Pearls on Optimizing Skin Substitute Utilization

Greater than 20 years after introduction to the wound care community, skin substitutes are now entrenched as an adjunctive therapy. As such, they have undergone similar validation, praise, criticism, and scrutiny to other modalities, including debridement and hyperbaric oxygen.

With such widespread acceptance of skin substitutes after such an extended period, why has their use become so debated? Evidence to support their application is well documented, regardless of whether allograft or xenograft.¹ However, their continued presence as a treatment option remains tenuous considering proposed (later withdrawn) policy changes by the Centers for Medicare and Medicaid Services (CMS) that call for strict limits and restrictions of their use.²

Historical Perspectives on Skin Substitutes

From a personal and historical perspective, skin substitutes for treating diabetic foot ulcers made much sense when I first became acquainted with the concept in the last quarter of the year 2000. Although well-established as an option to expedite healing across many wounds, split-thickness skin grafts presented a conundrum with the need to create a new harvest wound on a patient who had already demonstrated an inability to heal. Potential for pain and an additional non-healing wound seemed like significant risks, considering that the successful outcome of a skin graft is never a given.

Histologically, skin substitutes shared enough similarity to, along with components of, healthy skin that trialing them made much sense, in my observation, and represented a solution with less potential risk to the patient than a split-thickness skin graft, not to mention no need for scheduling of operating room time, anesthesia, and the resources involved, among other concerns.

Ideally, and at the time of their introduction, clinicians saw skin substitutes as a potential alternative to skin grafting. However, the mechanism of action and limitations were not completely clear. Over time, more clinical data accumulated that showed reasons for optimism. This included understanding of the role of various growth factors and how skin substitutes were utilized by the body.^3–5 Despite an emerging and increasing understanding of the science, there was still a lack of consistency, as well as clearly defined guidelines, regarding how to optimize outcomes when applying skin substitutes.

Lessons Learned

Clinical results have further validated the the case for continued utilization of skin substitutes (also referred to as cellular- and tissue-based products, or CTPs) in both the present and future.^3–5 After 20-plus years, and much research since skin substitutes emerged as a viable treatment option for the management of chronic wounds, what have we learned as a medical community?

Identify what’s missing. As anyone who has performed wound care will attest, there is no silver bullet when it comes to healing wounds of any etiology, let alone diabetic foot ulcers. The physiological cascade common among all healing wounds is a delicate balance that requires components such as protein, vitamins, and other elements that extends beyond growth factors or an extracellular matrix. Remember, healthy individuals do not develop chronic wounds, so assisting the body in accessing what it needs for healing is essential. When there are deficiencies, healing will not progress, no matter what one applies to the wound.  

Know your enemies. Addressing the hostile wound environment is another concept that I’ve witnessed go from theory to best practice. In my observation, a greater understanding of the importance of biofilm colonies and overall controlling microorganisms through debridement, topical agents and antibiotics is now recognized as one of the tenets of wound management, sharing an equivalency with other aspects such as optimization of perfusion, edema management, and offloading. Using skin substitutes without doing these is an almost certain path to failure.

Pearls and Pitfalls to Consider

The good. In my experience, knowing how and when to use skin substitutes makes all the difference between success and failure. Randomly applying skin substitutes because a wound fits a certain criterion, such as being present for greater than 4 weeks, is risky at best. As they pertain to diabetic foot ulcers, an understanding of a patient’s anatomical and structural deformities, biomechanics, and lifestyle or living conditions are additional keys to a successful outcome. 

Adherence with offloading is another critical factor to consider and address when using skin substitutes for treating diabetic foot ulcers. Some describe offloading as a controlled environment where the clinician “protects the wound and the patient from themselves.” However, this does not suggest one defer to the patient when deciding on the type of offloading to use in conjunction with a skin substitute. Certainly, consideration of the patient’s ability to tolerate certain methods of offloading should be a factor, but to apply a skin substitute to a diabetic foot ulcer that is not protected from shearing and the patient’s gait, preferably 24 hours a day/7 days a week, is a waste of resources and reckless. It ultimately adds to the frustration of nonhealing after attempting multiple applications with minimal-to-no progress made. 

When considering application, I find timing is essential, not just in terms of allowing for the “appropriate waiting period” and authorization. A critical concept I feel clinicians do not commonly discuss is whether a wound has demonstrated an ability to heal or not. As mentioned earlier, there is no panacea in wound care, and unless a wound shows progress towards healing, applying a skin substitute will not guarantee acceleration of proliferation of the healing cascade.   

If the wound is healing, then why bother using a skin substitute at all? We have all heard the adage that “time is tissue” and the longer a wound remains open, the greater the risk of developing other complications, such as skin infection, osteomyelitis, amputation, sepsis, or death.⁶ Antibiotic resistance and the lack of new antibiotics being developed are concerning. Risk of continued use of many of the antibiotics used in treating chronic wounds, especially in the diabetic population with potential for exacerbation of chronic and end-stage renal disease, is another reason to expedite healing. Every dose can cause irreversible damage to glomeruli, further exacerbating the cumulative, deleterious effects of diabetes on renal function. Accelerating the healing process with the use of skin substitutes in wounds that have exhibited the ability to heal is an important concept, and in my opinion, is arguably their most important benefit.

