View source for Talk:Paper - A rare vascular anomaly-opening of the upper left pulmonary vein into a persistent left superior vena cava (1915)

A RARE VASCULAR ANOMALY—OPENING OF THE UPPER LEFT
PULMONARY VEIN INTO A PERSISTENT LEFT SUPERIOR
VENA CAVA. By T. B. Jonnston, M.B., Ch.B., Lecturer on
Anatomy, Edinburgh University.

THE following vascular anomaly was found in the body of an adult male
subject, dissected in the Anatomy Department of the University of
Edinburgh. Unfortunately, nothing is known about the clinical history
of the case, but the subject, who died from the inhalation of poisonous
gases, was stated to be 56 years of age, and his muscular development was
rather above the average. It may therefore be assumed that the anomaly
to be described had had little effect on the health of the subject.

The condition of the great vessels of the thorax was, briefly, as follows
The superior vena cava was normal in its mode of formation, in its course,
and in its termination, but its lumen was rather greater than usual. This
increase in size was attributable to the left innominate vein, which, constituted in the ordinary way, received a large ascending tributary at a
point about half an inch from its commencement. When this anomalous
vessel was traced downwards, it was found to cross the left side of the
arch of the aorta, and, in front of the left pulmonary artery, it deviated to
the left in order to enter the upper and anterior part of the hilus of the
left lung. In the vertical part of its course, this vein was joined, on the
right side, by mediastinal and thymic tributaries, and, on the left side, by
the left superior intercostal vein. At the point where it turned to the
left, its lower border received the upper attachment of the ligamentum
vene cave sinistre. The latter descended in front of the left pulmonary
artery, and, at the lower border of that vessel, it entered the fold of pericardium with which it is normally associated. On reaching the surface
of the left atrium, the ligamentum vene cave sinistree became continuous
with the upper end of the oblique vein of the left atrium, which coursed
downwards and to the right on the posterior aspect of the left atrium, and
terminated by joining the coronary sinus. At the point where the oblique
vein and the ligamentum vene cave sinistre became continuous, a small
vein arose, and, after a short course, opened into the left atrium in the
neighbourhood of the orifice of the lower left pulmonary vein.

The pulmonary veins of the right side showed the usual arrangement,
and they opened into the left atrium by two separate orifices.
A Rare Vascular Anomaly 183

The ligamentum arteriosum was not patent, and the aorta, the pulmonary
artery, and the other thoracic blood-vessels showed nothing unusual.

Certain additional anomalies were present in the heart. The organ
was definitely enlarged, and this increase in size affected, more particularly,
the atria and their auricles. When the interior of the right atrium was
examined, the condition of the interatrial septum at once attracted attention. The floor of the fossa ovalis was unusually thin, and it showed a
number of small perforations. In addition, it was definitely redundant, and

   
 

A, superior vena cava ; B, left innominate vein ; C, left superior
vena cava ; D, left superior intercostal vein; E, vein issuing
from upper and anterior part of hilus of left lung; F, ligamentum vene cave sinistree ; H, small vein opening into left
atrium ; K, oblique vein of left atrium ; L, coronary sinus;
M, aorta; N, pulmonary artery ; P, vena azygos.

it would appear to have bulged into the cavity of the left atrium during
life. The limbus fosse ovalis was well formed, but, in its upper and
anterior part, it had failed to fuse with the floor of the fossa ovalis, and the
handle of a knife could be passed upwards between the two into the left
atrium. When the interatrial septum was examined from the left side,
the orifice through which the instrument passed was readily seen. It
possessed a sharp, slightly thickened, crescentic lower border, which was
concave upwards, and in its neighbourhood numerous smaller openings
occurred, giving this portion of the septum a somewhat fenestrated appearance. These openings were under cover of the limbus fosse ovalis, which
probably had a more or less perfect valve-like action, but the smaller

orifices in the lower part of the septum were quite unprotected.
VOL. XLIX. (THIRD SER. VOL. X.)—JAN, 1915, 13
184 Mr T. B. Johnston

Another anomaly was present in the interior of the right atrium. The
orifice of the superior vena cava was partially guarded by a valve, which
consisted of a single semilunar cusp. The valve was situated on the
anterior and right lateral aspects of the orifice. Its upper, attached,
margin was convex upwards, and its lower, free, margin was straight; in
its upper part the cusp showed several small perforations, similar to those
often found in the valve of the inferior vena cava. -The posterior extremity
of its lower margin could be clearly traced down the posterior part of the
right wall of the atrium, lying on the surface of the crista terminalis.
Inferiorly, it became continuous with the valve of the inferior vena cava,
which was also markedly fenestrated in appearance. The anterior or medial
extremity of the valve of the superior vena cava could not be traced further.

Previously recorded cases of connexions between the pulmonary and
the systemic veins are very few in number, and I have only been able to
collect nine examples. Of these, all except two occurred on the right
side; in two cases there was no opening in the interatrial septum. In
none of the recorded cases is any mention made of an additional small
vein opening into the left atrium; and in none was there any valve at the
orifice of the superior vena cava.

The explanation of a connexion between the pulmonary and the ©
systemic veins must depend on the view accepted for the development of
the pulmonary veins. If one accepts the view, put forward by Flint (1)
and others, that the pulmonary veins originate in the lungs and grow
towards the heart, then it is quite clear that, under abnormal conditions,
one of the pulmonary veins might meet and open into one of the systemic
veins instead of into the left atrium. Such an explanation would account
for the previously recorded cases, but it would leave unexplained the small
vein opening into the left atrium in the present case. .

