What is the diagnosis and treatment for Hydronephrosis (swelling of the kidney due to impaired renal function)?

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From the Guidelines

Hydronephrosis requires prompt treatment to prevent permanent renal damage, and the treatment approach depends on the underlying cause and severity of the condition. The condition is characterized by swelling of the kidney due to urine buildup from obstruction in the urinary tract. According to the most recent study 1, hydronephrosis can be classified by cause and by unilateral versus bilateral involvement, and obstructive hydronephrosis can be further classified by level of obstruction, complete versus partial obstruction, and intrinsic versus extrinsic obstruction.

Causes and Classification

The causes of hydronephrosis include urolithiasis, malignant obstruction, stricture, upper urinary tract infection, traumatic or ischemic injury, postradiation changes, retroperitoneal fibrosis, supravesical or bladder dysfunction, bladder outlet obstruction as with prostatic hyperplasia, mechanical compression as with enlarged uterus or pelvic organ prolapse, endometriosis, schistosomiasis, drug effects as with cyclophosphamide or ketamine, vessel-related and/or congenital ureteropelvic junction obstruction, and congenital posterior urethral valves 1.

Diagnostic Approach

For patients with symptomatic hydronephrosis, CT abdomen and pelvis without IV contrast can be useful in evaluating obstructive urolithiasis, especially when US is inconclusive 1. CT urography (CTU) is an imaging study that is tailored to improve visualization of both the upper and lower urinary tracts, and it can help predict the likelihood of ureteral stone on subsequent CT 1.

Treatment Approach

Treatment of hydronephrosis should focus on addressing the underlying cause of the obstruction, which may involve removing kidney stones, inserting a ureteral stent or nephrostomy tube to bypass blockages, or surgical correction of anatomical abnormalities. Antibiotics such as ciprofloxacin (500mg twice daily for 7-14 days) are necessary if infection is present, and pain management typically includes NSAIDs like ibuprofen (400-600mg every 6-8 hours) or, in severe cases, opioid medications 1. Patients should increase fluid intake to 2-3 liters daily unless contraindicated.

Key Considerations

  • Regular follow-up with urinalysis, renal function tests, and imaging is essential to monitor kidney recovery and prevent recurrence.
  • The condition can lead to permanent kidney damage if left untreated, as prolonged pressure from backed-up urine damages kidney tissue and impairs function.
  • Symptoms may include flank pain, urinary changes, nausea, and fever if infection develops.
  • Percutaneous antegrade ureteral stenting (with or without safety nephrostomy) can be an effective treatment option for patients with urinary tract obstruction, with a technical success rate of 91.8% and a clinical success rate of 89.8% 1.

From the Research

Definition and Diagnosis of Hydronephrosis

  • Hydronephrosis is diagnosed more often with the increased availability of computed tomography and ultrasound scanning 2
  • It is an important consideration in patients with abdominal or pelvic pathology as progressive dilation of the upper urinary tract can lead to acute kidney injury and, if not corrected, permanent nephron loss 2
  • Hydronephrosis can be diagnosed using various modalities, including sonography, radiography, magnetic resonance imaging, and nuclear medicine technology 3

Causes and Effects of Hydronephrosis

  • Urine leakage from an obstructed kidney can lead to hydronephrosis, electrolyte instability, and a progressive loss of renal function 4
  • Pelvi-ureteric junction obstruction (PUJO) is a common cause of giant hydronephrosis, accounting for 91.4% of cases in one study 5
  • Delayed diagnosis and management of hydronephrosis can result in long-term complications like hypertension, rupture of the kidney, renal failure, and malignant change 5

Treatment Options for Hydronephrosis

  • Percutaneous nephrostomy is a superior method for diversion of hydronephrosis caused by stones, especially in patients with a high temperature, as well as in males and younger patients 6
  • Ureteral stents can also be used for diversion of hydronephrosis, but may have a higher rate of complications and a longer indwelling time compared to percutaneous nephrostomy 6
  • Reduction pyeloplasty with nephropexy can be an effective treatment option for giant hydronephrosis, with a success rate of 81% and a complication rate of 23.1% in one study 5
  • Treatment options for hydronephrosis also include placement of a drainage catheter, percutaneous nephrostomy tubes, and antibiotic treatment 4

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

An overview of hydronephrosis in adults.

British journal of hospital medicine (London, England : 2005), 2020

Research

Hydronephrosis: Diagnosis, Grading, and Treatment.

Radiologic technology, 2020

Research

Giant hydronephrosis: still a reality!

Turkish journal of urology, 2017

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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