Intestinal malrotation in patients with situs anomaly: Implication of the relative positions of the superior mesenteric artery and vein

Eur J Radiol. 2016 Oct;85(10):1695-1700. doi: 10.1016/j.ejrad.2016.07.013. Epub 2016 Jul 20.


Purpose: To assess the usefulness of the relative position of the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) in diagnosing intestinal malrotation in situs anomaly.

Materials and methods: From January 2004 to April 2015, 33 patients with situs anomalies were enrolled in this study who underwent abdominal USG, CT or MRI as well as upper gastrointestinal series (UGIS) or surgery: situs inversus (n=16), left isomerism (n=10), and right isomerism (n=7); age 21.2±23.2years (mean±standard deviation), range 0-72 years. The intestinal malrotation was confirmed with UGIS and/or operation in 16 patients. Relative positions of the SMV to the SMA were classified into four groups by reviewing abdominal USG, CT, or MRI: right sided, left sided, ventral sided, and dorsal sided. The incidence of malrotation was analyzed for each group.

Results: In 16 patients with situs inversus, there was reversed SMA-SMV relationship: left sided (n=11) or ventral sided (n=5). One situs inversus patient with ventral sided SMV had intestinal malrotation (6.25%). 17 patients with situs ambiguus showed various SMA-SMV relationships (ventral sided, n=7; left sided, n=5; right sided, n=4; dorsal sided, n=1). Among them, 15 patients (88.2%) had intestinal malrotation. Two patients with normal rotation had either right sided or dorsal sided SMV.

Conclusion: Situs ambiguus was commonly associated with intestinal malrotation with a variable SMA-SMV relationship. Reversal of the mesenteric vascular relationship was observed in situs inversus with normal rotation, not excluding the possibility of intestinal malrotation.

Keywords: Heterotaxy syndrome; Intestinal malrotation; Intestinal volvulus; Situs ambiguus; Superior mesenteric artery.

MeSH terms

  • Adult
  • Aged
  • Digestive System Abnormalities / diagnostic imaging*
  • Digestive System Abnormalities / pathology
  • Female
  • Humans
  • Intestinal Volvulus / diagnostic imaging*
  • Intestinal Volvulus / pathology
  • Magnetic Resonance Imaging*
  • Male
  • Mesenteric Artery, Superior / abnormalities
  • Mesenteric Artery, Superior / diagnostic imaging*
  • Mesenteric Veins / abnormalities
  • Mesenteric Veins / diagnostic imaging*
  • Middle Aged
  • Prospective Studies
  • Radiography*
  • Reproducibility of Results
  • Rotation
  • Situs Inversus / diagnostic imaging*
  • Situs Inversus / pathology
  • Ultrasonography*

Supplementary concepts

  • Volvulus Of Midgut