Skin necrosis is the death of skin tissue caused by inadequate blood supply, which deprives cells of oxygen and nutrients. This devitalized tissue cannot be revived and must be removed to prevent complications, as it serves as a breeding ground for bacteria and blocks natural healing. Necrotic tissue often appears as dry, leathery eschar or as yellow, moist, stringy slough. Prompt medical intervention is necessary; if left untreated, it can lead to severe infection, systemic illness, or limb loss. Treatment focuses on removing the dead tissue, addressing the underlying cause, and achieving lasting wound closure.
Principles of Initial Stabilization
Initial stabilization focuses on the patient’s overall health and stopping the progression of tissue death before removing the necrotic tissue. This involves aggressively addressing the root cause, such as stopping a causative medication or relieving prolonged pressure. For patients with systemic infection or sepsis, aggressive resuscitation with fluids and antibiotics is started immediately.
Systemic infection is controlled using broad-spectrum antibiotics, often before specific pathogens are identified. Improving circulation is another immediate goal, sometimes involving anticoagulants or vasodilators to maximize blood flow to the compromised tissue. Adequate pain management is also important, as pain can cause vasoconstriction and further decrease blood flow.
If immediate surgical debridement is not feasible, specialized topical agents may stabilize the necrotic area. Products containing cerium nitrate and silver sulfadiazine can form a protective crust over the dead tissue. This temporary stabilization helps prevent infection from spreading and allows the care team time to plan for definitive surgical treatment.
Methods of Necrotic Tissue Removal
Debridement, the removal of dead tissue, is necessary to prepare the wound bed for healing. The method chosen depends on the wound’s size, location, and the patient’s health status.
Surgical or sharp debridement is the most definitive and rapid method, using a scalpel to completely remove necrotic tissue. This approach is preferred for extensive necrosis or deep infection, as it quickly removes the source of sepsis.
Enzymatic debridement is a non-surgical method using topical chemical agents, such as collagenase, applied directly to the wound. This enzyme selectively dissolves the denatured collagen that binds the dead tissue, causing separation from viable tissue underneath. Although slower than surgical debridement, this technique is often used for patients who cannot tolerate surgery or as an adjunct to sharp debridement.
Autolytic debridement is a slow, gentle method that uses the body’s own moisture and enzymes to break down non-viable tissue. This is achieved by applying moisture-retentive dressings, such as hydrogels or hydrocolloids, which create a sealed, moist environment. While highly selective and virtually painless, this slow process is less suitable for wounds with a significant infection burden.
Mechanical debridement uses physical force to pull off dead tissue, historically involving wet-to-dry dressings. However, modern practice favors more selective methods because mechanical debridement is non-selective, potentially removing healthy, newly formed tissue and causing discomfort. Biological debridement, using medical-grade maggots, is a highly selective method that consumes only the necrotic tissue, leaving healthy tissue untouched.
Advanced Wound Management Techniques
After necrotic tissue removal, the focus shifts to creating an optimal wound bed environment to promote new tissue growth and prevent complications. Preventing secondary infection is managed through careful monitoring and the use of topical antimicrobial agents, such as silver-containing dressings, alongside systemic antibiotics when needed. Maintaining a precise moisture balance is also important; a dry wound halts cell migration, while an overly wet one can cause surrounding skin breakdown.
Advanced dressings are selected to manage wound exudate. Hydrogels add moisture to dry wounds, while foams and alginates are highly absorbent and used for high drainage. The goal is to stimulate the formation of granulation tissue, which is the pink, bumpy tissue composed of new capillaries and connective tissue that fills the wound defect.
Negative Pressure Wound Therapy (NPWT) uses a sealed dressing and a vacuum pump to apply controlled sub-atmospheric pressure to the wound bed. This gentle suction removes excess fluid, reduces the bacterial count, and draws the wound edges closer together. NPWT is effective in preparing large or complex wounds by promoting robust granulation tissue formation, making them ready for final closure.
Long-Term Healing and Reconstructive Options
Once the wound bed is clean and healthy granulation tissue has formed, the final stage is achieving permanent closure. Smaller wounds may be closed directly or allowed to heal naturally by secondary intention. However, larger defects resulting from extensive necrosis often require reconstructive procedures to cover the exposed area and restore function.
Skin grafts involve transplanting a thin piece of skin from a healthy donor site to the wound bed.
Split-Thickness Grafts
A split-thickness skin graft includes the epidermis and a portion of the dermis. This type is used to cover large areas quickly, though it may result in more noticeable scarring.
Full-Thickness Grafts
Full-thickness skin grafts include the entire epidermis and dermis. They offer a better cosmetic result but are typically reserved for smaller defects.
For complex wounds where bone, tendon, or vessels are exposed, a skin flap procedure is necessary because a graft would not survive. A skin flap transfers skin, subcutaneous tissue, and sometimes muscle, along with its own established blood supply, to the defect. Following closure, physical therapy may be necessary to minimize scarring and restore mobility. The reconstructed area will continue to mature and improve in appearance for up to 18 months.