Aim: of our study was to compare the safety and efficiency of percutaneous nephrolithotripsy (PNL)in patientswith positive urine culture results butwithout the symptoms of urinary tract infection (UTI), and to determine the optimal duration of preoperative antibiotic therapy in this group of patients.

Materials and methods. The prospective study comprised the results of 428 PNL operations performed on 388 patientswhowere divided into 2 groups.In the first group (n = 254, operationswere performed on 236 patients), the urine culture wassterile before the operation, whereasin the second group (n = 174, operations were performed on 152 patients) the urine culture was positive. In the first group, patients underwent preoperative (30 minutes before the operation) antibacterial drug administration, and then daily, for 7 days. In the second group, the drug was prescribed the day before the operation in a therapeutic dose taking into account urine culture results, and then daily as in group 1. On the first day aer PNL, all patients underwent native computed tomography of the kidneys and a clinical blood analysis.

Results. Significant differences in both the duration of the operation (85.2 ± 39.9 and 86.2 ± 43.5 min,(p>0.05)), and in the length of the postoperative bed-day (4.1 ± 1.7 and 4.2 ± 2.2, (p>0.05)) were not demonstrated in both groups. Blood transfusion was not required for any of the observed patients. The frequency of UTI manifestations also did not differ both according to clinical-the hyperthermia was more than 38 ° C (9.8% and 13.2% (p>0.05)), and laboratory data -the level of leukocytes in the blood was more than 14x109 / L (14, 9% and 16.7% (p>0.05)) in the 1st and 2nd groups,respectively. During the postoperative period, none of the patientsfrom both groups developed sepsis.The overall efficiency of the operation in the first group was 75.6%, in the second 72.9% (p>0.05).

Conclusion. A positive result of urine culture is not an independent risk factor for postoperative infectious complications. The antibacterial drug administration in a therapeutic dose to patients with a positive urine culture, considering the results of bacteriological urine examination 24 hours before the operation, allows to perform the PNL, wherein the data on overall efficiency and safety is comparable to the patients with sterile urine culture.

Authors declare lack of the possible conflicts of interests.