Risk factors for re-infection in patients after drainage of the upper urinary tract due to obstructive pyelonephritis

Abstract

Introduction. Reinfection after drainage of obstructive pyelonephritis exacerbates the postoperative course of the disease and delays the possible surgical intervention aimed at eliminating the cause of obstruction.Objectives. To determine the percentage of re-infection in patients drained with double-J stent or nephrostomy catheter for obstructive pyelonephritis. To assess the relationship between the timing of drainage removal and development of re-infection. To establish risk factors for the development of re-infection.Materials and methods. Medical records from 1022 patients who were treated from January 2019 to December 2021 and underwent drainage for obstructive pyelonephritis. The data in patients after nephrostomy and stenting were evaluated separately. A retrospective analysis of the time and frequency of the development of re-infection, as well as the effect of diabetes mellitus on pyelonephritis relapse, was carried out.Results. Re-infection during drainage developed in 16 (4.8%) patients with a nephrostomy and 45 (6.5%) patients with a stent. Among those who had re-infection in the nephrostomy-group, 4 (25.0%) patients noted it within two weeks from the moment of drainage, and 11 (69.0%) at three-four weeks. In the stent-group, the number of patients who had a complication during the first two weeks was 15 (33.0%), and it was 22 (49.0%) during the next two weeks, The proportion of patients with diabetes mellitus was higher among those who developed pyelonephritis again.Conclusion. The percentage of patients hospitalized with clinical re-infection after drainage of the upper urinary tract was 6.0%. There was an increase in the number of hospitalizations with recurrent pyelonephritis in cases where the drainage period lasted more than two weeks (p < 0.05).