The cause of renal pelvis-ureteral junction narrowing can be due to anatomical or functional reasons that cause narrowing of the junction, obstructing the flow of urine from the renal pelvis to the ureter, leading to hydronephrosis. To improve this condition, doctors will use laparoscopic surgery to reconstruct the narrowed junction, helping urine to flow normally and avoiding risks affecting the kidneys.

Renal-ureteral junction obstruction is a congenital malformation that causes obstruction of the junction, obstructing the flow of urine from the renal pelvis to the ureter, leading to hydronephrosis. Currently, the most commonly chosen treatment method for renal-ureteral junction obstruction is laparoscopic surgery to remove the pathological junction.