Update on Surgical Practice and Current State on Fontan Conversion Surgery:...

And we are back. This is now entering into the second half of the event. Uh, I have to say this has been a fantastic event, uh, so much, uh, in a, a pretty short period of time and a lot of great interaction from the audience. We do want to encourage, uh, questions. It, it's, uh, this is a, it's meant to be a very interactive, uh, mechanism of, of learning rather than just listening. So, Feel free to ask any question anytime and we'll try to feed it into the discussion. Uh, we are now going to, uh, move into the second half. So, uh, I wanna, uh, hand it back over to Doctor Veltman, who's gonna, uh, moderate the rest of the session. Well, welcome back, everyone, um, and I hope you're refreshed and ready for the next, uh, next portion of this, uh, webinar. Um, it gives me great pleasure to introduce, uh, Doctor Twaddle. Um, uh, before meeting Doctor Twaddle, I was very impressed, uh, about the concept of a surgeon wearing a stethoscope, and, uh, it was synonymous with a thinking surgeon in my mind, but I saw something very different in Doctor Tweddle. It was a surgeon. It was rephrased. It's a surgeon wearing a banjo, and that really takes it to a very different paradigm. Uh, Jim, we look forward to hearing what you've got to say on surgical practice and the current state of Fontaine conversion surgery. Thank you. I, I think, anyway, it's, uh, thank you. Um, I'm gonna talk a little bit about, um, surgery that, uh, occurs after the completion Fontan. Uh, I have no disclosures. Um, the Fontane is a surgically created condition of severe chronic right heart failure, and as we've heard earlier today about all of the sequelae of venous hypertension, hepatic congestion, lymphatic congestion, in addition, restrictive lung disease, altered pulmonary vasculature, and single ventricle dysfunction. Um, There are some ways potentially to um to uh. Help uh prolong uh this state. And I've listed, uh, the, the procedures that one might uh uh consider uh after completion Fontan. These include Fontan takedown, Fontan conversion, heart transplant, and lymphatic uh decompression. Um, I'm, and I'm gonna take them in this order. The first thing I'm gonna talk about is Fontaine takedown, and perhaps we can uh launch my third question out and see uh uh uh how that plays out. Fontaine, Fontaine takedown is generally something that's done uh early. Uh, it is, uh, the indications are low cardiac output, elevated CVP. This frequently, uh, results in a progressive, uh, downward spiral. Other options might include early revision, and that would be reasonable if the anatomic problem is clearly established, and the patient is not, uh, uh, too, uh, too debilitated by that point. Uh, other things might include, uh, temporary mechanical support, uh, if the problem were primarily arrhythmias or predictably temporary ventricular dysfunction. Uh, and, uh, the third option for early Fontan failure would be immediate takedown of the previous stage, usually a bidirectional Glen shunt. Uh, it has been contemplated for late Fontaine failure. It might help some of the problems related to hepatic congestion. Uh, but, uh, I think it's telling that there aren't a lot of large series of, of late Fontan takedown, and uh what you do hear about, uh, generally the outcome is poor. But there are some recent reports of Fontan takedown. This is one that was presented this year at the Society of Thoracic Surgeons from Bambino Jessu in Rome. They had 18 patients between 1990 and 2015. So over a 25 year period they had 18 Fontan takedowns. So not a very commonly performed operation. 2 were in the immediate postoperative period, and the remaining 16 were within 2 months of the completion Fontan. So a fairly uh uh uh early on after the Fontane. There were 17 uh early survivors. 3 underwent subsequent fontan palliation and were successful, and 4 underwent transplantation. Uh, 2 of those, uh, were late survivors, and 10 remained with the bidirectional Glenn hunt physiology, uh, but with reasonable saturations, and the median follow-up of those who remained as a Glenn was, uh, 7 years. So, uh, again, uh, not, uh, uh, uh, um, not, not too bad, uh, if you assume that all of these patients were in dire straits when this was contemplated. This is a study from Van Mellen colleagues. It's a multi-institutional registry-based study from Europe, and uh some of the previous patients I described are probably included in this as well. Uh, they, uh, they took a longer time span, 1971 to 2012, 38 takedowns. Um, the average time between the Fontan to Fontan takedown was 0.6 years. So again, pretty early, uh, although a few patients were farther out. Uh, the follow-up was just short of seven years. The early mortality was substantial, about 20, about a quarter of the patients, and there were five late deaths. 