < 0.05). It was indicated by histological examination that there was full differentiation of epithelium, orderly collagen proliferation and obvious reconstruction of the epithelial-dermal conjunction structure in G group. There was no obvious sign of acute immune rejection. CONCLUSION: The wound covering with recombinant composite skin graft of human epithelium and acellular xeno-dermis could improve wound healing quality. The composite skin could be a new skin substitute.

Animals↗

PubMed2002

[Experimental study on transplantation of acellular xeno-dermis and suspended keratinocytes].

OBJECTIVE: To investigate the outcome and histological changes of transplantation of acellular xeno-dermis combined with suspended keratinocytes. METHODS: Forty-two nude mice with full-thickness skin defect on the back were randomly divided into 2 groups, then acellular xeno-dermisand and suspended keratinocytes were adopted to cover the skin defect in the experimental group, pure suspended keratinocytes in the control group. The area of wound healing was calculated 2, 3 and 5 weeks after transplantation, and the rates of wound contraction were also calculated, and biopsy for histological examination was performed 3, 6 and 12 weeks after transplantation. RESULTS: Compared with the experimental group, the control group showed delayed wound healing (P < 0.05), intensive wound contraction (P < 0.05), poor durability, elasticity, and cosmetic appearances as well as disordered collagen fibers. In contrast, it was observed that the proliferation of collagen fibers was regularly organized, with no obvious acute immuno-rejection responses in the experimental group. CONCLUSION: The composite transplantation of acellular xenodermis and suspended keratinocytes could promote the wound healing with a satisfactory outcome.

Animals↗

PubMedDate not supplied

Biomechanical properties of materials used in static facial suspension.

OBJECTIVE: To compare the biomechanical properties of the superficial (human acellular dermis); (AlloDerm; LefeCell Corp, Branchburg, NJ) and deep layers of cadaveric dermis and expanded polytetrafluoroethylene (ePTFE); (Gore-Tex; W. L. Gore & Associates, Flagstaff, Ariz). METHODS: Sixteen samples of superficial dermis (AlloDerm), 12 samples of deep dermis, and 12 samples of ePTFE were axial loaded on a materials testing machine. Maximum load to failure and stiffness were calculated and statistical analysis was performed to compare the materials. RESULTS: Dermis samples had statistically greater mean stiffness compared with ePTFE samples. There was no statistical difference of maximum load to failure comparing ePTFE with superficial dermis. There was a statistical difference in maximum load to failure between ePTFE and deep dermis. There was no statistical difference between the superficial and deep layers of the dermis with respect to stiffness or maximum load to failure. CONCLUSIONS: Cadaveric dermis has some biomechanical properties to be a superior material for static facial suspension. There was larger than expected variability in both parameters (stiffness and maximum load to failure) tested in dermis samples, which may correlate with occasional clinical failure.

Biocompatible Materials↗

PubMed2003

[Skin tissue engineering].

Cultivated epithelial autografts as multilayered, thin sheets represent a common standard in clinically applied tissue engineering substitutes, outnumbering all experimental alternatives. However, the unsatisfying short- and long-term results concerning mechanical stability and scarring require alternatives. The cultivation and transplantation of cultured autologous keratinocytes as a single cell suspension in a fibrin matrix, combined with allogenic skin grafting, has been investigated extensively in athymic nude mice. Wounds can be reliably reepithelialized after a cultivation period of only 14 days. Moreover, the successful combination of keratinocyte fibrin suspension and acellular dermis in an attempt to regenerate full thickness skin defects in a pig model has been demonstrated. The usefulness of subconfluently cultured keratinocytes-which can be harvested very early and are easy to handle-is enhanced by cotransplantation with decellularized dermis.

Animals↗

PubMed2006

A large preclinical animal model to assess ex vivo skin gene therapy applications.

