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Retrograde Pedal Access Collaboration, Case Selection & Benefits

Retrograde pedal access is becoming popular among both patients and interventionalists for the treatment of critical limb ischemia and peripheral vascular disease. Vascular surgeon Dr. Jim Melton and interventional radiologist Dr. Blake Parsons discuss IR and vascular surgery collaboration in their practice, how to get started with pedal access, and benefits of retrograde pedal access.


We’ve provided the highlight reel below, but you can listen to the full podcast here.


The BackTable Brief

  • Dr. Parsons and Dr. Melton both prefer pedal access over groin or femoral access. In their practice, Dr. Melton states he is able to place a sheath in the distal anterior or posterior tibial artery, and provide all treatment from tibial access 95% of the time.

  • Pedal access requires practice. When starting out, ideal patient candidates include those with two or three vessel runoffs, or individuals who are considered high risk to stick in the groin. Dr. Melton advises staying away from one vessel run offs for the first 100 cases or so.

  • Benefits of pedal access include less radiation and faster recovery time for the patient. For physicians, Dr. Melton reports that he is able to see 2 to 3 more patients per day as a result of the time savings achieved with retrograde pedal access.


Image Courtesy of Sabeen Dhand MD

Disclaimer: The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.


IR and Vascular Surgery Collaboration


Dr. Jim Melton and Dr. Blake Parsons work together in a multidisciplinary private practice that opened in 2015, treating patients with gangrene, ulcers, wounds, and peripheral vascular disease. Their procedures are now completed almost exclusively with pedal access.


[Aaron Fritts]

My goal with this episode is to cover pedal access and hopefully inspire others to learn how to do it. I also want to talk about how IR and vascular surgery can successfully work together for better patient care and possibly even a better business or practice model for a lot of the IRs coming out of training, especially for the more clinically-oriented trainees coming out of the new IR residency.


[Jim Melton]

For Blake and I, most of our practice is gangrene and ulcers… Blake does some crazy IR stuff that I don't do sometimes, but my practice is probably 98% pedal. I think Blake's practice is starting to reach that too, whether it's BK disease, SFA disease, or three level disease including the iliacs, we just feel a lot better with just multiple things.


[Blake Parsons]

Mainly everything we've been doing, on Jim and my part, has been peripheral vascular work. We do have a lot of patients with ulcerations and wounds. On the vascular side, it's all been primarily wounds and stuff. Now, for the other, we have three interventional cardiologists that are partners at our clinic as well. We’re still able to do coronary stuff and screenings and procedures for those people.


[Aaron Fritts]

That is the other unique thing about your center... having cardiology, vascular surgery, and IR all under the same roof. I imagine the level of patient care you're providing is unparalleled in other parts of the country where there's a lot of turf wars. I just think collaboration is the way to go in terms of better care and so hats off to you guys for making that happen.


[Blake Parsons]

From me, coming as an IR doc, some people are going to be like, "Why the hell would you join forces with a vascular surgeon?" And I'll be honest. There's a huge benefit. I got to see it firsthand in my fellowship. I mean, at least, it happens every single week where I do an angiogram on a case or I get access and I'm going through and I'm like, "You know, I don't think this is a great endo revasc case. I think we're going to jeopardize future bypass options or treatment options." Then it's great for me as an IR doc because I've got a guy right here, as my partner, that we go over cases all the time, go over imaging and say, "Hey, you know, from a surgery standpoint what are your thoughts here?" And so, I think, from a patient care standpoint it's great. There are alot of places where they don't have that and so you feel a lot bigger push to go ahead and try fixing someone endovascular because that's the option that you have when maybe that may not be the best option. For me, anyway, it's been great. It's been good just to continue to always understand too, from a surgery point of view, what's he looking for? What's he thinking for future treatment options also?


[Jim Melton]

Blake just adds so many different skill sets and different procedures that work perfect in the OBL space, or the surgery center. I first met Blake himself in probably late 2015. I was a little worried about the clinical skills of IR. When I was working, they were proceduralists only. And when he got out of his fellowship, I was extremely impressed with his ability to run a clinic and clinically be sound, as far as deciding what patients need. And also politically correct, with referrals and everything like that. So, it's been a great experience for us and obviously looking to grow that side of the business with another IR or two, for sure.



Getting Started with Pedal Access and Patient Selection


Dr. Jim Melton began experimenting with retrograde pedal access in 2013. Dr. Blake Parsons was learning TAMI during IR fellowship at MCW, finishing in 2017. He then joined Dr. Melton’s practice where he now performs procedures using pedal access for 95% of cases. When starting out with pedal access, Dr. Melton notes that ideal candidates for the first several cases are patients with two or three vessel runoffs, total SFA with an ulcer, or individuals who are considered high risk to stick in the groin.


