Venous Drainage

Introduction

The pulmonary veins drain the lungs of the blood supplied by the pulmonary artery, and the bronchial veins drain the blood from the areas supplied by the bronchial artery. Whereas the pulmonary veins contain oxygenated blood the bronchial veins contain deoxygenated blood.  98-99% of the blood in the lungs is in the pulmonary arterial –venous circulation while the remaining blood is in the bronchial circulation.

The bronchial veins have a deep and a superficial system.  The deep bronchial veins drain either into the pulmonary veins or into the left atrium.  The superficial bronchial veins drain the extra pulmonary bronchi, visceral pleura, and hilar lymph nodes and drain into the azygous system on the right side and the superior intercostal vein or the hemiazygous system on the left.

Atelectasis, bronchiectasis, hyperinflation.

This normal anatomic specimen from a posterior aspect showing the LPA (1) and upper lobe pulmonary veins (2) and lower lobe pulmonary veins (3).  The two veins to one artery is the usual.  Venous inflow must of course equal arterial outflow and so each vein carries about half the load and are about half the size of the main branch pulmonary artery  Courtesy Ashley Davidoff MD. 06881labelled

Pulmonary Veins
In this coronally oriented CTA the lower lobe pulmonary veins can be seen traveling horizontally into the LA and below the pulmonary arteries. Courtesy Ashley Davidoff MD.   32807

 

Normal pulmonary veins.
This is a collage showing the CT appearance of the pulmonary veins as they converge onto the left atrium. Note the vertical course of the right superior (a) and left superior veins (b) in image 1, where they appear as rounded to ovoid structures. In image 6, the right inferior (c) and left inferior (d) are seen as tubular structures since their course is more horizontal.

Courtesy Ashley Davidoff MD 31662b3_1

There are usually 4 pulmonary veins.

They are the superior and inferior right pulmonary veins and the superior and inferior left pulmonary veins.

The right superior pulmonary vein drains the right upper and middle lobe. The two veins join to form the most anterior structure in the hilum.

The left superior pulmonary vein drains the left upper and lingular segments.

The inferior veins drain the lower lobes.

The veins are the shortest of the three major vessels originating in the hilum. The longest structures are the bronchi and second to them are the pulmonary arteries. This has implication in cross sectional imaging where all these structures converge. Therefore when the central areas are viewed there will be a single bronchus and artery, but usually two veins on either side. The upper veins will be anterior to the bronchus and artery and the lower veins will be posterior and inferior.

Normal pulmonary veins.
Surface rendering of the left atrium and pulmonary veins seen from the posterior apsect. Courtesy Ashley Davidoff MD 39704b01

Pulmonary Veins

34763 heart cardiac anatomy venous drainage pulmonaryveins left atrium LA LV left ventricle normal anatomy Davidoff MD

Normal pulmonary veins.

This series of MDCT demonstrates the pulmonary veins and the left atrium in coronal projection (a), and using virtual projections (b, c, d).  Courtesy Ashley Davidoff MD 37236c

 

Position of the veins

In the upper lobes lie lateral to the arteries, while in the lower lobes the veins lie horizontal and inferior to the pulmonary arteries

 

Applied Anatomy

Diseases of the pulmonary veins are most commonly secondary to left sided heart disease where an elevated left ventricular or left atrial pressure is reflected in the pulmonary veins.  There are a series of congenital anomalies of the pulmonary veins including partial and total anomalous venous return.

Congenital Pulmonary Venolobar Syndrome

This chest series are characterised by an abnormal curving vascular structure that appears to get larger as it approaches the diaphragm.  In addition, the volume of the right lung is smaller than the left, and there is an odd shape to the right hilum.  The findings are consistent with a diagnosis of congenital hypoplasia of the right lung associated wth partial anomalous venous return to the IVC below the diaphragm. (aka congenital pulmonary venolobar syndrome)  The curved  anomalous vein is known as the scimitar sign since it has the shape of a scimitar.

01714c03 Courtesy Ashley Davidoff MD

Total anomalous venous return (TAPVR) can occur with the final destination either above the diaphragm or below.  Sometimes, the TAPVR below the diaphragm connects to primitive venous origins of the hepatic circulation so that pulmonary venous return is to the sinusoids of the liver.  This condition as an untreated anomaly, cannot sustain life since the pressure of the oxygenated blood in the sinusoids is close to zero, and there is therefore no driving force to allow it to traverse the sinusoids.  Hence there is a functional obstruction.

