QUAD #21: Management of Concurrent Cardiac Pathologies with Dr. David Lehenbauer

Global Cast MD along with Cincinnati Children's Hospital, sharing knowledge to improve child health around the globe. Hi everyone. I'm Emgodi from Cincinnati Children's Hospital Medical Center. In October 2022, Cincinnati Children's hosted the quad conference, which was a combination of four conferences. The International Organization for Esophageal Atresia. The Aerodigestive Society Conference, the Cincinnati Children's Airway course, and the Cincinnati Children's pediatric Dysphagia series. And in this video, we are going to hear from Dr. David Lehmbeuer, a cardiothoracic surgeon at Cincinnati Children's on cardiac surgeons perspective of complete tracheal rings, the slide tracheoplasty, using ECMO versus cardiopulmonary bypass, the associated cardiac lesions and the timing and management of those lesions. A slide tracheoplasty is a surgery done to make the airway larger. During the surgery, the trachea is opened at both the front and back, then slid onto itself and rejoined, making it shorter but significantly wider. If the child has any vascular or heart abnormalities, a cardiothoracic surgeon may address these issues simultaneously. And this is why we're hearing from Dr. Lehmbauer today. Here in Cincinnati, almost all of our operative interventions are slide tracheoplasty. Sank introduced slide tracheoplasty back in the late 80s, and Hermes Gillo popularized it in the 90s. And then back when I was in high school, Mike Rudder was knocking slide tracheoplasties out of the park in Cincinnati Children's. We've come a long way from a uh perfusion standpoint. If you'd like to learn more about the slide tracheoplasty technique, please watch one of our previous videos featuring Dr. Mike Rudder. The main difference between bypass and ECMO is the Venus reservoir. So whenever surgeons splice in the Venus reservoir, that allows them to add on accessories to the bypass circuit. We can use pump suckers, we can use vents, and all of those things are very helpful if we're doing open heart repairs. But if you get rid of all those things, essentially what we're left with is a ECMO circuit. And that basically just includes an oxygenator and then pump. So we can maintain the patient while we're doing this operation. Here in Cincinnati, almost all of the time, unless we're doing concurrent cardiac repairs, we prefer to use an ECMO circuit. We only load with 100 units of heparin per kilo. Our activated clotting time goal is much lower, it's cheaper, the patient remains pulsatile, which has been shown to be advantageous. The actual pump is much smaller, which gives plenty of room for pulmonary to get in there and do their bronchoscopy. And in the rare cases that we need postoperative ECMO, it conserves another circuit. And there's also less interaction between the blood and the patients and the air, which will reduce inflammation. The problems with using ECMO are that we don't get complete cardiac decompression. So you have a little bit more cardiac volume in the area where you're doing your slide tracheoplasty. Most of the time that's not a problem and if it really is, we can take blood volume off the patient to decompress things. Probably one of the major concerns of using ECMO. The Venus circuit in a cardiopulmonary bypass pump will tolerate air very well. If you train air on ECMO, you're in a lot of trouble because there's no way to evacuate that air other than just turning the pump off. The advantages when we use full cardiopulmonary bypass, we get complete decompression. We can move the heart out of the way, we can deal with air if we encounter any. We get to use the pump suckers. Although this really isn't that advantageous for slide tracheoplasty because you don't want to use pump suckers with tracheal secretions. Dr. Lehmbauer states that one of the big drawbacks is that they give a lot more heparin and the patient's blood is a lot more thin. We shoot for a much higher ACT and that will help reduce some of the clotting as the blood is going through those cardiotomy suckers and the Venus reservoir. So why is ECMO favored over full cardiopulmonary bypass? There's unfortunately not a lot of information about this in children undergoing slide. But if we extrapolate a lot of the data that's available for adults undergoing lung transplantation, they have significantly less bleeding, renal failure, require tracheostomy, less blood transfusions, they're on the vent longer, and they stay in the hospital a shorter amount of time. And when are we forced to use bypass? Open heart repairs and a redo slide. As we're doing that redo sternotomy with the risk for encountering major bleeding, we'll have a pump at least available in case we need emergently go on bypass. Whenever we are doing redo operations, there are additions around the trachea, and it is very important to mobilize them fully. And one of the ways from a cardiothoracic surgeon's perspective is to do hilo releases. So you start off in the plural spaces, find the inferior pulmonary ligament, go all the way up to the pulmonary veins, mobilize the pericardium around the inferior vein, and that will help reduce some of the tension for your tracheal reconstruction. With slide and congenital tracheal stenosis, what's the big deal? Even in the modern era, we still have