CNA Conference - Dr. Stephen Manu - Minimizing radiation exposure during CNA

And now we are going to have, I would like to introduce uh our very friend, uh Doctor Stephan Manu, that, and he's our friend and he's electrophysiologist in Akron Children's Hospital in Ohio, United States. And he's talking about minimizing radiation exposure during cardio ablation. It's a, it's a very good issue, very important issue. My name is Steven Manu. And I'd like to thank Dr. Clark and Dr. Pashan for this opportunity to present at this conference. In this talk that I have entitled zero floral cardinal ablation. I'd like to discuss with you an emerging trend in electrophysiology being applied to CNA or cardio neuroablation. I have no disclosures. I begin with two objectives in mind. The first is to review the current trends of fluoroscopy use in electrophysiological studies. And the second is to discuss the elements that are necessary for radiation-free cardio ablation or CNA. Here's a question for you to ponder. There is a young lady who has been admitted to your hospital for severe recurrent vasovagal syncope. Her symptoms have progressed to such that she is no longer able to take in solid foods without passing out. CNA is a very attractive option in this scenario. However, the fluoroscopy machine at your institution is down. Do you A, cancel the procedure because it is impossible to do this without fluoroscopy, or do you cancel it because it is not safe? Or perhaps you'll consider and see where you claim that it is very possible to do CNA without fluoroscopy. I want to posit to you that cardio neuroablation can be performed without fluoroscopy in a safe and efficient manner, but there I even go further and declare that it can be done in a very elegant fashion. The history of EP, or at least interventional cardiology, cannot be dissociated from fluoroscopy. In the first cardiac catheterization procedure, Doctor Forschmann was able to visualize the tip of his catheter in his right atrium simply because of fluoroscopy. And these wonderful advances have made much medicine possible. And despite these great advances, the damaging effects of ionizing radiation have been identified and extensively studied in the past recent years. From the deterministic effects that are those that are dose dependent, such as skin injuries, cataracts, myocardial damage. Versus the stochastic ones which are not dependent on the amount of radiation, such as the risk of malignancy or effects on fertility, these all affect both patients and the various members of the medical team. I propose we push the envelope even further and utilize zero radiation. Knowing that it is safe and efficient. In fact, this is how we've been doing it at Akron Children's Hospital, both for pediatric and adult cases and under the leadership of Dr. John Clark, this goal truly is being reached. Let me show you our technique. The steps to a successful no flow CNA case begins or can be divided into four main categories. That is, first, to obtain central access, to outline the 3D geometry of the heart, and to be able to safely move the catheter into different positions in the heart, to to be to being able to transepally access the left atrium as well. And then finally using extra cardiac vehicle stimulation to provide an elegant endpoint. To guide procedural success. Let us begin with obtaining access into the vasculature. Gaining access into the femoral vasculature is the gateway to any cardio neuroablation procedure. Yet it can be one of the most frustrating parts of any case. Using the anatomic method and identifying relevant anatomical structure as the femoral triangle is helpful. Nevertheless, vascular complications remain an important complication during EP procedures. So the question we ask ourselves is how can we safely access the femoral veins while minimizing complications. In this situation, ultrasound has proven to be critical in this pursuit. Here's an example showing direct puncture of the femoral vein. Being able to see what is happening underneath the skin and watch the dynamics between the needle and the femoral vessels adds a level of clarity and safety not easily obtained otherwise. Often when going up the IVC 1 may enter the vasculature and meet resistance which would prompt fluoroscopy use. However, patients and. And the and and the understanding that the anterior portion portion of the IVC does not have collaterals and therefore a gentle bend of the catheter anteriorly can help move the catheter safely up into the atrium without meeting much resistance. In the latter part of 2022, that is last year, the EP team at the German Heartat Center in Munich sought to compare the rate of complications utilizing ultrasound for vascular access versus the conventional method with patients undergoing ablation for cardiac arrhythmias. And in agreement with multiple other publications that are that are out on this, on this topic, they found a much lower rate of complication using ultrasound compared to not doing so. Here we see that they pointed out that