Which procedure is performed in Stage II for hypoplastic left heart syndrome?

The Bidirectional Glenn or Hemi-Fontan procedure is specifically performed during Stage II for patients with hypoplastic left heart syndrome (HLHS). This stage typically occurs after the initial Norwood procedure, which is the Stage I operation.

In the context of HLHS, the Bidirectional Glenn procedure serves several vital functions. Primarily, it connects the superior vena cava directly to the right pulmonary artery, allowing unoxygenated blood from the upper body to flow to the lungs for oxygenation. This is essential for improving oxygen saturation levels in children who have undergone the Norwood procedure, as the heart and systemic circulation is still adapted to inadequate flow due to the anatomical abnormalities associated with HLHS.

By the time patients reach Stage II, the heart has undergone previous surgical interventions that allow for this direct connection, facilitating the transition toward a more stable circulation before the eventual Stage III procedure, which is the Fontan operation. This sequencing ensures that the child develops a functional single-ventricle physiology that can adequately support growth and long-term outcomes.

In contrast, other procedures listed, such as PDA ligation, typically are not connected directly to the surgical strategy for managing HLHS at this stage, as the focus shifts from maintaining pulmonary blood flow to optimizing the