Materials and methods. We have conducted a prospective study of patients with acute obstructive pyelonephritis, who were admitted to the Spaskukotsky clinical hospital (urological department) of the Moscow State University of Medicine and Dentistry over the period of2015-2016. According to the method ofupper urinary tract (UUT) drainage, the patients were divided into two groups. The first group comprised patients, who had internal ureteral stenting (n=100); the second group included patients, who underwent percutaneous puncture nephrostomy (n=101).

Results. We have analyzed the results of the general examination of patients, who were hospitalized with acute obstructive pyelonephritis. We have determined the causes of UUT obstruction, the number of peripheral blood leukocytes, body temperature and the size of the renal calyces and pelves. The details and results of surgery procedures and the duration of hospitalization were considered. Based on the analysis of the data obtained, we have developed the following statistical model. The probability of choosing percutaneous puncture nephrostomy equals 1/(1+exp(-A)), where А=0,334х(0 for women, 1 for men)+0,116х(age)+ G^^eMs size, mm)+0,264х(calyces size, mm)+0,552х(number of peripheral blood leukocytes at the moment of hospitalization)-23,931. According to the ROC analysis, the accuracy of the model developed was 0.93 (1 is for the maximal effectiveness).

We have also analyzed the results of surveys of patients’ preferences for the methods of UUT drainage. It has been shown that patients with acute obstructive pyelonephritis do not possess the necessary information and are unaware of the advantages and disadvantages of various methods of drainage at the moment of hospitalization. Therefore, they are unable to make rational and independent decisions. The majority of patients prefer ureteral stenting.

Results. Patients with acute obstructive pyelonephritis are not well informed of the methods of drainage at the moment of hospitalization. Internal ureteral stenting and percutaneous puncture nephrostomy are equally effective with minimal complications. Internal ureteral stenting is linked to discomfort in patients. According to the data obtained from multivariate data analysis, we have determined that percutaneous puncture nephrostomy may be more effective for elderly patients and for patients, who demonstrate more apparent inflammatory response. The statistical model developed may help to facilitate the choice of the method of the UUT drainage in patients with acute obstructive pyelonephritis.

Authors declare lack of the possible conflicts of interest