DISCUSSION
Early intervention and surgical closure is mandatory before it leads to
irreversible PAH. APW may occur as an isolated lesion, or it can be
associated with other cardiac abnormalities in one-third to one-half of
cases.1 Echocardiography usually establishes diagnosis
in most cases. Assessment of operability can be determined by the
clinical status, absence of cyanosis, cardiomegaly on chest X-rays,
features of left ventricular volume overload on electrocardiogram and
cardiac catheterization findings.2
Still, presentation beyond infancy is not so uncommon in developing
countries due to poor socioeconomic conditions.3 In
the presence of severe PAH, if significant reversibility in the
pulmonary vascular resistance index could be demonstrated with oxygen,
the condition can be successfully corrected with good long-term
outcomes. Mori and colleagues4 divided APW into three
types; types I-III. The classification scheme used by the Society of
Thoracic Surgeons adds a fourth ‘intermediate’ category, suggesting a
continuum of morphologies. 5 Severe PA dilatation has
been described as a predisposing risk factor for LMCA compression in
patients with PAH.6 The pulmonary artery diameter is
the most important aspect of the LMCA stenosis in these cases, but other
aspects like mean pulmonary artery pressure or angina symptoms are not
significantly associated with coronary compression.6
It is important to confirm myocardial ischemia due to LMCA compression
before indicating a treatment.7 There are patients in
whom the hemodynamics can be stabilized only by treating the cause of
pulmonary hypertension. Although PCI and rarely CABG may be an option,
but as in our case, just treating the cause of the massive PA dilatation
could help resolve the compression of LMCA.
In the presence of reversible pulmonary vascular disease, surgical
correction is indicated and may result in a regression of both symptoms
and PAH. The evolution of the surgical management of APW has progressed
from off-pump ligation toward patch repair. Simple ligation of APW has a
risk of a residual defect and is justified for small defects only.
The intermediate type, which has adequate superior and inferior rims, is
best suited for device closure. Device closure of APW in adolescents is
rarely reported because of the rarity of the defects with good margins,
associated congenital cardiac anomalies requiring cardiac surgery, early
development of Eisenmenger syndrome in this population or due to
technical challenges precludes device closure.8 Our
case was a type-I APW with no other associated cardiac anomaly. We
approached through the window for surgical closure. It provides
excellent exposure of the defect along with a clear view of ostia of
LCA, RCA and RPA. It isn’t associated with semilunar valves distortion
and post-surgical great arteries stenosis. With a single PTFE patch, the
posterior part of the defect was closed with suturing at the posterior
aortic wall. For the anterior part, the anterior sandwich
approach9 was used taking bites from the aorta, patch
and through the pulmonary artery anterior wall at the defect level.