Wound Dehiscence

Wound dehiscence is partial or complete separation of the edges of a closed surgical wound. It may involve skin only (superficial) or extend through deeper layers (deep or full thickness, including fascia, which is a distinct event when abdominal).

Epidemiology. It affects about 1% to 5% of laparotomy wounds, with higher rates after sternotomy, groin incisions in vascular surgery, and contaminated or emergency operations. Onset is usually 5 to 10 days after surgery.

Causes and risk factors. Infection, haematoma or seroma, tension from distension, obesity, diabetes, malnutrition (albumin under 30 g/L), smoking, corticosteroids, immunosuppression, chemotherapy, radiotherapy, vascular insufficiency, poor technique, coughing and straining.

Pathophysiology.

Healing needs oxygen, perfusion, protein and an absence of infection. Collagen deposition peaks at days 5 to 14, so loss of wound strength in the first 2 weeks makes disruption likely when tension exceeds tissue strength.

Infection and ischaemia degrade tissue and sutures.

Serosanguinous discharge ("pink fluid" in abdominal wounds is a warning of deeper failure), gaping, visible subcutaneous fat or fascia, erythema, tenderness, swelling, purulent discharge and fever. Evisceration shows bowel or omentum through the wound.

Red flags.

• Evisceration.
• Sudden gush of serosanguinous fluid after a strain.
• Fever with rapidly spreading erythema or crepitus.
• Exposed vascular graft, prosthesis or sternal instability.
• Signs of sepsis.

Clinical examination under sterile conditions, with careful probing to assess depth and fascial integrity. Culture discharge or deep tissue. Check full blood count, C-reactive protein, glucose, albumin and nutritional status. Ultrasound or CT shows deep collections or fascial defect.

Differential diagnosis.

• Wound infection.
• Haematoma or seroma.
• Fascial dehiscence with incisional hernia.
• Enterocutaneous fistula.
• Anastomotic leak.
• Pressure injury.

Superficial dehiscence without infection. Clean, pack or apply negative pressure dressing to promote healing by secondary intention, or perform delayed closure.

Infected wound. Open fully, debride, irrigate, culture and dress. Antibiotics are needed with cellulitis, systemic signs or immune compromise.

• Cefuroxime: 1.5 g IV every 8 hours, then oral switch; duration 5 to 7 days; maximum 6 g daily; monitor renal function and for Clostridioides difficile; for creatinine clearance 10 to 20 mL/min give 750 mg every 12 hours, under 10 mL/min give 750 mg every 24 hours.
• Metronidazole (add for bowel or perineal wounds): 500 mg IV or orally every 8 hours; duration 5 to 7 days; maximum 1.5 g daily; monitor for neuropathy in prolonged courses and avoid alcohol; halve the dose in severe hepatic impairment.
• Add vancomycin for meticillin resistant Staphylococcus aureus: 25 to 30 mg/kg IV loading dose, then 15 to 20 mg/kg every 8 to 12 hours; monitor area under the curve and creatinine; extend the interval in renal impairment.

Evisceration. Cover with warm saline soaked gauze and a dressing, keep the patient supine with knees flexed, nil by mouth, start IV fluid and antibiotics, avoid pushing bowel back, give analgesia and arrange urgent return to theatre.

Nutrition and optimisation. Correct anaemia, control glucose (7.8 to 10 mmol/L), stop smoking, review steroids, give protein of 1.5 g/kg daily and treat distension and cough.

Monitoring. Wound dimensions and photographs, exudate, temperature, white cell count and C-reactive protein, and nutritional markers.

Referral and escalation. Surgical review for any deep or full thickness dehiscence, evisceration, exposed prosthesis or vascular graft. Tissue viability or plastic surgery advice for complex wounds.