A. C. Sheka1, S. Tevis1, G. Kennedy1 1University Of Wisconsin,Department Of Surgery,Madison, WI, USA
Introduction: Over 4% of patients undergoing colorectal surgery develop post-operative UTI, twice the rate of patients undergoing other gastrointestinal surgery and over three times greater than for those undergoing non-gastrointestinal surgery. Surgical patients who suffer post-operative UTI have increased mortality rates, lengths of stay, and costs of care. The aim of this study was to analyze the risk factors and post-operative complications associated with urinary tract infection (UTI) after surgery for colorectal malignancy.
Methods: The ACS-NSQIP database was queried for patients who underwent surgery for colorectal malignancy from 2005-2012. From these records, patients were identified and included in the study using International Classification of Diseases (ICD-9) and current procedural terminology (CPT) codes. Chi square analysis and Mann Whitney U test were used to identify pre-operative and intra-operative risk factors for post-operative UTI. Pre-operative and intra-operative variables found to have a p<0.1 in univariate analysis were included in a logistic regression model that was used to identify independent predictors of post-operative UTI. Chi square and Mann Whitney tests were also used to evaluate the association between UTI and post-operative outcomes.
Results: A total of 47,781 patients were included in this study. The overall rate of post-operative UTI was 3.7%. Independent predictors of UTI included female sex (OR 1.66, 95% CI 1.47-1.88), open procedure (OR 1.46, 95% CI 1.28-1.67), older age (p<0.001), non-independent functional status (OR 1.51, 95% CI 1.22-1.88), steroid use for a chronic condition (OR 1.54, CI 1.13-2.10), neoadjuvant radiotherapy (OR 1.31, 95% CI 1.09-1.59), higher anesthesia class (p<0.001), and longer total operation time (p<0.001). Patients who suffered post-operative UTI had an average hospital stay five days longer than those who did not contract a UTI (7 vs. 12 days, p<0.001). They also had significantly higher reoperation rates (11.9% vs 5.1%, p<0.001). Of patients with post-operative UTI, 3.3% had death with 30 days of surgery, compared to 1.7% of those without UTI after surgery (p<0.001). Post-operative UTI also correlated with other complications, including sepsis, surgical site infections, and pulmonary embolism (p<0.001 for all).
Conclusions: Post-operative UTI in patients undergoing surgery for colorectal malignancy correlates with longer hospital stay, higher reoperation rate, and increased 30-day mortality compared to patients without UTI. It also appears that patients who contract post-operative UTI may be at increased risk of developing multiple complications. This analysis demonstrates significant benefit to laparoscopic surgery for colorectal malignancy when controlling for other factors. In addition, it identifies several risk factors that may be targeted in prospective interventions aiming to reduce complications, specifically post-operative UTI, in this population.