Gastric bypass with unknown intestinal malrotation: Required attitude

Intestinal malrotations are rare and may be asymptomatic until adulthood. There are only a few descriptions of gastric bypass with intestinal malrotation. If the duodenojejunal angle is not correctly seen, as is generally the case, there is a risk of creating an antiperistaltic anastomosis.

We describe required attitude and cases of gastric bypass performed on two patients who had a complete common mesentery. In both of our patients, the transverse colon was not running across the abdomen and the duodenojejunal angle was "absent". We therefore looked for the caecum in order to unravel all of the small intestine. We were able to carry out Roux en Y gas- 42 tric bypass with uncomplicated post-operative courses for both 43 patients. The result in weight loss was perfect and identical to that of patients without anatomical abnormality.

In our cases, ultrasound to investigate for gallstones did not provide a pre-operative diagnosis. It is extremely difficult to investigate for the mesenteric vessels by ultrasound in obese patients and for this reason the finding was not made preoperatively. The most important thing to do is make the diagnosis of malrotation preoperatively. For this reason the golden rule in performing a gastric bypass is to clearly visualise the duodenojejunal angle which allows an unknown bowel malrotation to be identified. Following these cases, the study of the oeso-gastro-jejeunal transit is now part of our pre-operative assessment.

Bariatric surgeons need to be aware of these abnormalities. If a common mesentery is present the gastric bypass can still be performed.