The role of altered fatty acid in pathological scars and their dermal fibroblasts.

PURPOSE: The proposed pathological mechanism for scar formation is controversial, and increased attention has been paid to the fatty acids (FAs) in the formation of pathological scars. Notably, FAs are known to be important in inflammation and mechanotransduction, which is closely related to scar formation. Therefore, it is necessary to clarify the roles of FA in scar formation. METHODS: Hypertrophic scar and keloid formed for more than a year and without other treatment, as well as normal skin samples were obtained from patients who underwent plastic surgery. Finally, keloids (n = 10), hypertrophic scars (n = 10), and normal skin samples (n = 10) were collected under informed consent. Primary dermal fibroblasts were isolated and cultured. The amount and variety of FAs were detected by lipid chromatography-mass spectrometry. Immunohistochemistry, real-time PCR, and western blotting were used to verify the expression of sterol regulatory element-binding protein-1 (SREBP1) and fatty acid synthase (FASN) in the samples and their fibroblasts. Student's t-test, ANOVA, and orthogonal partial least square discriminant analysis were performed for statistical analysis (∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001). RESULTS: Compared with full-thickness normal skin, there were 27 differential FAs in keloids and 15 differential FAs in hypertrophic scars (∗p < 0.05 and variable influence on projection >1.0). The expression of SREBP1 and FASN was lower in pathological scars both at mRNA and protein levels (all ∗p < 0.05). However, the mRNA levels of SREBP1 (∗∗∗p = 0.0002) and FASN (∗∗∗p = 0.0021) in keloid-derived fibroblasts were higher than that in normal skin fibroblasts (NFBs), while the expression in hypertrophic scar-derived fibroblasts was lower than that in NFBs (both ∗p < 0.05). Whereas there was no significant difference in FASN protein expression between keloid-derived fibroblasts and NFBs (p > 0.05). CONCLUSION: FAs involved in pathological scars are abnormally changed in scar formation. Thus, fatty acid-derived inflammation and de novo synthesis pathway of FA may play a key role in the formation of pathological scars.

[Ear reconstruction after rupture of postauricular expanded flap].

OBJECTIVE: To summarize the principles of ear reconstruction after rupture of postauricular expanded flap. METHODS: The rupture of the postauricular expanded flap was graded as I-IV degree. For flap rupture of I and II degree, the ear reconstruction was performed immediately with autogenous cartilage framework. For flap rupture of III degree, topical and systemic treatment should be done to relieve the redness and swelling. Then the ear reconstruction was performed. For flap rupture of IV degree, the expanded postauricular flap was smoothened. Ear reconstruction was performed 3 months later. RESULTS: There were 67 cases with flap rupture, including 43 cases as I and II degree, 17 cases as III degree and 7 cases as IV degree. Ear reconstruction with autogenous cartilage framework was performed in 43 cases, with Medpor framework in 17 cases. Flap smoothing and secondary ear reconstruction with autogenous cartilage framework was performed in 7 cases. The results were satisfactory with complications in 4 cases (7%), which resolved after treatment. Primary healing was achieved in all the patients. CONCLUSIONS: Good result could be achieved in ear reconstruction, even after flap rupture. Proper treatment should be adopted according to the rupture degree.

[Application of quantitative tissue expansion in ear reconstruction].

OBJECTIVE: To explore the application of tissue expander in ear reconstruction and to deal with the complications. METHODS: 50 ml kidney-shape tissue expanders were implanted subcutaneously in the mastoid area. The drainage tube was removed 3 days after operation. The suture was removed 10 days later. Since 7 days after operation, 5 ml NS was injected into the expander every time, three times a week. The total injection volume was about 60 ml. After that, the expander was maintained for one month. RESULTS: From January 1992 to December 2006, 5,248 patients of microtia were treated with 6,252 expander. After the maintaining period, the expanded skin was thin and well-vascularized. The complication rate was 7.79%, including hematoma, malunion and infection. CONCLUSIONS: The quantitative tissue expansion is easily manipulated with few complications. It can provide hairless, thin skin with reliable blood supply for ear reconstruction.

[Fabrication and application of three-dimensional autogenous cartilage framework in auricular reconstruction].

OBJECTIVE: To explore the fabrication and application of three-dimensional autogenous cartilage framework in auricular reconstruction. METHODS: The process of fabrication of three-dimensional cartilage framework consisted of cartilage harvesting, carving and assembling the cartilage. The rib cartilage was harvested separately. The three-dimensional framework was composed of three main parts:the helix, the base and the pad, at different layer. The framework was fabricated according to the development of rib cartilage and contour and height of the reconstructed ear. RESULTS: From January 1992 to December 2006, 5,248 patients of microtia were treated with 6,252 autogenous cartilage frameworks. CONCLUSIONS: The three-dimensional framework is easily manipulated. The reconstructed ears look natural and had an erect contour. This method can effectively use the cartilage.

[Study of methylation of promoter of EYA1 gene in microtia].

OBJECTIVE: To explore the methylation of CpG islands in promoter of eye absent gene 1 (EYA1) in microtia. METHODS: The methylation of CpG islands in EYA1 gene in 64 microtias and 36 healthy controls were measured using the technique of matrix-assisted laser desorption/ionization-time of flight. RESULTS: The methylation of CpG_Unit3 and CpG_Unit5 of EYA1 gene in microtia were 0.09258 +/- 0.033846 and 0.0922 +/- 0.02379, respectively, which were significantly lower than those in control. CONCLUSIONS: Hypomethylation in microtia may be related to the pathogenesis of the disease.

[Ear reconstruction using soft tissue expander in the treatment of congenital microtia].

OBJECTIVE: To explore surgical procedure of congenital microtia. METHODS: Ear reconstruction was made using soft tissue skin expander and autogenous rib cartilage framework. RESULTS: Long time follow-up showed that the flap of reconstructed ear was ruddy, soft, with normal sensory function; cartilage framework had no degeneration, absorption and deformation. In addition, the reconstructed ears were coincidence with the normal side on location, form and dimension. CONCLUSIONS: It was a good method for congenital microtia to use soft tissue skin expander together with autogenous rib cartilage framework at present time.

[External ear reconstruction using expanded postauricular scar flap and Medpor framework].

OBJECTIVE: To investigate the possibility of external ear reconstruction using expanded postauricular scar flap and Medpor framework in burn cases. METHODS: External ear reconstruction using expanded postauricular scar flap in combination with Medpor framework was performed in 17 cases whose ear had burn injury. RESULTS: Of the 17 cases, 15 cases achieved success; 2 cases experienced partial exposure of the framework due to inadequate wrapping of the subcutaneous fascia flap and later injury. The longest follow-up was three years, and the final result was satisfactory. CONCLUSIONS: External ear reconstruction using expanded postauricular scar flap in combination with Medpor framework is a reliable method for adult (over 25 years) who has ear defect from burn injury.