4 underwent heart transplantation with 2 deaths. Uh, 2 patients underwent a subsequent, uh, Fontan. And uh uh with a reasonable outcome at 34 months, um, 17, 44% of patients had reached their final endpoint by the time of the study, and this is the survival curve from that study. So, again, not, uh, not a, uh, uh, uh, certainly a strategy for a desperate group of patients, but uh did uh potentially salvage some of them for uh future Fontan or heart transplantation. Fontan conversion is the, uh, is a, a procedure primarily used for patients after atrial pulmonary uh Fontan with atrial arrhythmias. These are just some uh drawings from. The group at Luri in Chicago. Um, you can see here, uh, uh, a right atrial to pulmonary artery connection. Uh, the dotted lines indicate the areas of resection. This always involves a large reduction of the atrium. And it's combined with uh a maze operation or a set of lesions uh to prevent the propagation of macro reentrance circuits, which are thought to be the mechanism for, uh, which are the mechanism for most of the arrhythmias we encounter. Uh, and that's uh the lesion set is shown here. Uh, this is accomplished both by incision. As well as by use of a cryo catheter. And uh this uh uh uses uh frozen uh argon uh to achieve a cryo lesion. And you can see this uh malleable wand here is extended from a sheath uh to allow you to make lesions of uh various sizes and shapes, and, uh, creates a, uh, um, an area of tissue, um, uh, death in the, uh, uh. Around the cryo catheter. Ultimately, uh, pacing wires are pacing leads are placed and a permanent pacemaker is attached, and an extra cardiac conduit, uh, Fontan, is established. And maybe we could launch those first two questions now also. Um, the, the lesion set, uh, is, uh, for a, for a maze procedure is shown here on the left. Um, and these are, uh, Established using the cryo catheter or, or uh cut and sew strategies. But of course, uh, many of our patients don't have a tricuspid and a mitral valve, and so on. So, the, the lesion set has to be altered uh to accommodate the uh specific anatomy of the patient. And some of the lesion sets used by the group in Chicago are shown here to the right. Uh, they might include uh uh uh Slightly different lesions when you don't have a tricuspid valve or the coronary sinus might not be in the typical position as seen as in a patient with heterotaxy syndrome. The question has come up, what kind of arrhythmia procedure is the best for these patients? Uh, this is, uh, uh, the most recent data summary, uh, from, from the Chicago group, the largest single center experience with Fontan conversion. And, uh, this shows the arrhythmia recurrence rate using the different uh strategies, either a bi-attrial maze, uh, right atrial maze alone, or simply isthmal ablation. And I think it's pretty clear that the more complete the arrhythmia procedure, the lower the risk of recurrence. So this is sort of suggests that if you're going to do the operation for arrhythmias, that the more complete lesion set is indicated. Uh, the results with Fontan, uh, conversion, uh, the group from Chicago, a large single center experience, had a low mortality of 1.4%. Multi-center trials have shown, uh, uh, the early mortality to be, uh, more in the range of about 10%. And this includes data both from the STS, uh, congenital Heart Surgery database, as well as the European multi-institutional, uh, study I showed before. But, The conditional survival appears to be pretty similar between the European experience and that in Chicago, suggesting that the difference in mortality is primarily due to patient selection and execution of the operation. This is a study that was published this year from Japan. And they asked an interesting question, uh, could you justify prophylactic fontan conversion for an otherwise well, uh, and, uh, and arrhythmia-free individual with an atrial pulmonary fontan. They looked at 32 patients. Uh, they had 25 who underwent surgery for tachyarrhythmias, uh, uh, plus or minus PLE. And group 2 were 7 patients with an atrial pulmonary fontan, but with no arrhythmias. They found that the group without arrhythmias had no late deaths. I didn't show the survival curves here. These are freedom from arrhythmia and freedom from PLE curves, but also they were completely free from uh arrhythmias and from protein losing and neuropathy. You know, it's hard to know whether this justifies the use of uh Prophylactic fontan conversion because we're not really sure how these patients would have done if we had just left them alone. Uh, but it does raise an interesting, uh, uh, question. The, the, the whole area of Fontan conversion, at least for atrial pulmonary fontans, may be, uh, a, a short-lived, uh, uh, concern, uh, because the number of patients with atrial pulmonary Fontan's is, uh, decreasing. Who is a candidate for conversion? Well, this is primarily an arrhythmia procedure, so preserved function, a ventricular function is important, as well as preserved end organ function. The risk factors, significant risk factors, what I would think would be contraindications would be protein losing enteropathy, older age, which has been identified as a risk factor in, in several series and may be related to the elevation of end diastolic pressure with age, uh, ascites, right or indeterminate ventricular morph. and interestingly, a biattrial arrhythmia operation has been identified as a