Neuroanatomy of the female continence complex: Clinical implications

Objectives. Improved understanding of pelvic neuroanatomy in women has led to modified surgical approaches and additional considerations in pelvic sur gery. The innervation of the external urinary sphincter and urethra is not well defined in women, and, as such, the continence complex is not well und erstood. Methods. Fourteen pelvic sections from seven fresh female cadavers were dis sected to investigate the neuroanatomy of the female continence complex. Results. Neuroanatomic dissections of the continence mechanism revealed tha t branches of the pelvic nerve travel beneath the fascia of the levator ani muscle and approach the urinary sphincter in near midline position, poster olateral to the rectum. This pelvic nerve branch passes laterally around th e vagina and rectum to enter the sphincter musculature at the 5-o'clock and 7-o'clock positions. The pudendal nerve, traveling in the pudendal canal, gives an intrapelvic branch that courses to the urinary sphincter. At the l evel of the proximal urinary sphincter, it joins the pelvic nerve branch to the urinary sphincter. Conclusions. These neuroanatomic dissections provide a basis for surgical m odifications that may address a variety of concerns regarding urinary conti nence in female surgical patients. With improved understanding of the femal e continence complex, we may now have a more precise anatomic explanation f or the high failure rates associated with transvaginal urethral suspension procedures. Additionally, awareness and preservation of the continence nerv es during cystectomy may allow for greater use of orthotopic bladder replac ement in women. UROLOGY 57: 382-588, 2001. (C) 2001, Elsevier Science Inc.