The new method for long-term hypothermic lung preservation with continuous ventilation

Abstract

Lung transplantation has established for end-stage respiratory failure. The number of lung transplantation is currently increasing in Japan. In terms of procurement of lungs from donor, there are cold ischemic time and warm ischemic time. According to the guideline, total ischemic time, which is both cold and warm ischemic time, should be within 8 hours, because long ischemic time leads to primary graft dysfunction as a cause of death after transplant operation. Actually, the average of total ischemic time was more than 9 hours in our lung transplant program. Therefore, it is necessary for safe lung transplantation to keep donor lung preservation stable for long time. While we take the metabolism during lung preservation into account, donor lungs need glucose and oxygen to produce energy as adenosine tri-phosphate. Glucose would be provided from perfusate which contains rich glucose. Also, oxygen should be supplied from airway. In case of 24 hours lung preservation by conventional preservation method, concentration of oxygen was significantly decreased and carbon dioxide was significantly increased in the airway of isolated lungs in swine. As the reason for that, harvested lungs need oxygen for long-term hypothermic preservation to keep their metabolism. We invented the method of continuous ventilated-lung preservation (CVLP) for the purpose of long-term lung preservation, collaborating with Department of Biomedical Engineering. The container of CVLP consists of a ventilator, ice packs, a circulator and an air filter. And this container can be conveyed by public transportation. When we preserved harvested lungs from swine with CVLP container, the donor lungs were kept well for 24 hours in terms of improving atelectasis in appearance. We hope the new method of hypothermic lung preservation with continuous ventilation contributes to better outcome of lung transplantation in future.