Important Insights from a Unique Limb Preservation Center

Ronald Sherman, DPM, MBA:

I'm an Assistant Professor here at Johns Hopkins Hospital in the Department of Surgery, specifically in the Division of Vascular and Endovascular Therapy. I'm also the Program Director of our Limb Preservation and Wound Care Fellowship. I am the Principal Podiatric Surgeon in our multidisciplinary practice. I've been associated with Dr. Abularrage now over 10 years in developing our multidisciplinary diabetic foot and wound care service. To that end, we've been able to develop a variety of paradigms based on his insight and experiences.

Christopher Abularrage, MD:

So my name is Christopher Abularrage. I am a Professor of Surgery here at Johns Hopkins in the Division of Vascular Surgery and Endovascular Therapy. I'm a Peripheral Vascular surgeon specializing in both open and endovascular surgery, and I'm director of our multidisciplinary Diabetic and Limb Preservation Service.

Ronald Sherman, DPM, MBA:

Well, I think that from a vascular perspective, Dr. Abularrage and our division are eager and do not shy away from actually doing bypasses in patients that can have a bypass. You have to recall that when patients have endovascular therapy, that we're on a clock, and we know that those procedures don't last as long as we'd like them to last. And we hope that the intervention that's been performed is enough to heal the wound that they have.

But we've also found that when you have, and this is more of Dr. Abularrage's thunder, that when they jump in to do a bypass where no one else would want to do a bypass, then we're getting a bigger bang for the buck, and we're optimizing the patient, for them to have the highest vascular potential to heal. Once that happens, then that opens up so many doors as a podiatric surgeon to be able to do a variety of things that we can't do without having adequate blood flow. So I think the first thing is, in my opinion, is the ability to really optimize a patient vascularly.

I think of also another key intervention is the use of CTPs. What we've done over the time is that we've been able to quantify the success using some of these CTPs for a variety of comorbidities in these patients, and we've been able to reconstruct the tremendous soft tissue losses that these patients have without having them undergo significant plastic reconstructive surgeries. So I think that the utilization of dermal templates, I think has been a terrific advantage.

I think another intervention is [inaudible 00:03:07] which we talked about, and keeping the recurrence rate very, very low. I think that so many times we see that there's transfer ulcerations, that there's ulcerations that have occurred on the contralateral foot now, and that we're able to identify these areas of potential ulceration without any clinical signs whatsoever. No callous, no blister, no temperature changes, just by having them do a gait analysis. So I think from my point of view, I think that those are some of the key interventions.

Christopher Abularrage, MD:

I agree. I think there are a couple of things that I would point out. I think that if you're asking what most podiatrists can do today to improve their involvement in the continuum of care, I would point out that many foot wounds don't need referral to a multidisciplinary center. Most people in the pediatric world do a great job at taking care of foot wounds, getting them to heal it, and then managing them long term.

However, if you think about it, wounds don't heal for a couple of reasons. It's poor perfusion, persistent infection, poorly controlled diabetes, structural deformity, among others. The reality is that for those complex diabetic foot wounds where the general podiatrist is not able to get those closed or at least keep them closed, that's when they should start thinking about an early referral. Because as Dr. Sherman pointed out before, we get many second opinions where it's just too late. We can't get to them early enough to fix. There's too much tissue loss. They've undergone too many revascularization procedures. That type of thing.

If you think about what type of revascularization goes on, we do many endovascular procedures, not just bypasses. It's been our practice to do endovascular first, despite the fact that many of these people otherwise may require a bypass. But part of the paradigm that we have is that when they follow up with us, we're reevaluating that intervention. Did the angioplasty or stent actually improve their perfusion? If it did, great. Then they should be able to heal with good wound care and good podiatric surgery. If it didn't, then hey, let's reconsider what we did, and maybe start to think more about a bypass. That's very important is to assess your perfusion after your intervention relatively soon after it was done. Because if you wait four to six weeks, next thing you know the foot may be falling off and you've lost your opportunity.

