Does delayed primary closure (DPC) have a lower infection rate compared to no closure when closing the skin?

Delayed Primary Closure vs. No Closure for Reducing Infection Rates in Skin Closure

Primary closure is preferable to delayed primary closure for most contaminated wounds as it shows similar or lower infection rates while reducing hospital stay and costs. 1

Evidence Analysis

Current Guidelines and Recent Research

The World Journal of Emergency Surgery guidelines (2020) indicate that delayed primary closure (DPC) may be considered in contaminated abdominal surgeries for high-risk patients, but the evidence supporting this practice is limited 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%) in complicated appendicitis cases, though this difference was not statistically significant 1.

Key findings from the evidence:

• Primary closure resulted in shorter hospital stays (1.6 days less than DPC) 1
• Primary closure was significantly less expensive than DPC (cost difference of $2083) 1
• When analyzing only high-quality studies with low risk of bias, the apparent benefits of DPC disappear 1

Regional Variations in Outcomes

The meta-analysis by Tang et al. showed that while studies from resource-limited settings (India and Pakistan) demonstrated improved infection rates with DPC, this benefit was not consistently observed in studies from other regions 1. When using a random-effects model to account for heterogeneity between studies, there was no significant difference in surgical site infection (SSI) rates between DPC and primary closure (risk ratio 0.65; 95% CI, 0.38–1.12; P = 0.12) 1.

Clinical Decision Algorithm

1. For most contaminated wounds: Use primary closure

   • Benefits: Similar or lower infection rates, shorter hospital stay, lower costs
   • Evidence: Siribumrungwong RCT showing 7.3% vs 10% infection rates favoring primary closure 1

2. Consider DPC only in specific scenarios:

   • Severely contaminated wounds in resource-limited settings 1
   • Patients with multiple high-risk factors (diabetes, malnutrition, obesity) 2
   • When wound assessment indicates excessive contamination that cannot be adequately debrided

Common Pitfalls and Caveats

• Overuse of DPC: Many surgeons continue to use DPC based on traditional teaching rather than current evidence
• Increased costs: DPC requires additional dressing changes, nursing care, and longer hospital stays 1
• Patient discomfort: DPC involves leaving wounds open, which can cause increased pain and anxiety
• Selection bias: Many older studies supporting DPC had significant methodological flaws and high risk of bias 1

Practical Considerations

• When using primary closure, meticulous surgical technique and appropriate perioperative antibiotics remain essential
• Proper wound irrigation and debridement are critical regardless of closure method
• The decision should consider the specific wound characteristics, degree of contamination, and patient risk factors
• In resource-constrained environments, DPC may still have a role in selected high-risk cases 1, 2