Small bowel volvulus

Case contributed by Hoe Han Guan


Sudden onset of abdominal pain, vomiting and constipation. History of total abdominal hysterectomy for non-malignant menorrhagia.

Patient Data

Age: 90 years
Gender: Female

Small bowel loops dilatation (identified to be small bowel loops in view of the central location and the presence of valvulae conniventes). The large bowel loops are not dilated.
No pneumoperitoneum.

Severe osteoarthritic changes noted at the left hip joint. Mild lumbar scoliosis.


Stomach, duodenum, jejunum and most of the ileum are dilated and fluid-filled, with abrupt transition at distal ileum located in the suprapubic region. Whirl sign present with swirling appearance of vessels at the small bowel mesentery. Short segment of radially distributed dilated mushroom shaped / U shaped loops seen near to the transition point where mesenteric edema seen. Double-beak sign at the transition point. This abnormally shaped distal ileum has reduced bowel wall and mucosal enhancement compared to the rest of bowel loops.

The distal bowel loops (short segment of distal ileum and large bowel loops) are collapsed.
No pneumoperitoneum, intramural gas or portal venous gas. Minimal ascites.

Incidental finding of L4 vertebral plana with generalized osteopenic bone.

Case Discussion

Typical appearance of small bowel volvulus / closed loop obstruction due to adhesion band at the transition point.

Intraoperatively, multiple adhesion bands surrounding the volvulus segment (twisted x2) to pelvic region. Adhesiolysis performed. 20cm segment of distal ileum was ischemic and in view of impending perforation this was resected with primary bowel anastomosis.

Therefore, it is important to scrutinise the CT images in different planar views (axial and coronal, sometimes sagittal views) in order to identify the transition point and possible whirl sign. 

Signs of bowel ischemia should be assessed and mentioned in all cases of bowel obstruction, including intramural gas, portal venous gas , pneumoperitoneum and free fluid. As if there is evidence of bowel ischemia and impending bowel ischemia (reduced bowel wall/mucosal enhancement), the reporting radiologist should inform the surgeon immediately and emergency laparotomy is usually warranted.

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