Type B1 Truncus Arteriosus (Van Praagh) was reported before as autopsies or fetuses with hypoplastic ventricle. We report a unique patient who presented late, had two adequate ventricles and successfully underwent conduitless repair into separate ventricular outflows.
Case Report: A 4 years old girl presented with growth retardation and frequent pneumonias. She was acyanotic with hyperdynamic precordium, single S2,prominent early diastolic murmur. ECG, ChestXray showed moderate cardiomegaly (LV contour),plethoric lungs. Echocardiography revealed intact cardiac septae, normal systemic venous return, dilated left heart, adequate right heart, common outlet (type I truncus arteriosus), redundant truncal valve, moderate regurgitation and severe PAH. Our dilemmas were absence of intracardiac shunt and RV connection to truncus. Cardiac catheterization revealed operable hemodynamics but failed to distinguish from proximal aortopulmonary window.
Peroperatively, a single semilunar valve seen with annulus directly attached to crest of IVS without VSD. It had three leaflets: anterior, rightlateral and posterior (latter had pseudocommissure). Rightlateral leaflet was directly committed to Aorta and other leaflets were doubly committed to both great vessels. Utilising the pseudocommissure, the common valve was septated by Goretex patch into separate pulmonary and aortic outflows.PApressure normalized immediately.Postoperative echo showed laminar RV and LVOTs, mild AR, moderate PR,normal ventricular function.
Conclusion: Type B1 Truncus with this particular morphology allowed survival without VSD and septation.Echocardiography correctly identified the lesion,angiography was inconclusive. This unique conduitless strategy hopefully means decreased reoperations. Selective incomplete development of distal conal cushion with normal development of proximal and middle cushions is a possible embryological explanation.