a lot of morbidity and associated mortality. In a recent study out of Japan, there was still 25% risk of infectious complications. And we learned from Dr. Lehmbauer that they pre-op test everyone at Cincinnati Children's, looking for organisms and treat those patients with appropriate antibiotics. In most modern series now you'll find people report slide tracheoplasty mortality between 5 and 30% with the known risk factors of operating on kids less than a month of age, children that have a single lung, and then we'll look at the associated cardiac disease. Here's a recent study out of Japan with 80 patients and a 22-year experience. They found that complex cardiovascular anomalies and preop ECMO was also risk factor for mortality. Cardiac surgeons publicly report all of their information into the society of thoracic surgeons database. So they went back and surveyed the STS database and they found a total of 2,000 operations. Over 400 of them were combined airway and cardiac operations. And just as we suspected, patients that underwent tracheal intervention at the same time as their cardiac operation had significant risk for morbidity and mortality. So what are the associated cardiac lesions that we see whenever someone has tracheal stenosis? The overwhelming majority or the prototype lesion is the PA sling. We see ASDs and VSDs, uh fair amount of tetratology of follow patients, PDAs, and vascular rings. So the sling is probably the thing that they most frequently manage. Almost all of these PA slings can be fixed concurrently as we're doing the tracheal repair. The sling coming off the LPA coming off the proximal original RPA and then reimplantation. The diagram or the artwork shows that basically you're planting it back where it was harvested, in reality that's not usually what happens. Dr. Lehmbauer mentions that most of the time the reimplantation happens much closer to the main pulmonary artery, usually at the insertion of the ligamentum. So there is some controversy that still exists. Different groups will advocate when is the appropriate time to fix the cardiac lesion, when should we do the slide? Should we do them at the same time? The proponents of cardiac first and defer the trachea, you're going to put that child at risk due to the residual tracheal pathology. If we fix the trachea and then defer the cardiac repair, all of the trachea healing is going to have to uh occur with impaired circulation and possible hypoxemia. And then if you're staggering the approach, you're going to end up doing a lot of redo operations. The role for palliation is really undefined. So if you have somebody with complex disease, and this was a patient that we recently had that had a tetratology variant with discontinuous pulmonary arteries, feeding intolerance and other birth abnormalities. So what is the right way to manage that complex patient? From a cardiac surgery perspective, there's been a great increase in the amount of patients that are being managed with ductal stenting and stenting of PAs. But again, the literature is really unclear about palliation cardiac disease and concurrent tracheal pathology. Let's go back to the main question about what is the appropriate timing? This paper out of Japan had simultaneous reconstruction for simple disease and then advocated a staged approach for complex heart disease with overall low mortality. And if you look at the series out of Great Orman Street, they have an overall very low mortality. In their particular experience did not find the cardiac disease was a significant risk factor for mortality. They found that preop ECMO, Tracheomalacia, and bronchial stenosis were actually risk factors. So they would advocate for a combined repair. In the modern era, a single stage or combined repair is preferred. The PA sling, ASDs, VSDs, PDAs and vascular rings, those are all going to be straightforward simple disease that we should be able to manage concurrently. Tetratology of Flow is really a spectrum of disease. There are basic ones that are going to be straightforward to manage and fix with simple repairs. And then the very complex patients, their specific comorbidities and complexity of the cardiac disease and the complexity of their tracheal disease is what's really going to drive their treatment modality. So in summary, ECMO is preferred for smaller size, lower heparin requirements and reduced blood air interaction, despite some drawbacks like incomplete cardiac decompression. Common associated cardiac conditions include PA slings, ASDs, VSDs and tetratology of flow, often requiring concurrent repair during tracheoplasty. Timing of repairs, either simultaneous versus staged is debated with recent studies favoring a combined approach for simpler cases and staged for complex conditions with mortality risks linked to preop ECMO and tracheomalasia. Treatment plans are tailored based on individual anatomy and comorbidities with ECMO offering full potential benefits over full cardiopulmonary bypass in managing these complex cases. Thank you for watching this video. Don't forget to subscribe to the Stay Current MD YouTube channel. Follow our social media channels and download the Stay Current MD app for tons of content in pediatric surgery. Global Cast MD along with Cincinnati Children's Hospital, sharing knowledge to improve child health around the globe.