Talking Tall Rounds: SVS Highlights

Podcast Transcript

Announcer:

Welcome to Cleveland Clinic Cardiac Consult, brought to you by the Sydell and Arnold Miller Family Heart, Vascular and Thoracic Institute at Cleveland Clinic.

Sean Lyden, MD:

Well, good morning, everybody. My name is Sean Lyden, I'm the chairman of the Department of Vascular Surgery, and I'd like to welcome everybody to the Heart, Vascular and Thoracic Institute Tall Rounds. Today, I have the pleasure to introduce my other two speakers. One is Dr. Frank Caputo, who is the director of both our Vascular Surgery Residency, our Vascular Surgery Fellowship, as well as Director of the Center. And Dr. Lee Kirksey, who is our vice chair, who also heads up the diversity efforts within the Heart, Vascular and Thoracic Institute. Today, we're going to present presentations that were given by our department at the Society for Vascular Surgery 2023 Vascular Annual Meeting. And I'm going to start off with talking about the PQ Bypass trial.

So, this presentation's on the durability of PQ Bypass for the treatment of Femoral Popliteal Disease with the two-year outcomes for the DETOUR 2 trial. The really relevant disclosure is that I was the National PI for this trial, and I was compensated for that role. You can see where I've been a consultant, have had stock options, and research studies that I participate in. So, if we talk about patients with long and complex SFA lesions, the change from when I was a trainee to now, is it was all open surgery and now it's probably 90% endovascular surgery. But when it's a long complex lesion, when it involves the common femoral, when it involves the popliteal segment, the current Trans-Atlantic Inter-Societal Consensus document still actually recommends bypass as the gold standard for those long complex lesions.

If we look at vein bypass, it has great limb salvage rates with patencies of almost 80% in five years. However, the procedures can have high morbidity, lengthy hospitalization stays, high remission rates. We know from the Vascular Quality Initiative databases that almost 35% of patients will have wound complications and wound healing issues with even vein bypass. We know that endovascular therapy is possible for long complex lesions, but it's limited by calcification, elastic recoil and limited by shortened durability over both one and two years.

So, the DETOUR system was really developed as a percutaneous technique to create a femoral popliteal bypass, using a prosthetic conduit to avoid the limitations and complications of traditional open repair. So, the way to think about it is, this is a procedure where you originate in the origin of SFA. You then use a crossing device called the ENDOCROSS that crosses through the artery into the femoral vein. You then travel down the femoral vein and then use an ENDOCROSS to cross back into the artery, and then use covered stents to treat the entire segment, basically creating a percutaneous fem pop bypass. And the femoral vein then becomes the channel or pathway for the stent graft.

So, schematically how to do it, you need just a small stump or origin of the SFA to get the ENDOCROSS device in. You need to get it in at least three centimeters into the SFA. You then get a venous access from a posterior tibial vein with the 6 French sheath. The ENDOCROSS device requires an 8 French sheath to come up and over, then across devices and oriented towards the femoral vein, fired, and then a 014 wire is used to be snared from the other side. Once that's done, through and through access is created, the ENDOCROSS is then pulled across that proximal anastomosis, it's then oriented towards the distal popliteal artery, and then fired again to enter into the native circulation. Once a wire is in the native circulation and confirmed, you then angioplasty that proximal crossing anastomosis, the distal crossing anastomosis, and then placement of PTFE line, nitinol stent grafts, from at least three centimeters into the distal native artery to the origin of the SFA, flush with the profunda.

So, this was a study that had 202 viable subjects at 36 centers in both Europe and the United States. The patient followed at 30 days, six months, 12 months, 24 months, and then they'll be followed through three years. The primary safety event was major adverse events at 30 days, which included death, clinically driven target lesion revascularization, amputation, DVT, pulmonary embolism and major bleeding, with a primary patency at one year. Looking at a duplex derived peak systolic velocity ratio of less than 2.5 with no clinically driven TLR. Our enrollment finished in October of 2020, and there was an independent core lab here at the Cleveland Clinic and a Clinical Events Committee run by Syntactx.

