Omental torsion
From Medical-Wiki
The omentum is a free fold of peritoneum that connects visceral organs. It is divided into the greater omentum that covers the stomach and sweeps down like an apron over its anterior surface, and the lesser omentum that forms a partial covering of the stomach and the common bile duct. Torsion of the omentum' occurs when the omentum twists about its long axis. This can cause vascular compromise and create a situation that closely emulates a surgical abdomen.
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Classifications
Omental torsion is characterized as being either primary or secondary.
- Primary torsion is not associated with any other abdominal pathology. A mobile segment of the omentum rotates around a fixed position. Associated with this type of torsion are the presence of an accessory omentum, a bifid omentum, unusual configurations of omental fat in obese patients, redundancy of omental veins, past history of trauma, violent exercise, and hyperperistalsis.
- Secondary torsion is more common than primary torsion. It is associated with cysts, tumors, areas of inflammation, post-surgical adhesions, and hernia sacs, i.e. intra-abdominal pathology. The most common cause of secondary omental torsion is inguinal hernias.
The omentum usually twists in a clockwise fashion. The venous return is initially compromised, prior to arterial compromise. This leads to an omentum that is significantly congested and boggy. It will also produce a characteristic serosanguineous peritoneal fluid.
Later in the course of the torsion, arterial compromise leads to infarction. The fact that the omentum can spontaneously reduce probably explains the existence of omental adhesions.
Clinical presentation
Patients will present with diffuse abdominal pain that may quickly migrate to the right side. This may be accompanied by nausea, vomiting, and low grade fever. Occasionally, an abdominal mass is palpable.
These symptoms may easily be confused for appendicitis, cholecystitis, or ovarian patholgy. That is why the differential for omental torsion is basically inclusive of all etiologies for abdominal pain. [1]
Diagnosis
Without surgery, diagnosis of this condition is very difficult. Success in this regard has been estimated to be as low as only 0.6% (and only as high as 4.8%). The right side is the most common area for torsion to occur.
There is no specific test that “nails” a diagnosis of omental torsion. Computerized tomography may reveal an omental mass, but this may be seen in a variety of conditions and is not specific for torsion.
Even at surgery, the operator may discover completely normal anatomy if the omentum has derotated. Only the presence of the serosanguineous fluid remains as a footprint of what preceded intervention. [2]
When the offending omentum remains twisted, it may be rotated as many as 4 or 5 times. It appears as a purple and firm mass.
Treatment
Treatment is complete surgical excision of the involved omentum. [3]
