Twenty cases with skin defect of forearm and hand were treated by free skin graft with subcutaneous fat from 0.5 to 0.7 cm in thickness. The maximal area of free skin graft is 27×10cm, and the smallest one is 1.5×2cm. All of skin flaps survived except one having partial necrosis. Follow up shown round external figure, clasticity, and no change of skin color. It preserved the function of sweat gland and the cutaneous sensation began to recover 4 months postoperation.
OBJECTIVE: To fabricate artificial human skin with the tissue engineering methods. METHODS: The artificial epidermis and dermis were fabricated based on the successful achievements of culturing human keratinocytes(Kc) and fibroblasts (Fb) as well as fabrication of collagen lattice. It included: 1. Culture of epidermal keratinocytes and dermal fibroblasts: Kc isolated from adult foreskin by digestion of trypsin-dispase. Followed by comparison from aspects of proliferation, differentiation of the Kc, overgrowth of Fb and cost-benefits. 2. Fabrication of extracellular matrix sponge: collagen was extracted from skin by limited pepsin digestion, purified with primary and step salt fraction, and identified by SDS-PAGE. The matrix lattice was fabricated by freeze-dryer and cross-linked with glutaraldehyde, in which the collagen appeared white, fibrous, connected and formed pores with average dimension of 180 to 260 microns. 3. Fabrication artificial human skin: The artificial skin was fabricated by plating subcultured Kc and Fb separately into the lattice with certain cell density, cultured for one week or so under culture medium, then changed to air-liquid interface, and cultured for intervals. RESULTS: The artificial skin was composed of dermis and epidermis under light microscope. Epidermis of the skin consisted of Kc at various proliferation and differentiation stages, which proliferated and differentiated into basal cell layer, prickle cell layer, granular layer, and cornified layer. Conifilament not only increased in number, but also gathered into bundles. Keratohyalin granules at different development stages increased and became typical. The kinetic process of biochemistry of the skin was coincide with the changes on morphology. CONCLUSION: Tissue engineered skin equivalent has potential prospects in application of repairing skin defect with advantages of safe, effective and practical alternatives.
Objective To investigate the possible mechanism of the fibroblasts inducing the vascularization of dermal substitute. Methods Fibroblasts were seeded on the surface of acellular dermal matrix and cultivated in vitro to construct the living dermal substitute. The release of interleukin 8 (IL 8) and transfonming growth factor β 1(TGF β 1) in culture supernatants were assayed by enzyme linked immunosorbent assay, the mRNA expression of acid fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF) were detected by RT-PCR. Then, the living substtute was sutured to fullth ickness excised wound on BALBouml;C m ice, and the fate of fibroblast w as observed by using in situ hybridizat ion. Results Fibroblasts cultured on acellular dermalmat rix p ro liferated and reached a single2layer confluence. Fibroblasts could secret IL 28 (192. 3±15. 9) pgouml;m l and TGF-B1 (1. 105±0. 051) pgouml;m l. There w as the mRNA exparession of aFGF and bFGF. Fibroblasts still survived and proliferated 3 weeks after graft ing. Conclusion Pept ides secreted by fibroblasts and its survival after graft ing may be relat ive to the vascularizat ion of the dermal subst itute.
OBJECTIVE To repair facial and neck scar using tissue expanding technique. METHODS From January 1991 to January 1995, 16 cases with facial and neck scar were treated. Multiple tissue expanders were put under the normal skin of facial and neck area, after being fully expanded, the scars were excised and the expended skin flaps were transplanted to cover the defects. The size and number of tissue expanders were dependent on the location of the scars. Normally, 5 to 6 ml expanding volume was needed to repair 1 cm2 facial and neck defect. The incisions should be chosen along the cleavage lines or in the inconspicuous area, such as the nasolabial fold or submandibular region. The design of flap was different in the face and in the neck. In the face, direct advanced flap was most common used, whereas in the neck, transposition flap was often used. Appropriate tension was needed to achieve smooth and cosmetic effect. It was compared the advantages and disadvantages of several methods for repair of the defect after facial and neck scar excision. RESULTS Fifteen cases had no secondary deformity after scar excision. Among them, 1 case showed blood circulation disturbance and cured through dressing change. Ten cases were followed up and showed better color and texture in the flap, and satisfactory appearances. CONCLUSION Tissue expanding technique is the best method for the repair of facial and neck scar, whenever there is enough expandable normal skin.
Objective To observe the differences in protein contents of three transforming growth factorbeta(TGF-β) isoforms, β1, β2, β3 andtheir receptor(I) in hypertrophic scar and normal skin and to explore their influence on scar formation. Methods Eight cases of hypertrophic scar and their corresponding normal skin were detected to compare the expression and distribution of TGF-β1, β2, β3 and receptor(I) with immunohistochemistry and common pathological methods. Results Positive signals of TGF-β1, β2, and β3 could all be deteted in normal skin, mainly in the cytoplasm and extracellular matrix of epidermal cells; in addition, those factors could also be found in interfollicular keratinocytes and sweat gland cells; and the positive particles of TGF-β R(I) were mostly located in the membrane of keratinocytes and some fibroblasts. In hypertrophic scar, TGF-β1 and β3 could be detected in epidermal basal cells; TGFβ2 chiefly distributed in epidermal cells and some fibroblast cells; the protein contents of TGF-β1 and β3 were significantly lower than that of normal skin, while the change of TGF-β2 content was undistinguished when compared withnormalskin. In two kinds of tissues, the distribution and the content of TGF-β R(I) hadno obviously difference. ConclusionThe different expression and distribution of TGF-β1, β2 andβ3 between hypertrophic scar and normal skin may beassociated with the mechanism controlling scar formation, in which the role of the TGF-βR (I) and downstream signal factors need to be further studied.
Superficial cervical artery skin flap is widely used in clinical practice. In order to inprove the outcome of the flap in clinic, eleven cases of skin defect of scalp who were treated with the flap was discussed. After operation, the donor area healed but there was no hair growth on recipient area. Among them, six cases occurred partial necrosis of skin flaps. In order to avoid these problen, the relevant solution discussed as follows: 1. Handle well the pedicle of the skin flap to prevent the interference with venous returm. 2. Adhere strictly to indications. 3. Apply skin expander to obtain "extra" skin, then carryout the tranfer of skin flap and 4. Better use the skin flap with residual hair.
Abstract The narrow pedicled intercostal cutaneous perforater (np-ICP) thin flaps were successfully used for reconstruction of hand deformity from scar contraction. This flap was designed with a narrow pedicle (3～5cm in width) which included ICPs of 4th～9th intercostal spaces, and with awide distal part (the maximum is 15cm×15cm) which covered the lower chest and upper abdomen. The thickness of flap was cut until the subdermal vascular networkwas observed. The pedicle was divided between the 7th～14th days after operation. Sixteen flaps in 15 cases were transferred for covering of the skin defects at the dorsum of the hand. The perforators which were included in the narrow pediclewere mostly from the 7th intercostal spaces in 9 flaps. Fifteen of the 16 flapswere survived almost completely, except in one case there was necrosis of the distal portion of the flap. It seemed that this flap was more useful than the conventional methods, not only functionally but also aesthetically. Moreover, the operative techinque was more simple and safer than the island or free intercostalflap due to without the necessity to dissect the main trunk of the intercostalneurovascular bundle. Gentle pressure on the thinning portion of the flap for a short time after operation was important.