[Aaron Fritts]

Jim, what inspired you to first start trying pedal access, since it is a relatively newer technique? How did you learn it and how long did it take you before you felt comfortable?


[Jim Melton]

Over at the heart hospital, in 2013, I started sticking... if I was going to try to get through a CTO with an ulcer of an SFA or something, I got tired of not getting all the way through it or even being able to get past the proximal cap at all. I started sticking pedals with ultrasound guidance which, as you know, an interventional radiologist is the best, by far, no questions asked, period. And then, I mean, it was a skill I had to learn. I learned that and just stuck small needles and put a wire in, just so I could know I could do it. And then I said, "You know what? Let me try to get through this distal cap." And it just became very obvious, very quickly, that distal caps were so much softer than the proximal caps. A lot of times you just fly up with not a lot of product cost involved and you're able to save a bypass for another rainy day. I hardly ever stick a femoral or anything. That's from 2015 to present.


[Aaron Fritts]

Blake, was pedal access something that you learned in fellowship?


[Blake Parsons]

Sure. We did a lot of peripheral arterial work. We were fortunate, and this kind of goes back to me working with a vascular surgeon. At MCW you kind of worked hand-in-hand with the vascular surgery program there, so I had already had previous relations during fellowship between vascular surgery and interventional radiology. It was great. I would say we only did a handful of true retro-pedal, what people call TAMI cases. When we stuck tibial arteries it was because you were doing a Safari or something of that nature. I talked to Jim on the phone and he'd be bragging about how many retro-pedal cases he's doing and giving me a hard time. I was like, "Yeah, yeah, yeah." And then sure enough I got back and my practice was obviously slow at the beginning because trying to get the general public to understand what the heck an interventional radiologist is, is just part of the battle. So, I'd scrub in on cases with him and watch him do cases and, sure enough, he had a lot of retro-pedal access… I became a believer. And then my peripheral work increased over the past three years to 95% pedal. Now, there's still times I'll go integrate a femoral or SFA or up and over femoral if I know it's all below ankle or pedal loop or something like that where I want to get a better vantage point. But, for the most part, I also go retro-pedal from the foot.


[Aaron Fritts]

You talk about the Safari technique where you're still getting the access in the groin and in the foot. Would you mind clarifying that? Like, what you guys are doing? You're just solely getting access in the foot in the majority of the cases rather than getting dual access, right?


[Blake Parsons]

So we call it retro-pedal. I know the other name out there is TAMI. But, yes, we're talking single access within a distal tibial artery, PT or AT, sheath placed, and then all treatment is done from that sole tibial artery access. We're able to, like we said, accomplish that probably 95% of the time.


[Jim Melton]

I can tell you, my practice since we opened in '15, I haven't done one Safari. I think Blake's done a few just because of the extent of the disease or whatever.


[Blake Parsons]

Pretty rare.


[Aaron Fritts]

Let's go into how you guys approach a case. The majority of your cases are done by pedal access because you guys have the experience and the confidence. But, for somebody maybe newer... you guys get a lot of visitors that come through and watch you guys. Probably a common question is, what are the big contraindications to pedal access for you?


[Jim Melton]

It all starts with a really good clinical exam. That's what, again, what I was a little worried about with IR in general. But Blake, like I said, he came from a program that had that and it was really a pleasant surprise. A good clinical exam with a hand-held Doppler in the room, trying to figure out where these lesions are, is really the coolest thing that I do in clinic. I walk out and I know, pretty much, exactly where this lesion is. I also tell the docs that come and haven't done much pedal to go ahead and do a Duplex below the knee and visualize that the AT and PT is open. It makes them feel a little more comfortable sticking it. Or the interosseous, any of those three vessels. For your first 100 cases or so I would probably stay from one vessel run off. Blake and I both, still to this day, do that a little bit. If we think it's a one vessel run off case, we'll probably do a diagnostic first with either a little antegrade dilator or something like that, or an up and over small sheath and then decide whether we want to go primary pedal or not. Pretty rare on that but I think, at the end of the day, once you get some under your belt you feel more comfortable doing one vessel run off also. But, I think that just comes with a comfort level and experience as you go, going down the road. Pedal access is a really good way to recanalize a lot of vessels below the knee that are totally occluded with the selection of wires. I think at the end of the day, it's good for all three levels, below knee, obviously SFA's that have never dreamed of getting through, and then in foot disease also.


[Aaron Fritts]

And so, a lot of your patients are obviously CLI patients, guys with wounds. Anything in terms of like where the wounds located or do you worry about the access itself causing a wound?


