Left superior vena cava: cross-sectional imaging overview

Area of Science:

• Cardiovascular Anatomy
• Thoracic Imaging
• Embryology

Background:

• Persistent left-sided superior vena cava (PLSVC) is the most common thoracic venous anomaly, found in up to 0.5% of the general population and 10% of patients with congenital heart disease (CHD).
• While often asymptomatic and incidentally discovered, PLSVC can complicate cardiac procedures like catheter or pacemaker lead placement.
• Its prevalence is significantly higher in situs ambiguous (60-70%) compared to situs solitus or inversus.

Purpose of the Study:

• To review the embryological origins of PLSVC.
• To detail the anatomical course and various drainage pathways of PLSVC.
• To discuss the clinical significance of PLSVC, particularly its association with CHD and viscero-atrial situs.

Main Methods:

• Review of existing literature on persistent left-sided superior vena cava.
• Analysis of anatomical variations and drainage patterns.
• Correlation of PLSVC with congenital heart disease and situs abnormalities.

Main Results:

• PLSVC typically drains into the right atrium via the coronary sinus (CS), but drainage can vary, especially in situs ambiguous.
• Shunting typically does not occur unless PLSVC is associated with an unroofed CS or drains directly into the left atrium.
• Increased use of CT and MRI has led to more frequent detection of PLSVC.

Conclusions:

• PLSVC is a significant venous anomaly with implications for cardiovascular surgery and patient management.
• Understanding its embryology and anatomical variations is essential for accurate diagnosis and treatment planning.
• The association between PLSVC, CHD, and situs abnormalities requires careful consideration in clinical practice.