ABSTRACT
BACKGROUND: The study of tissue-engineered cartilage with predetermined shaping and regeneration has provided novel ideas and techniques for repair of laryngeal cartilage erosion; however, due to the special natures of the morphology, location and function of laryngeal cartilage, tissue engineering research has not, to date, exhibited its ful advantages in the reconstruction of laryngeal cartilage. OBJECTIVE:To explore the feasibility of building tissue-engineered larynx-shaped cartilage using poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHH) as a scaffold filed and encapsulated with pedicled myofascial flaps. METHODS:Porous PHBHH was prepared and formed into a holow like larynx-shape, and the cel PHBHH composites were cultured for 1 weekin vitro prior to implantationin vivo. The cel-PHBHH composite was filed and encapsulated with myofascial flaps with the pedicle forin situ implantation in nine rabbits as experimental group. PHBHH scaffold with no chondrocytes was implanted alone in three rabbits as control group. Cartilage regeneration was assessed at 6, 12 and 18 weeks after surgery through morphological observation, histological and immunohistochemical detection. RESULTS AND CONCLUSION: In the experimental group, the shape and porosity (> 90%) of the material were ideal, the cels exhibited good adhesion with the material and the blood supply within the myofascial flap with pedicle was rich for effective filing and encapsulation of the cel PHBHH composite. Tissue-engineered laryngeal cartilage with the holow, semi-trumpet shape was idealy formed at 6 weeks after the surgery. Further maturation of the cartilage was observed at 12 and 18 weeks after the surgery. However, there was no cartilage tissue in the control group. This study shows that PHBHH is a suitable material for the formation of a holow, semi-trumpet shape with good celular compatibility. Myofascial flap filing and encapsulating can be used to build tissue-engineered laryngeal cartilage with a holow, semi-trumpet shape.
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BACKGROUND:A great development has been achieved in essential research on tissue engineered cartilage. However, its real application in otolaryngology has been rarely reported. It is faced with the topic to explore the simple and convenient method of repairing laryngeal cartilage by tissue engineering technique. OBJECTIVE:To compare the effect of porous spongy poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) seeded with chondrocytes or using senior tissue engineered cartilage in repairing al ogenic thyroid cartilage defects.METHODS:Chondrocytes at passage 3 were harvested from infant rabbits within 3 days. Porous spongy poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) seeded with chondrocytes composites were made by tissue engineering technique. The chondrocyte-poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) composites were co-cultured in vitro to form junior tissue engineered cartilage. And then respectively used for repairing the thyroid cartilage defects and directly transplanted with junior tissue engineered cartilage (experimental group A, n=5), or firstly the junior tissue engineered cartilage to be implanted subcutaneously for a period of time to further maturity for relative senior tissue engineered cartilage and secondly to be transplanted (experimental group B, n=5) into adult New Zealand white rabbits. Simple poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) sponge scaffold (control group A, n=4) and chondrocyte suspensions(control group B, n=4) were used as reparative materials in defect areas as control groups. Final y, the reparative effect was respectively studied grossly and histological y at 4 weeks (experimental group B) and 8 weeks (experimental group A, control group A and control group B) after transplantation. RESULTS AND CONCLUSION:The cartilage defects were wel repaired in the experimental groups. It was smooth between the reparative area and original cartilage without dents and defects. Both were similar grossly. But few chondrocytes at interfacial region between the reparative area and original cartilage and poor matrices were observed in the experimental group A. A Few chondrocytes and more matrices were observed in the experimental group B. Inflammatory cellinfiltration was not obvious in two experimental groups. Control groups showed soft tissue of dark-red color accompanied with local concave in gross specimens. Histological examination and special staining showed there were no cartilage-like structure and secretion of matrix components. The results showed that it is possible to repair thyroid cartilage defect using junior tissue engineered cartilage directly or junior tissue engineered cartilage after in vitro implantation in al ograft rabbits with immunity, and the immunoreaction is not obvious;in the same period, the repairing effect of mature tissue engineered cartilage is better than that of junior tissue engineered cartilage. However, application of junior tissue engineered cartilage directly can save time, costs, workload and operational link, and avoid the pain from secondary skin surgery, which is one of the more practical approaches.
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OBJECTIVE@#To research the causes of postintubation vocal cord dyskinesia and its contributing factors.@*METHOD@#The causes of vocal cord dyskinesia were confirmed by laryngoscope, three-dimensional spiral CT, stroboscope, and the analysis of therapy. The factors relevant to the causes of vocal cord dyskinesia were analysed based on the following elements: (1) the anatomic or pathological condition of patients or the technical skills of anesthetists. (2) emaciated or obese body and neck. (3) the age of patients. (4) the duration of endotracheal tube retention. (5) the types of operations. (6) anesthesia procedure.@*RESULT@#Among 135 patients, 128 cases (94.81%) manifested arytenoid dislocation, 7 cases (5.19%) vocal cord paralysis. The study showed that the vocal cord dyskinesia associated with anatomic or pathological condition of patients and technical skills of anesthetists (with intubation difficulty) accounted for 76.30%. The patients with relative emaciated body or neck accounted for 90.62% in cases without intubation difficulty. Age had no significant analytical relationship with vocal cord dyskinesia. Prolonged intubation (endotracheal tube retention over 12 hours) was accounted for only 17.64%. The incidence of vocal cord dyskinesia was nearly 0.5% in patients underwent cardio-thoracic surgery, accounting for 59.26% of all the patients.@*CONCLUSION@#There are two major causes of vocal cord dyskinesia: arytenoid dislocation and vocal cord paralysis, and the rate of vocal cord dyskinesia could be reduced by the improvement of technical skill of anesthetists and/or sufficient attention to the intubation condition of patients.
Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Young Adult , Intubation, Intratracheal , Laryngoscopes , Vocal Cord Paralysis , Vocal CordsABSTRACT
To investigate the formation of tissue engineered cartilage using polyglycolic acid (PGA) as three dimensional scaffold seeded with allogenic chondrocytes. First, chondrocytes were harvested from rib cartilage of one week old infant rabbits by collagenase digestion.The isolated cells were cultured in vitro for 2～3 generations, and then the cell suspension was concentrated. Next, the suspension was seeded onto PGA scaffolds soaked with poly l lysine. Then, scaffold chondrocyte constructs were transplanted into subcutaneous tissue of adult rabbits. Finally, the chondrogenesis was studied histologically at various periods. The results showed that chondrocytes were well distributed on the PGA scaffolds in the period of culture in vitro, and could secrete matrix around one week after seeding. 4 weeks after transplantation, the immature cartilage was regenerated in recipient animals. But some inflammatory cells surrounding the new cartilage and some PGA fibers were observed. 8 weeks after transplantation, mature cartilage with abundant matrix was obtained. PGA fibers were not found. This study proves that it is possible to regenerate new cartilage in animals possessing immune function by seeding allogenic chondrocytes onto PGA scaffold. Rejectionreaction is not strong.
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Objective:To evaluate the long-term effect of augmentation rhinoplasty with silicone. Method:360 patients underwent augmentation rhinoplasty with silicone. Improved L shaped implants were used in 343patients. Result: Among 360 patients, 334 cases were successful enough (92.83 ％0 ). Conclusion: The key to themaintenance of the long-term effect is to use properly improvedL-shaped implant,to choose a suitable tunnel,to prevent various complications and to ask patient's opinions for implant design.