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% (option D). 1

Classification and Infection Risk

Surgical 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 have the highest risk of infection among all surgical wound classes due to:

• Presence of large bacterial loads directly introduced into the surgical field
• Contamination of the peritoneal cavity with fecal material
• Disruption of the intestinal mucosa barrier

The CDC classification correlates strongly with infection risk:

• Class I (Clean): 1-3%
• Class II (Clean-contaminated): 5-8%
• Class III (Contaminated): 15-20%
• Class IV (Dirty-infected): 30-40%

Evidence Supporting the High Infection Rate

The high infection rate of 30-40% in cases with gross fecal spillage is well-documented in the literature:

• Primary closure of contaminated/dirty-infected laparotomy wounds results in a 37% infection rate according to data from the World Journal of Emergency Surgery 1
• Resection anastomosis procedures, particularly those involving the left colon, have higher leak rates which further increases infection risk 1
• Anastomotic leak rates vary by anatomical location (17% in right colon, 25% in transverse colon, and up to 50% in left colon), all contributing to higher SSI rates 1

Risk Factors for SSI in Colorectal Surgery

Several factors increase the risk of SSI in the setting of laparotomy with resection anastomosis and gross fecal spillage:

• Creation of ostomy (OR = 2.1) 2
• Contaminated wound (OR = 2.9) 2
• Use of drainage (OR = 1.6) 2
• Intra- or postoperative blood transfusion (OR = 5.3-6.2) 2
• Open surgical approach (versus laparoscopic) 3, 4
• Male gender (OR = 1.5) 2
• Higher ASA score (OR = 1.7) 2

Prevention Strategies

Given the high infection rate, several prevention strategies should be considered:

• Wound edge protectors, particularly dual-ring protectors, have shown significant benefit in reducing SSI rates (RR = 0.31) 5, 1
• Vacuum-assisted closure systems have demonstrated promising results, reducing infection rates from 37% (primary closure) to 0% in some studies 1
• Closed-incision negative-pressure therapy with delayed closure has shown significant reduction in SSI rates 1
• Delayed primary closure should be considered for contaminated and dirty incisions with purulent contamination 1
• Maintaining intraoperative normothermia decreases SSI rates 1

Clinical Implications

The high infection rate (30-40%) has significant implications:

• Deep incisional SSIs have a mortality rate of 5.7%, while organ/space SSIs have a mortality rate of 13.2% 1
• The case-fatality rate following gastrointestinal procedures with SSI is 7.2% 1
• Most surgical site infections are diagnosed around 10 days after surgery, highlighting the importance of vigilant postoperative monitoring 1

Common Pitfalls to Avoid

• Underestimating the infection risk in dirty wounds with fecal spillage
• Primary closure of heavily contaminated wounds without considering delayed closure or negative pressure therapy
• Failure to use appropriate wound edge protectors during the procedure
• Inadequate postoperative monitoring for signs of infection, especially after discharge
• Underappreciation of the significant mortality risk associated with deep and organ/space SSIs

The evidence clearly supports that the correct answer is D (30-40%), as this represents the established infection rate for Class IV/Dirty-Infected wounds with gross fecal contamination.