ultrasound guided venous puncture significantly reduces major vascular complications, but in particular hematomas greater than 5 centimeters and pseudoaneurysms, particularly in patients with elevated BMI, that is, those that are greater than 30 kg per meter squared. The second aspect of this procedure, of this goal is obtaining and identifying the geometry of the heart, that is outlining the heart in such a way that we're able to safely navigate through the chambers without trouble. With the introduction of electroanatomic mapping symptom systems which utilize impedance and or magnetic fields to identify where catheters are positioned in 3D space, along with versatile sheets and catheters, our ability to both shorten the procedure as well as minimize or even eliminate radiation has been vastly enhanced. In obtaining geometry, we advanced the catheter, in this case, the Abbott HD grade catheter from the IVC and gently into the right atrium. And with slow methodical movements of the catheter, accurate geometry can be drawn, and during this time, thousands of electrograms are being collected, which will be analyzed and serve as targets for the ganglion plexi, which will belated later on in the case. Along the time along the way, we will also obtain respiratory gate and information which will help keep the catheter movement more stable. Here we're going up into the neck, but however, and that's just to make a track which will be used later on to approach the internal jugular vein. However, we do come back down into the SVC, track down into the right atrium, and carefully map out the right atrial geometry. Typically this process takes about 10 to 15 minutes. However, it is important to be slow and careful and methodical. What's interesting is the question that we must ask ourselves is, what other parts of the procedure utilize radiation? And herein comes the the step of transeptal puncture. With the right side geometry complete, we move on to gaining access to the left side. In the current literature, transeptal axis is where the efforts to minimize radiation exposure meets the most challenge. However, again, this can also be done safely in a in a manner that is efficient and certainly can be done without ionizing radiation. In 2008, Dr. Clark and the rest of the team here at Akron Children's demonstrated very clearly that left side access of the heart can be achieved safely using 3D and electronatomic mapping and echocardiogram. And here's an example of such where the transeptal. The system is brought down from the SVC and headed towards the foreign valley which has been demarcated on the electron atomic mapping system previously. Thereafter we can complement the approach with Echo, in this case IC, where the septum has been identified, the left atrial structures have been identified, and then also the system is then again brought down from the SVC and headed down towards the septum. And once enough of a tent has been approached and the position is satisfactory, the left atrium is safely accessed. The same can also be done using transesophageal. Echocardiogram. But here's a question for us to think about. How safe is it to perform a transeptal puncture without ultrasound guidance and utilizing just the electro anatomic mapping systems? Doctor Bowen and his group evaluated this question earlier this year, and they found out in their study that being able to position the transeptal system centrally on the on the on the on the Formento Valley was they were successfully able to do this about 85% of the time. And and and and in 16% of the time they were able to do that while not centrally, it was in a safe location. More importantly, they identified no situation where the needle or where the system was, was at a dangerous location, such that it is very possible to perform a transeptal access even without ultrasound. Once the geometry of the left side has been obtained, we finally turn to extracardiac vagal stimulation. Typically for extra cardiac vagal system, a stimulation to be performed, it is not under fluoroscopy, and the jugular vein is accessed and the stimulating catheter is advanced to the jugular vein, or excuse me, the jugular foramen and stimulated under the guidance organ of flora. And in Figure B, we can see that the trend or the new beginnings is being performed. Typically for extracardia vagal stimulation, this is done under fluoroscopy. The jugular vein is accessed, is accessed, and the, and the catheter is advanced with the jugular foramen and stimulated. Again, under the guidance of fluoroscopy. In Figure B, we see the beginnings of an alternative where ultrasound is being used to scan the cervical area. To find the vagus, the vagal nerve. Being able to reproducibly stimulate and capture the vagus nerve clearly is an important part of extra cardiovascular stimulation, particularly when we're aiming for binodal, that is sinus and AV nodal cardio neural ablation. Dr. Petrovsky and his group have clearly and nicely outlined the steps in achieving vagal stimulation reproducibly without radiation, that