Because of its easy accessibility, the skin is a very attractive target for gene therapy purposes. To study potential clinical applications in a preclinical setting, appropriate animal models are needed. Pig skin is very similar to human skin, and a variety of human diseases that are potentially amenable to gene therapy applications also occur in pigs. Only a few studies have analyzed the engraftment of transduced keratinocytes (KC) in pigs, however, with limited success. We describe a porcine model in which pig KC were transduced ex vivo with a retroviral vector encoding a marker gene and subsequently grafted onto the autologous host, utilizing a relatively simple grafting technique. Enhanced transduction efficiency was achieved by an optimized transduction protocol including centrifugation of the retroviral vector at a temperature of 32 degrees C. Transduced KC were then seeded onto acellular dermis, forming a stratified epidermis. Grafting was performed by creating full thickness wounds and placing the skin graft onto the muscle fascia, covered by a protective skin flap for several days. Successful engraftment of transduced KC was demonstrated by immunohistochemistry of biopsies taken at different time points, showing transgene expression in 40-50% of grafted KC. After 4 weeks, KC expressing a foreign marker gene was lost, suggesting a transgene-specific immune response in the immunocompetent pigs and highlighting the potential problems for clinical gene therapy studies when transferring new genetic material into a patient. The model presented here may be used to examine applications of skin gene therapy, where retroviral vectors encoding endogenous pig genes will be expressed in the skin.

Animals↗

PubMed2006

Ventral herniorrhaphy: experience with two different biosynthetic mesh materials, Surgisis and Alloderm.

OBJECTIVE: The aim of this study was to compare the efficacy and the complications associated with the use of two new bioactive meshes, Surgisis Gold 8-ply mesh, a product obtained by the processing of porcine small intestine sub-mucosa (Cook Surgical, Bloomington, IN, USA), and Alloderm, processed cadaveric human acellular dermis (Life Cell Corporation, Branchburg, NJ, USA), for ventral herniorrhaphy. BACKGROUND: Ventral hernia repair in potentially contaminated or potentially infected fields limit the use of synthetic mesh products. In this scenario, biosynthetic mesh products that are absorbed and/or replaced with the body's own tissue reduce the incidence of post-operative chronic wound complications (Franklin et al. in Hernia 8(3):186-189, 2004; Franklin et al. in Hernia 6(4):171-174, 2002; Hirsch in J Am Coll Surg 198(2):324-328, 2004; Holton et al. in J Long Term Eff Med Implants 15(5):547-558, 2005; Buinewicz and Rosen in Ann Plast Surg 52(2):188-194, 2004). Rapid revascularization, repopulation, and remodeling of the matrix occur on contact with the patient's own tissue. Only limited, and mostly preliminary data, is available on the use of these types of mesh and concerning the potential complications associated with the use of these types of meshes. We publish our experience with the use of these mesh products, along with their associated complications. Furthermore, we have also provided suggestions for improvements in the mesh designs. METHODS: Between June 2002 and March 2005, 74 patients underwent ventral hernia repair using biosynthetic or natural tissue mesh. The first 41 procedures were performed using Surgisis Gold 8-ply mesh formed from porcine small intestine sub-mucosa, and the remaining 33 patients had ventral hernia repair with Alloderm. The patients had their first follow-up 7-10 days after discharge from the hospital. They were again seen at 6 weeks, or, if needed, earlier, and, thereafter, as needed. Patients who reported any complications to the office were followed up immediately within 1-2 days. Any signs of wound infection, diastasis, hernia recurrence, changes in bowel habits, and seroma formation were evaluated. RESULTS: Non-perforated Surgisis mesh resulted in significant seroma formation in 10/11 patients. The seroma complication was reduced, but not eliminated, with the use of the perforated Surgisis mesh (3/30 patients). Explanted material revealed separated layers of un-incorporated middle layers of the 8-ply Surgisis mesh. Three of the patients had the mesh placed in a contaminated field with no resultant sequela, and there were no hernia recurrences. Patients also had a significant degree of discomfort and pain during the immediate post-operative period. The use of the Alloderm mesh resulted in eight hernia recurrences. Fifteen of the Alloderm patients (15/33) developed a diastasis or bulging at the repair site. Seroma formation was only a problem in two patients. CONCLUSIONS: Seroma formation was a major problem with the non-perforated Surgisis mesh repair, as was the post-operative pain. On the other hand, post-operative diastasis and hernia recurrence were a major problem with the Alloderm mesh. Further design improvements are required in both forms of these new mesh products. Surgeons should be aware of these potential complications prior to the selection of either of these products and the patient should be informed and educated accordingly.

