by George Taniwaki
Cold perfusion device
The Associated Press just reported the first successful use of a warm perfusion device during a transplant performed in the U.S. The headline of the article says “Beating heart transplants tested.” The operation was an important milestone, but the headline overstates the case a bit.
First, some background. Historically, organs recovered from deceased donors are placed in a preservative solution, packed in sterile ice, and placed in a standard picnic ice chest for transport to the hospital that will perform the transplant into a patient needing the organ.
Kidneys, because they are the most commonly transplanted organ, get slightly better treatment. Each kidney is placed in specially designed transport device that perfuses (pumps) a chilled preservative around the kidney. The most common one is called LifePort, produced by Organ Recovery Systems of Chicago. It looks like a very large egg, with a white body and lid, and a light blue stripe in the middle that contains a display console.
I recently took a tour of the facilities of LifeCenter Northwest, the organ procurement organization for the northwestern region of the U.S. They have several LifePort devices in their surgical storage room, all lined up and ready to go at a moment’s notice.
LifePort perfused kidney transport container. Image from IDEO
The use of a cold perfusion device can extend the useful life of a donated organ by more than 24 hours, nearly doubling the useful storage and transport time of donated kidneys. Conversely, it can improve the quality of an organ for a given time in storage. Thus, use of cold perfusion devices can both increase the number of usable organs and improve patient outcomes.
The next improvement beyond cold perfusion, is warm perfusion. Keeping an organ warm reduces the damage caused by temperature change. But it requires a special perfusion solution that contains blood so that it can circulate oxygen to the cells in the organ. The organ also has to be carefully monitored to keep it within acceptable metabolic ranges. A company called TransMedics that was mentioned in a May 2010 blog post has developed such a device for heart transplants. It pumps an oxygenated solution through the heart in pulses, but does not keep the heart itself pumping. It is now in clinical trials as described in the AP article.