Handa 9781496386441 Full Sample Chap 1

CHAPTER 1

Surgical Anatomy of the Female Pelvis Marlene M. Corton and John O. L. DeLancey

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The Abdominal Wall Skin and Subcutaneous Tissue Musculoaponeurotic Layer Neurovascular Supply of the Abdominal Wall Other Lumbar Plexus Branches Vulva and Erectile Structures Subcutaneous Tissues of the Vulva Superficial Compartment Pudendal Nerve and Vessels Terminal Branches of Pudendal Nerve Autonomic Innervation to Erectile Structures Lymphatic Drainage Medial Thigh Compartment

The Pelvic Floor Perineal Membrane Perineal Body Posterior Triangle: Ischioanal Fossa Anal Sphincters Levator Ani Muscles Pelvic Viscera Genital Structures Lower Urinary Tract

Extraperitoneal Surgical Spaces Anterior and Posterior Cul-De-Sacs Retropubic/Prevesical Space Vesicovaginal and Vesicocervical Space Rectovaginal Space Region of the Sacrospinous Ligament and Greater Sciatic Foramen Retroperitoneal Spaces and Lateral Pelvic Wall Retroperitoneal Structures above the Pelvic Brim Presacral Space Pelvic Retroperitoneal Space Lymphatics

Sigmoid Colon and Rectum Pelvic Connective Tissue Uterine Ligaments Vaginal Connective Tissue Attachments and Extraperitoneal Surgical Spaces Urethral Support

apparent. Closer to the rectus sheath, the fibrous tis- sue predominates relative to the fat, and this portion of the subcutaneous layer is called the membranous layer (formerly Scarpa fascia ). The fatty and membra- nous layers are not discrete or well-defined layers but represent regions within the subcutaneous tissue. The membranous layer is best developed laterally and is not seen as a well-defined layer during midline verti- cal incisions. It is most evident at the lateral borders of low transverse incisions, just above the rectus sheath. Musculoaponeurotic Layer Deep to the subcutaneous tissue is a layer of muscle and fibrous tissue (“fascia”) that holds the abdominal vis- cera in place and controls movement of the lower torso ( FIGS. 1.1 and 1.2 ) The muscles of this layer can be con- sidered in two groups: the vertical muscles in the mid- line (rectus abdominis and pyramidalis) and the more lateral flank muscles (the external oblique, internal oblique, and transversus abdominis). The fascia, prop- erly called the rectus sheath, is created by the broad, sheetlike tendons of these muscles, which form aponeu- roses that unite with their corresponding member of the other side.

THE ABDOMINAL WALL The superior border of the abdominal wall is the lower edge of the rib cage (ribs 7 through 12). The inferior margin is formed by the iliac crests, inguinal ligaments, and pubic bones. It ends posterolaterally at the lumbar spine and its adjacent muscles. Knowledge of the lay- ered structure of the abdominal wall allows the surgeon to enter the abdominal cavity with maximum efficiency and safety. A general summary of these layers is pro- vided in TABLE 1.1 and discussed below. Skin and Subcutaneous Tissue The fibers in the dermal layer of the abdominal skin are oriented in a predominantly transverse direction follow- ing a gently curving upward line. This predominance of transversely oriented fibers results in more tension on the skin of a vertical incision and in a wider scar. Deep to the skin lies the subcutaneous tissue of the abdomen. This tissue is made of globules of fat held in place and supported by a series of branching fibrous septa. In the more superficial portion of the subcuta- neous tissue, called the fatty layer (formerly Camper fascia ), fat predominates, and fibrous tissue is less

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