Latest / Behind The Knife: The Surgery Podcast / Journal Review in Thoracic Surgery: VV ECMO in Pre-Lung Transplant Patients - A Bridge to Somewhere
Transcript
- Casillan_episode3 updated === [00:00:00] Hi everyone. I'm Kyler Ozzi, current PGY three at Johns Hopkins, here with your BTK Thoracic Surgery subspecialty team. Joining me today is Dr. Alfred Castillian, attending thoracic surgeon here at Johns Hopkins. Dr. Castillian focuses on lung failure surgery, including lung transplantation. And has a special interest in transplant related research. Al is well known in the surgery department for bringing residents along for every organ recovery he can, making it a valuable, memorable, educational experience, usually filled with a lot of laughs. Thank you for being here today. Thank you, Kyla. It's a pleasure to be here with you today. I'm looking forward to chatting with you and your audience. So Al. In the fleeting moments, you're not within the walls of Johns Hopkins Hospital. [00:01:00] What do you like to do for fun? As you mentioned, it's definitely fleeting moments since I'm here most of the time, but in my rare spirit time, I'm pretty low key and just enjoy relaxing, watching sporting events and traveling. Today we'll be discussing BV ECMO and its use as a bridge to lung transplantation. VV ECMO or vino venous Extra corporeal membrane oxygenation is a form of life support, which is used in severe respiratory disease, allowing for the removal of blood from the body with gas exchange occurring in a circuit. While importantly and different from VA or VEO arterial ecmo, the heart continues to maintain function. So imagine we're in the ICU. There's a 42-year-old patient with end stage pulmonary disease who is already listed for a lung transplant. [00:02:00] Earlier today, he was stable on high flow nasal cannula, but overnight his oxygenation got significantly worse. Unfortunately, he has to be intubated and despite trying everything to optimize his care while on the ventilator. It just doesn't seem to be providing enough support. You're the covering thoracic resident and get a call from the ICU with a very direct question. Should we cannulate him for VV ecmo? Al, what are some immediate questions or considerations we should be thinking about whenever we consider a patient for BV ecmo? There is one fundamental question that was always forced be answered, and that is. Is ECMO a bridge to somewhere or would it end up being a bridge to nowhere? Generally speaking, for the most cases, this translates into us asking whether we feel VV ECMO could be a potential bridge to lung recovery. [00:03:00] In the case that you established, however, the pace with is already on the waiting list for a lung transplant. So the question in this case is, would VV ECMO be an effective bridge transplantation? Namely, does the patient's transplant candidacy remain intact despite their acute clinical deterioration? And would VV ECMO preserve or improve the physiologic reserve that they need to undergo a successful transplant? Every patient in situation is unique and we need to think about a lot of different things before moving forward. When considering starting ecmo, this should include a patient's diagnosis, their overall disease. When we're thinking about starting it, how we're gonna get access, what our institution is capable of, and importantly, goals of care amongst a lot of other considerations, ECMO is an accepted bridge to transplant at experienced [00:04:00] centers with outcomes, sometimes approaching those of non bridge patients. ECMO bridging was once avoided at all costs and really viewed as an indicator of an overall poor prognosis. Research, including some of the papers we'll be reviewing today, has changed how people think about the utility of VV ECMO bridging for pre lung transplant patients. Al, in your experiences over the years, how have you seen the use of ECMO evolve? What about this interest or excites you the most A little bit. Before I entered the field, ecmo bridging to lung transplant was essentially a last resort. It's something that we did only when we had no other options, and the outcomes reflected that in the early two thousands survival, the discharge for rich patients was around 35 to 40%. Obviously, at that time, the prevailing mindset was at a patient who needed ECMO before transplant [00:05:00] probably wasn't gonna do very well. What we've seen in recent years is a fundamental shift in philosophy. We moved from thinking of ECMO as a rescue therapy to thinking of it as a strategy for preserving the patient's physiological reserve. Now, in experienced centers, we are seeing survival rates of 80 to 90% among patients who are successfully bridged. There's been a remarkable transformation in a relatively short period of time. As a research oriented physician, what excites me the most about this transformation is that it didn't happen because of a single breakthrough. It happened because of research efforts that is careful incremental studies that ask the right questions, and you've been really involved in that space. So thanks for your work. The first paper we're gonna be discussing today is titled Extra Corporeal Membrane Oxygenation in Awake Patients as Bridge to Lung Transplantation by F in Colleagues. This [00:06:00] paper published back in 2012 explored the use of awake VV ECMO as a bridge to lung transplantation. Prior to this in 2010 Mason and colleagues showed that patients requiring pre-transplant mechanical ventilation had a poor prognosis following transplantation. This was in part due to complications secondary to mechanical ventilation, including diaphragm dysfunction and deconditioning that typically follows. As well as ventilator associated pneumonias. This study by funeral was the first of its kind that demonstrated pre-transplant patients placed on VV ECMO could be extubated and therefore continue to engage in physical therapy without the need for sedation on a ventilator. What do they find? The small retrospective study showed an improvement in six month post-transplant survival from 50 to 80% in the awake ECMO group. Over the mechanically [00:07:00] ventilated one. Importantly, this was a low volume single center study, which emphasizes the importance of institutional expertise in influencing outcomes and may not be universally generalizable, but it was a strong proof of concept establishing the use of awake ECMO in lung transplant patients. This leads us to the next