To explore the effects of tissue expansion on the anastomoses and the survival of the axial pattern flap with a crossing area supply so as to improve the survival of crossing area axial pattern flap and to provide a new idea for the development of original crossing area axial flap. Methods The experiment included two parts. Experiment A was divided into expansion group and control group. Square flaps were randomly designed on own control bilaterally in each animal with a boundary of midl ine. Experiment B was divided into expansion group and delay group. The flaps were also randomly designed on own control bilaterally. Angiographic analysis and gross survival observation were carried on. Results ExperimentA: Angiography showed that there were abundant anastomoses with big cal iber between deep il iac circumflex artery and superior epigastric artery in expansion group and there were only 3-4 anastomoses in control group. Experiment B: Angiography showed that there were abundant anastomoses with big cal iber in expansion group and there were two arterial systems with relatively less anastomoses and smaller cal iber in delay group. The survival rates in expansion group was significantly higher than that in the control group (90.16% ± 3.61% vs 72.67% ± 5.35%) in experiment A, and in experiment B the survival rate was 92.08% ± 3.30% in the expansion group and 80.79% ± 4.52% in the delay group, showing significant difference (P lt; 0.01). Conclusion Expansi on prefabrication can and improve the survival of the crossing area supply axial pattern flap. The mechanism is the bridging effect.
OBJECTIVE: To evaluate the effect of vascular endothelial growth factor(VEGF) 165 or basic fibroblast growth factor (bFGF), which was slowly-released in fibrin glue patch, on expanded prefabricated flaps in rabbits to facilitate the neoangiogenesis process. METHODS: A total of 53 rabbits were divided randomly into 6 groups. The central auricular vascular bundle of the ear was implanted into the expanded prefabricated flap as the pedicle. Fibrin glue, sandwiched between the expander and the implanted vessels, was adopted for topical delivering and slow-releasing of VEGF(625 ng) or bFGF(2880U). After 14 days, the island flap with the implanted vascular bundles as the pedicle was elevated, sutured back to its original position and then harvested more 3 days later. Neoangiogenesis was measured by digital recording of survival area, laser Doppler flowmetry, PCNA immunohistochemistry, TUNEL, ink and PbO infusions. RESULTS: When compared with the other groups, flap survival improved; neoangiogenesis of flaps increased, together with the blood flow enhanced in the groups applied growth factors. The reduced cellular apoptosis and the increased proliferation were also observed. CONCLUSION: VEGF or bFGF slowly-released by fibrin glue shows the potential to facilitate neoangiogenesis and accelerate maturation of the expanded prefabricated flap.
ObjectiveTo review the research progress of in vivo bioreactor (IVB) for bone tissue engineering in order to provide reference for its future research direction.MethodsThe literature related to IVB used in bone tissue engineering in recent years was reviewed, and the principles of IVB construction, tissue types, sites, and methods of IVB construction, as well as the advantages of IVB used in bone tissue engineering were summarized.ResultsIVB takes advantage of the body’s ability to regenerate itself, using the body as a bioreactor to regenerate new tissues or organs at injured sites or at ectopic sites that can support the regeneration of new tissues. IVB can be constructed by tissue flap (subcutaneous pocket, muscle flap/pocket, fascia flap, periosteum flap, omentum flap/abdominal cavity) and axial vascular pedicle (axial vascular bundle, arteriovenous loop) alone or jointly. IVB is used to prefabricate vascularized tissue engineered bone that matched the shape and size of the defect. The prefabricated vascularized tissue engineered bone can be used as bone graft, pedicled bone flap, or free bone flap to repair bone defect. IVB solves the problem of insufficient vascularization in traditional bone tissue engineering to a certain extent.ConclusionIVB is a promising method for vascularized tissue engineered bone prefabrication and subsequent bone defect reconstruction, with unique advantages in the repair of large complex bone defects. However, the complexity of IVB construction and surgical complications hinder the clinical application of IVB. Researchers should aim to develop a simple, safe, and efficient IVB.