risk factor for for mortality, but certainly protein losing enteropathy, worse function and older age would be reasons to not proceed with Fontan conversion. This is a slide from the group from Melbourne, and they summarize the experience with Fontan in Australia and New Zealand. And this is the cumulative population of individuals with a fontan in those countries and the type of Fontan that they had. You can see here that the number of patients with an atrial pulmonary Fontan, uh hit its peak in the early 90s, is now decreasing over time. In Australia, and New Zealand, the only type of Fontan procedure performed since 2007 is an extra cardiac conduit. So at least the classic atrial pulmonary fontan conversion operation is uh is decreasing and uh we would anticipate decreasing in the next few years. Uh, Doctor Lawrence gave a terrific talk on heart transplantation, and I'm only going to touch on, uh, this, uh, just from some of the surgical, uh, uh, technique standpoints. Um, uh, this, uh, would be a fifteen-minute talk on the various ways to do transplant for the unique anatomy sometimes encountered. Uh, and we might talk about, uh, how to transplant situs and versus or any number of things. But, uh, all of these patients will have, uh, one, thing in common, and that is they will have, uh, uh, concerning, uh, pulmonary artery anatomy. This is just, uh, one, type of patient which we commonly encounter, uh, for heart transplantation, uh, Fontan after a hypoplastic, uh, after Norwood for hypoplastic left heart syndrome. You can see an extra cardiac conduit, a previous bidirectional Glenn hunt. A stent in the uh left pulmonary artery. And this can be, uh, this can create some challenges at the time of transplant. Uh, the pulmonary arteries have been at low pressure throughout this individual's life. Uh, they can be very delicate and thin-walled. In addition, you have a lot of aorta pulmonary collaterals. And so, uh, this really creates um an area of some uh challenge. When you get the heart excised and you've taken down the glen, you're left with this situation. Commonly, you have to repair the defects created by the glen and the extra cardiac conduit, as well as dealing with this, with the area that the stent has been placed, assuming it is not adequately dilated, and it frequently is not. Uh, some have recommended replacing the central pulmonary arteries, uh, with a cortex graft. You can see here, uh, a very narrow left, uh, pulmonary artery. Uh, uh, I, I've tried to, uh, stay away, uh, from the hilar pulmonary arteries. Again, these vessels can be very thin. They've frequently been manipulated at previous surgery. They may be deserosalized or the adventitia may be removed, and they're very prone to injury. And if you get an injury in the back of one of these vessels, it can be really very challenging to repair. My preferred strategy is to, to do this part of the operation with circulatory arrest. You might have this kind of anatomy, again, a bidirectional glen shunt, an extra cardiac conduit, a stent in the left pulmonary artery. After you've taken out the, uh, the extra cardiac conduit and taken down the uh the uh fontan, you can patch. This is relatively straightforward to sew a patch on there. And then incise out on this pulmonary artery during a brief period of uh circulatory arrest, this allows you to sew a patch on. And then really only manipulate the central pulmonary arteries rather than getting out here in this challenging area. And then you have something that looks like that and you're ready for a transplant using a bi-cable technique. Thoracic duct decompression is a relatively newer procedure that has been proposed for patients with um uh protein losing neuropathy. And the lymphatic circulation drains into the central venous circulation, venous hypertension will result in lymphatic hypertension, and lymphatic hypertension will lead to protein losing neuropathy and plastic bronchitis. Um This is a depiction of the. Lymphatic and venous anatomy viewed from the front and you can see here that most of the lymphatic drainage, the lower half of the body and the left half of the trunk drain to the junction of the left internal jugular vein and the innominate vein. So one potentially one approach, one innovative approach that's been Uh, published is this in which the innominate vein is detached from the superior vena cava and then anastomos to the, uh, to a low pressure atrium. Uh, Doctor Hiroska published a report of, uh, two case reports on this with improvement in, uh, uh, protein losing and neuropathy. Christian Creutzer, uh, from Argentina, um, Guillermo Creutzer's, uh, son, who's also a congenital heart surgeon, has suggested actually, um, uh, creating a second detachment here of the proximal in nominate vein from the left internal jugular and left subclavian vein, and then restructuring, uh. An ominent vein, uh, using a Gore-Tex tube graft. And this way, you might avoid the, uh, uh, right to left shunting and cyanosis that will be associated with this anatomy. So, uh, In conclusion, I would say the Fontan takedown is a life-saving operation for some patients with early