 

Total anomalous pulmonary venous return below the diaphragm

This is an angiogram of total anomalous pulmonary venous return to the portal system below the diaphragm. The pulmonary venous return has to go through a second low pressure capillary system of the liver sinusoids before it can get back to the left sided circulation and therefore there is a functional obstruction, resulting in pulmonary venous congestion, and secondary pulmonary hypertension..  Courtesy Ashley Davidoff MD 07498

Pulmonary Veins

The Common Vein Copyright 2008

Principles

Structure

Single common vein during embryology (4th week gestation) incorporated into the left dorsal atrium with 70% of patients having 4 pulmonary veins left superior (LS) left inferior (LI) right superior (RS) and right inferior (RI) which usually accomodates the middle lobe vein).  The myocardium of the left atrium extends  over the pulmonary vein for 1-2cms.

Congenital anomalies occur when there is overincorporation or under incorportation

 

Pulmonary Veins and Left Atrium

77612b.3kb08.8s heart left atrium pulmonary veins red cells normal anatomy copyright 2009 all rights reserved Davidoff art

Size

SPV ostia larger

 ostia (cms)

 1cms from ostia (cms)

  RSPV

1.7 +/-.24 cms

 1.4 +/-.21 cms

 RIPV

 1.59+/- .25 cms

1.16  +/-.25 cms

 LSPV

 1.76 +/-.41 cms

1.45 +/-.32 cms

 LIPV

 1.39 +/- .29 cms

 1.23 +/-.24 cms

More commonly on left over incorporation

supernumeray R>L

Shape

Left pulmonary veins are oval ostia oval

Right pulmonary vein ostia are circular

Position

Usually right middle lobe vein drains into right superior vein in 70% directly into LA 20% and 5% intp RIPV

Lingula vein usually arises from the left superior pulmonary vein.

In 10-25% patients there is a single vein on one side.  This is more common on the left

LA and Pulmonary Veins from Posterior

The specimen of heart and lungs is examined from posteriorly with the left atrium and 4 pulmonary veins. (overlaid in pearl white) The trachea and bronchi are intact (green). The left atrium lies just below in the angle of the carina.

Courtesy Ashley Davidoff copyright 2009 all rights reserved 08376c02.82s

Posterior View

Veins and Arteries

This normal anatomic specimen from a posterior aspect showing the LPA (1) and upper lobe pulmonary veins (2) and lower lobe pulmonary veins (3) shows the left pulmonary veins (1) and left pulmonary artery. The two veins to one artery is the usual. Venous inflow must of course equal arterial outflow and so each vein carries about half the load and are about half the size of the main branch pulmonary artery

Courtesy Ashley Davidoff MD. 06881labelled

Anatomy of the Left Atrium

The anatomic spcimen has been opened from its posterior aspect revealing a relatively smooth walled inner lining. The left atrial appendage(laa) has been opened revealing fine pectinate muscles. 5 pulmonary veins are seen entering the left atrium, with 2 entering from the left lower vein. The atrial septum with fossa ovalis and foramen ovale are smooth except for the “u” shaped upper border of the septum primum tha allows identification of the left atrium. the glisteningsurface of the endothelium is exemplified in this image.

Courtesy Ashley Davidoff copyright 2009 all rights reserved  06426c01.81s

 Diagram od the Secondary Lobule

Veins and Lymphatics Travel Together

The arteries and airways pair up and travel together down the respiratory tree branching in exactly the same way until they reach the pulmonary lobule. The pulmonary lobule, also called the secondary lobule is a structural unit surrounded by a membrane of connective tissue, and it is smaller than a subsegment of lung but larger than an acinus. This diagram shows two secondary lobules lying side by side. The pulmonary arteriole (royal blue) and bronchiole (teal) are shown together in the centre of the lobule (“centrilobular”), with two other pairs of bronchovascular bundles, while the oxygenated pulmonary venules (red) and lymphatics (yellow) are peripheral and also form formidable and almost inseparable pairs. Courtesy Ashley Davidoff MD art code lung secondary lobule bronchovascular bundle centrilobular polyhedral drawing normal anatomy histology 42440b08

Secondary Lobule and Interlobular Septa

Normal lung histology This image is a panoramic view of the lung showing secondary lobules and interlobular septa. Within the interalveolar septae, one sees small venules and lymphatics.Courtesy Armando Fraire MD. 32649b code lung pulmonary alveoli alveolus secondary lobule interlobular septa vein lymphatic histology interstitium interstitial

