Acquired Kidney Absence: Causes, Diagnosis & Clinical Implications

Acquired kidney absence (acquired solitary kidney) refers to the loss of a kidney after birth, distinct from congenital absence (born with one kidney).

Primary Causes

• Nephrectomy (surgical removal):
  • Renal cell carcinoma (most common)
  • Severe trauma (accidents, violence)
  • Chronic infection (pyelonephritis, TB)
  • Obstructive uropathy with irreversible damage
  • Living kidney donation
• Non-surgical loss:
  • End-stage renal disease requiring native nephrectomy
  • Radiation nephritis
  • Severe vascular injury (renal artery thrombosis)

Diagnosis

• Imaging: Ultrasound, CT, or MRI confirming single kidney
• History: Surgical records, trauma documentation
• Function assessment: eGFR, creatinine, urinalysis

Clinical Implications

• Renal function: Remaining kidney hypertrophies (compensatory hyperplasia), typically achieves 70-80% of two-kidney function
• Monitoring: Annual eGFR, blood pressure, urinalysis for proteinuria
• Nephrotoxin avoidance: NSAIDs, IV contrast, certain antibiotics require caution/dose adjustment
• Blood pressure control: Target <130/80; ACEi/ARB often first-line for renoprotection
• Sports participation: Contact sports generally discouraged; protective gear if played
• Pregnancy: Higher preeclampsia risk; multidisciplinary care

Distinction from Congenital Solitary Kidney

• Congenital: Present from birth; often detected incidentally; associated anomalies possible (ureteral, genital)
• Acquired: Known etiology; remaining kidney was previously normal; sudden functional reduction post-nephrectomy

Patients with acquired solitary kidney should have a nephrology consultation and lifelong monitoring.