Prevalence and Clinical Significance of Pulmonary Venous Orifice Variants

Abstract

Background: Awareness of pulmonary venous anatomy and variants is essential for diagnostic and interventional cardiology, especially in the scenario of atrial fibrillation ablation and cardiothoracic surgery. Even though the classical type of four discrete pulmonary venous orifices is the most prevalent, many anatomical variations have been described that could influence clinical results. Objective: To evaluate the prevalence, morphology, and clinical implications of pulmonary venous orifice variants by imaging-based analysis in a regional patient population. Methodology: A total of 65 patients were assessed to determine normal anatomy and variant patterns of pulmonary venous drainage. Variants examined were accessory pulmonary veins, common ostia, anomalous pulmonary venous return (PAPVR), and rare orifice anomalies. Prevalence rates were determined and contrasted with prior published studies. Data was analyzed using SPSS version 26. Results: Normal anatomy with four discrete pulmonary venous orifices was found in 66.2% of patients. Variants were identified in 33.8% of cases, with accessory pulmonary veins (18.5%), the most frequent being the right middle pulmonary vein; common ostium formations (10.8%), with a predominance involving the left superior and inferior veins; partial anomalous pulmonary venous return (3.1%), with drainage into the superior vena cava and brachiocephalic vein; and one rare case (1.5%) of missing left inferior pulmonary vein orifice with fusion into the left superior pulmonary vein. Conclusion: Pulmonary venous orifice variants are common and clinically relevant, with the right middle pulmonary vein and left common ostium being the most prevalent. Identification of these variants is necessary for proper imaging interpretation, secure operative planning, and successful catheter ablation procedures to prevent complications and recurrence of atrial arrhythmias.