STIMULAN in foot & ankle – surgeons’ views

I’m Stuart Miller. I’m a foot and ankle subspecialist in Baltimore, Maryland. I teach residents and fellows on a regular basis and do some lab work as well.

My name is Alastair Younger. I’m an orthopaedic surgeon, foot and ankle specialist. I work in Vancouver in British Columbia, and I have a referral practice from the rest of the province.

Dr. Miller: Usually it’s contamination from either outside sources or bloodborne later on. I think we have bacteria floating around our body all the time, and of course in an opportunistic situation like a bone infection, they have found a place to land and they’re going to keep growing and cause problems. Especially when you form a glycocalyx or something, it becomes a real problem and that’s when we need some real help.

Dr. Younger: I work in a downtown hospital, so I get a lot of infection from that type of care. Patients with unfortunate circumstances and musculoskeletal infections, sometimes fairly fulminating infections, sometimes even calls from the intensive care unit with extensive lower limb infection from IVDU or from other causes. I also get a fair amount of infection in my tertiary referral practice for the rest of the province from ankle fusions, previous trauma and ankle joint replacements, for example, post-reconstruction.  And finally, I get a fair number of patients with diabetes. So actually, the most common cause of treating infection would still be diabetes.

Dr. Younger: Well sometimes it’s pretty obvious, draining pus, red legs. Sometimes we get referred cases that need working up. Sometimes infection is assumed when it’s not there, such as in Charcot arthropathy, so basic workup is required. I use the Q-tip test. If a patient has a potential ulcer, I will take a Q-tip and if it penetrates deep to skin, penetrates towards tendon or bone, that usually is a surgical case that requires debridement.

Dr. Miller: With infection we’ll see erythema, redness around the wound, drainage of course, and pain. Pain’s a big indicator of a problem going on. And then we have to decide if it’s a deep infection or a superficial infection or cellulitis. And that’s what I need clinical evaluation for.

Dr. Miller: If someone comes in with an infection post-op or a deep bone infection, I’m going to debride the wound, irrigate it thoroughly, clean it the best I can, and then we’re going to put STIMULAN beads in. The beauty of STIMULAN of course is it’s a bone filler, but it’s also wonderful in the soft tissues. It gets resorbed beautifully later on. I use it to fill bone defects, but it’s a delivery vehicle for my antibiotics.

Dr. Younger: I will usually contact Infectious Disease afterwards. Depending on the culture results, which we may have pre-op or post-op, I will put the STIMULAN in and then I will consult Infectious Disease. And in conjunction with them, we’ll hopefully work together to eradicate the infection. The main thing in surgery is to try and keep the number of the debridements down to the minimum.

Dr. Miller: If there’s an infection, I’m using STIMULAN. Simple. If I’m opening anything up, I’m using STIMULAN beads to try and fight the infection. I feel I have to fight the infection from inside and from outside. And the STIMULAN is going to do it from the inside and I’ll use my Infectious Disease Specialist to tell me what drug from the outside.

Dr. Younger: I use STIMULAN, first of all, to try and expedite care. When I first started practice 25 years ago, pre-STIMULAN, I would do transmetatarsal amputations, for example, and they’d have to go back to the OR and have repeat debridements. And then we’re in trouble with trying to get the skin to heal. Whereas, if you can use an antibiotic with a carrier, such as STIMULAN, then you can do a single-stage procedure. It allows you to plan and create single-stage surgery with the local antibiotic depot to prevent recurrence of the infection in the surgical site. If I think that there’s a risk of recurrence of infection, then I’ll put in STIMULAN.

In some cases, it may be a bit more prophylactic. If I have a patient, for example with diabetes, and I think that they’re going to have a risk of wound breakdown and I have to do an open procedure, then I may consider putting STIMULAN in that environment to maintain an antibiotic prophylactic dose within the wound. I’ve also used it for patients that have had acute early infections after ankle joint replacement with liner exchange and with debridement and preservation of the metal components with a reasonable degree of success.

Dr. Younger: When you send a tissue sample off to the lab and they do an antibiotic profile, they’re assessing serum MIC levels. And when you’re using STIMULAN, you’re going to get four or five times MIC in the local tissue. So, the actual antibiotic and prophylaxis or sensitivity that you get from the lab may not be applicable when you’re using high dose in the local tissue.

Dr. Miller: Well, it depends on the infection that we have. Nine times out of ten, it’s a common problem. It’s either staph or strep or E. coli. Most often, you can assume it’s going to be staph. I’m still a big fan of vancomycin for most of my wounds, especially when you’re not sure what it is. When we’re going back in for a second or a third washout, then we have a bug identified and have been directed by Infectious Disease as to what antibiotics we’ll use.

Dr. Younger: It depends, the size of beads, degree of vascularity, degree of serum production, whether or not the wound is open. Usually, you’ve got pretty good MICs out four to six weeks, I would think.

Dr. Miller: Actually, the science behind STIMULAN is wonderful. We know that in a normal aqueous environment the beads last for about 42 days. So, I tell my patients 40 days because I’m biblical. 40 days and 40 nights of antibiotic stimulation seems to be the key for me.

Dr. Miller: I’ve used STIMULAN for more than 10 years, as have my partners. And in Baltimore, neighboring hospitals also use a lot of STIMULAN because we know it works. How does it work? We see a decrease in signs of infection. The wounds look cleaner, the erythema’s gone down, the patient’s complaining less of pain, and of course, our markers in the bloodstream show improvement in the infection as well. Again, it’s clinical monitoring. We see how the patient’s doing with their wound, we monitor their blood levels for inflammation as well as infection, and it’s a whole clinical picture of getting better.

Dr. Younger: Improvement of AC reactive protein, reduction of redness and inflammation, reduction of drainage in the wound would be most of the things. Patient symptoms, simply as well, they can usually tell you when they’re less painful, less swollen. They’re also fairly able to tell you when the infection is resolving.

Dr. Miller: The most common mistake is the misapprehension that it’s only a bone filler. STIMULAN is a carrier for these antibiotics and it has wonderful resorptive characteristics. So if it’s in bone, it can turn into bone. If it’s in soft tissue, it will be metabolically very simply processed and be gotten rid of easily so I don’t have any complications from this carrier giving me any problems.

Dr. Younger: You might use too much and overstuff. I don’t think choosing the wrong antibiotic is necessarily a major issue with treatment failure unless you’ve got a really strange infection. So, I do think you have to look at your organisms and the antibiotic profile beforehand.

Incomplete debridement is a big issue. I would think most of the failures I see in diabetic foot care or in less experienced surgeons, is just not doing a complete debridement. The debridement is really important.

Dr. Miller: STIMULAN is an antibiotic grenade. I can put STIMULAN into my infected wound and have a much higher level of antibiotics at the site of the infection, which is what you need, with minimal systemic effects.

Dr. Younger: It’s essentially cost effectiveness of treatment and also success of treatment. So for example, in patients with diabetic foot infections, they have limited life expectancy. They need to get out of the hospital, they need to get home, they need to get on with their lives. They can’t afford to be stuck in the hospital, it’s not good for them and the hospital needs their beds emptied. They can’t be blocked by patients having failed treatment.

Dr. Miller: I’ve used STIMULAN for well over 10 years. I don’t know how many cases. Certainly we’ll use it once or twice a month. Whenever you have any signs of infection, we’re going to put STIMULAN in to prevent further infection and try to prevent any glycocalyx formation. Obviously with diabetic foot infections, we’re worried about these infections getting much worse with a compromised host. The risk, of course, is going on to amputation. With the use of STIMULAN beads, we’ve significantly cut down on our post-operative complications such as further infection and progression to amputation.