is using ultrasound. And the ability to do this reproducibly again is based on is guided and afforded by the anatomy of the carotid sheath. And here we see that the Carotid sheath is made up of the. Internal jugular vein and the common carotid artery, and in between the two of them lies the vagus nerve. Here's a cross sectional view of the same. Again, we've seen the carotid sheath in cross section. We have the internal jugular vein more laterally and the carotid artery more medially and posterior to the two vascular structures is the vagus nerve. Here's a look at the same using ultrasound. Again, we can see the internal jugular vein is easily compressible, while the carotid artery is not as easily compressible, and posterior to the two vascular systems is the vagus nerve as as pointed out by the arrow here. And the vagus nerve can be identified as a hypoechoic structure with a very hypeechoic peripheral. Oftentimes it's been described as having a honeycomb appearance to it. And by being able to utilize Doppler, we're able to identify the two vascular structures, and the non-vascular structure, that is the vagus nerve can be seen and identified and be approached reproducively in an effective and safe manner. And here's an example of such where once the vagus nerve has been identified, the catheter, the stimulating catheter can be gently positioned right next to it and reproducibly stimulated. And by moving the catheter back and forth and watching the electrode tips, we're able to make sure that truly the electrodes are sitting right on the nerve and can ensure capture. Very, very regularly. A complementary view using the long axis view shows the same where there's a gentle curve of the catheter as it approaches the vagus nerve which sits and runs right below in this image here. Much like in human anatomy, there's often variations in the in in in the human in anatomy. And In this paper, To help categorize the locations of the vagus nerve, 3 or 44 main categories were identified. The most common was to find the vagus nerve. Posterior between the two vasculatures, that is the internal jugular vein and the common carotid artery. The next common was the vagus nerve being posterior to the common carotid artery, followed by being posterior to the internal jugular vein. And the least common position of location of the vagus nerve was anterior to the two vasculature system to the to the two vascular structures. Here's an example of a location A or anterior, where we see the vagus nerve sitting anterior to the interodigular vein and the carotid artery. Now I should remind ourselves that sometimes when going up the catheter or going up the nerve, the neck can be difficult, and there is much resistance in going up. But then being patient and also remembering that the jugular vein oftentimes has jugular veins in it, valves in it, I should say, and these valves, and here's an example of such by because of the pipe. You can even see the bicuspid nature of these valves. They can oftentimes impede catheter movement. However, because of ultrasound, you're able to see these very clearly and carefully can navigate around these, these vascular, these these structures. Such that we're able to take a difficult procedure that is being able to identify the vagus nerve and stimulate it accurately using ionizing radiation and using the concept of zero fluorocNA we're able to do this using electroanatomic mapping systems. Ultrasound and now not only are we able to identify the right atrium and the left atrial geometry, but also can identify where the frank nervous. We're able to position exactly and know where the esophageal probes are to monitor temperature changes during ablation procedures. I conclude by reminding us that zero fluorocardio neuroablation or at least minimizing fluoroscopy use during cardio neuroablation is very, very possible, as I've outlined and shown you the different steps that are involved in doing this and how this can be done safely and successfully. zero fluoro is very possible. It's a trend that is seen in our world today. Dare I even say it's the way of the future. The question that we must ask ourselves is why not now? In conclusion, significant exposure of ionizing radiation remain an important concern, and CNA can be performed safely and efficiently with arthroscopy. Akron Children's has been leading this initiative, particularly in the pediatric population. I trust by now you will agree with me that the young lady that we talked about earlier can still have a procedure done even when the fluoroscopy machine is done. And that I thank you for your attention. Wonder Thank you, Steven. Thank you, Doctor Manu. Thank you, Steven. Before we move on to questions for this lecture, uh, we have a little video, editorial video to play from Doctor Mansoor Razminiia. Doctor Razinia, uh, is in Chicago, and he is a tremendous proponent of floralist procedures. He's written the textbooks on how to do catheter ablation without fluoro, and so he wanted to give his input. And so can we hear from Mansoor