Mitral and aortic atresia associated with hypoplastic right lung, crossover segment of right lower lobe, and anomalous scimitar-like right pulmonary venous connection with inferior vena cava: clinical, angiocardiographic, and autopsy findings in a rare case

Fetal Diagnosis of Scimitar Syndrome in the Presence of Complex Congenital Heart Disease

Fetal diagnosis of scimitar syndrome requires a high index of suspicion. We present two fetal cases of complex congenital heart disease associated with scimitar syndrome, one of them is diagnosed with scimitar syndrome in utero. We emphasize prenatal echocardiographic findings that may assist with arriving at the correct prenatal diagnosis. We also discuss potential challenges in suspecting the presence of scimitar syndrome in utero. The postnatal echocardiographic findings and course are described for both patients. We reviewed the available literature on prenatal diagnosis of scimitar syndrome in the presence of complex congenital heart disease. We describe a new association of VACTERL, imperforate anus, scimitar syndrome, and double-outlet right ventricle all on the same patient, as well as the first prenatal diagnosis of scimitar syndrome associated with hypoplastic left heart syndrome with restrictive atrial septum. Advanced imaging modalities such as a fetal lung Magnetic Resonance Imaging is suggested as a confirmatory test when scimitar syndrome is suspected in utero in the presence of complex congenital heart disease.

Upper terminal of the inferior vena cava and development of the heart atriums: a study using human embryos

In the embryonic heart, the primitive atrium is considered to receive the bilateral sinus horns including the upper terminal of the inferior vena cava (IVC). To reveal topographical anatomy of the embryonic venous pole of the heart, we examined horizontal serial paraffin sections of 15 human embryos with crown-rump length 9-31 mm, corresponding to a gestational age of 6-7 weeks or Carnegie stage 14-16. The IVC was often fixed to the developing right pulmonary vein by a mesentery-like fibrous tissue. Rather than the terminal portion of the future superior vena cava, the IVC contributed to form a right-sided atrial lumen at the stage. The sinus venosus or its left horn communicated with the IVC in earlier specimens, but in later specimens, the left atrium extended caudally to separate the sinus and IVC. In contrast, the right atrium consistently extended far caudally, even below the sinus horn, along the IVC. A small (or large) attachment between the left (or right) atrium and IVC in adult hearts seemed to be derived from the left (or right) sinus valve. This hypothesis did not contradict with the incorporation theory of the sinus valves into the atrial wall. Variations in topographical anatomy around the IVC, especially of the sinus valves, might not always depend on the stages but partly in individual differences.

Hypoplastic left heart syndrome in PAGOD syndrome

Chromosomal abnormalities as well as non-cardiac anomalies have been identified as independent risk factors for surgical morbidity and mortality in Fontan palliation. The combination of malformations consisting of pulmonary hypoplasia, agonadism (sex reversal), omphalocele, and diaphragmatic defect is compatible with pulmonary artery and lung hypoplasia, agonadism, omphalocele, and diaphragmatic defect (PAGOD). Most cases have been associated with cardiac disease, particularly hypoplastic left heart syndrome (HLHS) that is potentially destined for Fontan palliation. Reported herein is the case of a Japanese female infant diagnosed with PAGOD syndrome along with HLHS (mitral atresia and aortic atresia), in whom intractable respiratory failure manifested as bilateral eventration of the diaphragm and presumed right lung hypoplasia. These characteristic pulmonary lesions associated with the syndrome precluded use of the Fontan pathway.

Hypoplastic left heart associated with scimitar syndrome

A child with the unique combination of hypoplastic left heart syndrome (HLHS) and scimitar syndrome is presented. Her HLHS was diagnosed in utero, and her scimitar syndrome was discovered during her immediate newborn period. She underwent a successful Norwood operation complicated by supraventricular tachycardia given her Wolf-Parkinson-White syndrome. She has also undergone successful Glenn shunt and at this writing is thriving.