| Background:Congenital microtia is a genetic disease with unknown causes.Its main clinical symptom is auricle dysplasia,often accompanied by external auditory canal atresia,middle ear and maxillofacial deformity.According to statistics,0.8 to 4.53 births per 10,000 births have congenital microtia around the world.At present,the best method for the treatment of congenital microtia is surgery.In particular,severe congenital microtia requires auricle reconstruction.In China,auricle reconstruction with extended flap is the main surgical method for patients with microtia,which is mainly divided into three stages.In the first stage,a skin dilator is placed into the subdermal layer of the mastoid region behind the ear.In the second stage,a dilated flap and a retroauricular fascia flap are used to cover the scaffold carved from the costal cartilage of the patient.In the third stage,the subunits of the reconstructed ear are repaired to perfect the morphology of the reconstructed ear.The application of retroauricular skin dilator is a key technique for auricle reconstruction with extended flap.However,in the application of retroauricular skin dilator,especially in the selection of the specifications of retroauricular skin dilators,the location of retroauricular skin dilators and the method of implantation to prevent downward migration during injection dilation of retroauricular skin dilators mainly rely on the experience of plastic surgeons,and there is no unified clinical guideline.Moreover,the capsular hyperplasia of the retroauricular skin dilators will reduce the expansion speed of the dilators and increase the thickness of the expanded flap,thus affecting the effect of auricle reconstruction with extended flap.At present,there is no unified treatment plan to inhibit the capsular hyperplasia of retroauricular skin dilators.Therefore,this study was conducted to solve four key problems,namely,the selection of the specifications of retroauricular skin dilators,the location of retroauricular skin dilators,the method of implantation to prevent downward migration during injection dilation of retroauricular skin dilators and the inhibition of the capsular hyperplasia of retroauricular skin dilators,so as to provide an optimization scheme for the application of retroauricular skin dilators in auricle reconstruction surgery.Methods:1.A total of 100 microtia patients who came to plastic surgery hospital from January 2021 to December 2021 were randomly selected for this study.The entire face and bilateral ears of all enrolled patients were scanned using the Artec Space Spider 3D scanner(Artec 3D,Redmond,USA).The scan data was synthesized into STL files using Artec Studio 10(Artec 3D,Redmond,USA)and then imported into 3-matic Research 9.0(Materialise NV,Leuven,Belgium).All measurements were performed using this software.The length and surface area of the auricle were plotted as scatter plots,and the linear regression equation was calculated.CT scanning technology,ProPlan CMF 3.0 software,and Geomagic Wrap 2015 software were used to measure the surface area of commonly used 50ml and 100ml retroauricular renal skin dilators in different dilated states.To find the simplest correspondence between the dilators size and the length of the auricle.2.The research team designed and developed a positioning ruler for the preoperative positioning of the retroauricular skin dilators.Patients who underwent auricle reconstruction with extended flap in plastic surgery hospital from August 2020 to September 2021 were randomly selected,and the locations of retroauricular skin dilators were positioned with the positioning ruler.By evaluating the symmetry of the reconstructed auricles after auricle reconstruction and the satisfaction of the patients,the effect of the positioning ruler on the preoperative location of the retroauricular skin dilators was evaluated.3.A total of 137 patients with microtia who met the inclusion criteria from January 2020 to April 2021 were retrospectively selected.Patients who received the biplanar method were included in the experimental group and those who received the conventional method were included in the control group.The therapeutic effect of the biplanar method was evaluated by comparing the down moving distance,complications and satisfaction rate of patients and their families between experimental group and control group.4.Enveloped fibroblasts were cultured,and the optimal concentration of proliferation inhibition of rapamycin was explored using a enzyme-label analyzer.Muse cell analyzer was used to detect the effect of Rapa on the apoptosis and cycle of enveloped fibroblasts.Tandem Mass Tags(TMT)technology was used to conduct proteomic analysis of enveloped fibroblasts after Rapa intervention,in order to explore the mechanism of Rapa inhibiting enveloped fibroblasts.Results:1.In this study,85 male and 15 female patients with unilateral microtia were included,including 29 on the left side and 71 on the right side.The mean age of patients was 9.75±4.2 years.The average auricle length of the collected data is about 58.88 ± 4.77 mm,the average auricle width of the collected data is about 33.15±2.75 mm,the average auricle projection of the collected data is about 20.92± 2.70 mm,the average auricle perimeter of the collected data is about 104.67 ± 8.40 mm,and the average auricle surface area is 4502.1479± 633.4493 mm2.Excel automatically draws a scatter plot of the relation between auricle length and surface area,and the equation of trend line is:y=76.92 1x.In the equation of trend line,y is the auricle surface area and x is the auricle