STIMULAN in spine – surgeons’ views

My name is Christopher Kleck, I go by CJ.  I have practiced complex spine surgery in Denver, Colorado for the last 10 years.  I do a lot of complex cases, including deformity, tumor and I also love treating spine infections. The joy in treating everything from epidural abscesses to mycobacterial osteomyelitis comes from the ability to change a patient’s life and the complexity of care involved.

My name is Stu Hershman – I’m a spine surgeon specializing in complex spine surgery and spinal reconstruction with a focus on spinal deformity. My practice is located in Boston at a large tertiary facility.

Dr. Hershman: There are a lot of different reasons why infections occur. Sometimes it can be related to the length of a surgery or the fact that there’s a large open exposure. Oftentimes, it’s related to patient host factors. For example, patients may have diabetes, they can be smokers, they can have all sorts of medical comorbidities which might increase the risk of infection. Occasionally, it’s due to contamination. Occasionally it’s due to other factors that we really can’t put our fingers on. While there are a number of different reasons why infections occur, we don’t like any of them.

Dr. Hershman: Infection can present in a number of different ways. Sometimes it can present simply as fever, chills, or an increase in low back pain. Other times it can be persistent drainage, a wound that doesn’t close, or some redness or erythema around the wound itself. Any of those signs or symptoms can alert a surgeon to the fact that an infection may be brewing.

Dr. Kleck: It’s a broad spectrum. Acute symptoms can include fevers, increasing pain, hypotension, and tachycardia as patients become increasingly ill. Chronic cases tend to present with more subtle findings such as broken rods, failure of fusion, and pseudoarthrosis. Those are the things I key in on more often, especially when I’m treating chronic indolent infections.

Dr. Kleck: Whether a patient comes through the clinic with a chronic infection or acutely through the Emergency Department, the goals tend to be similar. At my hospital, we have developed an algorithmic multi-disciplinary approach. We start by trying to get control of the infection and identify the organism.  Surgically that includes serial debridement, the use of antibiotic beads and stabilization of the spine.  All three are key in spine surgery, but can be challenging. Once we get control of the infection (sometimes shown through negative cultures and healthy/viable appearing tissues look healthy) the surgical treatment can be completed. Antibiotic STIMULAN beads are key both through initial treatments and at the final stage.

Dr. Hershman: Many infections can be treated non-operatively and this is especially true if there’s no hardware in there. The medical guys, the infectious disease guys can prescribe antibiotics that can attack and eradicate many of the different bacteria that could theoretically infect the spine. In an instrumented wound, things become a little bit different. In those cases, we really need to irrigate and debride, and make sure we’re killing those bacteria, not just reducing the amount of them, but really eradicating the bacteria as much as possible.

Me, in my practice, I like to also place STIMULAN beads into the wound at the time of irrigation and debridement. And really, what we’re trying to do, is kill the bacteria through a multi-pronged approach. We’re trying to eradicate the bacteria with irrigation and debridement. We’re trying to eradicate the bacteria using a locally placed antibiotic, and we’re trying to eradicate the bacteria using a systemic antibiotic that is going through the IV.

Dr. Kleck: Every case needs STIMULAN.  In infected patients, the biggest issue is failure to gain control of the infection. In fact, there are plenty of cases that have been treated with multiple small “clean outs”. The infection is never truly treated, and the patients continue to have symptoms. The failures often include failure to identify the organism, failure to adequately debride the tissues, and failure to appropriately stabilize the spine. Ultimately, the use of STIMULAN can aide at every step by achieving local antibiotic delivery. Further, when the organism can’t be identified (~50% of cases) or the infection is polymicrobial, STIMULAN can provide coverage locally without systemic toxicity. In the end, if you can increase the antibiotics to the local tissue, that’s the best thing for the patient.

Dr. Hershman: In my practice, where I specialize in complex spinal deformity and spinal reconstruction, we know that there’s an infection rate that, in my opinion, is really unacceptable. Previously, in the literature, the infection rate was reported to be somewhere between 5 and 12%.  And nowadays, we’ve really brought that down to around 3 to 6%. But that’s still too high. Really, we’re trying to get that infection rate down to as close to zero as possible. And so I think that STIMULAN is a great product because I get to use it in a setting where I can try to bring that infection rate down as low as possible, to less than 1% or as close to zero as we can possibly get.

Dr. Hershman: The common bacteria that we see are things like methicillin-sensitive staph aureus as well as methicillin-resistant staph aureus.  And using an antibiotic such as vancomycin, which really has pretty good coverage against both staph aureus types, that’s really something that we like to add.  And we’ll use vancomycin impregnated into the STIMULAN beads.  Occasionally we’ll also put gentamicin or even tobramycin into the beads and we’ll use those in settings where we like to make sure that we’re eradicating the bacteria that we’re afraid of the most.

Dr. Kleck: This question is key, and the answer is not always simple. In work done at my hospital, we have found that a significant number of cases are polymicrobial.  So to start, we often pick an antibiotic regimen that provides broad coverage. Once the organism(s) is/are identified, the antibiotics can be tailored. Again, we utilize a multi-disciplinary approach, working closely with our Musculoskeletal Infectious Disease Doctors, and they’ll often tell us what grew on the plates, the sensitivities, and then we work to determine which antibiotic is best to use in the STIMULAN beads.