Biocompatible Materials↗

PubMed2005

Irradiation as a safety procedure in tissue banking.

The Central Tissue Bank in Warsaw was established in 1963 and since then ionising radiation has been routinely applied to sterilise tissue grafts. Connective tissue grafts such as bone, cartilage, tendons, sclera, pericardium, skin, acellular dermis and amnion irradiated with a dose of 35 kGy in a (60)Co source and/or with an electron beam 10 MeV accelerator are prepared in our Tissue Bank and two other multi-tissue banks operating in Poland. Over 250,000 radiation-sterilised tissue grafts have been prepared and used in hospitals throughout Poland and no infectious disease transmission or other adverse post-transplantation reactions have been reported up to today. It should be kept in mind however, that high doses of ionising radiation can evoke numerous chemical and physical changes that may affect the biological quality of tissue allografts. Therefore, interdisciplinary research has been undertaken at the Central Tissue Bank in Warsaw to establish the origin and stability of free radicals and other paramagnetic entities induced by irradiation in bone. The effects of various preservation procedures (e.g. lyophilisation, deep-freezing) and irradiation conditions (doses, temperature of irradiation) on the osteoinductive potential and mechanical properties of bone and on the degradation of collagen, a major constituent of all connective tissue grafts, have been also studied. The results of these studies indicate that radiation-induced changes can be diminished by modification of tissue preservation methods and that, to some extent, it is possible to reduce undesired radiation-induced damage to the tissue grafts.

Collagen↗

PubMed2004

Ex vivo produced human conjunctiva and oral mucosa equivalents grown in a serum-free culture system.

PURPOSE: We sought to develop full-thickness ex vivo produced human conjunctiva and oral mucosa equivalents using a serum-free culture system without a feeder layer and to compare conjunctiva and oral mucosa equivalents to assess their suitability as graft materials for eyelid reconstruction. MATERIALS AND METHODS: Human conjunctival and oral mucosal keratinocytes were cultured, expanded, and seeded onto AlloDerm (LifeCell Corp, Branchburg, NJ), a cadaveric, acellular dermis, to produce ex vivo produced full-thickness mucosa equivalents. Histology of equivalents and their expression of immunoreactive Ki-67, a proliferation marker, and GLUT1, a membrane antigen seen in barrier tissues, were examined at 4, 11, and 18 days after seeding onto AlloDerm. RESULTS: Progressive epithelial stratification was observed on day 4, 11, and 18 conjunctiva and oral mucosa equivalents. Ki-67 immunoreactivity progressively increased with cultured time in both types of equivalent, indicating the continued presence of actively proliferating cells. GLUT1 immunoreactivity, concentrated in the basal keratinocytes of stratified epithelia of both types of equivalents, mimicked native tissue and indicated a high glycolytic state of the basal cells. CONCLUSIONS: Conjunctival and oral mucosal equivalents are similar to native tissue and demonstrate high proliferative and glycolytic states. Due to the similarity to conjunctiva, oral mucosal equivalents may be useful for eyelid reconstruction. Their advantages for surgical reconstruction include 1) ease of obtaining autogenous oral epithelium for expansion in vitro without the possibility of contaminating cellular- or serum-borne biologic agents, 2) growth of intact, confluent epithelia on rigid, transplantable human allogeneic dermis that may be surgically transplanted, and 3) reduced donor site morbidity and surgical time.

Biocompatible Materials↗

PubMed2000

Oestrogenic steroids and melanoma cell interaction with adjacent skin cells influence invasion of melanoma cells in vitro.

