A novel approach to establish orthotopic right lung transplantation in rats

Although the left lung transplantation model in rats is widely adopted, the right lung transplantation remains less common due to anatomical complexity and technical challenges. As the right lung contributes approximately 70% of total lung function, the orthotopic right lung transplantation model provides a more physiological and clinically relevant platform for evaluating graft function, particularly during the survival period, compared to the commonly used left lung model. In this study, we developed a novel orthotopic right lung transplantation technique based on our previous "pendulum model" in rats, incorporating several innovations to enhance accessibility for beginners and provide a more feasible and reliable platform for basic research.

Twenty consecutive orthotopic right lung transplantation were performed on Sprague-Dawley rats by a single surgeon using our modified techniques. The duration of each procedure, ischemia time, post-surgery complications, survival rate at 2 weeks, and histological staining for graft evaluation were recorded.

The key innovations of our novel model mainly include extending the donor's right pulmonary vein by ligating the left branch, improving the visibility by integrating anterior and posterior surgical fields of the right pulmonary hilum, and modifications to the incision of vessels. All transplantations were successfully completed without bronchial or vascular tearing, twisting, or folding. The heart-lung block retrieval, donor lung preparation, cold ischemia time, anastomosis time, and total operation times were 7.5 ± 0.3 minutes, 22.6 ± 1.8 minutes, 38.3 ± 1.6 minutes, 20.2 ± 1.3 minutes, and 76.1 ± 2.2 minutes, respectively. During the follow-up, only 2 rats (10%) succumbed to complications related to atelectasis and infection. Histological findings showed preserved pulmonary architecture without evidence of acute injury, infection, or other pathological abnormalities.

Our novel technique streamlined the learning process for rat right lung transplantation and yielded reliable outcomes, suggesting a feasible option for basic research in lung transplantation.