question. If we can bridge people to transplant on the ecmo. Then who actually does well on it? Between the years of 2009 and 2018 typo Graph and the team at Columbia approached this question with a study which aimed at terminate the outcomes and the predictors of successful for using ECMO as bridge the lung transplantation. It was a single center retrospective study that reviewed 121 patients and found that 70 out of the 121 were successfully bridged with ECMO to transplant. Survival post discharge was [00:08:00] 88% at one year, which was pretty great. And the single predictor of a successful bridge to transplant was something we're always encouraging our patients to do in all facets of surgery. Ambulation Veian team dug into this finding in his article on the topic published in 2024 in the American Society for Artificial Internal Organs Journal. Also in 2024. And then in 2025 we have our next papers of interest to discuss the first authors of which were Alice Zow and Ben Show. I had the privilege and joy of working with both Alice and Ben personally. There were both outstanding Hopkins medical students when they this work, and both of them are now integrated cardiothoracic surgery residents at Stanford. We are so proud of both of them using ECMO as a bridge to transplant. Has become an accepted practice. So our group here at Hopkins has published a couple of studies that provide [00:09:00] insight regarding this, how this practice can be optimized. You're on this paper with Dr. Z and Dr. Bush, among others and some familiar names. This one is entitled, utilization and Outcomes of Non Intubated Extra Corporeal Membrane Oxygenation as a Bridge to Lung Transplant. This study analyzed patients from 2005 to 2023. To answer the question for patients who were bridged to transplant using ecmo, does being intubated at the time of transplant change the outcomes of 1,600 patients? Analyzed the data suggests that non intubated ECMO only patients did better in the short term with a lower risk of being intubated 72 hours after transplant, and they also had shorter lengths of stay. Longer term. We also found that the non intubated ECMO only bridging strategy was associated with an improved 90 day survival, with also no [00:10:00] differences seen in survival out to 10, out to five years. Based on these findings, it seems that upfront avoiding intubation is impactful, but patients can still do well, even if they do require pre-transplant intubation. Our final paper to discuss is titled. Impact of extra corporeal membrane oxygenation. Bridging duration on lung transplant outcomes. This Hopkins paper published in 2024 written by Shaun. Colleagues, reviewed over 500 patients and found the median ECMO bridge lasted about 10 days. 31% of patients died on the wait list before ever reaching transplant. Increased length of time on ECMO pre-transplant. Correlated with an increased risk of mortality. However, ECMO duration didn't impact one year survival outcomes in those who successfully received a lung transplant. It's a balance. Keeping patients on [00:11:00] ECMO to recover for some time before transplant and to secure a better lung donor may be beneficial, but this must be balanced with an acknowledgement that prolonged ECMO exposure leads to known complications including stroke, intracranial hemorrhage. Bleeding and thrombosis events. Helping patients to receive a transplant as early as possible during an ECMO run may improve waiting list outcomes in this high risk population. What a whirlwind research review through ev ECMO bridging and lung transplant patients. That team that called earlier asking us if we should cannulate the patient or not is still on the line. We should probably do a quick recap so we can get them off of hold, but before we do that. Just wanted to ask you, looking to the future, I'd love to hear what excites you the most about the future of lung transplantation surgery. Where do we go from here? The field of lung transplantation is really evolving with the emergence of some new technologies.[00:12:00] Primarily are the devices that we use to preserve the donor allografts as well as ex vivo lung perfusion. Which helps us to evaluate, preserve it, and also in the future, intervene and provide therapeutics to the allografts. So that's definitely changing the field. And in addition to that, all of these are all contributing to potentially making lung transplantation a more elective type surgery. That's really exciting stuff. I'm looking forward to that paper that you told me will be quote, the greatest paper I've ever read, and one that it seems like you wrote with Dr. Bush. Titled, waiting for a well-rested team facilitating semi elective lung transplantation. As soon as we sign off here, I'll have to give that one a read. But I guess for now, let's recap our VB ECMO bridging lung transplant episode. So the day we reviewed the key evidence shaping ECMO as a bridge to lung transplantation, emphasizing the shift toward keeping [00:13:00] patients awake and will avoiding pre-transplant mechanical ventilation and it all of its associated complications. We also know how important ambulation is while on ECMO and can appreciate the impact of non intubated ecmo, only bridging as being associated with better short and long-term outcomes. Pre-transplant length of time on ECMO also matters with higher mortality risk being associated with longer ECMO runs. However, if a patient is able to reverse through this ECMO run preoperatively. There is no impact on ECMO duration on one year survival among those who get transplanted. Historically, ECMO before lung transplant was reviewed largely as a salvage therapy for patients who were otherwise crashing. Being on mechanical ventilation, ECMO pre-transplant was often viewed dismally, partly due to the complications like deconditioning infection, diaphragm dysfunction, delirium [00:14:00] ICU required weakness. But now pre-transplant VB ECMO is seen as a bridging strategy that can be used to optimize a transplant candidate rather than attempt to rescue them. Ideally, patients on ECMO will be awake and non intubated and able to therefore participate meaningfully in physical therapy and ambulation. ECMO is far from without risks, but with advances in technology, resources, education, and research. ECMO has transitioned from being avoided to appreciated. This has been your Johns Hopkins thoracic surgery subspecialty team signing off. Be sure to dominate the day. The day dominate.