This case study details the critical intervention of Left Ventricular Outflow Tract (LVOT) stenting in a 3-month-old infant with Tricuspid Atresia IIB and an absent Patent Ductus Arteriosus (PDA), successfully alleviating severe cyanosis.
Case Summary
A 3-month-old infant, previously diagnosed with Tricuspid Atresia IIB, was admitted presenting with profound and acute cyanosis. The child exhibited “gasping respiration” and was visibly “extremely blue,” indicating severe oxygen deprivation. Comprehensive screening echocardiography confirmed the diagnosis of Tricuspid Atresia IIB and, critically, revealed an absent Patent Ductus Arteriosus (PDA). Further assessment noted only a “trickle of flow” across the Left Ventricular Outflow Tract (LVOT), highlighting the severely compromised pulmonary blood flow.
Diagnosis
The primary diagnosis was Tricuspid Atresia IIB. This is a complex congenital heart defect where the tricuspid valve, which normally separates the right atrium from the right ventricle, is absent or abnormally formed. In Type IIB, this is typically associated with a ventricular septal defect (VSD) and pulmonary stenosis or atresia. The consequence is that systemic venous blood cannot enter the right ventricle, instead shunting to the left side of the heart, leading to mixed blood circulation and cyanosis.
A key contributing factor to the child’s severe presentation was the absent Patent Ductus Arteriosus (PDA). The PDA is a vital fetal vessel that normally closes shortly after birth. In infants with certain congenital heart defects like Tricuspid Atresia, a patent PDA is crucial for maintaining pulmonary blood flow. Its absence meant that the only source of pulmonary blood flow was the inadequate “trickle” across the LVOT.
The combined effect of these anatomical anomalies led to severe cyanosis, a critical condition resulting from insufficient oxygenated blood reaching the systemic circulation due to inadequate pulmonary blood flow.
Line of Treatment
Given the life-threatening severe cyanosis and the absence of a PDA to provide pulmonary blood flow, the immediate decision was made to stent the Left Ventricular Outflow Tract (LVOT) to augment the pulmonary blood flow. This intervention aimed to create a more stable and adequate pathway for blood to reach the lungs for oxygenation.
The procedure involved:
- Antegrade LVOT Stenting: The LVOT was stented using an antegrade approach, meaning the stent was advanced in the direction of normal blood flow. This was achieved by crossing a Patent Foramen Ovale (PFO), which provided access from the right side of the heart to the left, and subsequently to the LVOT and pulmonary circulation.
- Coronary Stent Utilization: A standard coronary stent was selected and deployed for this purpose, demonstrating its versatility in pediatric cardiac interventions.
Results
The intervention yielded immediate and positive results. Post-stenting, the child’s oxygen saturation significantly improved, rising to 80%. This increase in saturation indicated successful palliation of the severe cyanosis, demonstrating that the LVOT stenting effectively augmented pulmonary blood flow and improved oxygen delivery to the body. This critical intervention provided immediate relief and stabilized the child’s condition, allowing for further management and planning of future staged procedures typical for univentricular hearts.