The bad. For some time, I have observed an elephant in the skin substitute room, which began to emerge and grow as more products entered the market. How well wounds healed, or how patients responded to a specific treatment, not to mention the science or efficacy of a product, all too often became secondary to reimbursement.

The fee-for-service system that has existed since skin substitutes’ introduction has compensated physicians for performing procedures, not achieving outcomes. I implore providers to focus on patient impact and outcomes over potential profit.  

The better portion of 2023 found the wound care community on the defensive as proposed policy changes by the CMS emerged, limiting the number of skin substitute applications, as well as introducing outright exclusion of coverage for 130 products. In my observation, mitigating potential for abuse of these products was a likely consideration when CMS drafting this proposal.  

The ugly. JW and JZ modifiers represent, I feel, an early indication that CMS had concerns about the spending on such therapeutics. The JW modifier, introduced on January 1, 2017, carried recommendations that providers and suppliers use this code to report any amount of a drug or skin substitute that was discarded or not applied. CMS determined that the JW modifier was being underutilized, and as a result, created modifier JZ to indicate that no waste of product occurred (effective January 1, 2023, as a voluntary code, subsequently became mandatory on July 1, 2023). CMS stated that claims not including the modifiers after July 1 could be subject to audit, and that claims submitted after October 1, 2023, could be rejected.⁷

JW and JZ Modifier Pointers

Here are examples of how to include the JW/JZ modifiers in a skin substitute claim submission:⁷

To submit claims for a non-discarded claim, submit one complete claim line:

• HCPCS level ll code
• JZ Modifier to indicate no waste
• Number of units applied to patient
• Calculate the submitted price for the amount applied

To submit claims for a waste-required claim, submit two complete claim lines.
 
Claim line #1:

• HCPCS Level ll code
• No modifier
• Number of units applied to patient
• Calculated submitted price for only the amount of product used

Claim Line #2:

• HCPCS Level ll for product wasted
• JW modifier to indicate waste
• Number of units wasted
• Calculated submitted price for only the amount of product wasted
• Number of units applied to patient

What Does the Future Hold?

The future of skin substitutes will be determined by multiple factors, from their proven history and efficacy, to proper use and economics. The at-risk populations that benefit most from skin substitutes are those whose medical-related expenses are among the most draining on the healthcare system.  

Of greater concern is that despite the technological advancement that skin substitutes have represented, they may be judged more as an economic burden than asset, especially when non-traumatic, diabetes-related lower extremity amputation rates have been increasing since 2009.⁸ Placing limits and other restrictions on CTPs’ use is a first step. I am concerned that outright disallowing their use may be next, unless data can be produced that demonstrates indisputable benefits.

Otherwise, until other technologies emerge that demonstrate greater efficacy than skin substitutes, physicians and patients alike will be subjected to this unsettling uncertainty, and questions raised regarding quality of and access to care. Overall, focusing on optimizing clinical outcomes and appropriate billing and coding practices are, in my opinion, the best steps providers can take regarding the use of skin substitutes.

Dr. Desmond Bell is the Founder and President Emeritus of “The Save A Leg, Save A Life” Foundation, a multidisciplinary nonprofit organization dedicated to the reduction in lower extremity amputations and improving wound healing outcomes through education, evidence-based methodology and community outreach. He also serves as Chief Medical Officer of Omeza and an Executive Physician Coach for MD Coaches.

References

1. 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.
2. Schaum KD. As CTP coverage changes, focus on what you can and should do! Today’s Wound Clinic. 2023; 17(8). 
3. Buchberger B, Follmann M, Freyer D, Huppertz H, Ehm A, Wasem J. The evidence for the use of growth factors and active skin substitutes for the treatment of non-infected diabetic foot ulcers (DFU): a health technology assessment (HTA). Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet].
4. Sierra-Sánchez Á, Kim KH, Blasco-Morente G, Arias-Santiago S. Cellular human tissue-engineered skin substitutes investigated for deep and difficult to heal injuries. NPJ Regen Med. 2021 Jun 17;6(1):35. doi: 10.1038/s41536-021-00144-0. PMID: 34140525; PMCID: PMC8211795.
5. Yamakawa S, Hayashida K. Advances in surgical applications of growth factors for wound healing. Burns Trauma. 2019 Apr 5;7:10. doi: 10.1186/s41038-019-0148-1. PMID: 30993143; PMCID: PMC6450003.
6. Oliver TI, Mutluoglu M. Diabetic foot ulcer. StatPearls.
7. Centers for Medicare and Medicaid Services. A55932: Billing and Coding: JW and JZ Modifier Billing Guidelines. Original Effective Date: 1/1/2018. Revision Effective Date: 1/10/2023.
8. Geiss LS, Yanfeng L, et al. Resurgence of diabetes-related non-traumatic lower extremity amputation in the young and middle-aged adult US population. Diabetes Care. 2019 Jan; 42(1):50-54