Current And Emerging Debridement Options In Wound Care

Given the well-documented importance of debridement in converting a chronic wound to an acute wound, these authors explore the merits of various methods of debridement with an eye on newer modalities such as hydrosurgery and ultrasound-guided debridement.

Wound healing is a complex and yet well-orchestrated process.¹ It is well established that acute wounds heal in a succinct fashion as the wound moves through each phase of wound healing: hemostasis, inflammation, proliferative and remodeling.

However, when a wound enters a chronic state, it often stalls in its uniform progression toward healing within the inflammatory phase. This renders the wound chronic as inflammatory cells, proteases and matrix metalloproteinases (MMP) infiltrate the wound, and ultimately delay healing. The practitioner often faces the challenge of moving these wounds toward healing by ultimately converting a chronic wound into an acute state. This conversion to the acute state often requires aggressive and effective debridement of the wound bed, one of the basic tenets of wound healing.

In today’s wound care arena, one will find an array of products and techniques available to facilitate the process of debridement and wound healing in patients. Despite the readily available nature of advanced wound care products and offloading devices, the consistent mainstay to treatment remains appropriate wound bed preparation, which is dependent upon appropriate and aggressive wound debridement. Selection of the debridement technique and the appropriate amount of frequency are critical to facilitating wound healing and successful outcomes.^2,3

Successful debridement can address all the factors of “TIME”: tissue, infection/inflammation, moisture and edges (see “A Guide To The Principles Of Wound Bed Preparation” at right). This paradigm provides an all-inclusive evaluation of the wound in question, allowing for the identification of barriers that are delaying healing. In doing so, one may then tailor treatment regimens to address each inhibiting factor.¹

• Tissue. In addressing the tissue component, identify nonviable tissue to allow for the implementation of appropriate removal techniques.
• Infection/inflammation. Evaluate infection/inflammation and identify bacterial bioburden versus contamination or blown out infection, and address with topical or oral agents as appropriate.
• Moisture. One then addresses the moisture in the wound as the extent of exudate or lack thereof will impede wound healing by excessive maceration of tissue or, in contrast, desiccation of the wound. Both of these factors in extreme will impede the progression of keratinocytes and cell migration.
• Edges. The final factor, edges, calls for the critical evaluation of wound margins for undermining or lack of epithelial budding or migration.

Each of these components depends upon a degree of debridement to properly face the challenges introduced by chronic inflammatory markers, senescent cells, proteases and MMPs that ultimately stall progress. It is debridement of the wound that facilitates the conversion of a chronic wound to its acute state, rendering the wound more conducive to healing and more prepared to receive advanced therapies such as skin graft substitutes, advanced wound dressings or offloading devices that promote final wound closure.⁴

There are a variety of techniques to consider when choosing an appropriate method for debridement. This can often pose challenges for the provider including but not limited to: availability of the product, cost, experience with the product or device, and prior outcomes. Techniques most commonly considered and implemented include mechanical, biosurgical, enzymatic, autolytic and surgical means of debridement.

A Closer Look At Biosurgical Debridement

Before the 20th century, wound care included biodebridement via maggot therapy. Although not often readily well received by patients, the benefits of maggot therapy have been successful in patients who are not surgical candidates and have intermittent responses to surgical debridement. It is particularly the green bottle fly (Lucilia sericata) that has demonstrated a selective degradation of nonviable tissue while leaving healthy tissue intact.⁵ The larvae have a five-day lifespan once shipped and applied onto the wound. Therefore, from the point of receipt, they will provide a three- to five-day treatment.

There have been several proposed mechanisms for the use of larvae. They are known to secrete proteolytic enzymes and are able to selectively degrade nonviable tissue similar to collagenase, leaving healthy tissue intact. There is also evidence supporting the antimicrobial benefits of the larvae via pH changes inducing bacterial destruction.⁶ The larvae are also an inexpensive form of therapy and readily ship for use in wound debridement.

The work of Gilead and colleagues demonstrated the successful outcomes of maggot therapy in 723 wounds, undergoing a range of one to 48 treatments.⁵ They noted successful complete debridement in 82 percent of the wounds they treated. However, many of the studies we reviewed correlate the success of therapy to the successful debridement of the wound and not necessarily to the successful healing or closure of the wound, therefore rendering the wound in need of adjunctive long-term treatments.⁵  

Current Concepts With Enzymatic Debridement

Collagenase is the most commonly utilized form of enzymatic debridement today and is the only Food and Drug Administration (FDA)-approved product in this category. It derives from the bacterial strain Clostridium histolyticum. The use of collagenase allows for selective removal of wound bed debris or necrotic tissue in both the sensate and insensate patient as it is a painless process. We can attribute the selective nature of collagenase to the selective breakdown of one protein: collagen.

