RESUMEN
PURPOSE: The clinical application of autologous tissue-engineered skin analogs is an important strategy to cover large skin defects. Investigating biological dynamics, such as reinnervation after transplantation, is essential to improve the quality of such skin analogs. Previously, we have examined that our skin substitutes are reinnervated by host peripheral nerve fibers as early as 8 weeks after transplantation. Here, we wanted to investigate the presence and possible differences regarding myelinated and unmyelinated host nerve fibers 15 weeks after the transplantation of light and dark human tissue-engineered skin analogs. METHODS: Human epidermal keratinocytes, melanocytes, and dermal fibroblasts were isolated from human light and dark skin biopsies. Keratinocytes and melanocytes were seeded on fibroblast-containing collagen type I hydrogels after expansion in culture. After additional culturing, the tissue-engineered dermo-epidermal skin analogs were transplanted onto full-thickness skin wounds created on the back of immuno-incompetent rats. Skin substitutes were excised and analyzed 15 weeks after transplantation. Histological sections were examined with regard to the ingrowth pattern of myelinated and unmyelinated nerve fibers into the skin analogs using markers, such as Substance P, NF200, and S100-Beta. RESULTS: We found myelinated and unmyelinated peripheral host nerve fibers 15 weeks after transplantation in the dermal part of our human skin substitutes. In particular, we identified large-diameter-myelinated Aß- and Aδ-fibers, and small-diameter C-fibers. Furthermore, we observed myelinated nerves in close proximity to CD31-positive blood capillaries. In the long run, both types of ingrown host fibers showed an identical pattern in both light and dark skin analogs. CONCLUSION: Our data suggest that myelinated and unmyelinated peripheral nerves reinnervate human skin substitutes in a long-term in vivo transplantation assay. Our tissue-engineered skin analogs attract A- and C-fibers to supply both light and dark skin analogs. Potentially, this process restores skin sensitivity and has, therefore, a significant relevance with regard to future application of autologous pigmented dermo-epidermal skin substitutes onto patients.
Asunto(s)
Dermis/inervación , Epidermis/inervación , Fibras Nerviosas Mielínicas/trasplante , Fibras Nerviosas Amielínicas/trasplante , Piel Artificial , Ingeniería de Tejidos/métodos , Adolescente , Animales , Células Cultivadas , Niño , Preescolar , Dermis/trasplante , Epidermis/trasplante , Femenino , Humanos , Lactante , Masculino , Ratas , Trasplante de Piel/métodosRESUMEN
BACKGROUND: Self-filling, hydrogel-based osmotic tissue expanders have been successfully used for several years, mainly in adult patients. We wanted to test this novel device in pediatric plastic and reconstructive surgery. MATERIAL AND METHODS: Between November 2004 and September 2009, we implanted 53 osmotic tissue expanders following standard surgical principles in a total of 30 children and adolescents with burn scars, congenital nevi, alopecia, or foot deformities. RESULTS: All expanders reached their predicted volume within 6 weeks and 51 (96.2%) produced a sufficient amount of additional skin for the intended coverage of the defect. A serious infection precluding the planned reconstructive procedure occurred with 2 expanders (3.8%). Minor complications occurred at 6 implantation sites (11.4%), and consisted of small necrotic areas and perforations (n = 3) and minor infections (n = 3). These problems could be controlled and did not interfere with the subsequent plasty. The final results recorded at the last follow-up (mean: 21 months, range: 9-48 months) were rated as excellent in 25, good in 19, moderate in 6, and poor in 1 patient. CONCLUSION: This is apparently the largest pediatric series in which self-filling expanders have been used. The data obtained indicates that self-filling expanders can be safely and effectively used for various plastic, reconstructive and orthopedic procedures in children and adolescents. The fact that numerous painful and distressing filling sessions are obviated with these expanders is particularly beneficial for those children too young to understand and cooperate. Moreover, this approach minimizes the risk of infection and lowers costs.
Asunto(s)
Pie Equinovaro/cirugía , Procedimientos de Cirugía Plástica , Enfermedades de la Piel/cirugía , Dispositivos de Expansión Tisular , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Estudios Retrospectivos , Expansión de Tejido/instrumentaciónRESUMEN
BACKGROUND: Extended avulsion injuries are associated with significant loss of skin and subcutaneous fat, leaving the reconstructive surgeon with the challenge of substituting all tissues lost in the best possible way. We wanted to test whether the combined use of a Vacuum Assisted Closure system (VAC) and Integra Dermal Regeneration Template (IDRT) matched the required treatment profile encompassing initial control of infection, remodeling of body contours, and reconstruction of near normal skin. MATERIALS AND METHODS: 4 children with massive lower extremity avulsion injuries were treated with early necrosectomy, VAC application for 3-5 weeks for wound cleansing and wound bed conditioning, subsequent implantation of IDRT, and finally autologous split thickness skin grafting (STSG) for definitive wound closure. Thereafter, a standard rehabilitation program was used. The key parameters of VAC and IDRT application, take rates of IDRT and STSG, complications, length of stay, and final outcome were recorded. RESULTS: In all patients, early removal of necrosis and infection control was successfully achieved. Continuous VAC application fostered the formation of a several millimeters thick new tissue layer partly compensating for the lost hypodermis. IDRT implantation and subsequent STSG yielded take rates of nearly 100% and both functionally and cosmetically excellent long-term results. There were no major complications. CONCLUSION: The combination of VAC and IDRT in children with massive leg avulsion injuries is feasible, safe, and delivers high-quality long-term outcomes that appear to justify the multiple operative procedures, the long hospitalization times, and the comparatively high costs entailed.
Asunto(s)
Traumatismos de la Pierna/cirugía , Terapia de Presión Negativa para Heridas/métodos , Satisfacción del Paciente , Procedimientos de Cirugía Plástica/métodos , Trasplante de Piel/métodos , Traumatismos de los Tejidos Blandos/cirugía , Adolescente , Niño , Desbridamiento/métodos , Femenino , Estudios de Seguimiento , Humanos , Traumatismos de la Pierna/psicología , Masculino , Estudios Retrospectivos , Piel Artificial , Traumatismos de los Tejidos Blandos/psicología , Índices de Gravedad del Trauma , Resultado del TratamientoRESUMEN
The risk of endobronchial intubation during laparoscopy because of displacement of the tip of the tracheal tube is a well known problem in adults. Laparoscopy in children is increasingly performed, but there are no data available regarding the above problem. We prospectively studied 46 children aged 2 months to 15.7 years (median 4.2 years) undergoing laparoscopy. After tracheal intubation with the Microcuff Pediatric Endotracheal Tube, with the 'intubation depth marking' of the tube at the vocal cords, the distance from the tracheal tube tip to the carina was endoscopically measured with the patient in the neutral position and with 20 degrees head-down tilt, both with and without capnoperitoneum. Maximal displacement of the tip of the tracheal tube tip in cm was 0.5+(0.05xage (years)) for 20 degrees head-down tilt, 0.6+(0.09xage (years)) for capnoperitoneum alone, and 1.2+(0.11xage (years)) for 20 degrees head-down tilt with capnoperitoneum. In no patients did endobronchial intubation occur with the tracheal tube placed according to the intubation depth marking.