Have you ever wondered how a lung transplant happens? My transplant surgeon answered some questions about the transplant process from beginning to end. This is a general overview & is not the exact process taken for all transplants. This process may also vary depending on the hospital where the transplant is taking place. He explained this process in an understandable way. Whether you have had a lung transplant or not, I think you will find it interesting.
The transplant pulmonologist and transplant coordinator (who is usually a nurse practitioner or physician assistant) receive a call from the organ procurement organization (an organization that evaluates and procures deceased-donor organs for transplantation) regarding an offer for an organ. They then determine whether or not the donor organs are sufficient for donation. Some organs may be viable, while others may not be. The transplant surgeon then receives a call from the pulmonologist and coordinator with basic information regarding the donor. The surgeon will accept, decline, or ask for additional testing to be done. If they accept, they proceed with the transplant. The procurement surgeon (a transplant surgeon can do procurement and the actual procedure but they never do both for the same patient) drives or flies with two operating room nurses to the other hospital to bring the organ back to the hospital where the surgery will take place. There are four operating room nurses for the recipient and two operating room nurses for the donor. Cardiac perfusion runs the heart/lung machine if it is used during the operation and they help initiate ECMO support post-operatively, if necessary.
The process of taking out old lungs is relatively straight-forward but depends on the recipient’s underlying condition. Cystic fibrosis lungs and sarcoidosis lungs are generally very difficult to remove due to chronic infection and inflammation. The lungs are quite literally fused to the walls of the chest cavity and have to be peeled away. (This was the cause for excess bleeding post transplant in my case.) Conversely, COPD, chronic obstructive pulmonary disease, and PPH, primary pulmonary hypertension, are generally quite easy. They dissect out the pulmonary artery (the artery carrying blood from the right ventricle of the heart to the lungs for oxygenation), the pulmonary veins (the veins that transfer oxygenated blood from the lungs to the heart; there are two or three per side) and the bronchus (any of the major air passages of the lungs that diverge from the windpipe). If they are doing a double lung transplant, this process is done for both sides through a clamshell incision (shaped like a curved ‘W”, and is typically cut just below the breasts). If a single lung transplant is being done then it is through a thoracotomy (incision on the side of the chest towards the back).
My surgeon does most of his single lung transplants and all of his double lung transplants on bypass support. There are many reasons for this – his feeling is that it minimizes blood loss, keeps the heart stable while they’re working, and lets him take both lungs out at the same time during a double lung transplant. The alternative is bilateral sequential lung transplant off of bypass but this means that at some point, the new lung and one of the old lungs is in the body at the same time. This leads to potential contamination of the new lung. Not many people do double lung transplants this way in the modern era.
Time is of the essence, in two senses. One, they try to time their explant procedure to coincide with the arrival of the donor lungs. They don’t want a patient sitting on bypass for hours waiting for an organ. Conversely, they also don’t want the donor lungs to arrive before they are ready to put them in…which leads to the second component. In general, the lungs need to be put in the recipient within 6 hours from the time they were removed from the donor. This is why donor organs are allocated on a regional basis. It would not be possible for a recipient in California to receive donor lungs from Virginia. There are centers that push this number up to 7 or 8 hours but the majority of centers look at 6 hours as the maximal tolerable ischemic time (a restriction in blood supply to tissues, causing a shortage of oxygen and glucose needed to keep tissue alive).
The most critical point in the surgery is the airway anastomosis (connection between the recipients airways and the donor lung airways). Blood vessels bleed so if there is a problem its pretty obvious. The bronchial anastomoses do not – if there is a technical error, they don’t know until sometimes weeks later.New lungs are put in by matching the bronchus to bronchus, pulmonary vein to pulmonary vein and pulmonary artery to pulmonary artery. They are all matched up and sewn end-to-end.
A dry run is when it is decided that the donated organ is not viable. This happens 25-30% of the time in lung transplants and less than 10% of the time in heart transplants.
My surgeon’s longest double lung transplant was 8 hours and shortest single lung transplant was less than 2 hours. This is the amount of time he performs the actual transplant with other medical professionals assuming roles in the operating room before and after.
The advances of modern medicine are quite remarkable. To think that one person can donate an organ to another person is just incredible. Seventy-five years ago, no one would believe heart & lung transplants would be happening. So far in 2017, my hospital has performed twenty-some lung transplants.