Although collagen is an important structural component of the extracellular matrix, its selective degradation can augment wound healing.¹ This is due to the destruction of the denatured collagen fibers, which in essence function to bind necrotic tissue to the wound bed. Research has shown that collagenase leaves healthy granulation tissue intact and promotes keratinocyte migration over the wound bed.¹ A secondary dressing is always required, however, and it facilitates wound care in both the clinical setting and the home environment.

Enzymatic debridement has gained further popularity in the maintenance of a wound after sharp debridement. This therefore prevents the accumulation of necrotic soft tissue and reduces the presence of inflammatory cellular markers.  

When Is Autolytic Debridement Most Effective?

Physicians often utilize advanced wound dressings to facilitate or enhance the body’s own mechanism of autolytic debridement. This process relies on the body’s activation of phagocytes to promote the debridement or sloughing of nonviable tissue or eschar.⁷ When one introduces moisture-donating or moisture-retaining therapies to a wound, the body’s own digestive enzymes release into the wound fluid and will liquefy the eschar, allowing it to slough. Though it is advantageous in patients for whom surgical or more aggressive techniques may compromise overall healing or pose a greater risk to the patient, the process is a slow one.

Hydrocolloid dressings are the most frequently used dressings but there have been advances with these dressings in combining them with alginates, hydrogels and foam dressing components. Given that these dressings are often occlusive, they are not an option in patients in whom one suspects underlying infection. These dressings are often easy to apply and one may leave them on a wound from three to five days. This process depends upon the body’s immune system to trigger the necessary response so patient selection becomes crucial. It is also important to note that once the autolytic process has taken effect, irrigation is helpful in eliminating the slough. However, many times, one may need to implement other forms of debridement to further assist in the removal.

Pertinent Insights On Sharp Debridement

Surgical or sharp debridement remains a mainstay in modern day wound care. It is often the first form of debridement in the clinical setting and surgical setting.^8,9 Not limited to the use of a scalpel, clinicians may also employ tissue nippers, scissors and/or a curette to perform sharp debridement. Surgical debridement remains fast and effective in converting the wound bed from a chronic to an acute state by the aggressive removal of necrotic tissues that would otherwise promote both increased bacterial bioburden and inflammatory cells within the wound.

Although physicians often perform sharp debridement in the office, they may encounter limitations with larger wounds that require controlled hemostasis or sensate wounds that require the use of anesthesia and more formal debridement in the operative suite. Sharp debridement is often more conducive to effective debridement and can be selective to target removal of only non-viable tissue.¹⁰

How Mechanical Debridement Techniques Have Evolved

Mechanical debridement has advanced significantly from the days of the wet-to-dry dressings that physicians utilized to remove fibrous slough and nonviable tissue from the wound bed as the dressing dried onto the wound before removal. Some limitations to this technique include pain and time to achieve the desired outcome. However, one may employ mechanical debridement as a maintenance adjunct to the application of enzymatic debridement agents. Wound cleansers and wound scrubs have also been effective in reducing fibrous slough of tissue but are not as effective in the removal of adhered eschar. Often, aggressive wound scrubs can be a source of pain for the patient despite the benefit.

More recently, hydrodebridement techniques have moved to the forefront, whether it is pulse lavage or the use of devices such as the Versajet (Smith and Nephew) hydrosurgery system. Pulse lavage or the Pulsavac (Zimmer Biomet) offers a pulsating pressure irrigation system, which one can enhance with the addition of antibiotics or utilize with saline alone. This debridement technique applies between 4 and 15 psi to the wound in an effort to remove nonviable tissue and stimulate the wound into an acute environment. However, this technique is not selective to the extent and quality of the tissue one removes, and requires the operative room setting for use.  

The Versajet hydrotherapy system provides the benefits of sharp debridement and hydrotherapy in one system. By utilizing a razor thin saline jet that excises at a depth of 50 to 200 μm, the system allows for selective debridement of nonviable tissue structures at the hand of the surgeon. This technique also allows for pressure irrigation of the wound to further reduce bacterial bioburden and stimulate the wound in the production of necessary cellular mediators for healing such as growth factors. Research has shown the system reduces time spent in the operating room and reduces time to closure by allowing for immediate graft coverage.⁹ However, the process is non-selective and depends upon the user for selection of tissue removal.

Ultrasound-guided debridement offers selective debridement of the wound bed at the hand of the facilitator. Similar to hydrotherapy systems, ultrasound debridement systems combine irrigation with therapeutic ultrasound in an effort to denature and debride devitalized tissues, and reduce bacterial bioburden.

Other Factors In Treating The Chronic Wound

The relevance of good wound bed preparation remains a vital part in the overall success in the management and healing of chronic wounds. However, it is important to critically evaluate every wound for local variables contributing to any delay in healing. The astute provider will always rule out the VIPs of healing — including vascular status, infection and pressure — and ultimately follow the parameters set forth within the TIME principle of wound management.

