Research On The Three-dimensional Digital Model Of Calcified Costal Cartilage And Two-stage Method For Adult Congenital Microtia

PurposeCongenital microtia is one of the common major body surface malformations,and the clinical manifestations are abnormal auricle morphology and size,which often present with peanut or shell-shaped malformation,with or without hearing impairment.At present,the mainstream means of microtia treatment is autologous costal cartilage framework transplantation combined with skin coverage.The treatment time is mostly concentrated in 6 to 10 years old considering the development,mental health and other factors.However,some patients with microtia failed to receive treatment in childhood and missed the optimal treatment time.Calcification of costal cartilage is one of the main thorny problems facing adult microtia reconstruction.The current detection and imaging methods are not able to accurately and intuitively assess the relevant indicators of calcification.In order to expand the assessment methods,improve the analysis accuracy,explore the calcification characteristics of costal cartilage commonly used in plastic surgery,and supplement the experience of adult ear reconstruction based on calcified costal cartilage,we designed this topic for the main purpose:1.The computed tomography data of the patient’s chest were imported into ProPlan software,and three-dimensional models of the iconic bone,costal cartilage and calcification were constructed by means of two-dimensional image data segmentation and other methods.The three-dimensional anatomical morphology of the calcified costal cartilage was reconstructed by using the lamination method.The consistency between the cartilage model and calcification model was verified by intraoperative measurements and pathological sections.2.Using a three-dimensional digital model to quantitatively analyze a sample of thoracic data with a certain scale,explore 6th 7th 8th calcification regularity of costal cartilage.3.The case data of two stages of adult microtia were reviewed,and the treatment characteristics and strategies of adult microtia were summarized and supplemented.Method1.The computed tomography data of the patient’s thorax were imported into ProPlan software,and the three-dimensional models of landmark bone,costal cartilage and calcification lesions were constructed by two-dimensional image data segmentation,and the three-dimensional anatomical morphology of calcified rib cartilage was reproduced by laminated method.The consistency between the cartilage model and calcification model was veri fied by intraoperative measurements and pathological sections.2.On the basis of the first part of the model,a submodel which can be used to quantify isolated calcification is constructed.The costal cartilages of 340 people aged 21-45 years were used to quantitatively analyze the relevant parameters of calcification,explore and summarize the distribution of calcification,and explaining its clinical significance.3.The case data of 346 adult patients with the center from 2006 to 2021 were summarized.The key points of preoperative evaluation,construction ideas of ear stents,prevention and treatment methods of complications were summarized.Result1.The DICOM data of 43 patients(mean age 31.2 years)undergoing thoracic MSCT scan were collected.Based on which,the 3D digital model of calcified costal cartilage was constructed and the consistent validation of the model was completed.2.A submodel for quantifying isolated calcification was constructed to collect 5004 isolated calcification deposits from 1347 calcified costal cartilages.The data showed that dot calcification was the most common solitary calcification shape and shell calcification was the least common.The volume of calcification was negatively correlated with the occurrence probability.The outer half of the sagittal section of the costal cartilage and the part continuing with the ribs and sternum are the areas prone to calcification.The probability of adult 6th 7th 8th costal cartilage calcification is more than 2/3.The older the age,the higher the probability of calcification.The 8th has the lowest calcification tendency in the 6th-8th;The calcification of 6th and 7th costal cartilage clustered in the periphery and at the end of the cartilage most commonly and showed a polarization trend.8th calcification tend to occur in the interior of cartilage and non-adjacent areas of cartilage.3.Between 2006 and 2021,a total of 346 adult patients with congenital microtia performed two-stage auricle reconstruction method based on calcified costal cartilage in our center with an average follow-up time of 15.3 months.312 were satisfied with the procedure effect,26 were partially satisfied,and 8 were dissatisfied.Satisfaction rate was 90.2%.Conclusion1.In this study,we successfully constructed a 3D digital model of the calcified costal cartilage and completed the consistency test.2.In this study,a subset model that can be used to quantify the analysis of isolated calcifications was successfully constructed,and the distribution and regularity of calcification were refined and summarized.3.The experience of adult two-stage auricle reconstruction based on calcified costal cartilage is summarized,which provides a new reference for the treatment plan of small ear malformation in adult population.