ASPLENIA

- IVERMARK’S SYNDROME

In asplenia, or bilateral right-sidedness, left sided organs are a mirror image or the normal right sided organs. This is also called right isomerism.

Liver	Usually midline and horizontal.
Stomach	Right or left sided.
Spleen	Absent.
Lungs	Bilateral trilobed lungs Bilateral right bronchi Bilateral right pulmonary arteries.
Heart	Two "right atria" Large atrial septal defect Single AV valve Single ventricle Large VSD Transposition of the great vessels Double outlet RV or pulmonary atresia Total or partial anomalous pulmonary venous return.
Great Vessels	Both aorta and IVC are on the same side (left or right) IVC is anterior to aorta and the hepatic veins enter the atrium independently from the IVC Bilateral SVC
Kidneys	Normal, cystic, dysplastic or fused.
Adrenal Glands	Normal, absent or fused in the midline Horseshoe adrenal (1).

Midline Liver Absent Spleen
Atrial Septal Defect
Small VSD on color doppler
Pulmonary stenosis with small RV chamber and endocardial fibroelastosis
Total Anomalous Pulmonary Venous Drainage - - Veins draining into IVC. Note the large hepatic veins Ascites present due to RV failure
Pathological Specimen – pulmonary veins draining into IVC
Right sided stomach Absent spleen. Aorta and IVC on same side. Midline central horizontal liver.

· More common in male fetuses.
* Few survive past the first few weeks or months of life.