Wound Dehiscence - An Overview

What Is Wound Dehiscence?

In the absence of proper wound healing, the approximated edges of the surgical wound will begin to separate, either partially or completely, this is known as wound dehiscence. It is usually seen in the early stages of healing post-surgery, typically after five days to eight days.

The clinician should be able to promptly identify the presence and type of dehiscence to take appropriate measures and prevent further damage. There are two types of dehiscence-

• Superficial Dehiscence - It happens when the skin along the lines of the suture splits open, but the underlying fascia is intact, occurs as a result of local infection, poorly controlled diabetes, poor nutritional status, etc.

• Deep Dehiscence - In deep dehiscence, the skin and the fascia below the skin bursts open exposing the contents of the abdomen. This is a surgical emergency and must be addressed in the operating room to prevent evisceration (protrusion of abdominal contents through the surgical incision). If evisceration does occur, the wound should be covered with saline-soaked gauze until the herniated organs are pushed back into the abdomen.

Dehiscence is caused by the same factors that cause poor wound healing, they are obesity, smoking, infection, increased abdominal pressure, etc. It is imperative that the clinician addresses these underlying conditions while treating dehiscence to prevent a recurrence.

What Are the Causes of Wound Dehiscence?

The causes of wound dehiscence are the same ones that cause poor wound healing, they are-

• Infection- This is one of the leading causes of wound dehiscence. Complete healing occurs when the wound goes through all three phases of wound healing; inflammation, proliferation, and maturation. In the presence of an infection, the wound gets stuck in the inflammation phase without proceeding to the next stages. Unless this is resolved the edges of the wound will not coalesce, leaving the wound open and unhealed.

• Ischemia- Proper wound healing can only happen in the presence of a sufficient amount of oxygen. If patients have underlying vascular diseases or venous insufficiency, the wound will not receive sufficient blood flow and with it the required amount of oxygen.

• Smoking- This is more of a risk factor than a cause because smoking increases the chances of dehiscence but does not directly cause it. Nicotine, the chemical present in tobacco has a vasoconstrictive effect on the body, this will reduce the blood supply to the wound.

It also interferes with macrophage migration and fibroblast activation which are necessary for the proliferation phase of wound healing. As a result, the wound is deprived of the necessary oxygen, nutrients, and immune cells leading to improper wound healing and dehiscence.

1. Diabetes - Patients with diabetes often have wounds that are difficult to heal. There are three possible ways hyperglycemia contributes to wound dehiscence.

• In patients with increased blood glucose levels, the cell walls become rigid which impairs the blood flow through the small vessels at the wound surface. This reduces the oxygen and nutrient supply to the wound.

• Persistently elevated blood glucose levels also compromise chemotaxis and phagocytosis. This prolongs the inflammatory phase of the wound-healing cascade and increases the chances of infection.

• Insulin, which is lacking in diabetes, is an anabolic hormone that stimulates protein synthesis. Protein is essential for the synthesis of collagen structures that establish wound tensile strength. Inadequate protein synthesis will lead to reduced tensile strength causing dehiscence and evisceration.

2. Malnutrition - World Health Organization (WHO) defines malnutrition as deficiencies or imbalances in a person’s intake of energy and nutrients. This includes carbohydrates, proteins, vitamins, minerals, etc. all of which also play an important role in wound healing.

If a patient is malnourished, fibroblast proliferation, collagen synthesis, angiogenesis, and other events that are supposed to take place during wound healing will take place, as a result, the wound will not heal, leading to dehiscence, infection, and other complications.

3. Radiation - It is important to avoid surgery in patients who have had recent radiation because radiation causes microvascular obliteration and altered cellular replication. The former will reduce the blood flow to the radiated target area and the latter will increase fibrosis, both of which delay wound healing and increase the chances of dehiscence.

4. Prolonged Use of Corticosteroids - Corticosteroids work by suppressing immunity in the patient. They are prescribed for patients suffering from autoimmune conditions. In these patients, the immune reaction that is normally triggered after an injury (wound in this case) happens at a very slow ratewhich increases the risk for dehiscence.

5. Suturing Technique- This is a physician-related risk factor and can be avoided by incorporating proper surgical technique and suture material.

Other risk factors include obesity, age, and underlying medical conditions (like jaundice, chronic obstructive pulmonary disease, etc.) which increase the risk of impaired wound healing and dehiscence.

What Are the Symptoms of Wound Dehiscence?

The following are the symptoms of wound dehiscence-

• Visibly open wound with broken sutures.

• Bulging of the wound.

• Seepage of pink serous or blood-stained fluid.

• Pain.

• Fever.

How Is Wound Dehiscence Diagnosed?

Examining the site of the wound is sufficient for the diagnosis, if the clinician suspects an infection, the following will be done-

• A sample of seeping fluid from the wound will be tested for possible infection.

• Blood tests for signs of infection.

If the underlying causes are addressed, and yet the wound is not healing as expected, the surgeon will request imaging tests like an X-ray, ultrasound, or a CT (computed tomography) scan to examine any defects in the surgery that might be causing dehiscence.

What Is the Treatment for Wound Dehiscence?

Treatment often comprises antibiotics and medical therapy to undress infection and underlying medical conditions. Negative pressure wound therapy (NPWT) has shown promising results for superficial dehiscence. It is a method of drawing out fluid and infection from a wound to help it heal. A special dressing is sealed over the wound and a gentle vacuum pump is attached to it. The vacuum pump pulls fluid and infection from the wound, this helps pull the edges of the wound together.

Deep dehiscence on the other hand is treated by surgery. During the procedure, the surgeon will remove the damaged, infected, and dead tissue, followed by the placement of a prosthetic mesh for reinforcement, and finally closing the wound with sutures. Patients undergoing secondary closure through surgery heal faster and have reduced post-operative visits.

Conclusion

Wound dehiscence is a preventable complication, proper precautions during the three stages of surgery- presurgery, perioperative, and post-surgery, will decrease the chances of dehiscence. Some of the precautions are optimizing the patient's nutrition prior to surgery, maintaining optimal blood glucose levels, avoiding emergency surgeries, addressing chronic medical conditions, cessation of smoking, advanced suture techniques, and following post-operative instructions.