Wound Dehiscence and Wound Abscess
Wound dehiscence is the failure of a wound to close properly.
It most commonly affects patients after abdominal surgery, and can be divided into three clinical entities:
- Simple dehiscence – the skin wound alone fails
- Secondary to infection, diabetes, poor nutrition or any other co-morbidity that would impede normal wound healing.
- Burst abdomen – the separation of abdominal wall closure with protrusion of the abdominal contents
- This may occur secondarily to raised intra-abdominal pressure (for example in patients with intra-abdominal compartment syndrome or patients with an ileus) or from surgical technical failure (due to poor suture technique or poor suture choice)
Wound dehiscence is a costly post-operative complication and thus identification and appropriate management of the condition is key.
Aetiology and Risk Factors
The most common cause of wound dehiscence is infection (see surgical site infection). This is one reason why early identification and treatment of any surgical site infection is important.
The risk factors for wound dehiscence are listed in Table 1.
|Modifiable Patient Factors||Intra-Operative Factors||Post-Operative Factors|
Co-morbidities, especially DM
Obesity or malnutrition
Length of operation (>6hrs)
Poor surgical technique
Post-operative blood transfusion
Poor tissue perfusion (e.g. post-operative hypotension)
Excessive patient coughing
The most evident feature of wound dehiscence is the visible opening of the wound (Fig. 1), healing poorly following the operation; this typically happens around day 6 post-operatively. Other concurrent symptoms may include bleeding, signs of inflammation, or increasing pain.
The investigation of wound dehiscence should focus on the likely cause.
Any suspected surgical site infection should have swabs taken for culture at the wound site and appropriate drainage/antibiotics commenced.
Bloods for infection markers (FBC, CRP, ±blood cultures if evidence of sepsis) should be taken. Modifiable patient factors should be investigated, including nutritional markers and blood glucose.
Wound dehiscence may require a return to theatre, although it is occasionally managed with closure by secondary intention. This decision rests on the site and type of dehiscence, especially treating the underlying cause.
Contaminated or dead tissue should be surgically debrided and prophylactic antibiotics should be administered. Conventional surgical methods for wound dehiscence may involve re-suturing the wound using deep retention sutures.
If immediate closure is not possible (e.g. an unresolved abscess), then non-surgical temporary closure techniques such as saline-soaked gauze packing or negative pressure wound therapy may be used. They allow for the drainage and airing of the wound prior to surgical re-closure.
Note: A Cochrane review concluded there is currently inconclusive evidence regarding the effectiveness of negative pressure wound therapy in the healing of surgical wounds and skin grafts.
Management of Sudden Full Dehiscence
In the event of a sudden full dehiscence of a wound (or “burst abdomen”), provide suitable analgesia and start IV fluids. Broad spectrum IV antibiotics should be started as a priority.
Cover the wound in saline-soaked gauze and arrange urgent return to theatre for re-closure of the wound.
Optimisation of co-morbidities and treating any surgical site infections is key in the prevention of wound dehiscence.
Avoiding heavy lifting and encouraging adequate post-operative nutrition will reduce the risk further.
An abscess is a mass of necrotic tissue, with dead and viable neutrophils suspended in a liquefied tissue necrosis.
Post-operative wound abscesses tend to present within a week of operation, with the cardinal signs of inflammation and potential signs of underlying pus or a punctum. As with any infection, cultures are essential, alongside other routine bloods.
Management of any abscess will require it to be drained, as shown below. Antibiotics should also be prescribed and ensure the regular changing of sterile dressings; any deeper abscesses may need surgical re-exploration.