Origins and distribution of nerves to the female urinary bladder: new anatomical findings in the sex differences.

The development of nerve-sparing procedures is important in preventing bladder dysfunction following radical hysterectomy. In this study, we dissected 14 halves of 7 female pelvises (age range: 46-86 years; mean age: 74 years) to examine the origins, courses, and distributions of nerve branches to the bladder in females in detail, and 6 halves of 3 male pelvises (age range: 71-85 years, mean age: 78 years) to compare with the female specimens. Nerve branches to the bladder originated mainly from the inferior hypogastric plexus, but independent direct branches running along the ureter from the hypogastric nerve were also distributed particularly to the trigone in all female specimens. We classified these independent branches into four types according to their relationship to the ureter. In males the numbers of the independent branches were small and they were difficult to find. The present observations indicate that nerve distribution patterns to the bladder differ between females and males. In nerve sparing procedures for radical hysterectomy, the area between the ureter and the hypogastric nerve is important.