Truncus Arteriosus with Persistent Left Superior Vena Cava: Cardiac Computed Tomography Findings in an Unrepaired Adult Patient
A 24-year-old male patient with unrepaired TA presented to the adult congenital cardiology clinic for surgical operation and his history revealed that he had been diagnosed with a complex cyanotic congenital heart disease at the age of 4 years, when he had cyanosis while crying. He had been hospitalized many times for recurrent lung infections. He was placed on a heart-lung transplantation waiting list. Meanwhile, he was started on bosentan therapy as he had developed cardiovascular symptoms. Unfortunately, no appropriate donor could be found during the waiting time. A subsequent cardiac catheterization revealed pulmonary hypertension, for which iloprost had been added to the bosentan therapy.\nOn physical examination, he was normal, except for being cyanotic and his blood pressure was 120/70 mmHg, heart rate was 72 beats/min and respiratory rate was 20/min. Chest X-ray showed increased pulmonary vascularity with an enlarged cardiac silhouette. Echocardiogram was consistent with a TA Type 1, VSD, truncal valvular insufficiency, and Eisenmenger physiology. An electrocardiographic (ECG)-gated cardiac computed tomography (CT) was ordered to characterize the complex cardiac anatomy more in detail.\nECG-gated multidetector CT (MDCT) (Somatom Definition, 128-slice Dual Source CT, Siemens Medical Systems, Erlangen, Germany) was performed. Contrast material of 75 ml (Ultravist 370 mg/mL, Schering, Berlin, Germany) was given through the left antecubital vein at a rate of 5 mm/s. Afterward, 50-cc bolus of intravenous saline solution was given at a rate of 5 cc/s. The region of interest was located relative to the ascending aorta 1 cm distal to the tracheal bifurcation. The scan was automatically started 2 s after the threshold level reached 130 Hounsfield unit. Contrast administration was controlled using bolus tracking. ECG-gated MDCT was performed according to the following protocol: gantry rotation time, 330 ms; temporal resolution, 83 ms; slice acquisition, 64 mm × 0.6 mm; pitch, 0.38 adapted to the heart rate; tube voltage, 120 kV; tube current, 380 mAs per rotation. The scanning duration was approximately 8.2 s, depending on the cardiac dimensions and the pitch and took place during a single breath hold in the craniocaudal direction. The estimated effective radiation dose was 5.5 mSv.\nIn addition to traditional axial images, three-dimensional (3D) volume rendering (VR) images, multiplanar reconstructions (MPR), curved multiplanar reformation and thin-slab maximum intensity projection techniques were employed to evaluate truncus and the additional anomalies.\nMDCT clearly delineated the complex cardiac anatomy in this case with TA [Figure –]. PLSVC drained into great cardiac vein. The coronary sinus was larger than normal and measured 25 mm. The right coronary artery branched from the non-coronary sinus on the left side of the truncus [] while the left coronary artery originated from the non-coronary sinus on the right side of the truncus []. A 2.5 cm VSD was detected on interventricular septum []. The truncal valve was trileaflet. The left inferior pulmonary vein drained into the right side of the left atrium (LA) and a pulmonary vein drained into the left side of the atrium was observed []. Such a pulmonary vein has never been reported in previous cases with TA.