Discussion

Anomalous origin of a branch pulmonary artery from the aorta is a rare malformation, accounting for 0.12% of all congenital heart defects. This type of cardiac malformation was described first by Fraentzel in 1868.^{Reference Wang, Song and Cheng1,Reference Shakibi, Rastan and Nazarian2} AORPA has a reported mortality rate as high as 70% among those patients who did not undergo surgical repair within 1 year of life; the main cause of the high mortality rate was pulmonary hypertension and irreversible pulmonary vascular disease, because the pulmonary artery of abnormal origin receives high pressure from the systemic circulation, and as the pulmonary resistance decreases after birth, the flow through the anomalous pulmonary artery increases, leading to pulmonary artery hypertension (PAH) and congestive heart failure and subsequently irreversible pulmonary vascular disease.^{Reference Liu, Juan and Chen3,Reference Prifti, Crucean and Bonacchi4} The present case is important, because it is very infrequent, and is the oldest adult, reported in the literature, who has undergone surgical correction with favourable evolution. The AORPA is frequently associated with other cardiac malformations and is rarely presented as an isolated anomaly. AORPA was most commonly associated with patients with PDA, whereas anomalous origin of the left pulmonary artery (AOLPA) was most commonly associated with patients with aortic arch anomalies.^{Reference Shakibi, Rastan and Nazarian2,Reference Higeno, Inamura and Kayatani5,Reference Bockeria, Makhachev and Tkh6}

These patients may have a different clinical presentation; usually, most neonates and infants are asymptomatic, but they may develop a progression of symptoms, such as exercise intolerance, dyspnoea, chest pain, haemoptysis, and recurrent pulmonary infections, throughout infancy and adolescence.^{Reference Bockeria, Makhachev and Tkh6,Reference Pankaj, Sachin and Shyam7} These symptoms depend on the anatomy of the affected lung and the types of the blood vessels providing its perfusion.^{Reference Liu, Juan and Chen3,Reference Pankaj, Sachin and Shyam7,Reference Raymond, Pedretti and Privitera8} The heart catheterisation is a very important procedure and is the gold standard for diagnosis of PAH and should be indicated preoperatively in all patients.^{Reference Pankaj, Sachin and Shyam7,Reference Raymond, Pedretti and Privitera8} The acute vasoreactivity testing (AVT) is a particularly important component of the heart catheterisation in congenital heart disease (CHD) with PAH, as it informs prognosis and can guide the correct treatment. According to current guidelines, assessment of reversibility is limited to hemodynamic variables: those in favour of reversible PAH-CHD are a left-to-right shunt and a PVR index is <4 Woods units. Surgical correction is contraindicated when the net shunt is directed right-to-left and is discouraged when the PVR index is >8 Woods units. When the PVR index is between 4 and 8 Woods units, “individual patient evaluation in tertiary centres” is advised.^{Reference Van der Feen, Bartelds, de Boer and Berger9} These recommendations, however, are predominantly based on expert opinion and are hardly supported by data. In fact, in PAH-CHD, no prospective studies have yet identified reliable hemodynamic cutoffs that predict the reversal of pulmonary vascular disease and normalisation of hemodynamic after cardiac correction. Acute pulmonary vasodilator tests (AVT) are performed during heart catheterisation to test the effect of short-acting pulmonary vasodilators on PVR, pulmonary artery pressure (PAP), and shunting. Although the use of AVTs to estimate reversibility prior to corrective surgery is widespread in current clinical practice, no haemodynamic cutoffs have shown sufficient accuracy in predicting reversal after shunt correction.^{Reference Van der Feen, Bartelds, de Boer and Berger9,Reference Galie, Humbert and Vachiery10} The haemodynamic change that defines a positive response to AVT in PAH associated with a shunt defect (CHD) should be considered as a >20% fall in PVR and PVR/SVR with the respective final values of <6 indexed Wood units (iWU) and <0.3. Nevertheless, operative safety in PAH-CHD with a shunt cannot be, and an element of clinical subjectivity is inevitable.^{Reference Apitz, Hansmann and Schranz11} In the present case, the AVT was considered as “reactivity,” and give to this patient the possibility of surgical correction with favourable evolution. Different surgical techniques have been employed. The direct anastomosis of the anomalous pulmonary artery from the aorta remains the technique of choice.^{Reference Liu, Juan and Chen3,Reference Xie, Gao and Wu12} The most frequent complication is stenosis at the level of the anastomosis and pulmonary hypertension.^{Reference Prifti, Crucean and Bonacchi4,Reference Xie, Gao and Wu12,Reference Garg, Talwar, Kothari, Saxena, Juneja, Choudhary and Airan13} In our case, there were no complications during the medium-term follow-up, and the last heart catheterisation showed a decrease in vascular pulmonary disease, which is consistent with the notable improvement in symptoms and functional class, despite the fact that the diagnosis was made very late. The factors that determine this evolution are still unknown due to the low incidence and intervention in such cases.