Artificial Dermis Composite Tissue Flaps versus Traditional Prefabricated Flaps

Objective We compared the application of artificial dermis composite tissue flaps and traditional prefabricated flaps in a rat model of exposed bone and tendon injury. Methods Sprague Dawley rats were randomly divided into two groups (n = 40 per group). Group A rats received artificial dermis composite tissue flaps and group B rats received traditional prefabricated flaps. Flap appearance, range of motion, degree of swelling, tissue histologic results, and imaging findings were compared between groups at 7, 14, 21, and 28 days. Results There was no difference in flap appearance, range of motion, or degree of swelling between groups. However, blood perfusion of the artificial dermis composite tissue flap was better than that of the traditional prefabricated flap; the artificial dermis was also found to be thicker than the traditional prefabricated flap. Conclusions The artificial dermis composite tissue flap is an ideal method for repairing exposed bone and tendon, and it displays repair effects comparable with those of the traditional prefabricated flap and may be a better alternative.

Innervation of a Prefabricated Flap: A New Experimental Model

Introduction. Flap innervation by neoaxonogenesis is a promising field of investigation. The authors evaluated the possibility of innervating an acellular collagen scaffold as component of a potential prefabricated flap.Materials and Methods. Collagen matrix sheets were implanted around the femoral bundle of a murine model to produce two flaps on proximal and distal nerve stumps based on a flow-through model. After thirty days, nerve regeneration and integration into the collagen matrix were evaluated. The specimens were microscopically analyzed to study Schwann cell colonization and axonal integration with the matrix. Axonal count and density were assessed and statistically evaluated.Results. Qualitative structural and ultrastructural evaluation indicated integration, with axonal fibers merged within the collagen matrix, along with a newly formed vascular network on the proximal flap. Wallerian degeneration occurred inside the distal chamber. Axonal count and density did not show statistically significant differences between the nerve inside the proximal flap and the control side.Conclusions. Innervation of an acellular matrix can be obtained by direct nerve stump implantation. The flow-through system was relatively easy to build and reliable to provide adequate blood supply. The collagen scaffold may be a promising support or further studies of preinnervated microsurgical flaps.

The effects of local nitroglycerin on the surgical delay procedure in prefabricated flaps by vascular implant in rats

PURPOSE: To evaluate the effect of local nitroglycerin on the viable area of a prefabricated flap for vascular implant in rats, and to investigate the surgical delay procedure. METHODS: A femoral pedicle was implanted under the skin of the abdominal wall in forty Wistar rats. The animals were divided into four groups of ten: group 1 - without surgical delay procedure and local nitroglycerin; group 2 - with surgical delay procedure, but without local nitroglycerin; group 3 - without surgical delay procedure, but with local nitroglycerin; and group 4 - with simultaneous surgical delay procedure and local nitroglycerin. The percentages of the viable areas, in relation to the total flap, were calculated using AutoCAD R 14. RESULTS: The mean percentage value of the viable area was 8.9% in the group 1. 49.4% in the group 2; 8.4% in the group 3 and 1.1% in the group 4. There was significant difference between groups 1 and 2 (p=0.005), 1 and 4 (p=0.024), 2 and 3 (p=0.003), 2 and 4 (p=0.001). These results support the hypothesis that the closure of the arterial venous channels is responsible for the phenomenon of surgical delay procedure. CONCLUSION: Local nitroglycerin did not cause an increase in the prefabricated viable flap area by vascular implantation and decreased the viable flap area that underwent delay procedures.