Torsion of the greater omentum is a condition in which the omentum twists along its long axis with subsequent vascular impairment.The first reference to omental torsion in the literature is ascribed to Eitel in 1899. Secondary torsion is more common, occurring in association with intra abdominal pathologies, such as an internal or external hernia sac, a tumor, a focus of inflammation or adhesions. Primary omental torsion is much less common, and predisposing factors include anatomical malformations of the omentum, such as bifid omentum or tongue-like omental projections, local variations in omental fat distribution, particularly in obese patients, and constitutive anomalies of the omental blood supply or pedicle formation. Because we did not find any anatomic reason for the omental infarction, such as adhesions or hernias in our patient, the condition was considered as primary omental torsion.
No characteristic or specific signs or symptoms of omental torsion exist, whether primary or secondary. The cardinal feature of omental torsion is abdominal pain of sudden onset and short duration (24 to 48 h), which is constant, nonradiating, and gradually increasing in severity. The location of the pain may vary depending on which side the omental torsion is on, occasionally occurring on a side, or confined to a single quadrant (usually the lower right quadrant). Gastrointestinal symptoms, such as nausea, anorexia, and vomiting, are uncommon. Usually a mild fever is present, and white blood cell count, erythrocyte sedimentation rate, and C-reactive protein may be elevated. Other possible suspected diagnoses, include acute appendicitis, acute cholecystitis, or viscous perforation, and the final diagnosis is made during the surgical procedure in the majority of cases. The appendix and gallbladder are usually found to be normal at the time of surgical exploration, and it should be stressed that careful exploration of the whole abdominal cavity should be performed.
Because the clinical findings are not specific, CT findings of omental torsion should be searched for an accurate diagnosis. With segmental torsion of the omentum, the differentiation between primary infarction and infarction caused by torsion is impossible on the basis of radiographic studies. Imaging findings may be similar to those of epiploic appendicitis, abdominal pannuculitis, and focal necrosis due to pancreatitis. A helpful distinguishing sign for epiploic appendicitis is its location anterior or anterolateral to the ascending, descending, or sigmoid colon, while omental lesions are usually located medial to the ascending or descending colon. The key to the diagnosis of omental torsion is the presence of a characteristic concentric linear strand. This important radiological sign is not present in other omental diseases. With the characteristic CT findings of our patient, the preoperative diagnosis was consistent with the final operative picture.
Diagnosis can be made and resection performed using laparoscopic techniques.9 The advantages of the use of laparoscopy include complete examination of the abdominal cavity to confirm the diagnosis, aspiration and washing of the peritoneum, and decreased postoperative pain and wound-related complications. In the present case, therapeutic laparoscopy was also achieved. Resection of the necrotic omentum with the ultrasonic dissection device was performed successfully. Nonoperative management can be preferred in patients who are hemodynamically stable and have radiological signs of torsion of the omentum in the preoperative period, unless acute abdomen exists.