Obstructive uropathy includes congenital and acquired lesions which cause obstruction to urinary system and can lead to damage to renal parenchyma due to back pressure or urinary tract infections occurring in stagnant urine.

The approach to obstructive uropathy should be:

• To detect site of obstruction - pelviureteral junction (PUJ), vesicoureteral junction (VUJ), ureters, urethra.
 
• To find out whether obstruction is complete or partial, unilateral or bilateral.
 
• To detect the cause of obstruction.
 
• To decide need for surgery and to plan the medical treatment.

Causes of obstructive uropathy in children

• Congenital development defects of kidney and urinary tract :-
  
  
  • Commonest- pelviureteral junction(PUJ) obstruction.
    
    
  • Vesico-ureteral obstruction, ureterocele, diverticuli of bladder
    
    
  • Posterior urethral valves with subvesical obstruction, anterior urethral valves, urethral atresia, meatal stenosis.
    
    

  Dilatation of proximal part of urinary tract can be detected by antenatal sonography done at 16-18 weeks and then serially at 24-26 weeks and 30-32 weeks of gestation. Obstruction in utero can affect renal development and can cause permanent damage to renal function.
  
 
• Acquired conditions :-
  
  
  • Calculi in the ureter/s or urinary bladder or urethra
    
    
  • Strictures due to tuberculosis
    
    
  • Benign or malignant tumors in the urinary bladder or pressing from outside
    
    
  • Post urologic surgery due to blood clots or procedures like cystoscopy etc
    
 
• Functional obstruction :-
  
  
  • Neurologic diseases - meningomyelocele, lipomeningocele and other spinal defects.
    
    
  • Non neurogenic bladder
    
    

Clinical Evaluation :

Clinically obstructive uropathy presents as recurrent UTI, hypertension, renal failure or calculus disease or abnormal USG. Clinical evaluation of a suspected case of obstructive uropathy should include weight and height percentiles to detect growth retardation which may be the first clue to chronic renal insufficiency if diagnosis is missed in first year. B.P; examination of spine for nevus, tuft of hair or lipoma (indicates underlying spinal defects); palpation of abdomen for renal lumps (hydronephrosis); persistently distended, firm urinary bladder (indicates distal obstruction due to PUV) should be looked for. Observing urinary stream in male new born is important to diagnose posterior urethral valves wherein urinary stream is poor, interrupted with dribbling and straining while passing urine.