Correction of persistent truncus arteriosus.

Successful correction of a type 2 truncus arteriosus in an African boy of 10 years is reported. The surgical technique employed is described and preoperative and late postoperative haemo-dynamic data are documented. Failure of the primitive truncus arteriosus to partition results in one of a group of congenital cardiac anomalies called persistent truncus arteriosus. A single vessel, guarded by a semi-lunar valve, leaves the heart, and from this arise the coronary arteries , the aorta, and the pulmonary arterial supply. Successful correction of this congenital anomaly was first recorded in 1968 (McGoon, Rastelli, and Ongley, 1968). Wallace and his associates have reported successful total correction in four patients (Wallace, Rastelli, Ongley, Titus, and McGoon, 1968). The purpose of this paper is to record the surgical technique employed in the correction of a type 2 truncus arteriosus and to outline the preoperative and late postoperative haemodynamic state. An African boy aged 10 years was referred from an outlying hospital where he had been treated for pulmonary tuberculosis and congestive cardiac failure. He had suffered recurrent respiratory infections since infancy and complained of palpitations and increasing dyspnoea on effort. His weight was 51 lb (23 kg) and he was 4 ft 5j in (1-37 m tall). Cyanosis was not recognizable at rest but he became cyanosed, if only slightly, with exercise ; the peripheral pulses were collapsing in character ; the liver was palpable 2 cm below the right costal margin. There was clinical evidence of both right and left ventricular enlargement and a systolic thrill was palpable at the left sternal border. A pansystolic murmur (grade 4/6), maximal at the 4th interspace, and an early diastolic murmur along the left sternal border were audible. At the apex a mid-diastolic murmur and a third heart sound were heard. The second heart sound was accentuated and single. The electrocardiogram showed a mean frontal plane axis of +80° and evidence of bi-ventricular hyper-trophy. Radiographically (Fig. la) the cardiothoracic ratio was 0 58, the left atrium was enlarged, the ascending aorta dilated, and the pulmonary segment concave. Both pulmonary arteries were large and arose high at approximately the same level. Cardiac catheterization demonstrated equal systolic pressures in the aorta and right and left ventricles. The right and left pulmonary arteries were entered separately from the truncus, and there was not a sys-tolic gradient between the pulmonary arteries and the truncus arteriosus.