Are horse age and incision length associated with surgical site infection following equine colic surgery?

The research focuses on understanding the impact of factors such as age and incision length on the risk of surgical site infection (SSI) in horses after colic surgery. The observation suggests that breed, incision length, classification of the surgical procedure, and postoperative colic are more significant factors in determining SSI than age.

Objective and Methodology

• The study aimed to discover the risk factors associated with surgical site infection in horses undergoing colic surgery. It was based on a clinical impression that age and incision length have a stronger correlation with SSI than wound protection or skin closure methods.
• Data was collected on various factors pre, during, and post-operation. Statistical analysis was conducted, where variables with P value < 0.2 were included in a logistic regression model, and those with P < 0.05 were used in the final model.
• The performance of the model was assessed using the Receiver Operative Characteristic, with the area under the curve (AUC) providing a measure of how well the model was able to distinguish between cases with and without SSI.

Results and Findings

• The studied variables that were part of the final model included breed, incision length, surgical procedure classification, and postoperative colic. These all showed significant correlation with the occurrence of SSI.
• Compared to other breeds, Warmbloods, Thoroughbreds, and American breeds showed higher odds of SSI. Similarly, horses with incision lengths greater than 27 cm, heavily contaminated procedures, and postoperative colic also presented higher SSI rates.
• It was presumed that heavily contaminated procedures and postoperative colic resulted in more incisional contamination and trauma, leading to heightened occurrence of SSI.

Conclusions and Recommendations

• Contrary to the initial clinical impression, age did not show any significant association with SSI.
• However, it was found that a longer incision length (>27 cm) increased the risk of SSI. As a result, the researchers suggested that surgeons should aim to use the shortest possible incision length that safely allows for needed abdominal exploration and bowel manipulation.