So, to be eligible at trial, you got to have Rutherford's three, four, and five, so we have both rest, pain, and ulceration patients. They had to be complex lesions, they had to be symptomatic femoral popliteal lesions, at least 20 centimeters in length, that could either be a chronic total occlusion, diffuse stenosis, or in-stent restenosis. These are patients that have been excluded from pretty much any other endovascular trial that had been done to date. Because of limitations in the size of the covered stents, the reference vessel distally had to be greater than 4.5 millimeters and less than equal to 6.7 millimeters. You had to be having access at the SFA origin, and you had to have a patent popliteal artery distal to the landing zone with at least one patent continuous tibial runoff to the foot. And because we're using the femoral vein in conduit, it had to be at least 10 millimeters in diameter or duplicate.

So, the average patient was just under 70 years old. Most were male, similar to almost every other trial. You can see 77% were Rutherford 3, but we did have 18% Rutherford 4 and just under 5% in Rutherford 5. There are comorbidities for hypertension, hyper lipid diabetes, look very similar to almost every other PAD trial. If you look at the patient lesion characteristics, however, 96% were CTOs, 97% had diffuse stenosis, almost 20% had in-stent restenosis, and the average lesion length was incredibly long at 32 centimeters in length, plus or minus six centimeters. The average CTO length was over 20 centimeters. If you look at calcification, severe calcification was found in 70%. So, these are patients that would generally not have durable outcomes with a commercial endovascular treatment using off the valves devices.

So, if you look at the procedural outcomes for technical success of the procedure was at 100%, success through discharge was at 98.5%, and the amazing part of this is, this is basically an overnight stay. And so, instead of a three to five day hospital stay with a 30% chance of wound complications, it was a one-day length of stay. And if you look at our clinical success, it was 95.9% all the way out through 24 months. And so, one of the things we know when we do procedures like this with open surgery, there's procedure related infections, it's at almost 30%. In this trial, it was 0.5%.

Our primary endpoints have been met and have been presented previously. Our one-year freedom from CD-TLR and target lesion stenosis greater than 50%, was 68% when our derived goal was 60.9% based on the literature. And if you look at our primary safety endpoint with a target of 84%, the freedom from major adverse events at 30 days was 93% of patients. So, if you look at the duplex derived patency through two years, it's 59%. So, when people first stay, they say, "Well, that's okay. That's not so impressive, maybe that's not so different than endovascular therapy." But remember, the endovascular therapy, almost every trial had an average lesion length of eight centimeters, where this has an average lesion length of 32 centimeters.

But if you think about it, how we do a bypass? If we do a prosthetic PTFE bypass, we know that duplex actually is not predictive of failure. So, if we look at, first, just the freedom from clinically driven TORs, so it's not just duplex, so did they have to have a reintervention? 76.7% of patients were freed from re-intervention. And if you look at the way we do a prosthetic bypass, was it open or not? It was 87.6% of these were actually patent. So, the FDA, with using the femoral vein as a conduit, was very concerned about the risk of deep venous thrombosis. And so, you can see the freedom from symptomatic DVT was 96.5%, and the freedom from major amputation was 98.5%. So, one of the things we use in vascular surgery, is major adverse limb events to look at effectiveness and durability through two years, and that was 73%. And our secondary patency, so patients who had lost primary patency and had an intervention, was 82.3%.

So, in conclusion, this is now being termed the Percutaneous Trans-Arterial Bypass, or PTAB, and using the DETOUR system, it does create a percutaneous fempop bypass for very long and complex SFA lesions with very high procedural success. The primary and safety endpoints at one year and 30 days were met in the DETOUR 2 study. We've continued to now show low long-term venous event rates, and has comparable efficacy to open PTFE bypass. That's a 76.7% freedom from clinically driven TLR, and an 82.3% secondary patency through two years. They clearly mimic the results of surgical bypass. The advantage is, you don't need general anesthesia, you don't have a long length of stay, and you're avoiding that risk of 30% wound complications.

Clearly, as we're held more accountable for long-term outcomes, this will, in select patients, become a preferred route of treatment, because when patients otherwise have a 30% readmission rate for wound infections and they have these complications, being able to treat patients in this way will be an advance forward. And so, it does clearly provide a durable endovascular technique for complex lesions over 200 millimeters. So, with that, I'm going to turn the talk over to Dr. Caputo, who's going to present, and we'll save the questions about all three of our presentations to the end. Dr. Caputo.

