This case study details an urgent and complex intervention involving Right Ventricular Outflow Tract (RVOT) stenting in a 2-month-old infant with Tricuspid Atresia IB, severe cyanosis, and hemodynamic instability.
Case Summary
A 2-month-old male infant presented to the cardiac emergency department in a critical state, exhibiting severe cyanosis and hemodynamic instability, with an alarming oxygen saturation of 30%. He was also febrile and diagnosed with sepsis. Initial screening echocardiography revealed Tricuspid Atresia IB with an extremely restricted bulboventricular foramen. No additional ventricular septal defect (VSD) was observed. While tiny collateral vessels were noted, a patent ductus arteriosus (PDA) was absent. A subsequent CT angiography confirmed the absence of a PDA and showed hypoplastic branch pulmonary arteries. The child’s condition rapidly deteriorated, leading to collapse.
Diagnosis
The primary diagnosis was Tricuspid Atresia IB. This is a congenital heart defect where the tricuspid valve is absent, leading to a single ventricle circulation. In Type IB, this typically implies a restrictive bulboventricular foramen with no VSD.
A critical component of his diagnosis was an extremely restricted bulboventricular foramen, which is a severe narrowing of the connection between the single ventricle and the outflow tract, significantly impeding pulmonary blood flow.
The absent PDA and hypoplastic branch pulmonary arteries further compounded the lack of pulmonary blood flow, leading to profound hypoxemia.
The acute complications observed were severe cyanosis, hemodynamic instability, and sepsis, all resulting from the profound hypoxemia and systemic infection.
Line of Treatment
Given the child’s critical condition and collapse, an urgent cardiac catheterization was performed. The initial intent was to open a closed ductus arteriosus and perform ductal stenting. However, despite repeated attempts, the duct could not be recanalized.
The strategy was then shifted to:
- Retrograde RVOT Crossing: The Right Ventricular Outflow Tract (RVOT) was successfully crossed retrogradely from the aorta, traversing through the left ventricle (LV) and an additional apical VSD. Crucially, the bulboventricular foramen was left intact to preserve its function.
- RVOT Stenting: A 5 x 23 mm coronary stent was meticulously deployed in the RVOT, extending from the additional VSD to just below the pulmonary valve. This procedure aimed to create a stable, unobstructed pathway for pulmonary blood flow, thereby improving oxygenation.
Results
Following the RVOT stenting, the child’s oxygen saturation significantly improved, rising to 85%. This dramatic increase indicated successful palliation of the severe cyanosis. The patient was discharged from the hospital after a remarkably short stay of 2 days, demonstrating the immediate and profound impact of the intervention on stabilizing his condition and improving his prognosis.