Sa. Worthy et al., BALLOON DILATATION OF THE URETERAL ORIFICE ALONGSIDE THE URETEROSCOPETO FACILITATE THE EXTRACTION OF LARGE URETERAL CALCULI, Minimally invasive therapy, 3(1), 1994, pp. 59-61
Where ureteric calculi are too large to pass through the ureteric orif
ice, balloon dilatation used in conjunction with the ureteroscope give
s sufficient dilatation for safe removal.