Secondary Lobule and Interlobular Septa

Kerley B line

44194b01 81F hx atrial fibrillation cardiac failure heart failure CHF RA enlarged LA enlarged ground glass mosaic perfusion Kerley B lines varicose pulmonary veins squiggly sign Courtesy Ashley Davidoff MD

Venous Phase of the Pulmonary Angiogram Showing the Venous System

This is a normal venous phase of a digital pulmonary angiogram with arboristaion of the vessels almost from the venules to the upper vertically oriented veins and the lower horizontally oriented veins. Courtesy Ashley Davidoff MD.

CTscan with both Venous and Arterial Phases

This compounded CT of the chest shows the pulmonary vascular circulation including the the pulmonary veins draining into the left atrium. The pulmonary arteries can be seen in the background. Courtesy Philips Medical Systems 32653 code chest lung pulmonary vein LA RVOT infundibulum normal anatomy radiology imaging CTscan

Virtual Study Showing Entry of Pulmonary Veins into the LA

This series of MDCT demonstrates the pulmonary veins and the left atrium in coronal projection (a) , and using virtual projections (b,c,d). Courtesy Ashley Davidoff MD 37236C code CVS heart cardiac left atrium LA pulmonary vein virtual MDCT imaging radiology CTscan virtual CTscan

Applied Anatomy

Scimitar Syndrome

Partial Anomalous Pulmonary Venous Return to the IVC

01714c03 Copyright 2009 Courtesy Ashley Davidoff MD

AVM from hepatopulmonary Syndrome

24131 Copyright 2009 Courtesy Ashley Davidoff MD

A?P Embolization of AVM

24137 Copyright 2009 Courtesy Ashley Davidoff MD

Thrombosed Left Upper Pulmonary Vein and Secondary Hemorhage

26 year old male who presents with shortness of breath a few months following RFA ablation for atrial fibrillation.  Image a shows the left upper lobe thrombosed and the left lower vein contrast filled

  Image b (the lung windows) shows thickening of the interlobular septa and secondary lobules distended with material, porobably representing blood.

 

following male SOB s/p RFA ablation for atrial fibrillation lung pulmonary let upper lobe pulmonary vein thrombosed secondary lobule interlobular septa are thickened secondary lobule destroyed dx pulmonary vein thrombosis secondary to radiofrequency ablation therapy iatrogenic CTscan Courtesy Ashley Davidoff MD Scott Tsai MD ground glass changes pulmonary infarction venous infarction

75413c01

75413b01 26 male SOB s/p RFA ablation for atrial fibrillation lung pulmonary let upper lobe pulmonary vein thrombosed secondary lobule interlobular septa are thickened secondary lobule destroyed dx pulmonary vein thrombosis secondary to radiofrequency ablation therapy iatrogenic CTscan Courtesy Ashley Davidoff MD Scott Tsai MD ground glass changes pulmonary infarction venous infarction

75413c07 26 male SOB s/p RFA ablation for atrial fibrillation lung pulmonary let upper lobe pulmonary vein thrombosed secondary lobule interlobular septa are thickened secondary lobule destroyed dx pulmonary vein thrombosis secondary to radiofrequency ablation therapy iatrogenic CTscan Courtesy Ashley Davidoff MD Scott Tsai MD ground glass changes pulmonary infarction venous infarction

Thrombosed left Upper Lobe Vein in Coronal and Sagittal View

75413c08 26 male SOB s/p RFA ablation for atrial fibrillation lung pulmonary let upper lobe pulmonary vein thrombosed dx pulmonary vein thrombosis secondary to radiofrequency ablation therapy iatrogenic CTscan Courtesy Ashley Davidoff MD Scott Tsai MD pulmonary infarction venous infarction

Relationship of the Left Sided Pulmonary Veins to the Esophagus

The normal indentations on the esophagus include the aortic arch and knob seen in bright red in b. The left bronchus is usually seen as a oblique line crossing the back of th esophagus, but in this case is seen as a focal indentation on the anterior wall. The left atrium is seen pulsating against the distal esophagus (maroon) usually when the left atrium is enlarged.

Copyright 2009 Courtesy Ashley Davidoff MD 76119c02

Pulmonary Circulation

32807b03.8s heart cardiac pulmonarycirculation pulmonary artery pulmonary vein left atrium Davidoff art copyright 2009