Discussion
Persistence of the
left superior
vena cava (LSVC) is the most common anomaly of the systemic venous
connection, and in the absence of associated defects may be considered a
variant of normal. Its presence can be relevant when a central venous
catheter or a transvenous pacemaker is needed. Also, a LSVC can
interfere with optimal venous drainage and exposure during some cardiac
surgical procedures [1-6]. A persistent LSVC usually drains into the
coronary sinus, but sometimes can drain into the left atrium leading to
right-to-left shunt. When needed, surgical connection is possible with
either intra- or extra-cardiac procedures [1-6]. The few cases
reported in literature have been treated with: a) division and
re-implantation of the LSVC to right atrium [1,4]; b) an
intra-atrial baffle or graft to divert flow from the LSVC to the right
atrium and to close the ASD [1, 2, 4, 7]; c) anastomosis of
the LSVC to the left pulmonary artery [6,8,9] or d) simple
ligation of the LSVC [1, 2, 3, 4-6, 8].
Our patient presented with a combination of persistent LSVC draining
into the LA, a large ostium secundum ASD, coronary veins draining
into the LA and pulmonary hypertension responding to pulmonary
vasodilators. The multiple anomalous connections between the systemic
and pulmonary circulation did not translate into a particularly high
Qp/Qs, likely due to concomitant presence of left-to-right and
right-to-left shunts. However, as fast fibrillation entered the picture
the patient decompensated. An interatrial baffle would have been our
treatment of choice, but the ostium of the left superior pulmonary vein
was at risk of obstruction due to its proximity to the ostium of the
LSVC. Therefore, an extracardiac technique was used.
As there is no standardised procedure for the correction of a persistent
LSVC draining into the LA, whenever surgery is considered, the choice of
the technique should take into account several variables such as the
patient’s age, the intra-cardiac anatomy, the size of both the right
superior vena cava and the pulmonary artery, the pulmonary vascular
resistance and the site of drainage in the left atrium.