Left superior pulmonary vein
Vena pulmonalis sinistra superior
Definition
The left superior pulmonary vein is one of the four major pulmonary veins that drains oxygenated blood from the left upper lobe of the lung into the posterior wall of the left atrium. It typically has an oval-shaped ostium with a mean diameter of approximately 13.8-16.6 mm and is located in the superolateral aspect of the left atrium.
The left superior pulmonary vein originates from the confluence of venous tributaries draining the left upper lobe segments at the lung hilum:
It then courses medially toward the heart and It enters the left atrium through the posterosuperior wall, typically positioned more superiorly than the right pulmonary veins. The vein is anatomically separated from the left atrial appendage by the ligament of Marshall (Ligament of left superior vena cava), which is a triangular fold of pericardium that serves as an important anatomical landmark.
The left superior pulmonary vein has several distinctive anatomical features. It tends to have a longer distance from its ostium to the first-order branch (mean 15.1-17.6 mm) compared to the inferior pulmonary veins, and it typically has the smallest cross-sectional area and most flattened shape among the four major pulmonary veins. The vein enters the left atrium tangentially from lateral to medial direction, at a lesser angle than the right pulmonary veins.
In approximately 14% of individuals, the left superior and inferior pulmonary veins share a common ostium rather than entering separately, which represents the most common anatomical variant on the left side.
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