“LUNG AND HEART-LUNG TRANSPLANTATION IN PULMONARY HYPERTENSION”, MARCH 18, 2024
NB. This transcript can be translated into your preferred language – use orange button at the bottom centre of this page to select it (slides are not translatable).
DISCLAIMER: Despite every effort to ensure the accuracy of this transcript, we strongly encourage all visitors to consult with their healthcare professionals before making any decisions based on the information provided. Additionally, while the quality of Google Translate has improved tremendously in recent years, please remember that it is an automated service and not a human translation.
I work at the university of Vienna and I’m the head of the surgical faculty of the lung transplant program. I work as consultant for Medtronic promoting dual lumen cannula which are not usable in pulmonary hypertension patients and patients gave their permission to show their photographs.
My talk will be divided into three sections, first I will start by talking about the indication and timing for double lung transplant, second i will talk about the procedure, whether bilateral, heart lung, or single lung transplant, and I will finish my talk about the postoperative management and the struggle we face in the intensive care unit with the so called cardiac remodelling phase.
In the Vienna lung transplant program we are consistently performing between 100 to 120 lung transplants every year and this makes us one of the largest centers in Europe, and are also a referring center for pulmonary arterial hypertension and therefore pulmonary hypertension accounts for approximately 8 to 9 percent of our transplants.
This is unique in a way if you look at the International Society of Heart and Lung Transplantation (ISHLT) data you can see that only 2.8 percent of the recorded transplants are performed for pulmonary hypertension patients and this results in a relatively low number.
What are the indications for lung transplantation in general? In general we can transplant any chronic acute end stage lung disease which has failed medical management so for most patients it should be the ultimate treatment. We don’t want to see patients too early but also we don’t want to see the patient too late. So it’s important to remember that we are trading one medical challenge for another so a patient remains a patient but mostly the person has an excellent quality of life.
You have heard from Prof. Savale a couple of things about the clinical guidelines for pulmonary hypertension and when to step in. I think whenever there is an inadequate clinical response to primary therapy in high risk patients, we need to see them in the transplant center to decide if the person is a transplant candidate. When you see the changes between the 2009 to 2019 guidelines you see that lung transplantations have steadily moved up in the treatment algorithm for pulmonary hypertension patients and nowadays it’s more or less located in the center, which highlights the role lung transplantations now have in the treatment algorithm for pulmonary hypertension.
In the photos below you can see the problems arising when the patients arrive too late. The patients on the left have right heart failure and end stage pulmonary hypertension. All of these three patients got their transplant however it’s easy to understand that we struggle a lot in transplanting the ones on the left and we really like to see patients as you can see on the right hand side.
So once we have decided to transplant the patient we need to decide which type of procedure we should do.
Traditionally pulmonary hypertension was considered a classic indication for heart-lung transplantation because the heart was considered too damaged to last after lung transplantation, therefore the pioneers in transplantations of pulmonary hypertension decided to go for heart-lung transplantations and the pioneers hence were Norman Shumway (Stanford 1981) and Bruce Reitz (Stanford 1981).
Then, in the 1990s and 2000s, the transplant centers started to experiment with a double lung transplant approach, previously utilised for patients with pulmonary fibrosis and chronic obstructive pulmonary disease (COPD), exploring its application in cases where only the lungs needed replacement, thus preserving the patient’s heart. The rationale behind this technique is that the heart typically adapts well after receiving new lungs, undergoing a remodelling phase during the initial postoperative period. With advancements in postoperative care, it has been established that patients with pulmonary hypertension can successfully undergo lung-only transplantation instead of combined heart-lung transplants.
Current survival data, although based on studies from 15 to 20 years ago, show that patients receiving double lung transplants fare as well as those who undergo heart-lung transplants. Today, the outcomes for double lung transplantations have improved significantly, making it the standard care procedure for pulmonary hypertension patients.
However, the situation is different for single lung transplants. While feasible in chronic obstructive lung diseases or pulmonary fibrosis patients, this method is not advised for pulmonary hypertension patients. Performing a single lung transplant can lead to a disproportionate blood flow to the new lung, resulting in haemodynamic instability and a higher risk of primary graft dysfunction and then, down the road, these lungs tend to fail early, and we have seen cases with early chronic lung allograft dysfunction syndrome. Therefore, single lung transplants are not recommended for pulmonary hypertension.
What is cardiac remodelling? It describes the phase a patient undergoes after a double lung transplantation and the recovery he or she experiences during the Intensive care unit stay.
There are three important aspects of cardiac remodelling we are always concerned about: the right ventricle post-transplant, how the left ventricle copes with the new circumstances, and of course, the graft itself.
I don’t want to delve too much into detail here on how you can balance the right ventricle, left ventricle, and graft, but I want to highlight that the use of postoperative prolonged veno-arterial extracorporeal membrane oxygenation (ECM0) has really been a game-changer in treating pulmonary hypertension patients post-transplant. This is a kind of slimmed-down cardiopulmonary bypass machine, which drains blood from the venous system and returns it to the arterial system, thereby bypassing blood from the pulmonary circulation and helping a pre-damaged pulmonary hypertension heart to recover.
This is a typical picture of prophylactic postoperative veno-arterial extracorporeal membrane oxygenation in a pulmonary hypertension patient. We need an additional two to three cm incision above the femoral vessels, where two cannulas are placed into the artery and vein. A third cannula is used to perfuse the leg. Typically, such a postoperative veno-arterial extracorporeal membrane oxygenation in pulmonary hypertension patients stays in for two to three weeks and stabilises the heart function of the patient. Then the cannulas can be removed, and the patient usually recovers in a much smoother way after the transplantation.
Here again are survival curves from an important publication by one of my colleagues. You can see that with a postoperative prolonged strategy with veno-arterial extracorporeal membrane oxygenation, the cohort survival significantly improved. We now reach one-year survival rates of 90%, which is excellent for pulmonary hypertension.
Our data show that we are not alone with this experience. If you look at other transplant centers that promote postoperative prolonged extracorporeal membrane oxygenation in pulmonary hypertension patients, you can see that the early post-transplant mortality has significantly decreased, and we can now offer five-year survival rates of 75% to pulmonary hypertension patients, which is really excellent.
But, as we all know, survival is not a good outcome measure by itself. It’s also important to look at the quality of life that comes with the improved survival. On the left-hand side of this slide, activities are plotted in red that could not be done before the transplant, despite optimal medical treatment in pulmonary hypertension patients. Then, on the right-hand side, there’s hardly any red left, and most activities can be resumed by lung transplant recipients.
,
Sometimes the overall organ function is so good that patients can actually climb high mountains. Working in Austria, of course, I’m a proud mountain climber. The photo above shows a project led by our lead pulmonologist, Peter Jaksch, who lbrouht lung transplant recipients, including pulmonary hypertension patients, to the peak of Mount Kilimanjaro back in 2017.
This was the famous peak picture. I’m excited to announce that next year we plan to conquer Aconcagua, which is about 7.000 meters high, and I’m pretty sure that the transplanted patients will be successful there as well.
So, in summary, lung transplantation for pulmonary hypertension provides excellent outcomes in experienced centers. We now face one-year survival rates of above 90% and five-year survival rates of 75%, going towards 80%. Early selection is important, so you should refer to a lung transplant center immediately after the failure of initial treatment to decide who is a candidate and to offer the optimal treatment to pulmonary hypertension patients. Thank you very much.
,