The invasion of melanoma is complex and multi-staged and involves changes in both cell/extracellular matrix (ECM) and cell/cell interactions. Female steroids and alpha-MSH have also been reported to influence metastatic melanoma progression, but their mechanisms of action are unknown. Accordingly, our aim was to establish in vitro models to examine (a) the influence of sex steroids and alpha-melanocyte-stimulating hormone (alpha-MSH) on tumour invasion and the influence of (b) ECM proteins and (c) adjacent cells on melanoma invasion. In the first model, melanoma cell invasion through fibronectin over 20 hr under serum-free conditions was used to investigate the effects of 17beta-oestradiol and oestrone on the invasion of human melanoma cell lines, A375-SM and HBL. A375-SM, but not HBL cells, proved very susceptible to inhibition by female steroids. However, invasion of the HBL line was inhibited by alpha-MSH. Using the second model of reconstructed human skin based on de-epidermised acellular dermis, we found that the HBL cells on their own failed to invade into the dermis (irrespective of the presence or absence of the basement membrane). However, there was a significant synergistic interaction between keratinocytes, fibroblasts and HBL cells, such that a modest invasion of HBLs into the dermis was seen within 2 weeks when other skin cells were present. In contrast, A375-SM cells showed a significant ability to invade the dermis in the absence of other cells, with less invasion when other skin cells were present. In summary, these models have provided new information on the extent to which melanoma cell invasion is sensitive to oestrogenic steroids and to alpha-MSH and to interaction, not only with adjacent skin cells but also to the presence of basement membrane antigens.

Estradiol↗

PubMed1999

The requirement for basement membrane antigens in the production of human epidermal/dermal composites in vitro.

The importance of a dermal element when providing permanent wound cover for skin loss has become evident as the shortcomings of pure epidermal grafts are recognized. We are developing a skin composite formed from sterilized human de-epidermized acellular dermis, keratinocytes and fibroblasts with the ultimate aim of using this composite to cover full-thickness excised burn wounds. These composites can be prepared with or without basement membrane (BM) antigens initially present on the dermis. This study investigates the importance of retaining BM antigens on the dermis to the production and appearance of these composites in vitro. Skin composites prepared from dermis with BM antigens either present or absent initially were studied throughout 3 weeks. Composites with BM antigens present initially were significantly better than those initially lacking BM antigens in: (i) the degree of epithelial cell attachment to the underlying dermis (hemidesmosomes were seen only in the former); (ii) the morphology of the epithelial layer; (iii) the consistent presence of collagen IV and laminin and the increasing expression of tenascin; and (iv) the amount of soluble collagen IV and fibronectin detected in the conditioned media. We conclude that an initial BM antigen template is vital in this skin composite model for the attachment and differentiation of the epithelial layer and for the subsequent remodelling of the BM in vitro.

Antigens↗

PubMed1998

Characterization of a composite tissue model that supports clonal growth of human melanocytes in vitro and in vivo.

To aid in the investigation of factors that control the proliferation and function of melanocytes, we have characterized a skin equivalent model that supports melanocyte growth and function in vitro and in vivo. Passenger melanocytes survive and proliferate at low numbers when keratinocytes of the epidermis are cultured in serum-containing medium using a fibroblast feeder layer. When the surface of de-epidermalized acellular dermis was seeded with these cultured cells, the keratinocytes formed a stratified epithelium in vitro containing rete ridges, and the melanocytes were preferentially located in the bottom of these rete ridges. Melanocyte cell number was much less than in normal skin, but in some areas the melanocytes were in clusters, consistent with clonal growth of the cells. When transplanted to athymic mice, the grafts formed foci of pigmentation at 3 wk that expanded and repigmented the entire graft by 8 wk. Histologic examination of these foci revealed that they corresponded to clusters of melanocytes that proliferated and migrated to eventually repopulate the entire graft. In grafts of mixed cells from light and dark skin donors, distinct foci of pigmentation were obvious at 3 wk and, instead of progressing to complete repigmentation, these foci remained stable for over 6 wk. Histologic examination confirmed that these grafts of mixed cells were entirely repopulated with melanocytes and that the grafts contained distinct zones of melanocytes that were of exclusively dark or light skin origin. This model should be valuable for studying the clonal growth of melanocytes in the context of the epidermis.

Animals↗

PubMed1999

Selection of keratinocytes transduced with the multidrug resistance gene in an in vitro skin model presents a strategy for enhancing gene expression in vivo.

