Hemitruncus Repair

Introduction

Hemitruncus is an extremely uncommon anomaly, accounting for 0.1% of all congenital heart diseases (1). This defect is defined by the anomalous origin of one pulmonary artery, most commonly the right branch, from the ascending aorta. The first description of this disease was made by Fraentzel in 1868 (2). The lung that is normally connected receives the entire right ventricle output, while the anomalous artery is exposed to both pressure and volume overload. The first anatomic correction using tissue-tissue anastomosis was described by Kirkpatrick and colleagues in 1967 (3). Nowadays, this approach is the treatment of choice.

Description

The patient was a 47-day-old girl, weighing 3.7 kilograms. Due to failure to thrive and cyanotic spells, congenital heart disease was suspected. The chest x-ray showed an enlarged heart with congestion of the right lung. She was then transferred to the authors’ institution in fairly good condition. The transthoracic echocardiography revealed an anomalous origin of the right pulmonary branch, arising from the posterolateral aspect of the ascending aorta, about 1 cm above the aortic valve.

The surgery was scheduled for the following morning. The heart was approached through a median sternotomy. Prior to the connection to the heart-lung machine, the authors fully mobilized the great arteries and pulmonary branches. Before commencing the cardiopulmonary bypass, a tourniquet was applied to the anomalous pulmonary artery in order to prevent pulmonary overflow and organ malperfusion during the bypass. Prior to emptying the heart, the authors placed a marking suture in the future anastomotic site (on the lateral aspect of the main pulmonary artery). The bypass was established under mild hypothermia and cardiac arrest using a single venous cannula.

Once the aortic cross-clamp was applied, the aorta was transected above the origin of the right pulmonary artery. The anomalous branch was detached using fine microsurgical scissors, taking great care to avoid any injury of the nearby structures (mainly the left coronary ostium and the aortic commissures). The defect in the posterior wall of the aorta was repaired using a piece of autologous glutaraldehyde-treated pericardium, with a 6/0 polypropylene suture in a running fashion. Then, the authors performed an end-to-side anastomosis in the previously marked site, again using 6/0 polypropylene suture in a running fashion. Finally, the authors reanastomosed the transected aorta with another 6/0 suture line, rewarmed the patient, reperfused the heart, and weaned from cardiopulmonary bypass. Transesophageal echography showed adequate surgical procedure results, with no acceleration through the anastomosis and good biventricular function. After 24 hours, the patient was extubated.

The postoperative course was uneventful and the patient was discharged nine days later. At six month follow-up, she remained stable with no signs of anastomotic stenosis.

Conclusion

Since the pulmonary obstructive disease appears early, the surgery should be done at the moment of the diagnosis to avoid definitive injury of the pulmonary vasculature. Timely correction without complexity significantly improves the prognosis and survival rate (4).

References

1. Santos MA, Azevedo VM. Anomalous origin of a pulmonary artery from the ascending aorta: surgical repair resolving pulmonary arterial hypertension. Arq Bras Cardiol. 2004;83(6):503-507; 498-502.
2. Fraentzel O. Ein fall von abnormer communication der aorta mit der arteria pulmonalis. Arch Für Pathol Anat Physiol Für Klin Med. 1868;43(3):420-426.
3. Kirkpatrick SE, Girod DA, King H. Aortic origin of the right pulmonary artery. Surgical repair without a graft. Circulation. 1967;36(5):777-782.
4. Vázquez RM, Chávez IOM, López MES, et al. Anomalous origin of pulmonary branches from the ascending aorta. A report of five cases and review of the literature. J Cardiol Cases. 2015;11(1):1-6.