Hamasuna R et al. (2004) Bacteria of preoperative urinary tract infections contaminate the surgical fields and develop surgical site infections in urological operations. Int J Urol 11: 941–947

A new study from Japan has shown that preoperative urinary tract infection (UTI) is an important risk factor for the development of surgical site infection (SSI) in adults undergoing urological surgery. The study was based on patients undergoing 'clean' open or laparoscopic urological surgery at a single center during an 18-month period. Urine samples from all patients were analyzed to determine whether UTI was present preoperatively, and subcutaneous swabs were taken just prior to closure of the skin.

Of 134 patients included in the study, 20 developed SSIs despite receiving antimicrobial prophylaxis postoperatively. There were no significant differences between these patients and those without SSI in terms of several potential risk factors, including age, sex, duration of surgery, method or maximum volume of drainage, type of sutures used or day of their removal, blood loss or need for transfusion, or the lowest serum protein concentration or highest body temperature postoperatively. A significant difference was observed between the proportion of positive subcutaneous swab cultures obtained from patients with and without SSI (75% versus 12.3%, P <0.001). Preoperative UTI was also significantly more common in patients who developed SSI (55.0% versus 4.4%, P <0.001).

Hamasuna et al. conclude that preoperative UTI was an important risk factor for SSI in this setting. They recommend routine preoperative screening and aggressive treatment for such infections, and suggest that urological operations in the presence of UTI should be regarded as 'infected or dirty' procedures.