Rezmania. Hello. My name is Mansour Ezmini. I'm a cardiac electrophysiologist practicing here in Chicago for the past 20 years. About 14 years ago, I started performing all my catheter operations without using any X-ray. We have performed about over probably close to 4000 Consecutive catheter ablation of any type of endocardial arrhythmias, uh, using no X-ray. Um, I'm so glad to see that actually, uh, the procedure is, uh, actually everywhere throughout the world. Um, And that is becoming a paradigm shift and uh many centers now they are practicing it routinely and uh many uh like programs, like teaching programs, they are training their fellows to learn how to use uh intracardiac echo with combination of electroanatomical mapping and EGM to be able to perform these cat ablations without Uh, need of any, uh, X-ray, which also here is gonna, of course, uh, is gonna save our patients and ourselves from radiation exposure. Also, it's gonna help, you know, ourselves as well as our staff not to wear Heavy lead apron, um, which is gonna be causing a lot of orthopedic injuries in the long term, and we are all aware of that. Um, So, I'm so happy here actually to see that uh Uh, Doctor Manu and his team are Now, performing CNA procedures, uh, without using any fluoroscopy, this is so intriguing and I really enjoyed. Uh, the talk by Doctor Mao, especially being able to, you know, combine, uh, electroanatomical mapping into a cardiac echo, and now they're using ultrasound just to be able to locate the, uh, vagus nerve, uh, which is so fascinating to be able to see it and Um, being able to perform this procedure very safely, especially on young people who are gonna need, uh, CNA, uh, um, procedures. So, I really congratulate the team, congratulate uh Doctor Pican for pioneering this cardio neuroablation, uh, Doctor, um, Clark, who is one of the pioneers of uh performing catheter ablation without any X-ray, well before we even in adult cardiologists started doing that, uh, by using, um, Electroanatomical mapping and EGM and sometimes a TEE or 2D echocardiogram and performing these procedures without using any X-ray and actually, myself, I owe it to our pediatric uh electrophysiology colleagues for pioneering this. Again, um, thank you so much for everybody for, uh, joining this, uh, great talk and Um, I congratulate you again, Doctor Manuel, and the team for this great presentation. Have a wonderful day. So we have one question, uh, Nestor Lopez, uh, yes, uh, related to the workflow, uh, I want to know if it's better to start on the right or the left side and, and why. So, I can, we wanna get a perspective from each of you guys, Doctor Clark, please, John, give your opinion about it. For CNA, you know, we draw the right side first, then we go transeptal and draw the left side, and we get all of our geometry, so. The last place we're at before we start doing anything is on the left side, so we tend to start on the left side. And I would say more often than not, we don't end up doing anything on the right side because we're doing extracardiac vagal stem. And once we're done on the left, if we have no further vagal response, then we're done. Um, so that's our approach. We start on the left. Yes, thank you very much, Nestor, for your question. Nestor is, uh, an electrophysiologist. And he's the next president of LAHRS. So, uh, he's enthusiastic about, uh, cardio neuroablation. It is very important for the method. And, uh, we, in the, at the beginning, we used it to do, or we tried to do the cardio neuroablation by uh right side only. But unfortunately, the results were not enough. Because, uh, obviously, we were at the beginning and it was very important to get the best result. However, uh, I saw that the right approach was not enough. And obviously, there are some structures like the sinus node, like the sinus nodeal artery that will be, uh, damaged during the procedure. So because of it, we decided to uh Access the left uterum and uh assessing the left uterum, there is a, a, a, a protocol similar to the AF ablation that is too safe. So by this, we have been using the left hand and by using the vagal stimulation, the extra cardiovagal stimulation, it's easy to see that the left approach is better than the right approach. It's better. So, probably, uh, uh, an, an, um, uh, uh, uh, an option is to do like John, accepts the left heron, uh, uh, uh, obviously proceeded the the nervation of the left earron. And if the, the, there is no more vague response, the procedure is finished. I think it's a good, it's, it's a good way until now. Obviously, we are learning, we are changing the procedures, but I think it's better to begin by the left atrium. Yeah, and I, I totally agree with that, and that's why I think the value and the elegance of the extra cardiac vael stimulation comes into play here, where you can titrate, you know, their effects, and then when you know it, it's time to stop, you stop. And, and I think that's, that's the value of that comes up very well. Yeah, thank you. Thank you, Doctor Manu for your presentation.