Access Points and End Points in Peripheral Arterial Disease
Updated: Mar 10, 2019
Vascular access decisions should be tailored to the location of disease burden in patients with peripheral arterial disease. PAD experts Dr. Sabeen Dhand and Dr. Kumar Madassery review their tips and techniques for vascular access and end points when treating peripheral arterial disease.
The BackTable Brief
Ipsilateral antegrade access may give a mechanical advantage over a retrograde approach from the contralateral groin; the aortic bifurcation and potential tortuosity of the iliac arteries alters the maneuverability of the guidewire.
Subintimal approaches can be augmented with the OUTBACK re-entry catheter for both cases of above and below the knee disease.
Identification of endpoints can be difficult; blood flow restoration to at least two vessels is recommended by both Dr. Dhand and Dr. Madassery.
Reestablishment of blood flow to the pedal arch is critical when treating PAD complicated by toe wounds distally.
Disclaimer: The opinions expressed by the participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.
Antegrade versus Retrograde Approaches [Sabeen Dhand] ...And already in my head I'm thinking, "Where would I access this patient?" If they're large and their body habitus doesn't allow it, I typically go retrograde up and over. But if they have a good femoral pulse when I see them, and they're not huge, or they have a flat groin, I'll prefer antegrade any day. And as long as they don't have aortoiliac disease.
[Michael Barraza] And is that because of the mechanical advantage, or is it just avoiding the trouble of getting up and over?
[Sabeen Dhand] No, it's a mechanical advantage for sure. It's just a straight line shot to the tibials. You really do lose a little bit with fighting the vector of the bifurcation. And especially if there's tortuosity of the iliacs, it just hurts your torque ability and everything like that. Antegrade just makes things easier. I still use exchange length wires and everything, so I'm not using shorter systems when I'm antegrade. But I think the mechanical advantage is huge.
And then, the first thing I'm thinking about is access, but then also, when I see the patient, I'm looking where the wound is. I think the angiosome concept … it's been evaluated in a lot of detail, and the angiosomes are the three vessels, the trifurcations of where they're supplying the foot, and there's data showing direct intervention versus indirect intervention for the angiosome concept. Both are effective, but direct is better.
Practically speaking, I'm just thinking, "I want to improve any flow to the foot," whether it's indirect or direct. Before I go into my system, I guess I'll let Kumar talk about his approach before actually putting the patient on the table.
[Kumar Madassery] The majority of patients we’ll go up and over technique from the contralateral groin. If there's an issue, or if tortuosity we can easily go antegrade on the same side. Sometimes the antegrade I just don't like just because of the way the positioning with the sheath and the wires. Sometimes in the room it can become difficult. As long as you plan ahead it can be much easier.
Vascular Access Options for Above and Below the Knee Disease
[Michael Barraza] Yeah. Now, does your approach change if we're talking above the knee versus below the knee, approaching a chronic total occlusion? Are you going to spend time trying to go subintimal or go straight to the foot?
[Sabeen Dhand] It's funny. Even when I go pedal I feel like I ended up going subintimal but just in a retrograde fashion. I'm much quicker to go pedal if it's below the knee. Above the knee, I'll try a lot more to get back in. If I end up going subintimal, into the lumen, wherever it reconstitutes. But I don't use too many re-entry devices and things like that. I'll do a SAFARI or something like that if I need to. But yeah, I definitely work more in an antegrade fashion, or do the flow of the artery, if it's above the knee disease, like SFA and pop.
[Kumar Madassery] Yeah, I agree. I think above the knee, if you have a CTO of the SFA, it pops open, you have a target. We'll go antegrade and re-entry wise we do use quite a bit of the OUTBACK, which helps us re-enter from a subintimal plane. That's been a go-to for us in the above and below, even. Just kind of proximally below the knees, to go antegrade in direction.
Because coming, just like Sabeen said, retrograde from the pedal, it is typically a lot easier to get back up because of the way the caps. We can talk about the different kind of caps you have of the CTO. But antegrade when you're in the above knee, we can majority of the time do it just in the antegrade direction. With the re-entry or whatever else you need to use.
Identification of Endpoints When Treating PAD
[Kumar Madassery] ...Earlier on we used to say, "We need to get a single inline flow," that was kind of our thing. And for us it was always trying to get the single inline to the area of the wound. Now I think we're getting more aggressive and saying, "We need as many vessels as possible, and we want to complete that pedal arch."
[Michael Barraza] Yeah, I'm glad you said actually. For me it's been a challenge identifying an appropriate endpoint for below the knee particularly.
[Kumar Madassery] The need for us is about at least two vessels. If you can get one of the AT/PTs and a peroneal, great, but you want to also try and get that arch completed when you're dealing with toe wounds. We try to go for at least two nowadays, maybe three if possible. Primarily if we’re having trouble, we want to get that arch, because when you get that arch completed, you increase the outflow of the other vessels.
For us, that’s our goal. Whether or not that always happens, it might be a step by step process. You can open one or two, and see how they do in a few weeks, and then come back for the other if you can.
[Sabeen Dhand] I think it's a really good question, Mike, that you bring up is what is the endpoint? And a lot of times, before the initial angiogram that we perform, I really don't know what those tibials are going to look like. It could be a complete disaster where all of them are occluded, which happens a lot. Or sometimes there's one vessel that has a lot of disease and then the other two are occluded, but maybe one will reconstitute distally.
I think that two vessel is a great endpoint. And you have to consider time and everything, too. My techs and staff start getting pretty antsy after three and a half hours in a leg, and they're like, "what are you doing?" I'm like, "Okay, I got to stop and maybe bring the patient back for other stuff."
I think the whole direct angiosome intervention is great, but I think it's hard. Sometimes there's no anterior tibial or DP available, but if you can just establish one big inline flow, it's going to help. And maybe they won't be able to get away with a toe amputation, but they'll be able to get away with a TMA, rather than a BKA. You got to be in reason, but if you could establish a three vessel in the pedal arch, that would be awesome. You have to be reasonable on timing and everything, too. And staging is always reasonable.
Podcast Participants: Dr. Sabeen Dhand is a practicing interventional radiologist at PIH Health in Whittier, CA. Dr. Kumar Madassery is a practicing interventional radiologist with Rush University in Chicago. Dr. Michael Barraza Jr is a practicing interventional radiologist at Radiology Alliance in Nashville. Cite this podcast: BackTable, LLC (Producer). (2017, August 16). Ep 9 – #StopTheChop [Audio podcast]. Retrieved from https://www.backtable.com/podcasts Medical Disclaimer: The Materials available on the BackTable Blog are for informational and educational purposes only and are not a substitute for the professional judgment of a healthcare professional in diagnosing and treating patients. Disclosures: None.