Introduction

The term chronic wound is frequently used when discussing challenges in wound care, and it is widely recognized as a wound state that presents a formidable public health challenge.¹ Although this term has been used since the 1950s to describe wounds that are difficult to heal or those that do not follow the normal healing process, there has been uncertainty since that time about what conditions actually make a wound chronic. ² Despite the evolution of the definition of chronic wounds throughout the years, clinicians do agree that several dimensions of the wound healing process must be considered when determining whether a wound is chronic.

Duration of the Wound

Time is one of the first indicators that a wound may be chronic. Unlike acute wounds, which progress through the healing phases in a relatively short time, chronic wounds often stall within the inflammatory phase. As a result, they can remain unhealed after months or even years. Although there is no standard length of time that all clinicians use as a benchmark, 4 and 6 weeks are cited in the literature as wound durations that warrant evaluation for chronicity.^2,3 Although time to heal is an important dimension in defining chronic wounds; it is not the only one.

Responsiveness to Treatment

Many chronic wounds are identified because they fail to respond to standard wound treatment protocols. With general wound treatments, acute wounds undergo a series of molecular events that result in regaining structural integrity.⁴ These wounds progress in an orderly sequence through the stages of healing, from hemostasis to inflammation, to proliferation, and finally, to the remodeling stage. Chronic wounds fail to make this orderly progression and are characterized by pathologic processes, such as continuous inflammation, persistent infection, and potential for necrosis.⁵ Wounds have many etiologies, and the development of chronicity is heavily influenced by the colonization of bacteria and fungi, which are thought to interact through community etiologic processes to shape individual wound microbiomes and stall healing.⁵

Comorbidities and Complicating Factors

Chronic wounds fail to progress through the stages of healing by stalling. Often, this stalling results from patient comorbidities or complications of the wound itself. Despite differences in etiology, chronic wounds often share common features, such as excessive levels of proinflammatory cytokines, proteases, reactive oxygen species, and senescent cells, as well as persistent infection and a deficiency of stem cells that are often also dysfunctional.³ Common examples of complications include:

• Prolonged or excessive inflammation
• Persistent infections
• Formation of drug-resistant microbial biofilms
• Inability of dermal or epidermal cells to respond to reparative stimuli

Underlying disorders impacted by comorbidities may differ among various types of chronic wounds.³

When to Implement Advanced Wound Therapies

Chronic wounds are becoming more prevalent and more difficult to treat. Additionally, they are associated with higher treatment costs. Advanced care strategies to address chronic wounds are increasingly being relied on as clinicians attempt to achieve closure for these patients sooner. Advanced care strategies may include growth factors, extracellular matrices, engineered skin, and negative pressure wound therapy, among others. The costs of treating chronic wounds can be incredibly high, and the patient’s quality of life is often impacted by any related loss of mobility or productivity. Patients also often struggle with the stigma of nonhealing wounds because these wounds may have an odor. Subsequently, a decrease in the desire to socialize is another common side effect of chronic wounds. As such, clinicians should be attuned to the need for advanced therapies.

Conclusion

Chronic wounds are characterized by failure to progress beyond the inflammatory phase of healing despite standard of care treatment, and they often occur in patients with underlying comorbidities. The decision to incorporate advanced wound care therapies may be considered by clinicians when the wound fails to heal or decreases in size after an inordinate amount of time or when standard treatments have not been successful. Additionally, clinicians should stay abreast of potential complications, such as the presence of biofilm or infection, or other comorbidities.

References

1. Martinengo L, Olsson M, Bajpai R, et al. Prevalence of chronic wounds in the general population: Systematic review and meta-analysis of observational studies. Ann Epidemiol. 2019;29:8-15.
2. Kyaw BM, Jarbrink K, Martinengo L, et al. Need for improved definition of “chronic wounds” in clinical studies. Adv Dermatol Venereol. 2017;98:157-158.
3. Frykberg RG, Banks J. Challenges in the treatment of chronic wounds. Adv Wound Care (New Rochelle). 2015;4(9):560-582.
4. Raziyeva K, Kim Y, Zharkinbekov Z, et al. Immunology of acute and chronic wound healing. Biomolecules. 2021;11(5):700. Accessed August 19, 2022. heeps://doi.org/10.3390/biom11050700
5. Tipton CD, Wolcott RD, Sanford NE, et al. Patient genetics is linked to chronic wound microbiome composition and healing. PLoS Pathogens. 2020;16(6):e1008511. Accessed August 19, 2022. https://doi.org/10.1371/journal.ppat.1008511