HYDRONEPHROSIS AND ITS CLINICAL IMPACT ON RENAL FUNCTION: EVIDENCE FROM RECENT LITERATURE

Abstract

Background: Hydronephrosis is frequently identified on imaging and is commonly regarded as a marker of urinary tract obstruction. Although recent studies have clarified several mechanisms of obstructive uropathy, the relationship between hydronephrosis severity and renal functional impairment remains inconsistent. Increasing evidence indicates that radiological dilatation does not reliably predict the extent of renal injury, particularly in acute kidney injury (AKI) and in the presence of delayed decompression, infection, or malignancy. Objective: This narrative integrative review aims to synthesize recent evidence on the clinical impact of hydronephrosis on renal function, focusing on pathophysiological mechanisms, diagnostic challenges, acute and long-term renal outcomes, and determinants of renal recovery after obstruction relief. Methods: This study was conducted as a narrative integrative review of peer-reviewed literature published between 2021 and 2026. Relevant articles were identified from major biomedical databases and selected based on thematic relevance to obstructive uropathy, hydronephrosis, AKI, acute kidney disease (AKD), and chronic kidney disease (CKD). The review provides a conceptual synthesis of experimental studies, observational cohorts, systematic reviews, and consensus statements. No formal systematic review methodology, PRISMA framework, or quality appraisal tool was applied. Results: The evidence demonstrates that obstruction induces hemodynamic disturbance, tubular epithelial injury, inflammation, microvascular dysfunction, and fibrotic remodeling, processes that may persist after decompression and limit renal recovery. Hydronephrosis severity correlates poorly with renal dysfunction, and clinically significant obstructive AKI may occur without marked dilatation. Renal recovery is heterogeneous and influenced by obstruction duration, AKI severity, baseline renal reserve, infection, malignancy-related obstruction, and timing of intervention. Obstructive AKI may progress to AKD and increase long-term CKD risk. Conclusion: Hydronephrosis should be interpreted as a context-dependent indicator of renal vulnerability rather than a purely anatomical finding. Integrated clinical and functional assessment, together with structured follow-up, is essential to optimize renal recovery and mitigate chronic kidney disease progression.