Fig. 1

Enhanced computed tomography before the first surgery. Transverse section (a) and coronary section (b) images show the enlarged transverse colon (T) with an obstructed point at the splenic flexure with a whirlpool sign (yellow arrow). The ascending colon (A), transverse colon (T), and descending colon (D) were located on the left side of the abdominal cavity, and the small intestine (SI) was located on the other side. The cecum (C) inhabited the pelvic cavity. The superior mesenteric artery (red arrow) was located on the right side of the superior mesenteric vein (blue arrow). The duodenum did not cross the vertebral column but traveled down straight (red circle). The drainage veins were dilated, but there were no signs of ischemia. c and d illustrate the gastrointestinal tract of nonrotation and volvulus at the transverse colon before surgery