One of the most difficult task for the Pediatric Urologist is to be able to correctly and precisely define an obstruction in the urinary tracts. The presence (more and more often after an initial prenatal detection) of a “dilatation” is usually the result of different conditions (pyelectasis, hydronephrosis, hydro-uretero-nephrosis) and very often does not have any pathological implication.
The possibility of observing an obstruction (stenosis) can occur at different levels of the urinary tract (pelvi-ureteric junction, uretero-vesical junction, vesical or urethral) and the diagnostic process will necessarily require a sequence of instrumental investigations, from the least to the more invasive (Renal and Bladder US, MAG3 Renal Scintigraphy, Uro MRI).
In the presence of a confirmed obstruction the therapeutic decision on how to proceed is conditioned by the age and by the anatomical situation. The most common conditions are represented by the stenosis of the pelvi-ureteric junction (surgically corrected by a pyeloplasty) or the stenosis of the uretero-vesical junction or megaureter (surgically corrected by a ureteral reimplant with or without remodelling).