In gene therapy studies, achieving prolonged, high-level gene expression in a significant percentage of cells has been difficult. One solution to enhance expression would be to select for cells expressing both the desired gene and a linked selectable marker gene in a bicistronic vector. As a potential target tissue, the skin is easily accessible for safe topical application of a selecting agent that could lead to significant gene expression in a high percentage of keratinocytes. To test the feasibility of such an approach, a skin raft culture model was developed. Human keratinocytes were transduced with the multidrug resistance (MDR) gene, which confers resistance to a variety of cytostatic and antimitotic compounds, such as colchicine. While growing on acellular dermis, transduced keratinocytes were treated with various doses of colchicine (10-50 ng/ml). Colchicine treatment increased the percentage of keratinocytes expressing MDR to almost 100% in raft cultures, Significantly, keratinocytes in colchicine-treated, MDR-transduced raft cultures were able to proliferate normally and form a stratified, differentiated epidermis. This model suggests that topical selection for MDR-expressing keratinocytes in vivo should be feasible without hampering the biologic integrity of skin. Thus, topical selection leading to enhanced expression of a desired gene, linked to a resistance gene, holds future promise for skin gene therapy.

Animals↗

PubMed2001

Keratinocyte growth factor induces hyperproliferation and delays differentiation in a skin equivalent model system.

Keratinocyte growth factor (KGF) is a paracrine mediator of epithelial cell growth. To examine the direct effects of KGF on the morphogenesis of the epidermis, we generated skin equivalents in vitro by seeding human keratinocytes on the papillary surface of acellular dermis and raising them up to the air-liquid interface. KGF was either added exogenously or expressed by keratinocytes via a recombinant retrovirus encoding KGF. KGF induced dramatic changes to the 3-dimensional organization of the epidermis including pronounced hyperthickening, crowding, and elongation of the basal cells, flattening of the rete ridges, and a ripple-like pattern in the junction of stratum corneum and granular layers. Quantitative immunostaining for the proliferation antigen, Ki67, revealed that in addition to increasing basal proliferation, KGF extended the proliferative compartment by inducing suprabasal cell proliferation. KGF also induced expression of the integrin alpha 5 beta 1 and delayed expression of keratin 10 and transglutaminase. However, barrier formation of the epidermis was not disrupted. These results demonstrate for the first time that a single growth factor can alter the 3-dimensional organization and proliferative function of an in vitro epidermis. In addition to new strategies for tissue engineering, such a well-defined system will be useful for analyzing growth factor effects on the complex links between cell proliferation, cell movement and differentiation within a stratified tissue.

Cell Differentiation↗

PubMedDate not supplied

Differentiation and barrier formation of a cultured composite skin graft.

The differentiation and barrier formation of cultured composite skin grafts (CSGs) were assessed by histology and measurements of surface electrical capacitance (SEC) in vitro and in vivo. Keratinocytes cultured on the surface of acellular dermis were lifted to the air-liquid interface and analyzed for 30 days in vitro. Initially, SEC measurements of CSGs (n = 11) were high but quickly dropped between days 4 and 6 and remained steady for 30 days, indicating barrier formation by the epidermis. Histology of the CSGs (n = 6) demonstrated stratification of the epidermal cells and partial formation of the stratum corneum by day 3 that was complete by day 7. CSGs (n = 5) were transplanted to athymic mice, where they formed a stratified and differentiated epidermis. SEC measurements of CSGs remained low after transplant, suggesting that exposure to the air-liquid interface improved the maturation of CSGs in vitro prior to transplant.

Animals↗

PubMedDate not supplied

Oculoplastic approach to treating Barber-Say syndrome.

Barber-Say syndrome is a rare dysmorphic disorder with prominent facial involvement. Its primary features include skin, hair, and eyelid abnormalities, the last of which can cause significant ocular symptoms. This report describes a patient with symptomatic corneal exposure secondary to Barber-Say syndrome who benefited from surgical intervention. The patient underwent a bilateral mid-face lift, eyelid repositioning and reconstruction, botulinum toxin application, and acellular dermis grafting. Surgical exploration revealed dysfunctional features of the external and internal eyelid anatomy not previously described with this condition. Improvement was noted in overall facial symmetry and appearance. In addition, the patient noted increased comfort after the resolution of dry eye symptoms and exposure keratopathy.

Abnormalities, Multiple↗

PubMed2006

Revision tympanoplasty using scar tissue graft.

