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%, which corresponds to dirty wounds (Class IV). 1
Wound Classification and Infection Rates
Surgical wounds are classified according to the Centers for Disease Control and Prevention (CDC) system:
- Class I/Clean: 1-3% infection rate
- Class II/Clean-Contaminated: 5-8% infection rate
- Class III/Contaminated: 20-25% infection rate
- Class IV/Dirty-Infected: 30-40% infection rate
Laparotomy with resection anastomosis and gross fecal spillage falls into the Class IV/Dirty-Infected category due to the presence of gross fecal contamination, which introduces large bacterial loads directly into the surgical field 1.
Evidence Supporting High Infection Rates in Dirty Wounds
Several studies support the high infection rate in dirty wounds:
- A prospective study demonstrated that primary closure of contaminated/dirty-infected laparotomy wounds resulted in a 37% infection rate 2
- Older research showed infection rates up to 13.3% for dirty wounds, though this is likely an underestimation as 53% of infections were only detected after discharge 3
- The high bacterial load from fecal spillage significantly increases the risk of surgical site infections, with extended-spectrum β-lactamase (ESBL)-producing bacteria being common culprits 4
Factors Contributing to High Infection Rates
Several factors contribute to the high infection rate in laparotomy with resection anastomosis and gross fecal spillage:
- Gross fecal contamination introduces large bacterial loads directly into the surgical field 1
- Resection anastomosis procedures, particularly in the left colon, have higher leak rates which further increases infection risk 1
- Damage-control laparotomy and colon resection are significant contributors to organ/space surgical site infections 5
Strategies to Reduce Infection Rates
Given the high infection rate in dirty wounds, several strategies can be implemented:
- Wound edge protectors have shown significant benefit in reducing SSI rates, particularly dual-ring protectors (relative risk = 0.31) compared to single-ring protectors (relative risk = 0.84) 2
- Vacuum-assisted closure systems have demonstrated promising results, reducing infection rates from 37% (primary closure) and 17% (delayed primary closure) to 0% 2, 1
- Delayed primary closure should be considered for contaminated and dirty incisions with purulent contamination 2
- When delayed closure is performed, revision should be done between two and five days postoperatively 2
Timing of Surgical Site Infection Detection
Most surgical site infections are diagnosed around 10 days after surgery (median time with interquartile range of 7-18 days) 6. This highlights the importance of vigilant postoperative monitoring, as many infections may only become apparent after discharge.
In conclusion, the correct answer is D. 30-40% (for dirty wounds), as laparotomy with resection anastomosis and gross fecal spillage represents a Class IV/Dirty wound with the highest risk of surgical site infection.