In this case, what is the axis around which rotation has occurred?
The caecum has rotated around the caecal mesentery, which contains the ileocolic vessels.
What two underlying factors must be present in order for a caecal volvulus to occur?
Firstly there must be a developmental failure of peritoneal fixation, allowing the proximal colon to be free and mobile. This only occurs in 11 - 25% of the population. Secondly, there needs to be a restriction of the bowel at a fixed point within the abdomen that serves as a fulcrum for rotation, e.g. adhesion, abdominal mass, scarring from calcified lymph nodes.
What treatment options are available?
Colonoscopic decompression may be appropriate if the patient unfit for surgery. However, laparotomy is normally required. Where there is colonic ischaemia, a right hemicolectomy is performed; in some cases, a primary anastomosis is not possible and stoma formation at both ends is the safest option. In cases where the caecum is viable then fixation (caecopexy) is performed to avoid recurrence.
Scout view showing a markedly distended large bowel loop in the left side of the abdomen. CT demonstrates the large bowel mass is a grossly distended food-filled caecum that is not in the right iliac fossa but in the left side of the abdomen. The axial slices clearly show the ileum passing through a 360-degree rotation to enter the abnormally positioned caecum.