Reconstructive surgery with a dermal regeneration template: clinical and histologic study.

Integra artificial skin was introduced in 1981 and its use in acute surgical management of burns is well established, but Integra has also been used in patients undergoing reconstructive surgery. Over a period of 25 months, the authors used Integra to cover 30 anatomic sites in 20 consecutive patients requiring reconstructive surgery and then analyzed the clinical and histologic outcomes. The most common reason for surgery was release of contracture followed by resurfacing of tight or painful scars. The authors assessed patients' satisfaction using a visual analog scale and scar appearance using a modified Vancouver Burn Index Scale. They evaluated the progress of wound healing by examining weekly punch-biopsy specimens with standard and immunohistochemical stains. Patients reported a 72 percent increase in range of movement, a 62 percent improvement in softness, and a 59 percent improvement in appearance compared with their preoperative states. Pruritus and dryness were the main complaints, and neither was improved much. Four distinct phases of dermal regeneration could be demonstrated histologically: imbibition, fibroblast migration, neovascularization, and remodeling and maturation. Full vascularization of the neodermis occurred at 4 weeks. The color of the wound reflected the state of neodermal vascularization. No adnexa, nerve endings, or elastic fibers were seen in any of the specimens. The new collagen was histologically indistinguishable from normal dermal collagen. The authors conclude that Integra is a useful tool in reconstructive surgery. The additional cost of its use can be justified by its distinct benefits compared with current methodology.     

The use of skin grafts in postburn contracture release: a 10-year review

Postburn scarring and contracture affecting function remain the most frustrating late complications of burn injury. Various techniques are used to release contractures; the choice depends on their location and/or the availability of unaffected skin adjacent to the contracture or elsewhere. A retrospective review was carried out of the case notes of patients who had skin grafting for the release of postburn contracture at the Burns Unit, City Hospital, Nottingham between May of 1984 and August of 1994 to evaluate the experience over this period. Information was obtained about the burn injury, contracture site, interval between burn and release of contracture, indication, age at first release, intervals between releases, operative details (donor and graft sites), complications and nonoperative treatment, and follow-up to the end of the study period. A total of 129 patients underwent skin grafting for release of contractures as opposed to any other method of correction. Full-thickness skin grafts were used in 81 patients (63 percent) and split-thickness skin grafts in 26 (20 percent). Twenty-two patients (17 percent) had both types used on different occasions. Flame burns (41 percent) were the most common causes, followed by scalds (38 percent). Two hundred thirty-nine sites of contracture were released, with the axilla (59) and the hand/wrist (59) being the most common sites involved, followed by the head/neck region (42). It was found that for the same site, release with split-thickness skin grafts was associated with more rereleases of the contracture than with full-thickness skin grafts. Also, the interval between the initial release and first rerelease was shorter than with full-thickness skin grafts (p < 0.048). It was also noted that children required more procedures during growth spurts, reflecting the differential effect of the growth of normal skin and contracture tissue. Patients reported more satisfaction with texture and color match with the full-thickness skin grafts. There was comparable donor-site and graft morbidity with both graft types. The use of skin grafts is simple, reliable, and safe. Whenever possible, the authors recommend the use of full-thickness skin grafts in preference to split-thickness skin grafts in postburn contracture release.     

Bilobed flap in the release of postburn mentosternal contracture

We have described in brief detail our experience with bilobed flaps in the release of postburn mentosternal synaechia. We have found this method handy, and it gives very good results. We reckon that this method has a prominent place in the release of this contracture, particularly in children who cannot provide adequate free-skin flaps for revascularization and in centers where the procedure is technically impossible.     

Postburn breast reconstruction: tissue expansion prior to contracture release.

Tissue expansion of the scarred chest following burns results in a poor breast mound shape with little projection or inframammary fold, since the expander, like normal developing breast tissue, is kept flat by the scarred skin envelope. We present a case that demonstrates that adequate projection of the breast and formation of an inframammary fold can be achieved by expansion if extensive release and skin grafting of contractures over the breast mound are performed after expansion. Maintained expansion will act as a stent reducing secondary contracture of the grafted-areas.     

The isolated perfused bovine udder as a model of dermal eicosanoid release

The aim of this study was to examine whether the isolated perfused bovine udder could be used as a suitable in vitro inflammation model. A common in vivo inflammation model is arachidonic acid-induced inflammation in mouse ears. As an in vitro substitute for this model, arachidonic acid was administered topically to the skin of an isolated perfused bovine udder and the subsequent changes in eicosanoid synthesis were examined. As with the mouse-ear model, there was a significant increase in eicosanoid synthesis (prostaglandins E(2) and F(2 alpha) and leukotrienes B(4) and C(4)/D(4)/E(4)) following topical irritation. This effect lasted for 3 hours. In addition, the changes in prostaglandin E(2) synthesis in the skin following irritation with arachidonic acid were measured by the microdialysis technique. In conclusion, the in vitro model described seems suitable for studies of pharmacological effects on eicosanoid synthesis.     

Dkk2/Frzb in the dermal papillae regulates feather regeneration

Avian feathers have robust growth and regeneration capability. To evaluate the contribution of signaling molecules and pathways in these processes, we profiled gene expression in the feather follicle using an absolute quantification approach. We identified hundreds of genes that mark specific components of the feather follicle: the dermal papillae (DP) which controls feather regeneration and axis formation, the pulp mesenchyme (Pp) which is derived from DP cells and nourishes the feather follicle, and the ramogenic zone epithelium (Erz) where a feather starts to branch. The feather DP is enriched in BMP/TGF-β signaling molecules and inhibitors for Wnt signaling including Dkk2/Frzb. Wnt ligands are mainly expressed in the feather epithelium and pulp. We find that while Wnt signaling is required for the maintenance of DP marker gene expression and feather regeneration, excessive Wnt signaling delays regeneration and reduces pulp formation. Manipulating Dkk2/Frzb expression by lentiviral-mediated overexpression, shRNA-knockdown, or by antibody neutralization resulted in dual feather axes formation. Our results suggest that the Wnt signaling in the proximal feather follicle is fine-tuned to accommodate feather regeneration and axis formation.     

A pneumatic tourniquet as an aid to release of capsular contracture around a breast implant

The use of a pneumatic tourniquet to release fibrous capsular contracture around a breast implant is described. This method protects the operator's hands and, we believe, is potentially safer for the patient and for the breast prosthesis.     

Assessment of Spirulina-PCL nanofiber for the regeneration of dermal fibroblast layers

Skin is a barrier which protects injured tissues, and thus, skin regeneration is one of many important medical issues. Tissue engineering is an attractive approach to make artificial tissue or regenerate lost tissues. While constituting artificial tissues, cells must infiltrate through scaffolds, maintaining viability and proliferation. However, a three-dimensional tissue culture involves stressful environments due to several reasons such as mass or gas transport and high cell density. Once stressed, cells produce reactive oxygen species, resulting in alleviating cellular viability and activity. Spirulina is well known to have antioxidant molecules, which have been known to modulate oxidative stress to cells. Electrospun nanofiber has widely been used as a scaffold to mimic natural extracellular matrix. In this research, we assessed Spirulina extract-imbedded nanofiber as a scaffold for an artificial skin tissue. Spirulina extract was proven to positively affect viability and proliferation of mouse fibroblasts. In addition, fibroblasts infiltrated through Spirulina extract-imbedded electrospun nanofiber without cytotoxicity.