Predictive factors of postoperative septic complications after flexible ureteroscopy for urinary stones

Flexible ureteroscopy (fURS) is one of the recommended treatments for urinary stones. Urosepsis is one of the most frequent complications of fURS however its predictive factors remain uncertain. Our objective was to assess the septic complications rates of fURS and to determinate predictive factors of these complications in patients undergoing fURS.

Our retrospective analysis included all patients admitted for any fURS for stone disease in our center from December 2009 to April 2013. Patients' medical history, urine culture, stone composition, surgical and anesthetic characteristics were collected. The primary endpoint was defined by the presence of any septic complication (i.e. postoperative fever, urosepsis, septic shock or death). We used multivariate logistic regression to assess predictive factors of septic complication related to fURS.

Two hundred and eighty-two patients were included in this study. Urosepsis rate was 9.8% while 18.9% developed postoperative hyperthermia (>37.5°C). In multivariate analysis, the predictive risk factors of septic complication were: a neurologic disorder (OR=6.1; CI95%: 2.9-17.1), a history of urinary tract infection (UTI) (OR=19.6; CI95%: 7.3-52.1), exposure to peroperative nitrous oxide (OR=3.2; CI95%: 1.5-6.8) and intraoperative use of a laser (OR=8.0; CI95%: 13.0-30.3).

The use of fURS is associated with relatively frequent septic complications. Patients with neurologic disorders or a history of UTI carry an increased risk of postoperative complications. Limitations should be drawn with the use of peroperative nitrous oxide. These results should be further validated.

3. Retrospective cohort study.