7.1.1 Introduction

Debridement is the cornerstone of modern surgical treatment of open wounds. The term “debridement” originated with the French word “débrider”, which literally meant to unbridle or release something that was confining. It was used to describe the release of tight tissues around a wound. Today, debridement has come to mean the systematic removal of all grossly contaminated or nonviable, necrotic tissue from a wound with the ultimate goal to create a clean or even sterile wound. Effective debridement has been attempted for many centuries, eg, through the use of changed dressing or the application of maggots (chapter 9.4) [1]. However, during the Napoleonic Wars, the French surgeons Larrey and Desault strongly advocated the use of incision of traumatic wounds to allow drainage, conversely, John Hunter, the English father of surgery, felt that covering the wound with salve and a dressing was the mainstay of treatment. Not until the dawn of the 20th century has debridement turned into mainstream thought. This concept was cemented in surgical practice after the positive experiences gathered during World War I [2].

Despite major advances in the understanding of wound pathophysiology and bacteriology, little has changed during the past two centuries with regard to the basic techniques and assessment of tissues.

7.1.2 Assessment of viability (Video 7.1-1)

Skin

Viable skin has a healthy subcutaneous layer firmly attached to the dermis. Skin that shows significant ecchymosis within the subcutaneous fat is at risk ( Fig 7.1-2 ). Skin that has been avulsed from the subcutaneous fat—as may be observed in elder patients—is likely to lose its viability and, thus, may be debrided at once. Heavily contaminated skin should be removed because contaminants cannot be thoroughly removed without compromising the skin′s integrity significantly. Often, the subcutaneous layer may be avulsed from the underlying fascia ( Fig 7.1-3 ) (chapter 3.3). If the subcutaneous fat does not show ecchymosis, it may be left, but larger areas of avulsed fat will often become necrotic. Harvesting of the skin in order to use it as a split-thickness skin graft to cover the defect may sometimes be an option.

Muscle

Muscle viability can be assessed by checking the following four “C”s ( Fig 7.1-4a–c ) ( Video 7.1-1 ):

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  color

  
  
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  consistency

  
  
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  capacity to bleed

  
  
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  contractility.

Although very subjective, this time-honored method of assessing muscle viability is still acceptable [3]. Muscles should appear bright red in color, as dark red muscle indicates rupture of muscle capillaries and intramuscular hematoma formation. In that case, the muscle must be searched for areas of bruising ( Fig 7.1-5 ). Such a bruised muscle may survive, but there is a risk of future necrosis. Gray muscle tissue is already necrotic and must be removed, especially if there is continued risk of contamination, because such tissue provides the ideal conditions for infection to take hold.

Surgeons should be familiar with the consistency of viable muscle. The muscle should exhibit good turgor and should not pull apart with gentle teasing. Consistency remains good until muscle is clearly necrotic and, therefore, its loss is a rather late sign. The capacity to bleed is less reliable, because muscle with extensive rupture of capillaries may bleed initially as a result of an intramuscular hematoma. Furthermore, cutting muscle back to bleeding may require excision of some viable tissue. Muscle contractility is judged most commonly by touching the muscle with the electrocautery pencil, but it will respond to tapping or pinching with a forceps. Viable muscle should contract with direct stimulation, even when a depolarizing anesthetic substance has been administered or spinal cord injury has denervated the muscle. As muscle contractility may be decreased initially following blunt trauma, great care should be taken when assessing it.

Bone and periosteum

The latter should be carefully assessed especially if stripped from bone. Ecchymosis within the periosteum indicates a rather severe injury, but does not necessarily require excision. If there is good continuity with the remainder of the periosteum, the damaged periosteum is likely to survive. However, periosteum that is separated both from its overlying muscle and from the rest of the periosteal sleeve is not likely to provide much supply for the bone and may be removed. Bone that has lost all its attachments to surrounding tissues is probably dead and should be removed. In relatively clean wounds, small fragments may be left, but all necrotic bone must be excised, especially if the risk of contamination is high.

7.1.3 Techniques of debridement (Video 7.1-1)

There are many techniques for surgical and nonsurgical debridement of open wounds. Wounds that are not heavily contaminated and that do not have a great deal of necrotic tissue may be treated nonoperatively with changes of dressing. Chemical debridement is useful for very superficial, chronic wounds. High-pressure irrigation is not recommended in fresh wounds, but may be useful to clean infected and chronic environments (chapter 7.2). The most commonly used procedure for debridement of open wounds is sharp surgical debridement with a scalpel. Regardless of the methods used, the end result should be a macroscopically clean wound, which allows natural repair processes to proceed.

Many surgeons perform debridement procedures with a tourniquet, particularly if vessels and nerves are exposed. If after release of the tourniquet punctate bleeding of the exposed tissues is insufficient, additional debridement can be performed, even without tourniquet.

The surgeon must aggressively seek out and—by meticulous excision—remove all dead and devitalized tissues and foreign matter. This should be done in a thorough manner while avoiding additional trauma to the tissues as a result of excessively aggressive dissection (chapter 11.2). Surgical debridement ranks as the most important single activity influencing outcome in the management of the open fractures.

The cost of leaving dead, necrotic tissue in the wound is high. In case of doubt and if the first debridement was not extensive enough, a second or even third debridement must be performed within 48–72 hours. Any wound that received delayed initial care or that was grossly contaminated, should be considered for second debridement. Debridement should thus be regarded as a staged procedure. Surgical debridement of the contaminated wound is urgent before bacterial proliferation approaches the critical inoculum, above which infection becomes highly likely.

When using sharp debridement, care should be taken to prevent any further damage, especially to uninjured surrounding tissues. Excessive retraction or clamping must be avoided. A sharp scalpel with frequent changing of blades creates clean cuts and is most helpful, while the use of scissors should, whenever possible, be avoided as they cause local crushing of tissue (chapter 1).

Of course, debridement commences on the outside working inwards ( Fig 7.1-6 ). Skin that is manifestly dead and macerated should be excised. Skin of dubious viability can safely be left for the second look, when its status will be obvious (eg, avulsion injury). Damaged subcutaneous fat should be thoroughly excised.

Leaving devitalized muscle in the wound may have catastrophic consequences, even within a short period of time. Careful attention must thus be paid to muscle in the initial debridement. All muscle of dubious viability must be resected to pink bleeding edges, which contract when gently pinched. This implies that debridement procedures are performed without tourniquet. The intact tendon can be cleaned and reexamined during the second look. Major neurovascular structures should be preserved and repaired, if necessary.

Bone ends should be scrupulously cleaned mechanically, and any foreign material must be removed from the medullary cavity ( Fig 7.1-7a–b ). Bone ends must be exposed and debrided. Any loose fragments of bone, or bone without soft-tissue attachments, are removed from the wound and discarded. In some exceptional situations a large segment of bone might be preserved in order to help axial alignment and/or as a spacer.

Surgeons should realize that any penetrating injury may involve far more extensive damage below the skin, and a larger incision is required to allow for adequate deep debridement ( Fig 7.1-8a–b ). Most small wounds should be extended in order to allow full assessment of the underlying tissue.

7.1.4 Summary

Debridement and irrigation of a wound needs good judgment and much experience and, therefore, should never be delegated to the junior resident or an inexperienced surgeon. Despite the simple concepts behind debridement, it is the task that is most often inadequately performed. Surgeons should treat debridement in the same manner an architect treats the foundation of a building. Its design is simple, compared to the elaborate designs of the rooms of the building, but unless it is well designed and well executed, the building will fall. A “laissez-faire” attitude toward this procedure may put the limb and the patient at risk.