In a case that we’re not sure about infection, or in our deformity cases as prophylaxis, we use antibiotics that have effect against both gram-negatives and gram-positives. This broad approach helps cover for the majority of organisms that have been identified in post-operative infections. Often we’ll use vancomycin with tobramycin or gentamicin, both for the synergistic effect and for the broad coverage.

Dr. Hershman: I think that in our practice, we want to see fewer infections. Again, we want to see an infection rate that is as close to zero as possible. We know from the literature that in spinal deformity patients and especially in revision patients and long open surgeries, we see a higher rate of infection than we would like to see.  And the fact that we’re seeing an infection rate that’s now less than 1% is really the best way to tell us that the STIMULAN is working.

Dr. Kleck: Time. You have to follow the patients out for years and history is your best guide. I’ve seen primary aspergillosis in a patient that was treated for a long time with antibiotics alone and didn’t improve. We eventually treated them surgically, and two years out they came off of all antibiotics.  That patient’s now six years out, is doing fantastic, has a fusion, and is back to normal life. Cases like this are how I know STIMULAN works.

Dr. Hershman: You know, when you have a product like STIMULAN that is exciting, and we’re as optimistic as possible that it may eradicate infections or it may minimize the risk of infections, we almost want to use more of it. That could be a little bit of a slippery slope. We have to use the right amount of antibiotic and the right amount of STIMULAN beads in the wound. If you’re using too much, you can find that all of a sudden you can get a little bit of a post-operative seroma. And I think that making sure that we’re using the appropriate amount for the size of the wound and the appropriate amount of antibiotics for that wound is really the best way to go.

Dr. Kleck: While STIMULAN is a key factor, it alone does not treat the infection. It’s difficult, but surgeons have to be aggressive in the debridements and mindful of cases where stabilization is necessary. If you don’t get rid of the dead tissue and don’t stabilize the unstable spine, then you haven’t gotten rid of the infection. In that case, the STIMULAN hasn’t failed.

Dr. Kleck: We’re well over a thousand. That number is up higher than that for sure. I’ve used this in training. That experience is where I learned early on, and from there really developed the practice in utilizing the beads. I’ve used them everywhere from anterior abdominal approaches to posterior approaches, thoracic, cervical and lumbar. And the experience has been fantastic. STIMULAN is useful as an adjunct and also a very important tool in treating spine infections.

Dr. Hershman: I’ve been using STIMULAN now for a year and a half to two years. And we use it in our big spinal deformity patients. We do around 100 cases a year of spinal deformity cases, maybe a little bit more. And we now probably have close to 200 patients; maybe 150 to 200 patients that we have used STIMULAN and successfully reduced our infection rates.

Dr. Hershman: In our world, infection is not zero, and we want it to be as close to zero as possible, as close to zero percent. And anything I can do to improve the outcomes of my patients is something that I’m going to try to use. And STIMULAN has really been very helpful and instrumental in my practice in reducing the infection rate and trying to get that infection rate as close to zero as is humanly possible.

Dr. Kleck: I use STIMULAN because it achieves the goal, which is control of infections in spine patients.

Dr. Hershman: I think that if we can eliminate infection or reduce the incidence of infection, it’s not only a cost savings to the health care system, but it’s really changing people’s lives. If we can eliminate one infection or reduce one infection, that’s a big difference and it’s a huge difference in the life of that one patient. So, I think that from our perspective, really, any time we’re able to improve outcomes, even small changes, make a big difference.

Dr. Kleck: The reality is STIMULAN delivers toxic drugs locally in a way that doesn’t create toxicity for the host, the system. It allows us to put antibiotics in soft-tissue spaces that we may not achieve with IV or oral antibiotics. That alone is a benefit that you can’t put a number on or really overemphasize how beneficial that is to patients.

Dr. Kleck: Really there is no comparison. The idea of vanc dumping is limited when you think it through. The tissues are bleeding and the vanc is gone rapidly. If you use drains, which a lot of people commonly do, then the drains are pulling out all the vanc and you have nothing putting the vanc back in. With the STIMULAN beads, depending on the size of the bead, you can have two, three, four weeks’ worth of antibiotic elution. The vanc dumping, powder goes wherever you put it and then the powder’s gone. The STIMULAN beads are continuously eluting and those antibiotics are preventing or treating infection. So the reality is there’s no comparison.

Dr. Hershman: We used to use vancomycin powder in our wounds and the unfortunate part is that really, after 72 hours, that vancomycin is gone. The nice thing about STIMULAN is that it’s a slow elution. And we get to keep that antibiotic at a real concentration, at a therapeutically effective concentration, really for two to three weeks, if not longer.  So that’s something that we’re really excited about because when we see post-operative infections, it’s typically something that manifests within the first few weeks. And if we can eliminate all those early post-operative infections by having an antibiotic that’s locally infiltrating the wound, that would be a game-changer for us and it really has been a game-changer in my practice.