Looking Back at Innovations in Wound Care
Earlier this year, when asked about milestone innovations in podiatric wound care, Podiatry Today readers were clear: negative pressure wound therapy and cellular and tissue-based products stood out. So, we asked several leaders in the field about their historic and contemporary experience with these interventions, and where they think they may lead over the next 25 years.
The Emergence and Evolution of Negative Pressure Wound Therapy
Negative pressure wound therapy (NPWT) as clinicians know it today initially developed in the early 1990s, but its roots can be traced back much earlier to “cupping glasses” used in the Roman empire.1 However, when one looks back at the last 25 years, NPWT has clearly become a game-changer in wound management.
John S. Steinberg, DPM, FACFAS, noted that NPWT is now a standard of care in limb salvage and wound care. Although he shares its implementation across multiple places of service, he sees the most use specifically in the surgical and inpatient settings.
“It has really become the treatment of choice, particularly between staged procedures, and when we’re looking to fill large defects or cover sensitive exposed tissues,” Dr. Steinberg said. “When I was in training in the late ‘90s and early 2000s, it was very much a cutting edge, exceptional item that we used mostly in research and challenging cases.”
David G. Armstrong, DPM, MD, PhD, was one of the researchers on the front lines of this innovation.
“Because of a really high volume of patients in need and our proximity, Larry Lavery and I had the chance to really dive into what is now called NPWT in the mid-1990s,” he shared. “Back then, we were trying different form factors, different tubing configurations, and lots of different settings. Most notably, we had to admit all our patients to hospital to use the device. We helped to design the “VAC ‘07 and ‘08” studies, which led to some of the key publications in the 2000s.2 What we’ve seen is iteration to different form factors and configurations. Most notably, it is very easy to use instillation therapy. Back then our unit and colleagues in Europe (Wim Fleischmann and coworkers) really had a DIY-type experience. We envisaged a day when (NPWT) would be like an iPhone and the different instillation products would be like ‘apps.’ While that hasn’t yet happened, I believe that it will—especially as we cultivate current and develop new and better companion diagnostics.”
Lee C. Rogers, DPM, said that he is grateful to have trained in the early 2000s with early adopters of NPWT, but he recalled challenges at the time including device complications and payer coverage. However, due to its efficacy, he said he feels that NPWT is likely responsible for a steep decline in the need for free flaps in the foot and ankle.
Twenty-five years ago, Paul Kim, DPM, MS, FACFAS, recalled using traditional negative pressure to stage between surgical interventions, or to create neo dermis in preparation for skin grafting, rarely waiting for terminal epithelialization.
Kazu Suzuki, DPM, shared that early 2000s use of NPWT presented a learning curve.
“We were trying to figure out when and how to use the device, with which pressure, which interface (different foams), and in which setting to achieve the best clinical outcomes,” he explained. “I feel that we are past that stage and are very comfortable knowing when to use and not to use NPWT. We now know its utility (and there are many) as well as its limitations.”
Dr. Steinberg added that even more innovations have developed more recently, including the option of instillation and different materials for contact dressings.
Dr. Rogers agreed, sharing that n new indications for NPWT have continued to emerge, and that now, it plays an additional role enhancing other treatments, like when using cellular and tissue-based products (CTPs) over exposed deep structures.
Dr. Kim cited some of the same innovative discoveries in NPWT, but added portable device options and closed incision applications as important developments.
Looking at the Journey of Cellular and Tissue-Based Products
Dr. Armstrong framed his experience over the past 25 years through the lens of his research.
“We were principal authors of the early cultured tissue product studies,” he explained.3 “We have seen iterative change since then.”
However, I don’t believe these products, all of which have an immune-modulatory effect, have had the impact they could have. This is because we still likely aren’t implementing them in an optimized way. Until we develop good quality companion diagnostics to go along with each product, we are going to be applying these products into “hostile” wound environments.4 Imagine a future where we have image-guided debridement and can assess for “receptive receptors” in the wound bed and on the periphery. This will then become something like Moh’s surgery rather than what we’re doing now, which is somewhat less precise.”
Interestingly, the first artificial dermal substitute came about in the 1980s, but leading up to the year 2000, development continued in the realm of composite grafts and tissue engineering.5 Dr. Rogers recalled that 25 years ago, as a whole, CTP usage was infrequent, primarily due to cost, coverage, and materials mostly supplied as frozen. Since then, he shared that he has seen these products develop into a mainstay for indicated wounds, serving as a bridge to the next step of treatment.
“We learned a lot about the standard of care not related to CTPs, from the early CTP trials,” he commented. “Among other things, CTP trials taught us how important offloading was in diabetic foot ulcers.”
Dr. Steinberg commented that there is great technology present in this space today and that these products can help a lot of patients. However, he added that it is difficult to truly identify an evidence-based algorithm of when to use them. In the early 2000s, he recalled topical growth factors being an option of note, and the earlier iterations of skin substitutes beginning to emerge.
“I would say that the core concept was still the same,” he said. “We were trying to find the right product to bridge the right patient at the right time. I think we’re still trying to find that 25 years later. But we do have a lot of options and a lot of different products we can choose from now.”
Dr. Rogers is encouraged about the future potential of CTPs in wound care, now that most are shelf-stable with extended expiration dates, and that some less expensive sources and manufacturing processes have emerged. Dr. Kim agreed that lower production costs, shelf stability, lack of need for special handling, and ease of use will become cornerstones of the future of this treatment choice.
With the impending new Medicare LCD (as of time of press, set to go into effect on April 13, 2025), Dr. Suzuki feels that “we are entering a new chapter of CTPs” that will warrant a closer look at cost, goals of use, and alternatives. He shared that where some previously used CTPs to aggressively work towards healing for stalled, chronic wounds, limitations in volume of applications may lead some to explore more liberal use of options like split-thickness skin grafts.
References
1. Miller C. The History of Negative Pressure Wound Therapy (NPWT): From “Lip Service” to the Modern Vacuum System. J Am Coll Clin Wound Spec. 2013;4(3):61-2.
2. Armstrong DG, Lavery LA; Diabetic Foot Study Consortium. Negative pressure wound therapy after partial diabetic foot amputation: a multicentre, randomised controlled trial. Lancet. 2005;366(9498):1704-10.
3. Veves A, Falanga V, Armstrong DG, Sabolinski ML; Apligraf Diabetic Foot Ulcer Study. Graftskin, a human skin equivalent, is effective in the management of noninfected neuropathic diabetic foot ulcers: a prospective randomized multicenter clinical trial. Diabetes Care. 2001;24(2):290-5.
4. Armstrong DG, Gurtner GC. A histologically hostile environment made more hospitable? Nat Rev Endocrinol. 2018;14(9):511-512.
5. Vecin NM, Kirsner RS. Skin substitutes as treatment for chronic wounds: current and future directions. Front Med (Lausanne). 2023 Aug 29;10:1154567. doi: 10.3389/fmed.2023.1154567. PMID: 37711741; PMCID: PMC10498286.
