Variations Of Pulmonary Veins And Their Clinical Relevance

Abstract

Variations of pulmonary veins (PV) were previously considered rare, only documented as isolated case reports. Recent cadaveric, autopsy, CT, MDCT and MRI studies have revealed substantial variations with respect to their number and drainage pattern into the left atrium (Marom et al., 2004; Calkins et al., 2007; Wannasopha et al., 2012; Harbi et al., 2014; Rajguru and Fulzele, 2016). The most commonly described variations include supernumerary or less pulmonary veins and the corresponding arterial ostia. The article in this issue (Kinfemichael and Dawit, 2016) presents a case of 5th pulmonary vein originating from the middle lobe of the right lung. This is consistent with previous reports of supernumerary pulmonary veins and ostia (Marom et al., 2004; Calkins et al., 2007; Prasanna et al., 2014). These vary from 2 – 7 (Wei et al., 2014; Yuan et al., 2015; Rajguru and Fulzele, 2016; Kumzel – Piotrowska et al., 2016). The commonest cause of such variations is the right middle pulmonary vein (Calkins et al., 2007; Klimek – Piotrowska et al., 2016). These variations have informed various classifications based on number of pulmonary veins and ostia (Marom et al., 2004). One of the most straight forward classifications was proposed by Shukla et al (2012). The principle of this classification in the table below may be extended to include, say type VI or VII depending on the number of veins.