What is delayed primary closure?

Delayed Primary Closure

Delayed primary closure (DPC) is a surgical wound management technique where a contaminated or dirty wound is initially left open for several days with appropriate dressing, allowing for the development of granulation tissue with enhanced blood supply and oxygenation, before being closed secondarily 3-5 days later. 1, 2

Mechanism and Physiological Benefits

• DPC works by:
  • Decreasing bacterial inoculum in the wound
  • Promoting development of granulation tissue with enhanced blood supply
  • Increasing wound oxygenation
  • Supporting robust collagen formation and synthesis
  • Enhancing angiogenesis for better wound healing 2

Technique

1. Initial management: After the procedure, the wound is left open with appropriate dressing (commonly Betadine-soaked gauze or Xeroform gauze) placed between the skin and subcutaneous tissue 3
2. Wound care: Daily dressing changes and wound irrigation
3. Assessment: Wound is evaluated for closure readiness (typically after 3-5 days)
4. Closure: When the wound appears clean with healthy granulation tissue, closure is performed using sutures, staples, or Steri-Strips 3, 4

Clinical Indications

DPC is most commonly indicated in:

• Contaminated abdominal surgeries, particularly in high-risk patients 1
• Perforated appendicitis 5
• Dirty traumatic wounds
• War injuries
• Sternal wound dehiscence after cardiac surgery 4
• Situations where primary closure would carry high risk of surgical site infection (SSI)

Evidence on Effectiveness

The evidence regarding DPC's effectiveness is mixed:

• A 2012 prospective randomized controlled trial showed DPC significantly reduced wound infection rates in perforated appendicitis (2.9% vs 38.9% with primary closure) and shortened hospital stay (6.3 days vs 8.4 days) 5

• The World Journal of Emergency Surgery guidelines (2020) suggest that DPC may reduce SSI incidence in contaminated abdominal surgeries (Grade of Recommendation 2C) 1

• Meta-analyses have shown conflicting results:

  • Using a fixed-effect model, DPC significantly reduced SSI (odds ratio 0.65,95% CI 0.40-0.93)
  • However, when using a random-effects model to account for heterogeneity, the effect was no longer significant 1, 6

Advantages and Disadvantages

Advantages:

• Reduced surgical site infection rates in contaminated wounds
• Better wound healing foundation through enhanced granulation tissue
• Improved blood supply to the wound

Disadvantages:

• Increased length of hospital stay (approximately 1.6 days longer) 1
• Pain from routine dressing changes
• Need for second procedure for wound closure
• Increased treatment costs 1

Clinical Considerations

• Patient selection is crucial - DPC is most beneficial in contaminated or dirty wounds
• Proper timing of closure (typically 3-5 days) is essential for optimal outcomes
• Daily wound assessment and appropriate dressing changes are required
• The decision to use DPC should consider the contamination level of the wound and patient risk factors (age >60, diabetes, malnutrition, obesity) 3

DPC remains a valuable technique in the surgical armamentarium, particularly for contaminated wounds where the risk of surgical site infection is high. The most recent evidence continues to support its use in specific clinical scenarios despite some conflicting meta-analysis results.