3644341 UPJO ureteropelvic junction obstruction 818 3644338 UPJO UPJ obstruction 7 3644343 UPJO ureteropelvic junction 2 3644344 UPJO pelvi-ureteric junction obstruction 1 3644345 UPJO pelvo-ureteric junction 1 3644340 UPJO PURPOSE: Pelvoureteric junction obstruction 1 3644339 UPJO UPJO in children, who suffer from uretero-pelvic obstruction 1 3644342 UPJO ureteropelvic junction obstruction pyeloplasty 1