Definition
The abdominal wall encloses the abdominal cavity and protects the abdominal viscera. The layers of the anterior abdominal wall which may be encountered in a laparotomy include the following: skin, subcutaneous fat, fascia of Camper, fascia of Scarpa, external oblique muscle, internal oblique muscle, rectus abdominis muscle, transverse abdominis muscle, pyramidalis muscle, transversalis fascia, and peritoneum.The rectus abdominis muscle is the long vertical muscle on either side of the midline in the abdominal wall. It is split in two parts by the linea alba, a fibrous avascular plane that runs in the midline from the xiphoid process of the sternum to the pubic symphysis. The lateral border of the two sides of this muscle creates a surface marking known as the linea semilunaris. This muscle is divided by fibrous intersections that join the linea alba to give the impression of the well-known six-pack. The rectus abdominis attaches to the pubic crest and inserts into the xiphoid process and costal cartilages of ribs 5, 6 and 7. It is considered a flat muscle which compresses the abdominal viscera and stabilizes the pelvis during movements such as walking. It is innervated by the thoracoabdominal nerve supplied by nerve roots T7-T11.
In brief, indications for a laparotomy include the following:
- Blunt abdominal trauma
- Hemorrhage/haemoperitoneum
- Perforated viscus
- Peritonitis
- Intestinal obstruction with hugely distended bowel loops, making a successful laparoscopic intervention unlikely
- Large specimen extraction, eg. Whipple pancreaticoduodenectomy
- Multiple previous abdominal operations, making extensive adhesions likely
- Obscure gastrointestinal bleeding that is not controlled by endoscopic intervention or embolization
