What are the consequences of delayed primary wound closure?

Delayed Primary Wound Closure Results in a Wider Scar

Delayed primary wound closure results in a wider scar compared to primary closure. 1 This occurs because the wound healing process during delayed closure involves increased granulation tissue formation and wound contraction, ultimately leading to a wider scar appearance.

Consequences of Delayed Primary Wound Closure

Delayed primary wound closure is a technique where a wound is intentionally left open for several days (typically 3-5 days) before final closure. This approach has specific effects on wound healing:

Effects on Wound Healing and Scar Formation

• Wider Scar Formation: The most notable outcome is the development of a wider scar due to increased granulation tissue formation during the open phase 1
• Increased Angiogenesis: Delayed closure actually promotes increased angiogenesis (blood vessel formation) as part of the enhanced granulation tissue development 1
• Wound Strength: Despite the wider appearance, delayed primary closure does not result in decreased wound strength compared to primary closure 1
• Collagen Content: Delayed closure does not result in lower collagen content; in fact, the granulation tissue formed during the delay period is rich in collagen 1

Clinical Considerations

Delayed primary closure has both advantages and disadvantages:

Advantages:

• May reduce surgical site infection rates in contaminated wounds (though evidence is mixed) 1
• Allows for bacterial load reduction in heavily contaminated wounds 1
• Potentiates local wound resistance by increasing wound oxygenation and blood supply through granulation tissue 1

Disadvantages:

• Results in wider, more visible scarring 1
• Increases pain from routine dressing changes 1
• Requires additional procedure for later wound suturing 1
• Increases length of hospital stay (by approximately 1.6 days) 1
• Increases overall treatment costs 1

Evidence Quality and Controversies

The evidence regarding delayed primary closure shows mixed results:

• Meta-analyses have shown inconsistent findings regarding infection prevention benefits:

  • Fixed-effect models show reduced infection rates (OR 0.65) 1
  • Random-effects models show no significant difference in infection rates 1

• The most recent high-quality randomized controlled trial by Siribumrungwong et al. actually found that primary closure had slightly lower infection rates (7.3%) compared to delayed primary closure (10%), though this difference wasn't statistically significant 1

• For appendicitis wounds specifically, the 2020 WSES Jerusalem guidelines recommend primary skin closure with a unique absorbable intradermal suture rather than delayed closure 1

Clinical Decision-Making

When considering wound closure technique:

1. For clean or clean-contaminated wounds: Primary closure is generally preferred due to faster healing and better cosmetic results

2. For contaminated/dirty wounds:

   • Primary closure with appropriate antibiotics is increasingly preferred in most settings 1
   • Consider delayed primary closure only in high-risk patients with heavily contaminated wounds 1

3. For open fractures: Primary closure after thorough debridement has shown lower infection rates compared to delayed closure in some studies 2

The wider scar formation with delayed primary closure represents an important cosmetic consideration, especially for visible body areas, and should be factored into the decision-making process alongside infection risk assessment.