Abstract In order to have more selective sources of skin flaps to repair soft tissue defects, the prefabricated flap combining with skin expander was tried. Implanted the dorsal thoracic artery and vein with a muscle bundle of latissimus dorsi into the lateral thoracic wall subdermally andset a skin expander subcutaneously. Injected saline into the expander to inflate the flap gradually. In a month, an axial flap with the dorsal thoracic vesselswas prepared. the flap was transferred to the defect by vascular anastomosis technique. This method was applied in two cases, one to the left ankle, another to the left side of the neck. The sizes of the two flaps were 20cm×14cmand 22cm×15cm respectively. After operation, the flaps were alive completely. The advantages included selective source of vascular pedicle, thinpliable flap with enough blood supply, and direct closure of the donor site without skin graft.
OBJECTIVE: To sum up the experimental development and clinical application of prefabricated flap. METHODS: The reported experimental results and clinical application of prefabricated flap extensively reviewed. RESULTS: Previous studies had proved that the revascularization of prefabricated flap mainly through anastomoses of implanted vessels and the original vessels of the flap, the implanted vessels slowly formed a new and complete blood vessel network, which could dominate the whole flap, three to four weeks later, the new vessels were mature and the flap could be transferred. Clinically, the superficial temporal vessels, gastroepiploic vessels, circumflex femoral vessels and thoracodorsalis vessels could be harvested for prefabricated flap with satisfactory results. CONCLUSION: Prefabricated flap provides a new method for the treatment of complicated defects.
Objective To probe the principle and the method to repair facial soft tissue defect with the prefabricated expander flap the neck with the vessles of temporalis superficialis. Methods The expandor was implanted into the surface layer of the platysma in neck. The pedicle of the expander flap contained the arteria temporalis superficialis and its ramux parietalis. After 3 months, the prefabricated island expander flaps pedicled with the arteria temporalis superficialis and its ramux parietalis could be transferred to the face. From 1998 to 2003, 6 cases of facial soft tissue defects were repaired. The maximal flap size was 12 cm×8 cm.Thepedicel length was 7.8 cm.Results After a follow-up of 3-6 months, all expander flaps survived. The excellent function and cosmetic result were achieved. Conclusion The prefabricated expander flaps of the neck pedicled with the arteria temporalis superficialis and its ramux parietalis can be transferred to the upperface to repair tissues defect. The supply of blood of the prefabricated expander flaps were safe and reliable. The survived areas of the flaps are directly proportional to the areas of temporalis superficialis fascia combining the expander flaps.
Objective To investigate the feasibil ity of prefabricating urethra in the expander capsule with gelatin sponge and micro-mucosa compound transplantation. Methods Eight 8-week-old Guizhou miniature pigs (male and/or female) weighing 20-25 kg were used. Six expanders (15 mL) were placed subcutaneously on the dorsal thorax of each miniaturepig. Autologous oral mucosa of every pig was harvested 2 weeks later to prepare micro-mucosa with a diameter less than 1 mm. Gelatin sponge 3 cm × 2 cm in size was transplanted to the expander capsule after being coated by the autologous micromucosa at the area expansion ratio of 4 ∶ 1 (group A), 8 ∶ 1 (group B), and 16 ∶ 1 (group C), respectively (n=2 per group). The implantation of gelatin sponge served as the blank control (group D, n=2). Physiological sal ine was injected into the expander immediately after operation, and the pressure in the expander was 40 mm Hg (1 mm Hg=0.133 kPa). The postoperative general condition of the animals was observed. At 1, 2, and 3 weeks after operation, the animals were killed to receive general, HE staining, and immunohistochemistry staining observations. Results All animals survived till the end of the experiment. The wounds healed well. General observation: in groups A, B, and C at 1 week after operation, there was no obvious degeneration of gelatin, the mucous was survived partially, and there were significant differences among three groups in terms of mucosa healing rate (P lt; 0.05), groups A and B were better than group C, and group A was better than group B; at 2 weeks, the gelatin sponge was partly absorbed, most of the mucosa survived, and the mucosa healing rate of groups A and B was better than that of group C (P lt; 0.05); at 3 weeks, the gelatin sponge was still not absorbed completely, the wound reached epithel ial ization approximately,and there were no significant differences among three groups in terms of mucosa heal ing rate (P gt; 0.05). No neo-mucosa was evident in group D at each time point. Histology and immunohistochemistry staining observation: at each time point, the mucosa epithel ium survival, inflammatory cell infiltration, and pan-cytokeratin were evident in groups A, B, and C; at 3 weeks after operation, the stratified squamous epithel ium presented obvious polarity and the submucous neovascularization was abundant in groups A, B, and C. There was no mucosa epithelium and positive stained pan-cytokeratin in group D. For the percentage of positive pan-cytokeratin stained area, there were significant differences among groups A, B, and C 1 week after operation (P lt; 0.05); at 2 and 3 weeks after operation, there was significant difference between group A and group C, and between group B and group C (P lt; 0.05); but no significant difference was evident between group A and group B (P gt; 0.05). Conclusion Micro-mucosa and gelatin spongy compound transplantation on the expander capsule can form mucosal l ining, achieve complete epithel ial ization in 2 weeks, and contribute to maintain the normal function of prefabricatied urethra.
