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).