What specialist do you refer a patient with hydronephrosis (swelling of the kidney due to urine flow obstruction) to?

Referral for Hydronephrosis

Patients with hydronephrosis should be referred to a urologist for initial evaluation and management, with nephrology consultation indicated for cases with impaired renal function (GFR <30 mL/min/1.73m²) or suspected medical renal disease. 1

Primary Specialist Referral

Urologist

• Urologists are the primary specialists for evaluating and managing hydronephrosis due to their expertise in managing urinary tract obstructions
• Urologists can perform essential diagnostic procedures including:
  • Cystoscopy to evaluate lower urinary tract
  • Retrograde pyelography to visualize the collecting system
  • Placement of ureteral stents or percutaneous nephrostomy tubes for urgent decompression 1
• Urologists can also perform definitive surgical interventions when indicated:
  • Ureteroscopy with stone removal
  • Pyeloplasty for ureteropelvic junction obstruction
  • Tumor resection if malignancy is identified 1, 2

Indications for Additional Specialist Referrals

Nephrology Referral

• Refer to nephrology when:
  • GFR <30 mL/min/1.73m² 2, 1
  • Suspected medical renal disease (proteinuria, dysmorphic RBCs, cellular casts) 2
  • Progressive decline in renal function despite urological intervention 2
  • Need for renal replacement therapy planning when risk of kidney failure within 1 year is 10-20% or higher 2

Interventional Radiology Referral

• Consider referral to interventional radiology when:
  • Percutaneous nephrostomy is needed for urgent decompression
  • Patient is too unstable for surgical intervention
  • Temporary drainage is required before definitive treatment 1

Special Populations

Pediatric Patients

• Pediatric patients with antenatal or congenital hydronephrosis should be referred to pediatric urology
• Initial ultrasound should be performed 48-72 hours after birth with follow-up based on severity 1
• Voiding cystourethrography may be necessary to rule out vesicoureteral reflux 2

Pregnant Patients

• Pregnant patients with symptomatic hydronephrosis should be co-managed by urology and obstetrics
• Asymptomatic physiologic hydronephrosis of pregnancy typically requires no intervention
• Symptomatic cases may require intervention to prevent preterm labor 1

Diagnostic Approach Before Referral

• Initial evaluation should include:

  • Renal function tests (creatinine, BUN)
  • Urinalysis to assess for infection, hematuria, or proteinuria
  • Renal ultrasound to confirm hydronephrosis and evaluate for obvious causes 1

• If initial ultrasound shows moderate to severe hydronephrosis, urgent urological consultation is warranted, especially if accompanied by:

  • Acute kidney injury
  • Signs of infection/sepsis
  • Intractable pain 2, 1

Pitfalls to Avoid

• Do not delay urological referral when hydronephrosis is accompanied by signs of infection, as this can rapidly progress to urosepsis
• Do not assume physiologic hydronephrosis in pregnant women is always benign; symptomatic cases require urological evaluation
• Do not overlook the need for nephrology consultation when renal function is impaired (GFR <30 mL/min/1.73m²) 2, 1
• Do not miss bilateral hydronephrosis, which may indicate a systemic cause or serious pathology such as inflammatory abdominal aortic aneurysm 3

In summary, while urologists are the primary specialists for managing hydronephrosis, a multidisciplinary approach involving nephrology and interventional radiology may be necessary depending on the clinical presentation, severity, and underlying cause of the condition.