Editing Ureteropelvic Junction Obstruction (section)

==== Congenital ====

* '''<span style="color:#0000ff">SHAVA (5)</span>'''
#'''<span style="color:#ff0000">True ureteral </span><span style="color:#0000ff">S</span><span style="color:#ff0000">tricture</span>'''
#'''<span style="color:#0000ff">H</span><span style="color:#ff0000">igh insertion</span> found more frequently in the presence of renal ectopia or fusion anomalies'''
#'''<span style="color:#0000ff">A</span><span style="color:#ff0000">berrant vessels</span> (controversy persists). Regardless, the presence of crossing vessels has a detrimental effect on the success rates of endopyelotomy'''
#'''<span style="color:#ff0000">Kinks or </span><span style="color:#0000ff">V</span><span style="color:#ff0000">alves</span>''' produced by infoldings of the ureteral mucosa and muscularis
#'''<span style="color:#0000ff">A</span><span style="color:#ff0000">peristaltic segment</span>'''

* '''UPJO in newborns and infants is most often caused by an ''intrinsic'' narrowing'''
** '''The ureteral segment has an interruption in the development of the circular musculature of the UPJ''' and an alteration in collagen fibers in and around the muscular cells. This results in a narrowed segment of the UPJ with '''functional discontinuity of the muscular contractions and ultimately to insufficient emptying of the renal pelvis'''
* '''UPJO in childhood and adolescence is often extrinsic narrowing caused by an accessory vessel to the lower pole of the kidney''' giving rise to flank pain, nausea, and vomiting.
**'''Extrinsic obstruction seen in association with a lower pole vessel''' (aberrant, accessory, or early branching) '''that passes anteriorly to the UPJ or proximal ureter and contributes to mechanical obstruction'''
* '''Congenital renal malformations commonly associated with UPJO (8):'''
*# '''Contralateral UPJO (most common anomaly)'''
*# '''Renal dysplasia'''
*# '''Multicystic dysplastic kidneys'''
*# '''Renal agenesis'''
*# '''Horseshoe kidneys'''
*# '''VUR'''
*# '''Ectopic kidney'''
*# '''Duplex kidney'''