Current And Emerging Modalities In Wound Debridement
A poorly planned bone biopsy can create unnecessary trauma, which can often lead to more extensive bone infection and wound complications. Should we debride exposed bone? The old adage is that exposed bone is infected until proven otherwise. However, if the bone has normal color and consistency, is it more appropriate to use Vacuum Assisted Closure (VAC Therapy, KCI) and some sort of graft? Violating the cartilage or bony cortex may result in iatrogenic trauma to the natural barrier that had been present. This in turn would lead to seeding bacteria with the end result being osteomyelitis. One will most likely encounter these concerns with heel and midfoot ulcers, for example. For similar digital ulcers, are we better off performing bony debridement (to clear the wound margins) and subsequent primary closure to achieve optimal closure rates?
Surveying The Different Types Of Debridement
Here is a succinct review of the types of debridement.
Surgical (sharp) debridement. Surgical debridement is the quickest and most efficient method of debridement. It is the preferred method if there is concern of infection or abscess. This technique is quick and selective, but very user dependent.
Mechanical debridement. In mechanical debridement, a saline-moistened dressing dries overnight and adheres to the dead tissue. Removing the dressing pulls away the dead tissue. This process is one of the oldest methods of debridement. It can be very painful because the dressing can adhere to living as well as non-living tissue. It is non-selective and considered an unacceptable debridement method for clean wounds. Whirlpool therapy, gauze, paraffin and monofilament fiber pads are other examples of mechanical debridement.
Enzymatic debridement. This technique makes use of certain enzymes and other compounds to dissolve necrotic tissue. It is highly selective. Proteolytic enzymes hydrolyze peptide bonds, which helps to facilitate removal of non-viable tissue from the wound. These enzymes work synergistically with the wound’s endogenous enzymes. One then places a moist dressing over the wound. Enzymatic debridement is faster than autolytic debridement but more conservative than sharp surgical debridement.
Santyl (Healthpoint Biotherapeutics) is the most common product in this category. Santyl is a once-daily prescription product with no generic equivalent (other enzymes that have been derived from other sources have not gone through the FDA process). This collagenase ointment works from the bottom up by selectively degrading (dissolving) collagen anchored to the wound. It only breaks down denatured collagen, leaving other proteins unaffected. Also, it doesn’t harm the collagen needed to form a scaffold, which is crucial for healing during the second phase of the wound healing cascade.
Autolytic debridement. This process takes advantage of the body’s own endogenous enzymes to remove necrotic tissue slowly. The key to the technique is keeping the wound moist as these dressings are occlusive, which helps to saturate the wound. These dressings help trap wound fluid that contains the growth factors, enzymes and immune cells that promote wound healing. Autolytic debridement is more selective than any other debridement method but it also takes the longest time to work. It is inappropriate for wounds that have become infected. Patients usually change these dressings every two to three days. It is necessary to take precautions to protect the periwound from maceration.
Examples include: hydrocolloids, hydrogels, highly absorptive dressings (Sorbion Sachet S, Carolon Health Care Products), hydrofibers (Aquacel, ConvaTec) and iodine-based preparations such as Iodosorb (Smith & Nephew). Sorbion Sachet S is a cellulose fiber pad with gelling agents. It allows gentle debridement of the wound, provides anti-inflammatory action and removes excessive exudate.