Surgical repair of Truncus Arteriosus

Abstract

Truncus arteriosus is a rare congenital malformation accounting for about 3-9% of all congenital heart defects where a single great artery arising from the heart provides systemic, pulmonary and coronary circulation. The most common associated anomalies include ventricular septal defect, truncal valve dysplasia or dysfunction, aortic arch and coronary artery anomalies. A DiGeorge syndrome and velocardiofacial syndrome are the most associations. There are two major classification systems used to describe the lesion The Collett and Edwards classification and Van Praagh classification, with anew classification of Hyde M. Russell. It is based on the site of the origin of PAs and the degree of development of the ascending aorta and patent ductus arteriosus. The single truncal valve is slightly more anteriorly located than the normal aortic valve. It has a fibrous continuity with the mitral valve. Most often, it contains three or four cusps but it may be bicuspid too. Commonly, the cusps show myxomatous changes, which are associated with truncal valve regurgitation. The VSD is usually large and conoventricular and is occasionally muscular. Coronary artery anomalies are common and aortic arch hypoplasia or interruption and a large PDA are also a common associated anomaly. Echocardiography is the diagnostic technique of choice, chest X-ray is another investigation which should be correlated to the clinical picture. Adequate intra-uterine diagnosis can reduce both morbidity and mortality as long as the early prediction and diagnoses according to the early signs and symptoms. Patient Catheterization could be useful in identification of the coronary artery, pulmonary artery and truncal valve anomalies and also in pulmonary artery pressure and pulmonary vascular resistance measuring. The natural history of patients with truncus arteriosus is not favorable when left untreated. Patients die due to heart failure from truncal valve regurgitation or pulmonary overflow or due to shock from lower body hypoperfusion. Surgical treatment is indicated as soon as possible. Surgical treatment was initially confined to banding of one or both pulmonary arteries. Either due to another intracardiac