Overview:

INTRO:
Congenital heart disease remains the most common among birth defects, with prevalence estimated at 9.4 per 1000 live births. The majority of these lesions are mild or isolated defects. However, approximately 3% of affected infants will have left ventricular outflow tract obstruction, and a similar number will have total anomalous pulmonary venous return. These defects are fatal without surgical intervention, and successful single ventricle palliation depends on an adequate pulmonary circuit. Here, we present a case of a neonate with hypoplastic left heart syndrome, total anomalous pulmonary venous return, tracheal rings, and extracardiac airway malformations.

CASE:
A 2.542 kg female neonate with a prenatal diagnosis of unbalanced right-dominant atrioventricular canal defect with intact atrial septum and abnormal pulmonary venous return was born via uncomplicated spontaneous vaginal delivery. By 2 hours of life, the infant developed respiratory distress and bradycardic arrest. She was emergently taken for cardiac catheterization where she was found to have obstructed pulmonary venous return with a highly tortuous decompressing vein draining to the coronary sinus. Multiple attempts at balloon atrial septostomy were unsuccessful in achieving adequate decompression, and she ultimately required placement of an interatrial stent with a hybrid surgical approach.

RESULTS:
Despite successful decompression of pulmonary venous return, the infant remained difficult to ventilate, prompting the anesthesia team to attempt re-intubation with significant resistance. Given ongoing difficulty, she underwent intra-operative bronchoscopy, which revealed tracheal stenosis with multiple complete tracheal rings inferior to the cricoid. Median sternotomy views during the hybrid case raised concern for congenital aplasia of the left bronchus and lung. 

Postoperatively, she was admitted to the pediatric cardiothoracic intensive care unit and maintained on vasoactive and inotropic support and prostaglandin E1 for her severely hypoplastic aortic arch. Congenital aplasia of the left bronchus and lung was confirmed by computed tomography. Her case was discussed in cardiothoracic surgical conference, and she was deemed a potential surgical candidate for hybrid Norwood palliation. However, given the constellation of low birth weight with single ventricle and single lung physiology, she was considered extremely high risk. Her respiratory status remained tenuous with multiple episodes of bronchospasm with respiratory and bradycardic arrests. Her family opted to transition to comfort care, and she died on day of life 8.  

CONCLUSIONS:
There are few reported cases of infants with hypoplastic left heart syndrome and total anomalous pulmonary venous return, and even fewer describing the constellation of multiple complex cardiac defects with tracheal rings and airway aplasia. This case highlights the importance of fetal diagnosis and advanced imaging to ascertain the degree of cardiac complexity as well as the extent of extracardiac anomalies further affecting morbidity and mortality. 

In summary, the triad of left outflow tract obstruction, pulmonary venous obstruction, and airway malformations poses a likely lethal constellation. Early detection in pregnancy, and thorough prenatal counseling are crucial in the first steps of management. Postnatally, advanced imaging also plays a key role in the decision-making process for complex congenital heart management and assists in further postnatal prognostication and family counseling.