Debridement

Debridement is a vital medical procedure used to clean wounds. It involves the removal of dead, damaged, or infected tissue. By removing these problematic areas, doctors improve the healing potential of the remaining healthy tissue. This process is essential for treating serious burns and certain snake or spider bites. It is also used in podiatry to manage calluses and verrucas. In some cases, surgeons must debride tissue around a tumor. They do this because micrometastases, or tiny clusters of cancer cells, may exist at the edges. Removing this surrounding tissue helps prevent the tumor from returning.

There are several distinct methods for performing debridement. Each method works differently to target necrotic, or dead, tissue. Surgical debridement is often called "sharp" debridement. This can be done in an operating room or at a patient's bedside. It is one of the fastest methods available. Surgeons use tools or lasers to remove tissue until they reach viability. They determine viability by looking for healthy tissue appearance and active blood flow. This method is highly selective. The person performing the procedure has almost complete control over what is removed.

Autolytic debridement is a much slower and more gentle process. It uses the body's own enzymes and moisture to work. This moisture re-hydrates and softens the dead tissue. Eventually, the hard eschar and slough are liquefied. This process is very selective because it only affects necrotic tissue. Because it uses the body's natural systems, it is virtually painless. Doctors achieve this by using occlusive or semi-occlusive dressings. These dressings, such as hydrogels or transparent films, keep wound fluid in contact with the dead tissue. This method is best for wounds without extensive dead tissue or infection.

Enzymatic debridement uses chemical enzymes to slough off necrotic tissue. These enzymes are fast-acting. They can be derived from plants or micro-organisms like Clostridium histolyticum. Common examples include collagenase, varidase, papain, and bromelain. Some of these products are selective, while others are not. This method is often used for wounds with large amounts of necrotic debris, such as burns. However, the results can be variable. Because effectiveness is not always consistent, it is not considered a standard of care for all burn treatments.

Mechanical debridement involves physical force to remove tissue. One example is hydrotherapy, which uses directed wound irrigation. Some systems use therapeutic irrigation with suction. Another advanced version is hydrosurgery. This uses a high-pressure, water-based jet system to remove burnt skin. The goal is to leave unburned, healthy skin behind. A 2019 Cochrane systematic review investigated hydrosurgery. The authors looked at whether it helped burns heal faster than using a knife. They found only one trial with very low certainty evidence. Therefore, it is still uncertain if hydrosurgery is better than conventional surgery for mid-depth burns.

Another form of mechanical debridement is quite simple. A person can allow a dressing to go from moist to dry. When the dressing is manually removed, it pulls away debris. This is a non-selective method. It works best on wounds that have moderate amounts of necrotic debris. Doctors avoid using whirlpool baths for wound management. Whirlpools are not selective and can damage all types of tissue. They also create a risk of bacterial infection. In cases involving arms or legs, whirlpools can also cause complications from edema.

One of the most unique methods is maggot therapy. Doctors introduce small maggots into a wound to consume necrotic tissue. They use the larvae of the green bottle fly, known as Lucilia sericata. These maggots are incredibly precise. They feed on the necrotic tissue of the host without attacking living tissue. They clean a wound through a process called extracorporeal digestion. The maggots secrete a broad spectrum of proteolytic enzymes. These enzymes liquefy the dead tissue, which the maggots then absorb as nutrients.

These insects can complete their work in just one or two days. In an optimum environment, the maggots will molt twice. Molting is when they shed their skin to grow. They begin as tiny larvae, only 1 to 2 mm in length. Within 3 to 4 days, they grow to 8 to 10 mm in length. They also increase in girth during this time. Once the maggots are removed, the wound is left clean and free of necrotic tissue.