Laparoscopy (peritoneoscopy)

Laparoscopic surgery has developed rapidly over recent years (Chapter 70). Previously used largely as a diagnostic procedure, laparoscopy with the aid of modern video technology is now used to perform many ‘minimally invasive operations (Table 56.8).

The primary trocar for laparoscopy is inserted using either the ‘open’ or ‘closed’ technique. In the latter method a‘pneumopenitoneum’ is created by the insertion of a special needle (e.g. Verres’) through which carbon dioxide is delivered. Once the penitoneal cavity is adequately distended a sharp-ended trocar is inserted ‘blindly’ and the laparoscope then introduced. In the ‘open’ method, which is to be preferred, a small incision (usually subumbilical) is made through the abdominal wall down to the penitoneum which is opened under direct vision. This reduces the risk of visceral injury and eliminates the rare major vascular injuries (iliac, vena caval and aortic) that occur with the ‘closed’ method.

The greater omentum

Rutherford Morison called the greater omentum ‘the abdominal policeman’ [but it has not any feet, i.e. it does not move across the abdomen of its own volition, but passively due to peristalsis, and it may be pushed by the movements of the abdominal wall into an area of immobility (rigidity) where there is local peritoneal irritation]. Relatively larger and structurally more substantial in the adult than in the child, the discharge of its life-saving constabulary duties becomes more effective after puberty, and remains unabated throughout life. The greater omentum attempts, often successfully, to limit intraperitoneal infective and other noxious processes (Fig. 56.13). For instance, an acutely inflamed appendix is often found wrapped in omentum and this saves many patients from developing diffuse peritonitis. Some sufferers of herniae are also greatly indebted to this structure, for it often plugs the neck of a hernial sac and prevents a coil of intestine from entering and becoming strangulated.

Apart from a small portion of it becoming gangrenous while performing the last-mentioned duty (strangulated omentocele) this Good Samatitan1 of the peritoneal cavity seldom itself becomes diseased; when it does become overwhelmed, as in tuberculous peritonitis and carcinomatosis peritonei, it becomes rolled like a scroll.

Torsion of the omentum. Torsion of the omentum is a rare emergency and consequently is seldom diagnosed correctly. It is usually mistaken for appendicitis with somewhat abnormal signs. It may be primary or secondary to an adhesion of the omentum, to an old focus of infection, or to a hernia. Successive herniations of a portion of the omentum into a hernial sac of irregular bore are credited with giving the necessary stimulus to omental torsion.

The patient is most frequently a middle-aged, obese male. A tender lump may be present in the abdomen. The blood supply having been jeopardised, the twisted mass sometimes becomes gangrenous, in which case bacterial peritonitis soon follows.

Treatment. The abdomen having been opened, the pedicle above the twist is ligated securely and the mass removed.

Omental cyst (see below).