OBJECTIVE: To evaluate the success rate of subcutaneous postsurgical scar tissue as graft material for revision tympanoplasty operations. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Thirty-five patients who underwent revision tympanoplasty with or without mastoidectomy procedures and 36 patients undergoing primary operations who had all the data necessary for the study and a minimum follow-up of 6 months. The mean follow-up period was 12 months (range, 6-18 mo). Mean age, perforation size, cholesteatoma presence, time required for harvesting, and adjunctive mastoidectomies were similar between the two groups. INTERVENTION: The patients undergoing revision tympanoplasty had graft material harvested from the subcutaneous scar tissue. In the control group, temporalis fascia graft was used as graft tissue. MAIN OUTCOME MEASURES: The rate of perforation closure and postoperative hearing change was measured. RESULTS: In the scar tissue tympanoplasty group, 32 of 35 patients (91%) had successful closure of the tympanic membrane perforation, whereas in the control group, the success rate was 92% (p > 0.05). Mean postoperative pure-tone average improvement was 21 dB in the scar tissue tympanoplasty group and 18 dB in the control group (p > 0.05). CONCLUSION: Subcutaneous scar tissue is as successful in perforation closure and hearing improvement as temporalis fascia graft. The use of subcutaneous scar tissue graft is advantageous to other graft materials used in revision tympanoplasty operations in that it can be harvested through the same incision, does not add to the operative time, and does not carry the cost or risk of acellular dermis.

Adolescent↗

PubMed2004

Eyelid reconstruction: the state of the art.

PURPOSE OF REVIEW: The goals of eyelid reconstruction are corneal protection, restoration of the integrity of the lid lamellae, and improvement of facial symmetry. Inadequate reconstruction may lead to corneal exposure and sight-threatening keratopathy; in the younger patient, visual deprivation and amblyopia may also follow. The purpose of this review is to describe new materials and approaches used in reconstructing the damaged eyelid. RECENT FINDINGS: Although the surgical principles of lid reconstruction remain unchallenged, new materials and techniques have emerged. These include the use of both autogenous and cadaveric acellular dermis in the management of lower eyelid retraction, and amniotic membrane transplantation in the management of tarsal conjunctival disease. Recent work on upper facial nerve branch reinnervation in the animal model may also offer hope for eyelid reanimation after facial palsy. SUMMARY: The lid surgeon requires a sound knowledge of the principles involved in reconstructing the respective lamellae of the lid. Anterior lamellar reconstruction carries a significant risk of ectropion, and large defects may require several interposition flaps for optimum skin texture and color reconstruction. New materials (autogenous and cadaveric) for posterior lid reconstruction may reduce donor site morbidity and surgical time, but they may contract significantly after surgery. Recent experience with amniotic membrane transplantation may improve the prognosis for patients with entropion and symblepharon caused by conjunctival cicatricial changes.

Amnion↗

PubMed2006

Repair of oronasal fistulae with acellular dermal matrices.

BACKGROUND: The authors examined the efficacy of a novel technique for oronasal fistula repair using acellular dermal matrix grafts. In part I, an animal model was used to demonstrate proof-of-concept; in part II, the method was applied to oronasal fistula repair in the clinical setting. METHODS: In part I, oronasal fistulas were created in Yorkshire piglets (n = 6) and allowed to mature for 2 weeks. In three animals, acellular dermal grafts were interposed between the oral and nasal mucosa traversing the palatal fistulas. Mucosal edges were not closed. Three weeks postoperatively, the palates were examined histologically. The fistulas of control piglets (n = 3) remained unrepaired and were examined 5 weeks after their creation. In part II, acellular dermal grafts were interposed between the oral and nasal mucosa in nine consecutive patients undergoing oronasal fistula repair. Complete closure of the oral and nasal mucosa was achieved in two patients. In the remainder, nasal closure was affected by interposition of the dermal matrices beneath a complete oral mucosal closure. RESULTS: All animals that underwent fistula repair demonstrated successful healing with revascularization, complete reepithelialization, and cellular infiltration into the grafts. All control fistulas remained patent. Successful fistula closure was observed in all patients. In two patients, early oral mucosal dehiscence and exposure of the dermal graft was followed by complete healing. CONCLUSIONS: This study demonstrates successful closure of palatal fistulas in an animal model and in cleft palate patients using interposition grafts of acellular dermis. This novel method offers promise as a simple and effective technique for tension-free closure of oronasal fistulas.

Adult↗