Fascial dehiscence

When abdominal wall tension is greater than tissue or suture strength or knot security.

• Complete dehiscence: full partition of fascia and skin, possibly involving evisceration
• Partial dehiscence: separation of fascial edges of the wound, without evisceration, but often with exposure of the underlying omentum or viscera

Epidemiology

• Incidence is 3-3.5% after laparotomy
• Complete fascial dehiscence is associated with a mortality of 10% - this should not be interpreted as 'causative' though

Risk factors:

• Patient:
  • Age >70
  • Obesity
  • Smoking
  • COPD
  • Steroid use
  • DM
  • Malnutrition
  • Ascites
  • Previous laparotomies
• Disease:
  • Abdominal trauma
  • Ruptured AAA
  • Retroperitoneal haematoma
  • Pancreatitis
  • Peritonitis/sepsis
  • Bowel occlusion surgery with resection or suture
  • Wound infection - more likely with fascial infection rather than superficial
  • Wound class III or IV
  • Presence of enterocutaneous fistula
  • Synthetic mesh infection
  • Necrotising fasciitis
  • Abdominal wall defect >10cm width
  • Incision length >18cm
• Can use Veterans Affairs Medical Center score or Rotterdam score to predict risk of suture complications

Causes:

• Technical:
  • Knot failure or inadequate strength of suture
  • Fascial damage - tension, ischaemia, suture material failure
  • Poor closure technique - in the majority of cases, sutures have pulled through rather than broken - either placed too close to fascial edge or under too much tension
    • Poor quality of tissue
    • Increased intra-abdominal pressure
    • Bites too big or small
• SSI/intra-abdominal abscess
• Increased intra-abdominal pressure

Presentation

• Increased serosanguinous drainage from wound - 'moderate to large'
• Mostly 4-14 days post-op (mean 8 days)
• 'Popping' sensation
• Incisional bulge exacerbated by Valsalva manoeuvres
• Absence of a healing ridge by day 5

Management

• Partial dehiscence
  • Consider conservative management for small dehiscences if bowel is covered
  • Carefully consider why it happened
    • Should get a CT to rule out an intra-abdominal cause of dehiscence
  • Otherwise, to theatre for re-closure
• Complete dehiscence
  • Initial:
    • Moist dressing over wound, taped securely to skin
    • Assess for factors that may have led to this including infection/IAH
  • If superficial infection is present:
    • Drainage, antibiotics and local wound management then either
    • Option 1 - vac, then fix the incisional hernia later
    • Option 2 - debridement and delayed primary closure once the infection is resolved
  • If deep infection is present, and the abdomen is inaccessible:
    • Treat the intra-abdominal infection
    • Planned ventral incisional hernia once the infection is resolved
    • Consider biologic mesh to breach the defect
  • Early dehiscence with no infection:
    • Primary abdominal wall closure

Operation

• Debride wound edges
• Look for signs of infection or other reasons for dehiscence
• Close wound again, if no infection, and wound can be safely closed
• Retention sutures not recommended by Sabiston/UTD
• Common option seems to be to add some interrupted 0 PDS or Nylon every 5cm