There are both mild forms of ureteropelvic junction obstruction and severe forms which might result in severe obstruction.
One of the most prominent causes of such obstructions is congenital stenosis (crossing vessel).

The surgery performed to eliminate such obstructions is called pyeloplasty operation. Compared to an open pyeloplasty operation, advantages of the robotic operation include a smaller incision, less pain, reduced length of stay in hospital, lower risk of wound infection, and faster healing.