Frank Caputo, MD:

So, I was really excited about this talk, and I'm excited not just for the fact of what we're presenting, but for three reasons. One, it's presenting data from a company that was born and created here at the Cleveland Clinic. Technology. Two, it was a multispecialty institute study that was the first one I've ever participated in, so it was pretty exciting. And three, this talk, this data, and the entire presentation, and the entire study was actually created by one of our trainees. So, it just shows you the type of intellectual curiosity our trainees have, as well as what we can foster through research and mentorship. So, this was actually presented by Nick Hoell, one of our chief residents here, and he was one of a handful of trainees that actually presented a plenary at a national meeting. So, just kudos to Dr. Hoell.

So, I'm going to present about electromagnetic intraoperative positioning system as a safe and effective as 3D imaging adjunct and endovascular aortic aneurysm repair. Here's my disclosures.

Complicated endovascular aortic therapies have become more widespread and accessible, resulting in increased radiation to both the patients and practitioners. Emerging technologies will help mitigate the radiation hazards of these procedures, because it's not just the patients that's getting affected, it's us practitioners that are, every day, being bombarded with radiation. And when we think of endovascular surgery, it equals fluoroscopy. We get exposure to ionizing radiation, we have to give contrast that's damaging the kidneys, and it's really, when you think about it, a basic way of looking at something.

We're trying to look at a 3D structure through a 2D representation. Anatomy. Just to give you an overview of our intraoperative positioning system, it's pretty agnostic, meaning it can be adaptable to many systems. So, you have a cart, you have an imaging monitor, you have a registration pad, and I want you to think of IOPS kind of like GPS of the body, and it's not as simple as that. That's kind of complicated too, but that's for the most part about what it is. So, you have a registration pad, which think of your satellites underneath the patient. You have the field generator and the sensor interface unit that mitigates... not mitigates, works with the guide wires and the catheters. And then you have your TomTom, which is that monitor up there, just showing you the roadmap.

In order to do this, you need special adjuncts such as sensorized wires and catheters. And here, although a little bit crude, they do get the job done and they do work. We have two different types of catheters, and as you've heard, they're basically your basic types of catheters, a simple curved catheter as well as reverse curved catheter, and as well as a sensorized guide wire. So, they both have sensors in them so you're able to use them in conjunction to help each other. The workflow is pretty unique in that, you have to have a CAT scan on the patient, and then when the patient is now on the table, you merge the CAT scan with the registration, as well as fluoroscopy to come up with your roadmap, or your Atlas, per se.

Just to give you an idea of what it looks like as you're navigating the aorta and you're working through the visceral segment, this is kind of what it looks like. You can see the wire coming up, as well as the catheter as well, and it helps navigate the entire aortic and as well as its branches. And this is the catheter coming up with both the curve as well as recurve, and you can see them working in conjunction to access that renal artery. And you can see the catheter is able to cannulate it with some ease. The aims of this study was to demonstrate the safety and feasibility of IOPS as an adjunct to fluoroscopy in aortic surgery, TVAR, EVAR and fenestrated grafts. We had two sites, UNC as well as us, and there was 30 patients from 2020 to 2022. And the aim was to help with aortic navigation and branch vessel cannulation.

Catheter and wire location was always confirmed with fluoroscopy. We monitored serious adverse events and non-serious adverse events. The time point was intraoperative private discharge and 10 days post-op. Our mean age of our patients were 75, mostly white men. Comorbidities included coronary disease and hypertension, for the reason why they were going to endovascular aneurysm repair versus open repair. And as you can see, the majority of the patients underwent uneventful EVAR in 70% of the patients, FEVAR and 13% of the patients, and TVAR in 13% of the patients. And IBE is for iliac branch device. We had 100% technical success rate, zero to serious adverse events, and zero non-serious adverse events. So, the conclusion was, IOPS was safe and effective as an adjunct to fluoroscopic guidance and endovascular surgery. Of course, further research is not just to show that it's just safe to help with fluoroscopy, but to also show that it might be superior, and that we may be able to use it as a standalone. I want to thank you for the time at the podium.

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