failure. Uh, Fontan conversion is an option for individuals with atrial pulmonary fontan, arrhythmias and preserved function. The future role of the Fontaine conversion is unclear as the number of individuals with AP connections decreases over time. Lymphatic decompression may provide palliation, but as yet the experience is very early. And ultimately, I think the, the best uh uh and uh best hope for long-term survival probably rests with mechanical support and transplantation that will require a better understanding of support, as well as a better understanding of underlying sensitization and immunosuppression. And uh I don't know if we had any results from the the questions. Maybe we can show them. Um, The first one, an eight year old male with heterotaxy syndrome, had a bilateral bidirectional glen. Uh, at 8 months and is post-op day 2 from a fence rated Fontaine. He has low output with elevated central venous pressure, alleguria, ascites, and worsening acidosis. He has a good single ventricle function and um. I don't see the rest of the question. Uh, a mild common AV valve regurg. He is in sinus rhythm with no pathway obstruction, next best step. It's a huge breakdown here. So, most, 50% said take down to a bidirectional Glenn shunt. Um, then you have all the other answers. 20% said AVECMO, uh, 20% said hemodialysis, and 10% said VV ECMO. That's a perfect question then because I selected the, uh, the 40% if they got the right answer, so. Um, The next one was. Uh, which procedure will result in the, do you want to actually address those, those different answers about why? Sure. Um, well, I think that I was trying to create a scenario where uh the, the best option would be. Uh, Fontan takedown. Uh, you have somebody without an obvious problem to revise. Uh, and, uh, uh. Why are the other ones wrong? Well, you have to assume here that either the patient has an elevation of EDP or an increased pulmonary vascular resistance as the, as the cause of their failure. Um, uh, so, uh, ECMO is really not likely to fix either of those, uh, uh, and may make them worse, either VA or AV. VV really wouldn't have any, any much of a role in the face of low output, right. Um, and so that really makes, uh, and, and while dialysis might be, uh, uh, Required at some point it's unlikely to reverse the process. OK. And as you were just explaining that more and more people were going for the takedown. OK, good. So, uh, the next one is which procedure will result in the lowest rate of recurrent arrhythmias after fontan conversion? 90% said biattrial maze. Good. That's right. You're talking the right answer. OK. Um, and the last question, a 20-year-old man with tricuspid atresia and atrial arrhythmia status post atrial pulmonary fontan is being considered for a Fontan conversion procedure, which would be a contraindication, a mix here again. So, most, 50%, not much, not by far though, said severe mitral regurg. Uh, about equal to that, 40% said poor ventricular function and 10% said left pulmonary artery stenosis. Well, the, the answer is poor ventricular function. The other. Problems are potentially uh uh Can be rectified. The poor ventricular function is the one that would Would put this person out of the out of the fontan conversion category. Great. And I did want to tell everyone both here at the table and in the virtual audience, we can absolutely throw these polls up spontaneously. So if anybody has a question that they want to ask the audience, uh, even from the audience, if you want to ask the other audience members, just let us know your question and then your potential options, and we will throw the poll up. So as we put up the uh next uh talk for, uh, for Stacey, Jim, uh, you know, sometimes we don't really have many options open to us surgery, uh, VD options, uh, and really it's sort of a choice between, um, Uh, doing nothing in palliative care, uh, and going for, um, Fontan takedown in a, in an adult population. Is that anything you would consider a feasible option for the adult with the failing Fontane? Is, you know, is it really something we could consider in the older patients who've been down 1520 years with their Fontan? Is it a realistic option, uh, to pursue? Is, is what exactly? Fontaine takedown, uh, let's say to a bidirectional blend with accessory blood flow or well I've I've, I've heard that postulated. Um, I think the, I am, and there are certainly no, there is no shortage of individuals with hepatic congestion and protein losing neuropathy and so on. So, either people are not doing it, or if they're doing it, the results weren't uh worthy of publication, I guess is the answer. Uh, and I, I, I think that would, uh, I, I worry that the degree of cyanosis would be really dramatic, even with an additional source of pulmonary blood flow, even if you intended to put a shunt in. And I'm, I'm always impressed that uh uh older patients who have been ascyanotic for whatever reason, even if you think you're going to improve their cardiac output, uh, uh, if you subject them to a significant amount of cyanosis, even something well tolerated in a small child, they will not do well with that. Thank you.