[Jim Melton]

We like to try to identify the wound in these certain angiosomes for sure and try to figure out which vessel is important to healing that angiosome. That's part of that clinical exam deal on the front end. We try to cover up all the wounds on the prep, on the patient, and prep them out, if you will, and try to obviously stick away. We have over 2500 cases, CLI cases now for sure. I've never seen a wound caused by the perc stick that didn't heal or anything, to date. Distal AT, PT usually around the ankle--it just kind of depends whether we'll stick a DP more distal. Obviously, you're a little limited on your sheath size if you think there's more proximal disease. If I know and am pretty sure they've only got say a single vessel AT to the foot and I can't hear signal in their peroneal or their posterior, then I'll sometimes even just try sticking their occluded vessel and see how hard the plaque is. I'm not going to hurt it. So, I'll stick it and then it's kind of like a freebie. As long as I can get up through that, then I can get up and fix everything from there. We do have a pretty good idea before we ever step into the room. But, obviously, you've got to adjust on the fly some too.


[Aaron Fritts]

Getting started, I didn't want any bad outcomes so I was very particular in terms of my case selection. The best starter case for me, personally, was an obese patient with kind of a hostile groin and had an isolated tibial disease. It was relatively easy to get in, balloon angioplasty, give my post-injection and be done. And so, I think that, to me, was an ideal case to start out with. Do you guys have any suggestions on people who want to get started and maybe are a little bit hesitant?


[Jim Melton]

Yeah, you nailed it Aaron. I think, at the end of the day it’s those people that are just high risk to stick a groin. The radial's an option if you talk it through, but the radiation difference is drastic. I think that, at the end of the day, your ideal candidates for your first cases are two or three vessel run off and a total SFA with an ulcer. Those are your best ones to practice on. Below-the-knee disease is good. There's a lot of techniques that we try to teach when the docs come about up and over from PT to AT or AT to PT, or interosseous, either one. And so, we do those also without sticking the groin. The best cases and the most satisfying cases are the ones you can't get to from the top but you just fly through them from the bottom and you've healed up an ulcer. When you're a Critical Limb Ischemia Center of Excellence or that's what you want to be, you don't see a lot of those. But, at the end of the day, those are really good cases to practice and get a lot of confidence with.


Pros of Pedal Access


Pedal access provides several benefits to patients, including significantly less radiation and decreased recovery time. Meanwhile, the time savings gained from pedal access allows interventionalists to see more patients in a day.


[Jim Melton]

At the end of the day, we have a really large series of CTO's, iliac CTO's, that are easily fixed in the foot. I'd like to get that published some time soon. I think that it's a great way to keep somebody from having a fem that gets infected. That's a nightmare in my world… Also, the radiation dose decrease is gigantic going pedal. Contrast usage is markedly decreased going pedal. And the put through of actual patients goes up about 2.6 per day, if you do all pedal as opposed to femoral.


[Blake Parsons]

I just saw the ease and the decrease in time with pedal access. We're talking complex, multi-level leg maybe an hour and a half, typically. Total time. I'm not talking fluoro time, obviously. I'm talking total time of getting in there and doing the case. Significant reduction, like you said, in your contrast dose, patient dose, because you're not having to go up and over. You're not radiating the pelvis as much… After closing pedal access, we're continuously monitoring with valve pressures being held with Doppler, distal, making sure that we've got flow. After that, the pressure's probably held for 15-20 minutes, at the most. Those patients really start dangling their leg off the bed at about an hour or so, hour and a half, and then most of them are out the door within an hour and a half to two hours.


[Jim Melton]

It's usually a 90 minute protocol we have. Most of them are ready to go in 60 minutes. The beauty of it too is when they come back, they've ordered their box lunch from the deli down the street and they're up eating. They're not laying flat on their back and a nurse holding pressure on their groin. They're sitting up eating while either there's a radial band on the pedal site or there's two finger pressure with documented distal flow. At the end of the day, that's what people really want to know, if this procedure's safe and we intend on proving that.


[Aaron Fritts]

Like many others I was scared to do more harm than good with the whole pedal access thing, especially working in the outpatient setting. It just seemed to have so many benefits. I've heard stories of patients who've had both pedal access and femoral access and they come back to see their doc and they might need another intervention and they literally demand pedal access just because their patient experience is so much better. And so, I think, from an outpatient setting it just has so many benefits.


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Podcast Participants:

Dr. Jim Melton is a practicing Vascular Surgeon in Oklahoma City.

Dr. Blake Parsons is a practicing Interventional Radiologist in Oklahoma City.

Host Dr. Aaron Fritts is a Co-Founder of BackTable and a practicing interventional radiologist in Dallas, TX.


Cite this podcast:

BackTable, LLC (Producer). (2020, June 22). Ep 69 – Retrograde Pedal Access [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. The opinions expressed by participants of the BackTable Podcast belong solely to the participants, and do not necessarily reflect the views of BackTable.


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