Variation in Number and Drainage Pattern of Pulmonary Veins Draining into the Left Atrium

Pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart. The variation in the number and drainage pattern of pulmonary veins is frequent and this knowledge is valuable for various procedures involving the pulmonary veins. The present study is done on 29 hearts obtained from formalin fixed cadavers from the dissecting room of department of anatomy, MAMC, Agroha, Hisar. The left atrium of these hearts was studied from external aspect for the number of pulmonary veins draining into left atrium and from internal aspect for the drainage pattern. In 13 out of 29 hearts (44.8%), variation in number of pulmonary vein was observed. In the present study the most common variation of right pulmonary veins is three veins with two ostia (10.3%) and the most common variation of left pulmonary veins is a single vein with a single ostium (17.2%).The variations of pulmonary veins are quite common with an equivocal variability in right-sided and left-sided drainage patterns. A classification is proposed to describe these variations to facilitate communication with referring clinicians.