Heterotaxy Syndrome

Left Atrial Isomerism (Polysplenia)

  • Etiology: Congenital
  • Imaging cardiac abnormalities (less severe): Aortic stenosis, atrial septal defect, ventricular septal defect
  • Imaging vascular abnormalities: Bilateral atrial connection of pulmonary veins, inferior vena cava interruption
  • Imaging pulmonary abnormalities: Bilateral hyparterial bronchus (bronchus is anterio-inferior to pulmonary artery) and bilateral bilobed lungs
  • Imaging gastrointestinal abnormalities: Polysplenia, midline liver, stomach on either side, bowel rotation, biliary atresia
  • DDX:
  • Complications:
  • Treatment:
  • Clinical: Less severe congenital heart disease, presents later, associated with biliary atresia

Right Atrial Isomerism (Asplenia)

  • Etiology: Congenital
  • Imaging cardiac abnormalities (more severe): Atrioventricular canal defect, double inlet left ventricle, double outlet right ventricle, absent coronary sinus
  • Imaging vascular abnormalities: Totally anomalous pulmonary venous return is always present and 50% is extracardiac, discordant ventriculoarterial connections, pulmonary atresia, pulmonary stenosis, normal inferior vena cava
  • Imaging pulmonary abnormalities: Bilateral eparterial bronchus (bronchus is posterio-superior to pulmonary artery) and bilateral trilobed lungs
  • Imaging gastrointestinal abnormalities: Asplenia, midline or right side liver, abnormal bowel rotation in 70%
  • DDX:
  • Complications:
  • Treatment:
  • Clinical: Severe cyanosis, more severe congenital heart disease and thus worse prognosis, susceptible to infection

Radiology Cases of Heterotaxy Syndrome

Radiology Cases of Heterotaxy Syndrome – Malrotation Without Midgut Volvulus

Upper GI of malrotation without midgut volvulus in heterotaxy
AP image from an upper GI shows the ligament of Treitz to be in the right upper quadrant. There is no evidence of duodenal obstruction. The proximal jejunum is also in the right upper quadrant. There is also gastroesophageal reflux.
CXR of heterotaxy syndrome and upper GI of malrotation without midgut volvulus
CXR AP (above) shows the cardiac apex to be in the right hemithorax and the gastric bubble to be in the left upper quadrant. AP image from an upper GI (below) shows the ligament of Treitz to be in the right upper quadrant. There is no evidence of duodenal obstruction. The proximal jejunum is also in the right upper quadrant.
US and upper GI of malrotation without midgut volvulus in heterotaxy syndrome
Transverse color doppler US of the abdomen (below left) shows an apparent reversal of the normal positions of the superior mesenteric artery and superior mesenteric vein. This is confirmed on the spectral doppler US of the aforementioned mesenteric vessels (above). AP image from an upper GI exam (below right) shows situs inversus with levocardia and the stomach in the right upper quadrant. The duodenum is redundant and the duodenal jejunal junction is over the right pedicle of the T11 vertebral body. The cecum was in the midline.
AXR of lower extremity peripherally inserted central catheter / PICC in a left-sided inferior vena cava in a patient with situs inversus
AXR AP shows a left lower extremity PICC and a right femoral venous catheter both of whose tips project over a left-sided inferior vena cava. An umbilical venous catheter tip projects over the ductus venosus. An umbilical arterial catheter tip projects at the level of T9. Nasogastric tube tip projects over the stomach in the right upper quadrant. Feeding tube tip projects transpylorically over the duodenal bulb. The cardiac apex is in the right chest.

Radiology Cases of Heterotaxy Syndrome – Azygous Continuation of the Inferior Vena Cava in Left Atrial Isomerism

CT of azygous continuation of the inferior vena cava
Contiguous axial CT with contrast of the abdomen show a dilated azygous vein to the right of the aorta (above left, above right, below left). The liver is on the left side of the abdomen and the spleen is on the right side of the abdomen (below right).