Functional characteristics of idiopathic hydronephrosis

Area of Science:

• Nephrology
• Urology

Background:

• Idiopathic hydronephrosis affects kidney drainage function.
• Assessing functional characteristics is crucial for management.

Purpose of the Study:

• To evaluate the functional characteristics of idiopathic hydronephrosis.
• To determine criteria for surgical intervention.

Main Methods:

• Conventional renography and glomerular filtration rate measurement.
• Beta-2-microglobulin excretion and maximum concentration ability tests.
• Intrapelvic pressure measurement during perfusion and furosemide diuresis.

Main Results:

• Most patients (79%) had normal parenchymal function despite reduced drainage.
• Proximal tubular function was generally preserved.
• Elevated intrapelvic pressure (>20 cm H2O) during diuresis indicated obstruction, especially in kidneys with normal concentrating ability.

Conclusions:

• Surgery is advised for idiopathic hydronephrosis with reduced urinary concentrating ability or complications like infection/calculi.
• Diuresis renography and urography are useful for doubtful cases with normal kidney function.
• A pressure increase >20 cm H2O during perfusion suggests obstruction in compromised kidneys.