Left inferior pulmonary vein

At a glance

English

Left inferior pulmonary vein

Latin (TA2)

Vena pulmonalis sinistra inferior

System

Vein

Region

Trunk

Side

Single, on the midline

About the left inferior pulmonary vein

The left inferior pulmonary vein drains the lower lobe of the left lung and carries its oxygenated blood to the left atrium. It is a valveless vessel, as are all the pulmonary veins.

Its tributaries within the lobe run between the segments. The superior segment, at the top of the lower lobe, is drained by a superior vein, while the basal segments that rest on the diaphragm are drained by superior and inferior basal veins that join to form a common basal vein. The superior vein and the common basal vein then unite near the hilum.

At the hilum this is the lowest of the main structures. It lies at the upper end of the pulmonary ligament, the double fold of pleura that hangs down from the lung root, and so it is the first large vessel met when that ligament is divided from below. It runs medially in front of the descending thoracic aorta and enters the posterior part of the left atrium, below the left superior pulmonary vein. The oesophagus lies close behind the left atrium in this region.

In catheter ablation for atrial fibrillation the left inferior vein is isolated together with the other pulmonary veins, since the sleeves of atrial muscle that extend into the veins can fire abnormal beats. Narrowing of a vein after ablation is a recognised complication. During lower lobectomy the surgeon divides the pulmonary ligament to reach the vein safely; the left two pulmonary veins sometimes form a common trunk before entering the atrium, which must be recognised before the vessel is tied.

Course and drainage

Begins at

Formed at the hilum by the superior vein and the common basal vein of the left lower lobe.

Drains into

Enters the posterior part of the left atrium below the left superior pulmonary vein.

Drains

Returns oxygenated blood from the left lower lobe to the heart.