The Research Of Constructing Tissue-engineered Tracheal Cartilage Based On 3D-printed Supports And The Clinical Study Of Tracheoplasty For Tracheal Stenosis

Objective:To analyze and explore the therapeutic strategies of congenital tracheal stenosis in infants.ⅠThe Animal Experiment of Tracheomalacia with 3D-Printed Splint.Methods:The first is to establish an rabbit model of tracheomalacia and tracheal stenosis.Then,the splint was placed externally on the underlying collapsed trachea.Twelve rabbits were randomly divided into experimental group(n=6)and control group(n=6).After operation,bronchofiberscope were applied for evaluation.Results: Complete or nearly complete tracheal lumen collapse was observed in all animals and after splint placement,symptoms were relieved.At 8 weeks after operation,obvious stenosis was observed via bronchofibroscope in control animals.On the contrary,there was no visible narrow area in experimental animals.The anatomy results of the two groups were the same.Ⅱ Construction of C-shaped Cartilage with 3D Printed Supporter.Methods:Ultrafine composite fibers of GT/PCL(50:50)were fabricated via electrospinning.Chondrocytes were harvested and seeded on electrospun GT/PCL membrane.Then the cell-membrane complex was rolled onto a 3D printed supporter of PLCL material and cultured in vivo to construct C-shaped complex.Results:After 8 weeks of culture in vivo,mature cartilage-like tissue were formed with open-cylindrical bellow appearance and pecific mechanical property.C-shaped rings arranged at regular intervals on the inner surface of tissue.Histological and immunohistological shown a large number of typical lacunar structures and extracellular matrix secretions.Ⅲ Clinical Research of Tracheoplasty.Methods:A retrospective review was performed on 86 patients who received tracheoplasty from August 2001 to April 2015.Various clinical data including demographic data,operation records,imaging results and follow-up results were collected.Software SPSS 22.0 was used for data summary and analysis.Results:Repaired with autologous tracheal tissue were performed in 11 patients,resection and end-to-end anastomosis in 17 patients,and slide tracheoplasty in 58 patients.4 of above patients received the guidance of 3D printing in preoperative diagnosis,intraoperative decision-making and postoperative follow-up.All patients were followed up regularly after operation and the tracheal diameter was surveyed by CT.There were 7 deaths and the recovery of other surviving patients was satisfactory.Conclusion:It is feasible to apply the 3D-printed bioabsorbable tracheal splint in the animal model of tracheomalacia and tracheal stenosis.The 3D-printed supporter can be used to construct tissue engineered C-shaped cartilage tissue combined with chondrocytes and GT/PCL membrane.Surgical treatment is currently the best option for patients of congenital tracheal.Resection and end-to-end anastomosis is mainly suitable for short-segmental tracheal stenosis,and for long-segmental tracheal stenosis,slide tracheoplasty is the mainstream method.Furthermore,slide tracheoplasty is available to treating tracheal bronchus and bronchial stenosis.3D printing can provide a good help to preoperative diagnosis,intraoperative decision-making and postoperative follow-up of congenital tracheal stenosis,and improve the success rate of tracheal stenosis surgery.