Physical Address

304 North Cardinal St.
Dorchester Center, MA 02124

Heterotaxy Syndromes


KEY FACTS

Terminology

  • Disturbance of normal left-right asymmetry in position of thoracic & abdominal organs; typically described in terms of right atrial isomerism vs. left atrial isomerism

Imaging

  • Best diagnostic clue: Abnormal symmetry in chest & abdomen

  • Classic radiographic appearance: Transverse midline liver, discrepancy between position of cardiac apex & stomach, bilateral left- or right-sidedness in chest, cardiomegaly or other findings of congenital heart disease

  • Echo: Initial characterization of intracardiac anomalies & abnormal systemic &/or pulmonary venous connections

  • Multiplanar MR for segmental analysis of intracardiac connections & defects

  • CTA: Rapid examination of chest & abdomen for abnormalities of situs, systemic & pulmonary venous connections, tracheobronchial anatomy

  • Upper GI study: Malrotation frequently associated

  • Best imaging tools: Echocardiography, followed by MR

Pathology

  • Any arrangement other than situs solitus or inversus is termed situs ambiguous

  • Heterotaxy syndrome represents spectrum with overlap between classic asplenia & polysplenia manifestations & other anomalies

Clinical Issues

  • Asplenia

    • Neonate with severe cyanosis, susceptibility for infections, severe congenital heart disease

  • Polysplenia

    • Less severe cardiac disease (i.e., systemic venous malformations, atrial septal defect); often presents later

  • 1st year mortality: 85% asplenia, 65% polysplenia

PA chest radiograph demonstrates a left-sided cardiac apex
, a left-sided aortic arch
, & a right-sided stomach bubble
in this patient with situs ambiguous.

Axial CECT through the upper abdomen in a child with heterotaxy shows a right-sided stomach
& multiple spleens
. An enlarged azygous vein is noted
but no intrahepatic inferior vena cava (IVC) is visualized, consistent with azygous continuation of the IVC.

Axial CECT through the upper abdomen in a child with heterotaxy demonstrates a midline liver
, a left-sided stomach
, multiple spleens
, & an enlarged azygous vein
without an intrahepatic IVC, consistent with azygous continuation of the IVC.

Coronal CTA shows symmetric bilateral eparterial bronchi
above the visualized pulmonary arteries
, consistent with right isomerism. The bronchi both have a configuration typical of right main bronchi.

TERMINOLOGY

Synonyms

  • Situs ambiguous, right/left isomerism

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here

Related Posts