An Improved "cuff Technique" For Establishing A Rat Left Orthotopic Lung Transplantation Model

Background and purpose:Since the first lung transplantation successfully performed in 1983^[1],more than 60thousand lung transplantions have been performed worldwide^[2].At present,lung transplantation is the only effective and final method for the treatment of end-stage lung disease worldwide,giving the recipients longer survival and better quality of life^[3].China is a high incidence of lung disease,and at least 10 thousands patients with end-stage lung disease need lung transplantation each year.However,there are many lymphoid tissues associated with the bronchus in the lungs,so many different ways of immune response can occur in lung transplantation.This leads to earlier and more severe acute or chronic rejection in lung transplantation,relative to heart,liver and kidney transplantatio n^[4].At the same time,the ischemia-reperfusion injury,atelectasis and lung infection of the grafted lung all seriously affect the success of the procedure ration and the long-term survival of the recipient.Although the current level of surgical techniq ue,the choice of immunosuppressive agents and antibiotics have been greatly improved in recent years,the success rate of lung transplantation and the long-term survival rate of patients have not been qualitatively improved.Lung transplantation started earlier in C hina.In 1979,Xin Yuling was the first attempt to treat pulmonary tuberculosis through lung transplantation^[5].But until 1995,Chen Yuping and colleagues successfully completed the first case of single lung transplantation in our country and completed the double lung transplantation in 1998^[6].In 2016,there were 204 cases of lung transplantation in China.By 2017,the total number of cases reported on the China Lung Transplantation Registry was 260cases^[7].How to reduce the postoperative co mplications and improve the prognosis of lung transplantation have been the focus of research.And,the establishment of experimental animal model is the basis for the study of lung transplantation,which plays a crucial role in various studies of lung tra nsplantation.Rat orthotopic lung transplantation operation require high surgical technique,the long-term survival rate of recipients after surgery is low and the incidence of atelectasis is high,and so on.Those factors have hindered the study of lung transplantation.Therefore,it is necessary to simplify the surgical procedure of orthotopic lung transplantation in rats.The purpose of this paper is to explore the establishment of a rat left orthotopic lung transplantation model based on the improvement of the traditional"cuff technique".A stable,replicable and highly viable left orthotopic lung transplantation model in rats was established by this method.Method:In the study,20 rats?Sprague-Dawley,SD?were enrolled for left orthotopic lung transplantation.The one week survival rate and activity after operation were observed.The rat pulmonary artery,pulmonary vein,and bronchus were anastomosed using a modified cuff technique to establish a left lung orthotopic transplantation model.Record the operation success rate,donor operation time,receptor operation time,total operation time,sleeve time and one week survival rate after surgery.After one week,the blood gas analysis was performed on all surviving recipients.Result:All experiments were performed by single operator under direct visual.After the improvement of rat orthotopic lung transplantation operation process,the total success rate of rat left orthotopic lung transplantation operation was 90%?9/10?;donor operation time was 27.5�4.8 min;receptor operation time was 53.1�7.5 min;total operation time was 79.8�7.9 min;sleeve time was 18.3�4.4 min and one week survival rate after surgery was 89%?8/9?.There was no significant difference in the blood gas analysis before and fifteen minutes after clipping the right hilum?P02133.2�12.8 mm Hg VS 125.1�11.9 mm Hg,P=0.21;PC02 45.7�4.6 mm Hg VS48.6�3.7 mm Hg,P=0.19?.Conclusion:The improved technique has the advantages of rapid donor lung acquisition,simple and effective pulmonary arteriovenous and bronchial anastomosis,stable and high-survival rat left lung orthotopic transplantation model.Through the study of this experiment,a more stable,reproducible,high-survival rat left lung orthotopic transplantation model was finally established.It provides an simple,economical and efficient surgical approach for establishment of model to study lung transplantation.