Bacterial density in laparotomy wounds during gastro-instestinal operations

Area of Science:

• Surgical site infection
• Microbiology
• Wound healing

Background:

• Bacterial contamination of surgical wounds is a known risk factor for postoperative infections.
• Understanding the dynamics of bacterial load during abdominal operations is crucial for infection prevention.

Purpose of the Study:

• To quantitatively assess aerobic bacterial density in operation wounds across different types of abdominal surgeries.
• To investigate the relationship between bacterial density at wound closure and the risk of postoperative wound infection.

Main Methods:

• Prospective, randomized study involving 56 patients undergoing abdominal operations.
• Velvet pad rinse technique used for quantitative sampling of aerobic bacteria in operation wounds.
• Comparison of bacterial density at peritoneal entry and prior to wound closure across four surgical groups.

Main Results:

• Initial bacterial density in wounds did not significantly differ across the four operation types.
• Median bacterial density increased significantly by wound closure, especially after colorectal operations (21.3x10^-1 viable counts/cm2).
• Escherichia coli and other aerobic intestinal species increased in density post-colorectal surgery; Staphylococcus epidermidis contaminated wounds throughout.

Conclusions:

• Postoperative wound infection risk is strongly associated with the density and types of bacteria present at the time of wound closure.
• Localized areas of high bacterial density within wounds may contribute to infection despite overall low counts.
• Targeted interventions to reduce bacterial load before wound closure could mitigate infection risk.