Skin Reconstruction in Cats
Dr. Cathy Reese
Initially, your veterinarian will want to obtain a history and perform a physical examination. This initial examination may be followed by specific tests.
History. Your veterinarian will ask you many questions regarding the development and progression of the wound. If your pet was just involved in a traumatic event, he may require emergency stabilization before the skin wound is tended to. If the wound has been a chronic problem your veterinarian will ask about previous therapies and the results of those treatments. If there is a large tumor present, and its removal will create a large wound that may need reconstructive surgery, then your veterinarian will ask you about the development and progression of the tumor. If the tumor has been evaluated before, either by a biopsy or a fine needle aspirate, bring these results to your veterinarian's attention.
Physical exam. Your veterinarian will perform a complete physical exam. The wound will be examined closely to determine if it is clean enough to be closed surgically or if it needs further treatment to create a clean and healthy wound. The surrounding skin will be examined to determine what reconstructive procedure would be best suited to close the wound.
Radiographs (X-rays). Many wounds of the lower limb and paw are associated with fractured or dislocated bones and/or ligament tears. X-rays are necessary to determine whether the orthopedic injuries require surgical repair. If your pet was hit by a car or experienced other types of trauma, X-rays of the chest are often taken to check for injuries to the lungs, heart, ribs, and/or diaphragm, which is the muscle that divides the chest and abdomen and is responsible for breathing. These injuries may be life threatening and may need to be treated before the skin wounds are repaired.
Blood and urine tests. Blood tests are submitted to evaluate the white blood cell count, which is usually elevated with an infection, and the number of red blood cells to determine if your pet is anemic. The function of the kidneys is evaluated through testing the blood and urine, and liver function is ascertained through blood tests. All of these tests are important in determining whether your pet should undergo anesthesia and what type of anesthesia should be used.
Emergency stabilization. If your pet was hit by a car or has experienced other major trauma, your veterinarian may need to provide initial emergency stabilization therapy in the form of intravenous fluids and oxygen. If there is a dirty or contaminated wound present, your pet will also be given antibiotics. Pain medications will also likely be given.
Wound preparation. If the wound was surgically created, no preparation is necessary prior to reconstructive surgery. If the wound was created by an injury, then the wound is likely to be dirty and contaminated with gravel, hair, and other foreign material. The wound must be clean and have a healthy blood supply before reconstructive surgery can be done.
The dirt, hair, and necrotic (dead) tissue are removed, or debrided, manually while the cat is anesthetized. Another very effective method is by using a wet-to-dry bandage, which sticks to the wound as it dries. As it is removed it pulls off the dirt and necrotic tissue with it. Pulling the bandage off is painful, so the patient needs to be heavily sedated or anesthetized during each bandage change. The bandage needs to be changed frequently, usually once or twice a day.
As the wound becomes cleaner it will appear red and a little bumpy. These tiny red bumps are the buds of new blood vessels that will supply the wound. This type of red tissue is called a granulation bed. When a granulation bed has formed, your veterinarian will stop using adherent wet-to-dry bandages and will apply non-adherent dressings to protect the wound. Once the wound is at this stage it can be closed using any number of reconstructive techniques.
Healing by second intention. This phrase means that the wound is allowed to heal on its own. The skin edges around the wound contract and skin cells migrate toward the center of the wound. Very large wounds do not heal completely by second intention, but they can become significantly smaller and require less extensive reconstructive surgery later on. If your veterinarian chooses to allow the wound to heal by second intention, he/she will likely wait several months to allow the healing to go as far as it can before attempting reconstructive surgery.
Reconstructive surgery. Many different techniques are used to reconstruct wounds, and the technique chosen depends on the individual wound, as well as surgeon preference. If any of these reconstructive techniques result in only partial closure of the wound, then the rest of the wound may be able to heal by second intention or further reconstructive surgery may be necessary.
Tension relieving sutures. These refer to patterns of suture placement that are designed to hold the skin edges together, especially when the closure is tight or under a lot of tension.
Skin flaps. Areas of loose skin can be raised, leaving one border attached to the body, and the raised skin rotated to cover an adjacent defect. Loose skin is usually available near the neck and on the trunk (body) of the patient. Loose skin can also be created using skin stretching devices that are placed under the skin and inflated gradually, or by bands that are attached to the surface of the skin and gradually tightened.
Skin grafts. Areas of loose skin can be completely removed from the body and placed on a wound far from its original location.
Post-operative care. Skin grafts are usually bandaged and the limb immobilized to allow the blood vessels in the granulation bed to penetrate and grow into the skin graft. Improper exercise restriction and bandage care can result in death of the delicate skin graft. With any type of reconstructive surgery, it is important that the patient not be allowed to lick or chew at the stitches or bandage. This can lead to infection or re-opening of the wound. The patient should wear an Elizabethan collar.