ObjectiveTo investigate the effectiveness of using a sensory prefabricated flap to repair the heel avulsion injury. MethodsBetween August 2012 and August 2013, 6 cases of heel avulsion injury were treated. There were 4 males and 2 females, aged 16-54 years (mean, 29 years). The causes were crush injury in 4 cases and wheel twist injury in 2 cases. The injury to admission time was 2-6 hours (mean, 4 hours). The size of skin avulsion ranged from 5 cm×3 cm to 15 cm×8 cm. Avulsion skin had no replanted condition. At one stage operation, the avulsed heel skin soft tissue was made the full thickness skin graft which was fostered on the anterolateral thigh with lateral circumflex femoral artery perforator, and the lateral femoral cutaneous nerve was put beneath the skin to prefabricate the prefabricated flap; at two stage operation, the prefabricated skin flap pedicled with lateral circumflex femoral artery was used to repair the wound, and the lateral femoral nerve was anastomosed with the calcaneal nerve to reconstruct the feeling. ResultsSix prefabricated flaps all survived, and re-plantation flaps survived after operation. The wounds healed by first intention at donor site and recipient site. The patients were followed up 1-2 years (mean, 1.5 years). The flaps had satisfactory appearance and soft texture. At 1 year after operation, the sensation of the flaps was S3, with two-point discrimination of 22-27 mm (mean, 24.3 mm). According to ZHANG Ming's evaluation standards, the results were excellent in 5 cases, and good in 1 case. The patients could walk normally or with weight-bearing; only linear scar formed at the donor site. ConclusionFor patients with heel soft tissue avulsion injury without replantation qualification, a sensory prefabricated flap by the avulsed heel skin soft tissue can transplanted to repair the heel defect. Satisfactory effectiveness can be obtained in heel appearance and function recovery.
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 establish a method to prefabricate titanium plate with three-dimensional (3-D) printing technique for correction of mandibular prognathism in sagittal splint ramous osteotomy (SSRO). MethodsBetween January 2012 and May 2013, 12 patients with mandibular prognathism (Angle III malocclusion) were treated. Among them, 9 cases were male and 3 cases were female. Their ages ranged from 19 to 35 years (mean, 25.6 years). With the 3-D facial CT data of these patients, 3-D printer was used to print the models for preoperational simulation. SSRO was performed on 3-D models, and the titanium plates were prefabricated on the models after the distal segments were moved backward and rotated according to occlusal splint. During operations, the proximal segments were fixed to distal segments by the prefabricated titanium plates. 3-D CT scans were taken to examine the temporomandibular joint position changes before operation and at 6 months after operation. ResultsThe skull models were manufactured by 3-D printing technique, and the titanium plates were reshaped on the basis of them. Twenty-four prefabricated titanium plates were placed during operations, and they all matched with the bone segments well. Evaluation of 3-D CT scans showed that the temporomandibular joint position had no change. All patients were followed up 7-12 months (mean, 10.6 months). The face type and dental articulation were improved greatly. All cases obtained satisfactory opening function and occlusion. ConclusionWith the titanium plate fabricated based on 3-D models, surgeons are able to improve or refine surgical planning so that the operation can be performed according to preoperative simulation precisely and the complications, such as dislocation of temporomandibular joint, can be prevented.
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.
Flexible conductive fibers have been widely applied in wearable flexible sensing. However, exposed wearable flexible sensors based on liquid metal (LM) are prone to abrasion and significant conductivity degradation. This study presented a high-sensitivity LM conductive fiber with integration of strain sensing, electrical heating, and thermochromic capabilities, which was fabricated by coating eutectic gallium-indium (EGaIn) onto spandex fibers modified with waterborne polyurethane (WPU), followed by thermal curing to form a protective polyurethane sheath. This fiber, designated as Spandex/WPU/EGaIn/Polyurethane (SWEP), exhibits a four-layer coaxial structure: spandex core, WPU modification layer, LM conductive layer, and polyurethane protective sheath. The SWEP fiber had a diameter of (458.3 ± 10.4) μm, linear density of (2.37 ± 0.15) g/m, and uniform EGaIn coating. The fiber had excellent conductivity with an average value of (3 716.9 ± 594.2) S/m. The strain sensing performance was particularly noteworthy. A 5 cm × 5 cm woven fabric was fabricated using polyester warp yarns and SWEP weft yarns. The fabric exhibited satisfactory moisture permeability [(536.06 ± 33.15) g/(m2·h)] and maintained stable thermochromic performance after repeated heating cycles. This advanced conductive fiber development is expected to significantly promote LM applications in wearable electronics and smart textile systems.
OBJECTIVE To investigate the feasibility of prefabricating a specified shape autograft capable of transfer using coral and type I collagen as a carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2). METHODS In this study, the composite of rhBMP-2, coral and type I collagen was made certain shape to prefabricate vascularized osteomuscular autograft capable of microvascular free tissue transfer and autogenous bone graft with certain shape and titanium implant in it. The composite was implanted in the iliac area in dog with the titanium implant at the same time. After 3 months and 4 and a half months of implantation, the composites were studied with gross measurement, X-ray, and histological examinations. RESULTS After 3 months, composited bone was turned to bone tissue, and the shape of iliac bone was changed with implant in it, bone interface was seen between new bone and implant. And new bone was matured after 4 and a half months. CONCLUSION Coral and type I collagen are effective carrier for rhBMP-2 to prefabricate vascular osteomuscular autograft with certain shape. The use of rhBMP-2 for tissue engineered microvascular free bone flaps has an unlimited potential and adds a new dimension to maxillofacial reconstruction.