Rare cases of bowel obstruction: internal hernias.
Internal hernias are a rare form of dislocation of the abdominal viscera, usually in the small intestine, in the peritoneal sacs or cavities, resulting from the defective coalescence of the peritoneal flaps due to abnormal rotation of the medium intestine in the second stage of embryogenesis. In this paper the authors describe three cases observed during the last twelve months: two cases were ascribable to left paraduodenal hernia and one to a transepiploic hernia. Special attention needs to be paid to knowledge of the rotation process of the primitive medium intestine and to understanding whether an internal hernia underlies the clinical picture, when occlusive patients have not previously undergone surgery and show no signs of external hernias. In the surgical treatment of paraduodenal hernias, special attention must be paid to incarcerated loops, in order to prevent severe vascular complications caused by potential lesions to the mesenteric vessels.