It is important to establish a vascular baseline in patients who are dealing with chronic wounds and difficult healing. Obtaining lower extremity arterial studies and assessing ankle brachial indices (ABIs) or pulse volume recordings (PVRs) in patients may open the door to an unaddressed vascular component to the delay in healing. One may subsequently consult with vascular colleagues to explore revascularization opportunities that would further aid in long-term healing in the acute setting and long-term lower extremity function. Ascertaining the patient’s vascular integrity and risk of compromise to the wound can help one determine the appropriate level of debridement. In situations as these, it may be best to utilize processes that employ less painful techniques although patients may require more prolonged care.

Take infection into account and manage any infection present. It is well established by the Infectious Diseases Society of America guidelines that in the absence of infection, antibiotics are not necessary.¹¹ In these cases, good wound hygiene will allow for reduction in the bacterial bioburden. However, when infection is of concern, regardless of severity, one should employ appropriate management with a combination of antibiotics and debridement.

Furthermore, regardless of effective, efficient and adequate wound debridement, in the presence of a pressure causing deformity, all wounds must have appropriate offloading. Offloading, especially when it comes to diabetic foot ulcerations, is the cornerstone to management and ultimate healing. Several modalities, ranging from offloading boots and offloading sandals to total contact casting, are available to best accommodate the deformity and the patient needs.

In Conclusion

Although there are many established and emerging debridement techniques to choose from when faced with a chronic wound, it is without debate that more rapid wound healing occurs when aggressive, effective debridement is part of the treatment regimen. Steed and his group found in a study of 118 patients that those who had more frequent sharp debridement had a 48 percent increase in wound healing in comparison to a control group.¹² They also demonstrated that those who had less frequent debridement also had lower healing rates. In a similar study, Falaga and colleagues found a 2.5 times greater healing rate in patients who had more frequent wound debridement.²

While all of the aforementioned debridement methods can be effective techniques in wound management, there is not an overall consensus in regard to one technique being superior over another. In the course of wound debridement, it is not uncommon and often recommended that physicians utilize multiple techniques to allow for more comprehensive management of the wound bed. While some therapies have a slower process or function more in the role of wound bed maintenance, it would be appropriate to implement sharp or mechanical debridement to maximize your results. In addition to selecting the appropriate debridement technique for the given patient’s wound, ensuring the consistency and thoroughness of the debridement in an effort to keep the wound in an acute-like state can help propel the wound toward healing.

Dr. Hadi is a faculty member with the Louis Stokes Cleveland Veterans Affairs Medical Center. She is a Fellow of the American College of Foot and Ankle Surgeons.

Dr. Inwood is a third-year resident at Louis Stokes Cleveland Veterans Affairs Medical Center.

References

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6.     Armstrong DG, Salas P, Short B, et al. Maggot therapy in “lower extremity hospice” wound care: fewer amputations and more antibiotic free days. J Am Podiatr Med Assoc. 2005; 95(3):254-7
7.     Doerler M, Reich-Schupke S, Altmeyer P, et al. Impact on wound healing and efficacy of various leg ulcer debridement techniques. J Dtsch Dermatol Ges. 2012; 10(9):624-632.
8.     Panuncialman J, Falanga V. The science of wound bed preparation. Surg Clin N Amer. 2009; 89(3):611-26.
9.     Liu J, Ko JH, Secretov E, et al. Comparing the hydrosurgery system to conventional deridement techniques for the treatmenr of delayed healing wounds: a prospective, randomised clinical trial to investigate clinical efficacy and cost effectiveness. Int Wnd Jnl. 2015; 12(4):456–61.
10.     Beitz JM. Wound debridement: therapeutic options and care considerations. Nurs Clin. 2005; 40(2):233–49.  
11.     Infectious Diseases Society of America. Antimicrobial agent use. Available at https://www.idsociety.org/Antimicrobial_Agents/ .
12.     Steed DL, Donohoe D, Webster MW, Lindsley L. Effect of extensive debridement and treatment on the healing of diabetic foot ulcers. Diabetic Ulcer Study Group. J Am Coll Surg. 1996;183(1):61–64.

Additional References
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    14. Telford G, Brown AP, Seabra RA, et al. Degradation of eschar from venous leg ulcers using a recombinant chymotrypsin from Lucilia sericata. Br J Dermatol. 2010; 163(3):523–31.
    15. Altman MI. Collagenase: an adjunct to healing atrophic ulcers in the diabetic patient. J Am Podiatr Med Assoc. 1978; 68(1):11–15.
    16. Milne CT, Ciccarelli A, Lassy M. A comparison of collagenase to hydrogel dressings in wound debridement. Wounds. 2010; 22(11):270–4.