Handa 9781496386441 Full Sample Chap 1

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SECTION I  Preparing for Surgery

I midway between the pubis and umbilicus. Below the point at which the vessels pass under the rectus, they are found lateral to the muscle and deep to the transversa- lis fascia. After crossing the lateral border of the rectus muscle, they lie on the muscle’s dorsal surface, between it and the posterior rectus sheath. As the vessels enter the rectus sheath, they branch extensively, so that they no longer represent a single trunk. The angle between the inferior epigastric vessels and the lateral border of the rectus muscle forms the apex of the inguinal triangle (Hesselbach triangle), the base of which is the ingui- nal ligament. This triangle represents the area through which direct inguinal hernias protrude medial to the inferior epigastric vessels. Around the umbilical area, the inferior epigastric artery anastomoses with the supe- rior epigastric, a branch of the internal thoracic artery. Lateral laparoscopic trocars are placed in a region of the lower abdomen where injury to the inferior epigastric and superficial epigastric vessels can easily occur. The inferior epigastric arteries and the super- ficial epigastric arteries run similar courses toward the umbilicus. Knowing the typical location of these blood vessels helps in choosing insertion sites that

will minimize their injury, reducing the potential for hemorrhage and hematomas. Just above the pubic symphysis, the vessels lie approximately 5.5 cm from the midline, whereas at the level of the umbili- cus, they are 4.5 cm from the midline (see FIG. 1.6 ). Therefore, placement either lateral or medial to the line connecting these points minimizes potential vas- cular injury. In addition, the location of the inferior epigastric vessels can often be directly seen through the peritoneal layer laparoscopically (see FIG. 1.5 ), and during laparoscopic procedures, the superficial epi- gastric vessels can often be identified in thin patients by transillumination. The round ligament is traced to its point of entry into the deep inguinal ring, rec- ognizing that the vessels lie just medial to this point ( FIG. 1.7 ). Nerves of the Abdominal Wall The innervation of the abdominal wall (see FIG. 1.3 ) arises from the abdominal extension of intercostal nerves 7 through 11, subcostal nerve (T12), and iliohy- pogastric and ilioinguinal nerves (both L1). Dermatome T10 lies at the umbilicus.

Inferior epigastric artery and vein

Deep circumflex iliac artery and vein

Internal inguinal ring and round ligament

Ilio-inguinal nerve

External iliac artery External iliac vein Ovarian artery and vein

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Femoral canal FIGURE 1.7  Sagittal view of female pelvis, showing inguinal anatomy. Note that the inferior epigas- tric artery and vein lie just medial to the round ligament as it enters the deep inguinal ring. (The original illustration is in the Max Brödel Archives in the Department of Art as Applied to Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA. Used with permission.)

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