Oznur Baykal, Murvet Yilmaz
Among patients with a SK, those with URA group exhibited worse clinical outcomes compared to those who underwent nephrectomy. Individuals with a solitary kidney demonstrating initial indicators of kidney injury should be followed up by a nephrologist.
PURPOSE: Long-term kidney outcomes were evaluated in patients with a solitary kidney (SK), with a comparative analysis between congenital and acquired etiologies.
METHODS: In this retrospective study, the presence of SK was confirmed by ultrasonographic imaging. Inclusion criteria required an estimated glomerular filtration rate (eGFR) > 15 mL/min/1.73 m2. Patients were categorized into two groups: those with unilateral renal agenesis (URA, congenital group) and those who had undergone unilateral nephrectomy (acquired group). Primary outcomes included progression to kidney injury, sustained doubling of serum creatinine, and death.
RESULTS: A total of 490 patients (283 females, 207 males) were included. Of these, 337 patients (68.8%) had URA, while 153 (31.2%) had undergone nephrectomy. The median follow-up duration was 59.4 (34.3-95.4) months. The average annual eGFR loss was 3 mL/min/1.73 m2 in the URA group, compared to 2.2 mL/min/1.73 m2 in the nephrectomy group. During follow-up, 51 patients (10.4%) experienced doubling of serum creatinine, 14 (2.9%) initiated kidney replacement therapy (KRT), and 9 (1.8%) death. Kidney size was significantly larger in the nephrectomy group (p = 0.001). Baseline proteinuria and initial serum creatinine were independent predictors of kidney function loss. Kaplan-Meier analysis revealed that kidney survival was significantly higher in the acquired SK group compared to the congenital group (p = 0.043).
CONCLUSION: Among patients with a SK, those with URA group exhibited worse clinical outcomes compared to those who underwent nephrectomy. Individuals with a solitary kidney demonstrating initial indicators of kidney injury should be followed up by a nephrologist.