URINARY TRACT OBSTRUCTION

The basic function of the kidney is the formation of an ultrafiltrate. Once this occurs, the remaining portions of the urinary tract function is to eliminate urine. When there is a structural impedence to the flow of urine anywhere along that tract, it is described as obstructive uropathy. Obstruction with subsequent hydronephrosis is a common clinical occurrence.
Urinary tract obstruction can result in a wide range of symptoms from asymptomatic to severe renal colic and renal failure. The symptoms depend upon:

• Duration over which the obstruction occurs.
• Unilateral or bilateral obstruction.
• Complete or partial obstruction.
• Etiology of obstruction.

Causes of obstruction:

• Meatal stenosis
• Urethral strictures
• Posterior urethral valves
• Ectopic ureters
• Ureteroceles
• Ureterovesical obstruction
• Ureteropelvic junction obstruction
• Spina bifida/Myelo meningiocele
• Vesicoureteral reflux
• BPH
• Prostate cancer
• Bladder cancer
• Ureteral stone
• Retroperitoneal fibrosis
• Extrinsic obstruction of ureter
• Neurogenic bladder 

Diagnosis:

• Excretory urography
• Ultrasonography
• Renal flow scan
• Diuretic renal flow scan
• CT scan