Definition
In medicine, a volvulus is a rotation of a section of the digestive tract around its own axis. The rotation causes the blood vessels supplying the affected section to be pinched, thus reducing or completely interrupting the supply of oxygen. The consequences can range from intestinal obstruction to the death of the affected area (intestinal gangrene).
Frequency
The appendix, the caecum, and the posterior part of the colon, the sigmoid colon, are most frequently affected by intestinal twisting. In the small intestine, the volvulus is usually caused by a disturbance in the rotation of the small and large intestine during embryonic development, the so-called malrotation. Its frequency is 1:500 live births and occurs twice as frequently in boys.
Connection to the ileus
An ileus is colloquially called an intestinal obstruction. The intestinal obstruction disrupts the natural passage of the bowel. It is provoked either by a mechanical obstruction (mechanical ileus) or by intestinal paralysis (paralytic ileus).
The ileus caused by a volvulus is a typical mechanical intestinal obstruction. It leads to severe, usually sudden abdominal pain. Depending on the height of the intestinal obstruction, the ileus is the first to be noticed by vomiting or lack of stool.
When listening to the abdomen, the ileus presents itself through a volvulus with typical so-called elevated bowel sounds. In the X-ray abdomen overview a typical mirror image is impressive. The intestinal loops are also over-inflated.
In sonography, the mechanical ileus through a volvulus is characterized by a typical pendulum peristalsis. The intestine works against the twisting, which disturbs the natural peristalsis. The movement of the intestine is then returned in the opposite direction. In the case of a mechanical ileus, surgery is usually indispensable to prevent the intestinal loops from dying off.
Causes
The most common and well-known cause of volvulus is malrotation, i.e. an incorrect intestinal rotation during embryonic development. Inflammations of the intestine can also lead to the volvulus, these can be caused by bacteria, chemicals, allergies or radiation. Another possible trigger is intestinal cancer or adhesions in the intestine. After a perforated appendicitis, so-called bridging lesions (these are adhesions of connective tissue that have arisen in the course of an operation) can occur, which can also promote the appearance of a volvulus. People suffering from the hereditary disease cystic fibrosis also have a higher risk of getting a volvulus because the tough intestinal contents cannot be transported sufficiently.