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CHAPTER 1  Surgical Anatomy of the Female Pelvis

Its fibers originate from the lower pubis and some from the top of the perineal membrane. The muscle fibers pass beside the rectum forming a sling behind the ano- rectal junction. The iliococcygeus muscle arises from a fibrous band overlying the obturator internus called the tendinous arch of levator ani. From these broad origins, the fibers of the iliococcygeus pass behind the rectum and insert into the midline anococcygeal body, which includes the iliococcygeal raphe, and the coccyx. The ischiococ- cygeus (coccygeus) muscle arises from the ischial spine and sacrospinous ligament to insert into the borders of the coccyx and the lowest segment of the sacrum. These muscles are covered on their superior and inferior surfaces by fasciae. When the levator ani and ischiococcygeus muscles and their fasciae are consid- ered together, they are called the pelvic diaphragm, not to be confused with the perineal membrane (formerly called the urogenital diaphragm). The normal tone of the muscles of the pelvic dia- phragm keep the base of the U in the levator hia- tus close to the backs of the pubic bones, keeping the vagina and rectum closed. The region of the levator ani between the anus and coccyx formed by the anococ- cygeal body and iliococcygeal raphe is clinically called the levator plate. It forms a supportive shelf on which the rectum, upper vagina, and uterus can rest. The relatively horizontal position of this shelf is determined by the anterior traction on the fibromuscular levator plate by the pubococcygeus and puborectalis muscles and is important to vaginal and uterine support.

The levator ani muscles receive their innervation from an anterior branch of the anterior ramus of the third, fourth, and fifth sacral nerves called, appropri- ately, the nerve to the levator ani, which perforates the muscle from its pelvic surface. Some parts of the puborectalis muscle may also receive a small contribu- tion from the inferior anal (rectal) branch of the puden- dal nerve. PELVIC VISCERA This section on the pelvic viscera discusses the structure of the individual pelvic organs and considers specific aspects of their interrelations ( FIG. 1.21 ). Those aspects of blood supply, innervation, and lymphatic drainage that are unique to the specific pelvic viscera are cov- ered here. However, the section on the retroperitoneum, where the overall description of these systems is given, provides the general consideration of the pelvic vascula- ture, innervation, and lymphatic drainage.

I

Genital Structures Vagina

The vagina is a pliable hollow viscus with a shape that is determined by the structures surrounding it and by its attachments to the pelvic wall. These attachments are to the lateral margins of the vagina, so that its lumen is a transverse slit, with the anterior and posterior walls in contact with one another. The lower portion of the vagina is constricted as it passes through the urogenital

Abdominal aorta

IVC

Common iliac artery

Common iliac vein

Premontory of sacrum

Ureter

IP ligament

Fallopian tube Ovary

Uterosacral ligament

Uterus

Inguinal ligament

Posterior cul-de-sac

Round ligament

Cervix Copyright © 2019 Wolters Kluwer, Inc. Unauthorized reproduction of the content is prohibited.

Vesicouterine pouch Urachus Bladder Pubic symphysis

Rectum

Anus

Clitoris

Vagina External anal sphincter

Labium majus

Urethra

Labium minus

FIGURE 1.21  The pelvic viscera.

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