Discussion
SVC stenosis in pediatric population is usually because of postoperative
sequelae to prior cardiac surgery.1 “True”
Congenital SVC stenosis is an extremely rare entity. To the best of our
knowledge, co-existence of this anomaly with obstructed TAPVC, has never
been reported. We believe the etiology in our case was transmural
fibrosis emanating from the draining ostium of common chamber, involving
SVC circumferentially.
Symptomatic SVC obstruction may increase venous pressure, depicted as
SVC syndrome, but the degree and severity of symptoms depend on the
extent and rate of progression of narrowing.2 In our
case disproportionate edema in the SVC distribution was absent,
indicating gradual development of narrowing in-utero. Also massive
dilation of proximal SVC, could have acted as a reservoir. In the era
when a TTE is performed as a standalone test, subtle findings can be
overlooked.4 Disproportionate edema or dilated veins
in the SVC distribution are critical physical findings that should
prompt focused evaluation for this etiology. Focused TTE and CT can
readily establish the diagnosis in these sick infants.
Neonates and infants with obstructed TAPVC can present with severe
cyanosis, pulmonary hypertension, and low cardiac output, requiring
emergency surgical intervention.5 In our patient, the
drainage of CC was almost atretic, but the lungs were not congested.
Coexisting critical SVC stenosis can limit the amount of blood going
towards the common chamber. We are not sure, whether coexisting SVC
stenosis can decrease the severity of pulmonary venous hypertension, by
limiting the amount of blood flow into the obstructed common chamber.
Management of SVC obstruction needs to be tailored according to the
etiology and coexisting malformations. For isolated SVC stenosis,
stenting is becoming the modality of choice compared to surgery due to
its reduced post-procedure morbidity and faster recovery
time.2 Intravascular stent placement is safe and
effective even in term infants.3 However lack of
growth potential and recurrence of sympyoms, mandates reinterventions.
Considering the small vessel size as well the growth potential in
pediatric population, surgical repair with patch augmentation is ideal,
especially in the setting of an associated CHD which needs surgical
correction. In our patient, associated obstructed supracardiac TAPVC
mandated surgical intervention for SVC stenosis. We resorted to
pericardial patch augmentation of SVC along with anastomosis of common
chamber to the posterior wall of LA.
The hemodynamic effect produced by a combination of systemic venous
hypertension and pulmonary venous hypertension can be extremely lethal
especially in infants. Clinical condition should prompt focused
evaluation by TTE and CECT. We believe surgical repair with a
pericardial patch, can be curative for SVC stenosis in pediatric
population, by providing growth potential.