Left-Sided Persistent Superior Vena Cava with Superior Hemiazygos Arch

Area of Science:

• Anatomy
• Congenital Anomalies
• Cardiovascular System

Background:

• Persistent Left-side Superior Vena Cava (PLSVC) is a congenital anomaly of the superior vena cava.
• Typically, PLSVC drains into the right atrium via the coronary sinus without significant hemodynamic impact.
• Rarely, drainage into the left atrium or pulmonary veins can cause a right-to-left shunt.

Observation:

• A unique PLSVC variation was identified during routine undergraduate dissection.
• The PLSVC formed from the left subclavian and left internal jugular veins, draining into the right atrium via an enlarged coronary sinus ostium.
• This anomalous vein received the left hemiazygos vein and had a communicating vessel with the right superior vena cava.

Findings:

• Detailed anatomical description of an unusual PLSVC drainage pattern.
• Identification of a large coronary sinus ostium as a potential diagnostic indicator for PLSVC.
• Presence of a communicating vein between the right and persistent left superior vena cava.

Implications:

• Understanding such anatomical variations is crucial for interventional procedures involving the right atrium, especially via the left subclavian approach.
• Transthoracic echocardiography findings, such as a large coronary sinus ostium, should prompt consideration of PLSVC.
• This case underscores the importance of detailed anatomical knowledge for safe and effective cardiovascular interventions.