Surgical Anatomy of Anterior Abdominal Wall and Retroperitoneal Region

Anterolateral Abdominal Wall

• The most superficial layer in the anterolateral abdominal wall is the superficial fascia.
• The abdominal wall plays a crucial role in maintaining the anatomical position of the abdominal viscera.

Superficial Fascia

• Below the umbilicus, the superficial fascia consists of fatty areolar tissue.
• The superficial fascia is continuous with the superficial fascia in other regions of the body.

Abdominal Wall Function

• The abdominal wall assists in pushing the abdominal viscera upwards during coughing and vomiting.
• The parietal peritoneum's main function in the anterolateral abdominal wall is to provide a smooth slippery surface for the movement of abdominal viscera.

Muscle Layers

• The external oblique is the largest and most superficial flat muscle in the abdominal wall.
• The internal oblique lies deep to the external oblique and has fibers running superomedially.
• The transversus abdominis is the deepest of the flat muscles, with transversely running fibers.
• The pyramidalis is a small triangular muscle found superficially to the rectus abdominis, located inferiorly with its base on the pubis bone.

Surgical Incisions

• The paramedian incision involves making a cut through the Linea alba.
• The Kocher incision begins inferior to the xiphoid process and extends inferolaterally in parallel to the right costal margin, mainly used for gall bladder and/or biliary tree pathology.

Abdominal Regions

• The two horizontal planes used in describing the nine regions formed in the abdominal wall are the subcostal and transtubercular planes.

Muscle Functions

• The abdominal wall muscles, including the transversus abdominis, assist in compressing the abdominal viscera, stabilizing the pelvis during walking, and depressing the ribs.

Surgical Techniques

• The classic name for the incision described as consisting of two perpendicular lines, splitting the fibers of the muscles without cutting them is the Pfannenstiel incision.
• The McBurney incision is typically used for appendectomies.

Retroperitoneal Space

• The retroperitoneal space is located behind the peritoneum.
• Gerota's capsule contains the kidney and adrenal gland within the retroperitoneal space.

Inguinal Region

• The inguinal canal transmits the spermatic cord in males and the round ligament of the uterus in females.
• Hesselbach's triangle (inguinal triangle) is located in the inguinal region.
• The external oblique aponeurosis forms the superficial (external) inguinal ring.
• The femoral canal lies within the femoral sheath.
• The femoral vein is located posteriorly to the femoral canal.