The University Of Maryland Medical Center was the first center in the US to perform a lung transplant using ex-vivo perfusion. The procedure is used to make the lungs more suitable for organ transplantation. Only 15-20% of all donors end up giving their lungs due to several factors. This is a very low number compared to kidneys and liver who are used a lot more.
The lungs are very susceptible to their environment especially in a context of a brain dead patient. Those patients have a breathing tube in the throat which increases the risk of pneumonia. Since they are lying down and not moving some gastric content can potentially go in the lungs (this is called aspiration) and cause some infection. Lungs can also fill up with fluid due to previous attempt of resuscitation. Since lung transplant recipients are the most susceptible for complication after surgery, the transplant pulmonologist are pickier.
STEEN Solution with Xvivo Perfusion
This new technology comes from a company named Vitrolife from Sweden. They created the STEEN solution to perfuse the lungs outside of the body just like this picture.
The perfusion solution replaces the blood is made from human serum albumin, dextran (prevent white cells to react) and some electrolyte solution. The red color seen above is due to the addition of 15% of red blood cells to allow gas exchange (oxygen and Carbone dioxide) in the lungs. This process is done on lungs that otherwise would have been rejected for lung transplantation based on current guidelines and are given a second chance to improve. The doctors can also do a bronchoscopy to look at the lungs from inside or to open up a closed lobe. The whole thing is kept at 37 degrees Celsius which is the normal body temperature.
What about the Future?
The ultimate goal is to have more lungs available for organ transplant and save more people. If this new technology proves to be successful maybe all lungs may eventually be fine-tuned using the Xvivo perfusion. It seems that it could potentially reduce the number and the acuity of lung rejection thus increasing the survival for lung transplant recipient.