What is the percentage of surgical site infection (SSI) after laparotomy with resection anastomosis and gross fecal spillage?

Surgical Site Infection Rate After Laparotomy with Resection Anastomosis and Gross Fecal Spillage

The percentage of surgical site infection in a wound after laparotomy with resection anastomosis and gross fecal spillage is approximately 30-40%. 1

Classification and Risk Factors

Wounds with gross fecal spillage are classified as Class IV/Dirty-Infected wounds according to the Centers for Disease Control and Prevention (CDC) classification system. These wounds carry the highest risk of infection due to:

• Large bacterial loads contaminating the peritoneal cavity
• Compromised local tissue defenses
• Potential for systemic inflammatory response

The high infection rate (30-40%) is specifically associated with open laparotomy procedures involving fecal contamination. This is significantly higher than the overall SSI rates seen in elective colorectal procedures without gross contamination, which range from 4.7% to 15.7% 2, 3.

Infection Types and Mortality Risk

Surgical site infections following procedures with fecal spillage can be categorized as:

• Superficial incisional: Involving skin and subcutaneous tissue
• Deep incisional: Involving fascial and muscle layers
• Organ/space: Involving anatomic spaces opened during surgery

Deep and organ/space infections carry significantly higher mortality rates (deep incisional: 5.7%, organ/space: 13.2%) compared to superficial infections 1.

Risk Reduction Strategies

Several evidence-based interventions can reduce the 30-40% baseline infection rate in cases with gross fecal spillage:

1. Wound management techniques:

   • Primary closure: 37% infection rate
   • Delayed primary closure: 17% infection rate
   • Vacuum-assisted closure: 0% infection rate 1

2. Intraoperative interventions:

   • Wound edge protectors (particularly dual-ring): Reduces SSI rates (RR = 0.31)
   • Maintaining normothermia
   • Closed-incision negative-pressure therapy (cINPT) 1

3. Surgical approach:

   • Laparoscopic techniques when feasible reduce SSI risk by 72% compared to open procedures (OR 0.28) 4
   • This protective effect persists even in dirty wounds (OR 0.45) 4

Anatomical Considerations

The risk of anastomotic leak, which further increases infection risk, varies by anatomical location:

• Right colon: 17% leak rate
• Transverse colon: 25% leak rate
• Left colon: Up to 50% leak rate 1

Common Pitfalls and Caveats

1. Delayed diagnosis: Most SSIs are diagnosed around 10 days post-surgery, highlighting the need for vigilant monitoring beyond the immediate postoperative period 1

2. Implementation gap: Despite evidence supporting preventive measures, there remains a significant gap between guidelines and clinical practice 5

3. Transfusion risk: Blood transfusion significantly increases SSI risk (1-3 units: OR=5.3; ≥4 units: OR=6.2) 2

4. Creation of ostomy: This doubles the risk of SSI (OR=2.1) 2

The answer to the question is option D: 30-40%.