A preliminary study of the variability in location of the ureteral orifices with bladder filling by fluoroscopic guidance: the gender difference

To determine landmarks for stent positioning in both ureteral orifices (UOs) and the gender differences in their location in men and women. The location of the UO and the bladder neck (BN) was measured fluoroscopically by the intravesical distal location of an open-ended catheter marked with radiopaque materials. We compared the location in men (n = 12) and women (n = 12) with a full bladder (hydrostatic pressure of 50 cmH2O) or an empty bladder. The mean distances from BN to UO in men and women were significantly different both in an empty bladder (2.5 ± 0.4 and 2.1 ± 0.3 cm, respectively) and in a full bladder (2.9 ± 1.0 and 2.3 ± 0.6 cm, respectively). The location of UO was changed by bladder filling in women but not in men. In women, most UOs were found superior to the symphysis pubis (SP) in empty bladder (66.6 %). Most of this location was observed at behind the upper boarder of SP in full bladder of women (75 %). The BN of women was located at the lower level in basal state compared to men. Also, the location of BN was markedly changed by bladder fulling in women (p = 0.04) but not in men. Significant gender differences were observed in the location of UO and BN. Clinicians should keep in mind the anatomical differences between men and women during fluoroscopic-guided procedure.