Sutures and Wound Repair/ General Surgery (ABSA) Practice Test

In an upper quadrant oblique incision (subcostal), which muscle is typically retracted or transversely divided?

1. Transverse abdominis

2. Rectus abdominis

3. External oblique

4. Internal oblique

The correct answer is: Rectus abdominis

In the context of an upper quadrant oblique incision, specifically the subcostal incision, the primary muscle that is addressed is the rectus abdominis. This muscle runs vertically along the midline of the abdomen and is often retracted laterally during surgical procedures to gain access to underlying structures. When making a subcostal incision, the surgeon typically makes an incision through the skin and fatty tissue, and then carefully dissects through the external oblique muscle, internal oblique muscle, and transverse abdominis layers before reaching the rectus abdominis. The rectus abdominis may be transversely divided or retracted to facilitate exposure to the abdominal cavity, particularly for surgeries involving the liver, gallbladder, or other organs located in the upper quadrant. The other muscles also play roles in the abdominal wall's structure and support but are less commonly retracted or divided in this specific type of incision. The external oblique and internal oblique muscles are often incised laterally, while the transverse abdominis creates a deeper layer in abdominal surgery that remains intact more often than the rectus abdominis during this particular procedure.