By Steven A. Kahn, MD
When treating severe burns, surgeons generally consider eschar removal to be the major factor and the top challenge in both initiating and planning for the optimal course of treatment for each patient. Before grafting, all devitalized tissue must be removed, leaving a wound bed of only healthy tissue. Some burn wounds are clearly full-thickness on initial examination, and some are clearly superficial, with relatively straightforward decision making. However, some wounds have an indeterminate depth and are more challenging. Deep partial-thickness, indeterminate-, and heterogenous-depth wounds require more complex decision making and/or a protracted interval to allow the wound to declare. Eschar removal is sometimes necessary to allow surgeons to assess the wound bed and confirm the depth and severity of certain burns. This, in turn, provides the insights a surgeon needs to determine the best course of treatment, including whether a patient must be treated with an autograft to cover a wound area.
During an autograft procedure, healthy skin from another location on the patient’s body (often the thigh) is surgically removed and then used to cover the burn area. Although there are some important advantages to using autograft, it requires creation of a second wound that presents a risk of pain, infection, and a scar on non-burned skin. In addition, autografts usually result in scarring and rarely look like normal skin. Split-thickness skin grafts also require daily postoperative maintenance with lotion, stretching, and scar massage.
In treating burns, surgeons work to identify the least invasive options that can successfully close a wound while working to limit pain and blood loss and reduce infection risk. Surgeons also consider how different approaches in treatment may affect a patient’s time to recover, mobility, and quality of life. Decisions related to use of autograft can have a profound impact on these factors. As a result, there has been a widening focus on understanding the relationship between different strategies in eschar removal and how they may relate to the use of autografts.
Considerations for Use of Autograft
Three main approaches to eschar removal are (1) allowing the natural process of autolytic debridement, (2) surgical excision, and (3) enzymatic debridement. Before the modern paradigms of excision and grafting, autolytic debridement was the method most commonly used in burn care. In large and deep wounds, this method results in scarring, longer recovery periods, and a high risk of infection. For deeper and larger partial- and full-thickness wounds, surgical excision has become the mainstay of treatment. With surgical excision, surgeons work to clear the wound bed of eschar by using a sharp instrument. Enzymatic eschar removal uses the application of a chemical agent to break down dead tissue. In both options, the goal is to remove eschar down to the level of healthy tissue. At this stage, the surgeon can often complete a final assessment of the severity and depth of the wound and assess the use of autograft. Severe full-thickness burns generally require a closure procedure, usually an autograft or a tissue rearrangement procedure (a flap). Some of the more severe burns are treated with a staged skin substitute – either a dermal template (bioengineered) or a temporary epidermal replacement (e.g., allograft xenograft, or a synthetic material). Less severe burns, including some mixed-depth burns, are often allowed to heal naturally and are sometimes treated with skin substitutes.
Although the goal is to assess the depth of a wound as quickly as possible to advance patients to treatment, surgeons often face challenges in making this assessment when presented with mixed indeterminate-depth burns. Issues including wound location and patient characteristics can introduce additional considerations. In many cases it is not possible to complete eschar removal for several hours or days until a patient stabilizes or a wound declares. Although accurate assessments of wound depth and strategies in eschar removal play a central role in planning treatment protocols, surgeons must also often consider other factors, including the patient’s physical and emotional health, age, impact of pre-existing conditions, ability to tolerate pain, concern about cosmetic results or maintaining mobility, and the ability to work and remain independent. Strategies that can improve the speed and precision in eschar removal can have a positive benefit in terms of timelines to treatment based on the most appropriate forms of intervention.
Doctors Looking at Strategies in Treatment and Autograft
In efforts to improve standard of care, surgeons are increasingly looking at the impact of different strategies in eschar removal. They must consider a range of factors, including the ability to preserve healthy tissue, reduce blood loss, manage pain, and achieve complete removal of eschar. Although surgical excision is effective in experienced hands, it is a macroscopic procedure; even the best surgeons cannot see and excise down to a cellular level to preserve the maximal amount of healthy tissue. The introduction of additional options beyond sharp excision can expand the surgeon toolkit to be better able to match the appropriate strategy in eschar removal to each patient profile. This can, in turn, help advance many patients to wound closure while using the least invasive treatment options that can achieve optimal outcomes.
Surgeons also note that although there have been few advances in eschar removal over the past 50 years, research targeting new options in enzymatic eschar removal are showing significant promise. Initial studies suggest that enzymatic debridement may result in less blood loss, fewer autograft procedures, and smaller graft size when grafting is performed. In addition, it is likely that research over the next 10 to 20 years could reduce or eliminate the use of autografts through new, minimally invasive and regenerative medicine treatment options.
About the Author
Dr. Steven Kahn is the chief of burn surgery at the Medical University of South Carolina and has a strong background in the comprehensive care of the burn patient. He is regarded as an expert and a national leader in the field. Kahn is board certified in both general surgery and surgical critical care. He has completed fellowships in burn surgery, critical care, and trauma/acute care surgery. Kahn’s main research interests are centered around firefighter safety, burn resuscitation, smoke inhalation, wound healing, regenerative medicine, and burn reconstruction. He has published over 50 peer-reviewed articles and has received several awards for his work.
Dr. Kahn is a consultant to Vericel Corporation
The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, HMP Global, its affiliates, or subsidiary companies.