Congenital anomalies of the kidney

Congenital solitary kidney
- Usually asymptomatic
  - However, they have a higher risk for kidney disease and should be monitored regularly
- The remaining kidney is usually hypertrophic
- Anatomical congenital solitary kidney
  - The other kidney is absent (renal agenesis)
- Functional congenital solitary kidney
  - The other kidney is non-functional
  - Renal aplasia, renal dysplasia, or renal hypoplasia
Horseshoe kidney
- The left and right inferior poles are fused
- Usually asymptomatic, but have increased risk of kidney disease
Ectopic kidney
- Kidney is in abnormal position
- Usually asymptomatic
Autosomal dominant polycystic kidney disease
- Presents with chronic renal failure or hypertension in adulthood
- Decreases life expectancy
Autosomal recessive polycystic kidney disease
- Presents with chronic renal and liver failure in childhood
- Either die within the first month or within 15 years
  - Those that die within the first month have pulmonary hypoplasia

Ureteropelvic junction obstruction

Male > female
Etiology: malformation of ureter
Causes hydronephrosis in utero
- Most common cause of abdominal mass in children
- In most cases hydronephrosis is diagnosed in utero by US
Diagnosis
- Ultrasound
- IV urography
Treatment
- Observation in asymptomatic cases
- Surgical correction if symptomatic

Etiology
- Duplicated ureter
- Ectopic ureter
- Ureterocoele
- Posterior urethral valves
Causes hydronephrosis in utero
- In most cases hydronephrosis is diagnosed in utero by US
Causes recurrent UTIs and kidney failure in children
Diagnosis
- Ultrasound
- Voiding cystography
Treatment
- VUR often improves spontaneously
- Prophylactic antibiotics
- Bladder training
- Endoscopic injection
- Surgical correction if the reflux is high-grade