What are the treatment options for hydronephrosis?

Treatment Options for Hydronephrosis

The treatment of hydronephrosis depends on its severity, cause, and associated complications, with immediate decompression required for patients with fever, leukocytosis, and signs of sepsis, while many cases of mild to moderate hydronephrosis can be managed conservatively with close monitoring. 1

Diagnostic Approach

Initial Imaging

• Ultrasound is the first-line imaging modality with >90% sensitivity for detecting hydronephrosis, helping to:
  • Grade severity (mild/Grade I, moderate/Grade II, severe/Grade III)
  • Localize obstruction level
  • Evaluate renal morphology 1
• For pediatric patients with antenatal hydronephrosis:
  • Initial ultrasound should be performed 48-72 hours after birth (due to low urine production in newborns)
  • Earlier imaging indicated for severe bilateral hydronephrosis, bladder abnormalities, or oligohydramnios 2
  • Follow-up ultrasound recommended in 1-6 months even with normal initial studies 2

Advanced Imaging

• CT urography: Preferred for adults with severe hydronephrosis 1
• MAG3 renal scan: Optimal for evaluating hydronephrosis with impaired renal function 1
• MR urography: Recommended for asymptomatic hydronephrosis (unilateral or bilateral) 1

Treatment Algorithm

1. Emergency Decompression

For patients with:

• Fever, leukocytosis, and sepsis
• Infected hydronephrosis
• Acute kidney injury with severe obstruction

Options:

• Percutaneous nephrostomy (PCN): First choice for septic patients 1, 3
• Retrograde ureteral stenting: Alternative when PCN not available 1, 3

2. Non-Emergency Management

A. Severe Hydronephrosis (Grade III-IV)

• Surgical intervention indicated when:

  • Significant obstruction (T1/2 >20 minutes)
  • Decreased renal function (<40% differential function)
  • Deteriorating function (>5% change on consecutive scans)
  • Worsening drainage on serial imaging 1

• Procedural options:

  • Pyeloplasty: For ureteropelvic junction obstruction
  • Retrograde ureteral stenting: For non-septic patients with obstruction 1
  • PCN: Considered if stenting fails, extrinsic compression is present, obstruction at uretero-vesical junction, or ureteral obstruction >3cm 1
  • Dual stent placement: May provide better drainage than single larger stent in cases of extrinsic compression (success rate >75%) 1

B. Mild to Moderate Hydronephrosis

• Conservative management with close monitoring:
  • Regular ultrasound follow-up (1-6 months)
  • Periodic evaluation of renal function 1
  • Many cases improve or resolve spontaneously over time 4

Special Populations

Pediatric Patients

• Refer to pediatric urology for antenatal or congenital hydronephrosis 1
• Close monitoring is essential, especially during first 2 years of life 4
• In newborns with unilateral severe hydronephrosis:
  • 78% can be managed non-operatively
  • Only 22% require surgical intervention (typically before 18 months of age) 4

Pregnant Patients

• Co-management by urology and obstetrics
• Intervention may be required to prevent preterm labor 1

Patients with Impaired Renal Function

• Nephrology consultation recommended for:
  • GFR <30 mL/min/1.73m²
  • Suspected medical renal disease 1

Complications and Follow-up

• Potential complications if untreated:

  • Permanent nephron loss
  • Irreversible renal damage 1, 5

• Follow-up recommendations:

  • Regular stent exchanges (typically every 3 months)
  • Treatment of underlying cause when possible 1
  • Urgent urological consultation warranted for moderate to severe hydronephrosis with acute kidney injury, signs of infection/sepsis, or intractable pain 1

Important Considerations

• The decision between conservative management and intervention should be based on objective parameters including renal function, drainage half-time, and progression of hydronephrosis 4
• Standard tests for assessing obstruction in adults may not be valid in infants, as prolonged half-time and high-grade hydronephrosis alone are not absolute indicators for surgery in this population 4
• Various grading systems exist (AP diameter, SFU, UTD, Onen), but none is universally accepted as the gold standard for determining hydronephrosis severity 6