length.We also measured surface areas after injection of 50 ml,60 ml,and 70 ml with a 50 ml skin dilator and after injection of 80 ml,90 ml,100ml,110ml,and 120 ml with a 100ml skin dilator.By measuring the length of the healthy auricle of the patient,the auricle skin area can be estimated by this equation.Combined with the measured surface areas of the skin dilators,it can guide the plastic surgeon to choose the sizes of the skin dilators.2.A total of 47 patients were included in the study,including 29 males and 18 females,20 left microtitis and 27 right microtitis.The mean age was 10.77±2.64 years,and the mean follow-up time was 8.68±2.40 months.The average distance from the highest point of the reconstructed auricle to the central axis of the nose was 14.12±0.52 cm.The average distance from the highest point of the normal auricle to the central axis of the nose was 14.08±0.45 cm.The average distance from the lowest point of the reconstructed auricle to the central axis of the nose was 12.71 ±0.31 cm.The average distance from the normal auricle to the central axis of the nose was 12.67±0.26 cm.The average distance from the highest to the lowest point of the reconstructed auricle was 6.03±0.32 cm.The average distance from the highest to the lowest point of the normal auricle was 5.91 ±0.27 cm.These results demonstrate that the reconstructed auricle was highly symmetrical to the contralateral auricle.The satisfaction rate of patients and their families to the reconstructed auricle location was 100%.3.Sixty-three patients in the experimental group and 74 in the control group were included in the study.In the experimental group,there were 38 male patients,25 female patients,mean age 10.08±2.64 years,including 41 on the left side and 22 on the right side.In the control group,there were 43 male patients and 31 female patients,with an average age of 10.16±2.52 years,including 38 on the left side and 36 on the right side.The experimental group was followed up for 61.81±5.55 days after the first stage operation.The control group was followed up for 62.01 ±6.09 days after the first stage operation.The down moving distance of the skin dilator was 1.52±0.44 cm in the experimental group and 2.08±0.34 cm in the control group.There was a statistical difference in the down moving distance of theskin dilator between the experimental group and control group(P<0.05).4.The researchers successfully cultured enveloped fibroblasts using the dilator envelope tissue.The cells were consistent with the morphological characteristics of fibroblasts.The rate of fibroblast-specific protein-vimentin positive cells was 96.85%.The optimal concentration of rapamycin was 20μmol/L to inhibit the proliferation of enveloped fibroblasts.Rapamycin was determined using the Muse cell analyzer to promote apoptosis and inhibit cell proliferation in enveloped fibroblasts.Using TMT technique,proteomic analysis of enveloped fibroblasts after rapamycin intervention showed that 42 proteins were down-regulated and 55 proteins were up-regulated.Differential proteins are mainly correlated with the biological functions of extracellular matrix structural components,protein-glutamine-transglutaminase activity.In terms of biological processes,differential proteins are significantly related to peptide crosslinking,ATP reaction,antigen processing and presentation,and other biological functions of cells.In terms of cell components,differential proteins were significantly related to the biological functions of the cell membrane components,protein extracellular matrix,cell membrane and plasma membrane components.Differential proteins are highly correlated with the signal transduction pathways of protein digestion and absorption and relaxation protein signaling pathways.The differential proteins were significantly correlated with the C-terminal of fibrous collagen and the triple helix of collagen.Endoplasmic reticulum is the main cellular site where differential proteins exert their functions.Through the interaction analysis of different proteins,it is found that Q59EZ3,Q9UM47,A0A7I2V3R9,Q7Z7M4 and O75635 are the key proteins in the significantly highly expressed proteins.Through the functional annotation of the proteins,we found that these highly expressed proteins were mainly associated with inhibitory cell proliferation and differentiation.The key proteins in the significantly lowly expressed proteins were A0A384MDU2,P02452,P09486,P51911 and A0A024RAL1.Through functional annotation of proteins,we found that these lowly expressed proteins were mainly associated with promoting cell proliferation and differentiation.Conclusions:Through this study,we believe that the formula(y=76.921x)can be used to calculate the auricle surface area by measuring the length of the auricle,so as to select the specifications of the skin dilators.The positioning ruler designed and invented by our team can be used to determine the location of the skin dilators,and the biplane skin dilator implantation technology can be used to implant the skin dilators,so as to obtain better surgical treatment effect.It was found that rapamycin at 20μmol/L concentration can promote apoptosis and inhibit proliferation of enveloped fibroblasts.In the later study,we will develop a skin dilator with rapamycin sustained-release coating for auricle reconstruction surgery to solve the problem that the skin dilator envelope hyperplasia may affect the surgical effect.However,clinical trials are needed to further verify its efficacy and safety before it can be applied in clinical patients. |
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