A gynecologic surgeon must be familiar with the anatomy of the female pelvis and lower abdominal wall. Over the past 20 years, the rote knowledge of pelvic anatomy has been complemented by a better understanding of the neuromuscular physiology that governs pelvic function. In this chapter, a broad overview of these relationships is presented.
The anterior abdominal wall provides core support to the human torso, confines abdominal viscera, and contributes muscular action for functions such as respiration and elimination. In gynecology, comprehensive knowledge of the layered structure of the anterior abdominal wall is needed to effectively enter the peritoneal cavity for surgery without neurovascular complications.
The term Langer lines describes the orientation of dermal fibers within the skin. In the anterior abdominal wall, they are arranged in a primarily transverse orientation (Fig. 38-1). As a result, vertical skin incisions sustain more lateral tension and thus, in general, develop wider scars compared with transverse skin incisions.
Langer lines of skin tension.
This layer of the anterior abdominal wall can be separated into a superficial, predominantly fatty layer known as Camper fascia and a deeper, more membranous layer known as Scarpa fascia (Fig. 38-2). Camper and Scarpa fasciae are not discrete layers but represent a continuum of the subcutaneous tissue layer. Scarpa fascia is continuous with Colles fascia in the perineum.
Transverse sections of the anterior abdominal wall above (A) and below (B) the arcuate line.
Scarpa fascia is better developed in the lower abdomen and can be best identified in the lateral portions of a low transverse incision, just superficial to the rectus fascia. In contrast, this fascia is rarely recognized during midline incisions.
The aponeuroses of the external oblique, internal oblique, and tranversus abdominis muscles (flank muscles) conjoin, and their layers create the rectus sheath (see Fig. 38-2). In the midline, these aponeurotic layers fuse to create the linea alba. In the lower abdomen, transition from the muscular to the aponeurotic component of the external oblique muscle takes place along a vertical line through the anterior superior iliac spine. Transition from muscle to aponeurosis for the internal oblique and transversus abdominis muscles takes place at a more medial site. For this reason, muscle fibers of the internal oblique muscle are often noted below the aponeurotic layer of the external oblique muscle during low transverse incisions.
The anatomy of the rectus sheath above and below the arcuate line has significance to the surgeon (see Fig. 38-2). This horizontal line defines the level at ...