Radiologically Measured Renal Pelvis Urine Density Is Associated with Severe Infectious Complications After Ureteroscopy for Ureteral Stones: A Post Hoc Analysis of a Multicenter Prospective Study.

BACKGROUND AND

OBJECTIVE

Finding reliable and easy-to-obtain indicators of severe infectious complications after ureteroscopy represents a major clinical need. This study aimed to assess the association between Hounsfield units (HUs) in renal pelvis urine and severe infectious complications in patients with ureteral stones and asymptomatic hydronephrosis following ureteroscopy.

METHODS

In this post hoc analysis of a multicenter prospective trial, renal pelvis urine density (RPUD) was measured via non-contrast-enhanced computed tomography. Severe complications (septic shock, urosepsis, and systemic inflammatory response syndrome) were recorded. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated by multivariable logistic regression.

KEY FINDINGS AND LIMITATIONS: Among 601 patients, 9.5% (57/601) developed severe infectious complications. After adjustment, each one HU unit increase in RPUD was associated with 54% higher odds of severe infectious complications (adjusted OR = 1.54; 95% CI: 1.37-1.73; p < 0.001). Restricted cubic splines confirmed a linear relationship (nonlinear p = 0.2). Gender (female vs male, adjusted OR = 3.55; 95% CI: 1.57-8.02; p = 0.002), hydronephrosis grade (G3 or G4 vs G1 or G2, adjusted OR = 4.86; 95% CI: 1.89-12.5; p = 0.001), and mean stone density (lower vs higher, adjusted OR = 0.996; 95% CI: 0.994-0.997; p < 0.001) were also independently associated with severe infectious complications.

CONCLUSIONS AND CLINICAL IMPLICATIONS: This study demonstrates a positive linear association between renal pelvis urine HU values and severe infectious complications after ureteroscopy, independent of comprehensive patient and stone characteristics.

PATIENT SUMMARY: We found that higher urine density in the renal pelvis (measured by a computed tomographic scan) is significantly associated with the incidence of severe infectious complications after ureteroscopy for ureteral stones.