And the only other thing I would point out is that for these very complex diabetic foot wounds that go into the proximal forefoot or in the heel, one thing that we found out early in our experience is that those patients who were losing their legs were losing it because of persistent infection, not because of a failure of the revascularization. With that, we actually changed our paradigm. We actually sat down with our infectious disease doctors, went through the problems that we were having and why we were losing those limbs, and actually changed against their IDSA guidelines, the International Society of Infectious Diseases. We changed that.

Normally, they would treat people with two weeks of antibiotics after what was determined to be a clean margin. Once they had an infection in the heel or in the proximal forefoot, we actually do four to six weeks of long-term antibiotics. And I think that actually turned around our outcomes significantly. At the same time, the risk profile did not go up that much. So we saw a little bit of AKI. We saw other complications related to putting them on IV antibiotics. But in the long term, that actually improved our outcomes, which is definitely not standard of care across the country.

Ronald Sherman, DPM, MBA:

We also understood how A1C affects healing. Most of the literature will relate that patients who have a high A1C or above 8% will have the greatest complications of healing. But we've been able to recognize that once we revascularize the foot, once we move the structural pathology, once we get rid of the infection and actually begin with an acute wound, regardless of the A1C, their healing is no different.

And that's a big deal because most people will blame, or there has been blame on diabetics not healing because of a high A1C. But we have shown that the A1C is independent of healing, especially for acute wounds.

I think that's a very good question. I think the first thing would be preventative. So much has been written about that, about diabetics coming in for regular periodic care. Now, in my mind, there's two sets of diabetics. One set of diabetic who has never had a wound, and one set of diabetics who have had a wound. According to the International Working Group with a Diabetic Foot, the patients who have had a wound are the ones that are at the highest risk to lose their leg. So that's the first thing that a podiatrist should understand. That there's two groups of diabetics, and that preventative care is really important. What does that mean? That means that making sure that they can palpate pulses, making sure that the patient has adequate sensation to protect their feet. Studies have shown unfortunately that patient education doesn't necessarily retard recurrence rates. But I think on an ongoing basis that assessment of the vascular status of a patient is very important.

The other thing that should be recognized is the comorbidities of these patients. We have found, and it is in the literature, that patients who are also renal patients are in a separate category all to themselves. They can have palpable pulses, but yet they have very diminished flow to the foot. And that's consistent with the morbidity of chronic kidney disease. I think that our profession should realize how these comorbidities relate to the patient and that continued assessment of these patients moving forward with health for prevention. So if a patient is a renal patient and they get a digital wound, what's the chance of that healing? The answer is, might not be so good because of the manifestations of the kidney disease.

Treatment. Treatment would be the next thing. Treatment means that if a wound develops, why is the wound developing? Is it because of structural pathology? Is it because of the way that the person walks? Is it because of the patient needs revascularization and needs a higher vascular potential? So treatment is essential to be focused on once you've focused on as to why the diabetic ulcer has occurred.

Prophylactic surgery. Prophylactic foot surgery is an important aspect of treatment for these patients. These patients, as you know, have the glycosylation effect on their musculature and their joints within their foot, which can cause rigid joints. It causes the muscles to become non-flexible, and therefore it does require prophylactic surgery so that patients do not develop further ulceration.

The third thing is that they should use proven paradigms that show that if you do these steps, like Dr. Abularrage says, X-rays, noninvasive studies, cultures moving forward, follow up blood test, CRP, Sed rate. You need to use all these diagnostic tools to help you manage these patients. I think if you use these paradigms, if you use these things, then I think then the care of these diabetics can only get better.

Christopher Abularrage, MD:

I'll give you two things that the outpatient podiatrist can do. One is when the wound's not healing, early referral, I mean, it's just that simple. The second thing I would point out is I feel pulses for a living. I can only feel pulses in 10% to 20% of my patients. These patients inherently with diabetes have medial calcification. You can always see that on your foot X-rays. Essentially, they're not transmitting a pulse through the skin. So the need for objective vascular testing is underestimated in the community.