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.