Observations on some additional abnormalities in situs inversus viscerum.

The abnormal findings in a case of Situs inversus totalis are described. The duodenum was placed abnormally and retained its primitive mesentery. The proximal 22 in of jejunum were retroperitoneal. The attachment of the root of the mesentery to the posterior abdominal wall had a 7-shaped appearance, and there was a partial failure of the primitive mesocolon to adhere to the posterior abdominal wall. The common hepatic artery arose from the superior meseneric artery, which also provided a branch to the proximal jejunal loop. The right vagus nerve was found anterior to the oesophagus at the oesophageal hiatus in the diaphragm, and the left vagus was posterior. A double ureter was present on the right side. The findings are discussed in relation to mid-gut development.