Idiopathic Retroperitoneal Fibrosis-Related Hydronephrosis: Evaluation of Comprehensive Management and Prediction of Inflammatory Markers for Stent-Free Outcomes.

Objective: This study investigated the efficacy of comprehensive management and predictable inflammatory markers for idiopathic retroperitoneal fibrosis (iRPF)-related hydronephrosis outcomes.

Methods: Patients with iRPF-related hydronephrosis underwent surgical (ureteral stent and/or nephrostomy tube placement) and medical (corticosteroid-based multiple immunosuppressants) management were classified according to stent-indwelling outcomes. Univariate analysis of clinical profiles was conducted to screen possible predictors of hydronephrosis remission.

Results: In a series of 38 patients, 52.6% achieved hydronephrosis remission and stent/tube removal (stent-free group). The median indwelling time in the stent-free group (12 months) was significantly lower than that in the treatment-failure group (37 months, <0.05). Mean retroperitoneal mass diameters was significantly reduced (anteroposterior by 11.66 mm (95% CI 2.31-21.01), transverse by 15.41 mm (95% CI 3.37-27.46), suprainferior by 30.53 mm (95% CI 4.87-56.19); <0.05) during the treatment course, in line with mean renal pelvis width (by 36.2%) and renal function parameters (serum creatinine by 16.9%, blood urea nitrogen by 12.9%). Renal function improved (36.9%) or remained stable (44.7%) in most patients, the mean estimated glomerular filtration rate increasing by 8.7% (from 55.4 mL/min/1.73 m to 60.2 mL/min/1.73 m). At the initial diagnosis, median serum immunoglobulin IgG and CRP levels were significantly higher in the stent-free group than in the treatment-failure group (IgG 17.55 g/L vs. 13.50 g/L, CRP 19.60 mg/L vs. 3.15 mg/L; <0.05). Decline in serum IgG (-5.80 g/L vs. -2.30 g/L), CRP (-18.93 mg/L vs. -1.72 mg/L) and erythrocyte sedimentation rate (-22.00 mm/h vs. -1.50 mm/h) levels in the stent-free group surpassed those in the treatment-failure group (<0.05).

Conclusion: Comprehensive management benefits iRPF patients with hydronephrosis by preserving renal function. The 24-month scale might guide stent/tube removal. Elevated inflammatory markers (IgG and CRP) at the initial iRPF diagnosis and IgG, CRP, and erythrocyte sedimentationrate (ESR) variations associated with hydronephrosis outcomes.