Improvement Of Rat Orthotopic Lung Transplant Operation Process And Observation Of The Long-term Function Of Transplanted Lung

IntroductionLung transplantation (LT) is an established treatment for end-stage lung diseases, including chronic obstructive pulmonary disease (COPD), idiopathic fibrosis of the lung (EPF) and Idiopathic pulmonary hypertension [1]. According to the date of the International Society for Heart and Lung Transplantation (ISHLT),47,647adult lung and3,772adult heart-lung transplants occurred through June30,2013[2]. Although the surgical technique, the choice of immunosuppressive agents and antibiotics has been greatly improved in recent years, but because of its special anatomic structure and physiological function, rejection and infection rate after lung transplantation were higher than other solid organ transplantation of organs. Therefore, the long-term survival rate of patients after lung transplantation is obviously low than other solid organ transplantation patients.Chronic rejection after lung transplantation is the main reason that limiting the lung transplantation patients from long-term survival, bronchiolitis obliterans (BO) is the main forms of chronic rejection after lung transplantation. BO characterized by bronchiolar epithelial injury caused by infiltrating interstitial cells terminal respiratory tract and cause fiber hyperplasia induced by luminal stenosis in pathology, bronchiolitis obliterans syndrome (Bronchiolitis obliterans syndrome, BOS) is the clinical expression of BO, manifested as pulmonary function decreased Irreversible [3]. At present, the pathogenesis of BOS is not completely understood, and there is no effective treatment measure.Experimental animal models play an important role in the study of lung transplantation and chronic rejection after lung transplantation. At present, rat model of orthotopic lung transplantation has been used at the research of ischemia reperfusion injury and acute rejection after lung transplantation. However, research of chronic rejection after lung transplantation mostly depends on the model of orthotopic/heterotopic tracheal transplantation, to taking typical pathological manifestations of BOS replication. The orthotopic/heterotopic tracheal transplantation is easier to execute, but the orthotopic/heterotopic tracheal transplantation model in not conform to the normal physiological characteristics, clinical correlation is low, therefore, the use of tracheal orthotopic/heterotopic transplantation model in study of BOS after lung transplantation still have a lot of controversy. Rat orthotopic lung transplantation operation require high surgical technique and long-term survival rate of receptor rats are low, and these reasons are limiting the studies of chronic rejection of atelectasis after lung transplantation. Therefore, simplify the operation process of lung transplantation in the rat, establish a stable, replicable and long-term survival rat orthotopic lung transplantation model will conducive to the study of lung transplantation and chronic rejection after lung transplantation.ObjectivesTo improve the surgery process of rat orthotopic lung transplantation, simplify the difficulty of anatomize, improve the success rate of surgery and recipient survival rate and observe the function of lung transplantation receptors in long-term, provide a stable and long-term survival rat orthotopic left lung transplantation model for the researches related to lung transplantation and chronic rejection after lung transplantation.MethodsImprove the operation process of rat orthotopic lung transplantation, simplify the difficulty of anatomized. With the operation process improvement using cuff technique, the donor left pulmonary vein, left pulmonary artery, the left lung bronchus were anatomized with receptor to the establishment of rat orthotopic lung transplantation. Record the operation success rate, operation time, warm ischemia time and postoperative receptor survival rate and the function of transplanted. Respectively at the day of30d,60d,90d after lung transplantation, perform chest CT to evaluate the morphology and expansion of transplanted lung, and respectively in30d,60d,90d a group of receptors were put to death to observe the anatomic expansion of lung transplantation and general shape, and hematoxylin eosin (HE) staining, Masson staining were made to observe pathological manifestations of lung transplantation.ResultsA single operator completed the experiments under direct visual. After the improvement of rat orthotopic lung transplant operation process,the total success rate of rat orthotopic lung transplantation operation was93.3%(28/30); the donor operation time was32±5min; receptor operation time was42±12min; short-term survival rate (>1d) was100%(28/28); the long-term survival rate (≥30d) was78.6%(22/28). After surgery, CT images at30,60,90days showed that transplanted lung expansion and shape were basically normal, pulmonary function is good, and there is a small amount of real variable. Anatomy showed that the transplanted lung distension, colors are no obvious difference compared with autologous lung. The structure of HE and Masson staining indicated that the lung parenchyma and interstitial were normal.ConclusionsUsing improved rat orthotopic lung transplant operation process can establish a stable, repeatable and long-term survival rat orthotopic lung transplantation model. Through a year of exploration, the author simplified the difficulty of anastomosis, and established a method of stable and suitable for single operator; provide a long-term survival rat orthotopic lung transplantation model for the studies of lung transplantation and chronic rejection after lung transplant.