On the other hand, Fedorow (2) has recently put forward the view that
the pulmonary veins originate as an outgrowth from the sinus venosus and
grow into the lungs. If this view is accepted, then the anomalous connexion
between a pulmonary and a systemic vein is not so easy to explain.

It is known, however, that the bronchial veins, which normally
terminate in the systemic veins, establish anastomoses with the pulmonary
veins in the lungs. It may be suggested, therefore, that, in cases where a
pulmonary vein either fails to develop or fails to reach the lung, one of
these anastomosing channels becomes widely dilated, and the blood which
should pass through a pulmonary vein into the left atrium passes through
the anastomosis into a bronchial vein, and thus eventually reaches one of
the systemic veins.

If this hypothesis is applied to the previously recorded cases, it would
A Rare Vascular Anomaly 185

appear that the pulmonary vein outgrowth from the sinus venosus had
failed to break up into a sufficient number of smaller veins, 7.e. in the
previously recorded cases one of the pulmonary veins had failed to develop.
In the present case the condition is slightly different. All four pulmonary
veins have developed, as witnessed by the openings into the left atrium,
but the upper vein of the left side, instead of reaching the left lung, met
and opened into the left duct of Cuvier. It is therefore found connected
with the oblique vein of the left atrium. As a result of this occurrence,
the blood from the upper and anterior part of the left lung was compelled
to find a new channel of return, and this was effected by the wide dilatation
of an anastomosis with a bronchial vein which terminated in the left
superior vena cava.

The view put forward that the small vein which opens into the left
atrium and is connected to the upper end of the oblique vein is in reality
the upper left pulmonary vein receives additional support from its intimate
association with the ligamentum ven cave sinistre.

With reference to the anomalies in the heart itself, it is clear, since
they do not occur in all the previously recorded cases, that they are not
dependent on the vascular anomaly, but are simply additional signs of
developmental arrest. In the upper and anterior part of the interatrial
septum, the septum primum and the septum secundum have failed to fuse,
and the foramen ovale secundum has persisted. The numerous smaller
openings in the fossa ovalis suggest the possibility that the foramen ovale
secundum may be formed by the fusion of a number of small perforations,
and not in the way which is usually described.

The valve at the orifice of the superior vena cava is very similar to one
described by Sir William Turner (3) in a case where the pulmonary veins
and the interatrial septum were normal. It represents the persistence of
the greater part of the right venous valve at the opening of the sinus
venosus into the atrial chamber of the heart. It is possible that the part
at the orifice of the superior vena cava may represent not only the upper
extremity of the right venous valve, but also a portion of the septum
spurium. This, however, is only a possibility, and no proof can be brought
forward in its support.

I should like to thank Professor Robinson for granting me permission
to describe this somewhat rare anomaly of the vascular system.

Note.—Since the above was written, I have had the opportunity of
reading A. J. Brown’s paper on “The Development of the Pulmonary Vein
in the Domestic Cat,” Anat. Record, vol. vii., No. 9. The conclusions at
which he arrives are very similar to, although not identical with, the
conclusions drawn in the present note.
186 A Rare Vascular Anomaly

LITERATURE.

(1) Frint, J. M., “The Development of the Lungs,” American Journal of
Anatomy, vol. vi., 1907.

(2) Feporow, V., “Ueber die Entwickelung der Lungenvene,” Anat. Anz.,
Bd. xxxil. pp. 544-548 ; and Anat. Heft, Bd. xl.

(3) Turner, Sir Wm., ‘Heart in which the Superior Vena Cava possessed a
Valve at its Auricular Orifice,” Journ. Anat. and Phys., vol. iii. p. 452.

(4) THang, G. D., ‘A Specimen in which the Upper Pulmonary Vein of the
Left Side opens into the Innominate Vein,” Journ. Anat. and Phys., vol. xl. p. xi.

(5) Incatis, N. W., “Communication between the Right Pulmonary Veins
and the Superior Vena Cava,” Anat. Record, Jan. 1907.

(6) GuinLaBERtT, V., “Observation d’un cas d’ectopie des deux troncs veineux
pulmonaires, supérieur et moyen du cété droit allant s’insérer isolément dans la
veine cave supérieure et la grande veiue azygos, etc.,” Montpel. Méd., 1859.

(7) SuernerD, F. J., ‘‘Right Pulmonary Vein emptying into Vena Azygos
Major,” Journ. Anat. and Phys., vol. xxiv. pp. 69 and 70,

(8) Buatr, V. P., “Three Anomalies of Thoracic Blood-vessels,” American
Journal of Anatomy, vol. i. p. 513.

(9) Hersurn, D., “Double Superior Vena Cava, Right Pulmonary Veins
opening into the Right Auricle, and a Special Inter-auricular Foramen,” Journ.
Anat, and Phys., vol. xxi. pp. 438-443.

(10) PEacock, Malformations of the Human Heart, 2nd ed., 1866.

(11) Mecket, J. Fr., “ Einmiindung der Vena pulmonalis dextra superior in
die Vena cava superior,” Tab. Anat. Path., Fasc. ii., Lipsie, 1820.

(12) Gruser, W., “Ein Fall von Einmiindung der Vena pulmonalis dextra
superior in die Vena cava superior,” Virchow’s Archiv, Bd. Ixviii. pp. 284-287.