Half-turned truncal switch operation after single ventricle palliation in a patient with borderline left heart hypoplasia

Background: The optimal surgical strategy for the correction of double outlet right ventricle (DORV, transposition of the great arteries [TGA] type) or TGA with ventricular septal defect (VSD), pulmonary stenosis (PS), and borderline small left ventricle (LV) is still controversial. The half-turned truncal switch operation (HTTSO) introduced by Yamagishi and colleagues is a good option, but it is still challenging in a patient with borderline small LV. We aimed to describe our experience of a case of HTTSO conversion from single ventricle palliation. Case presentation: A 5-year-old girl with single ventricle physiology was referred to our hospital from Kazakhstan for a Fontan operation. At the time of birth, she was diagnosed with DORV (TGA type), PS, and situs inversus totalis, with moderate valvar and subvalvar stenosis and a relatively small LV cavity. Her LV volume was not adequate to support the systemic circulation; therefore, doctors in Kazakhstan selected the single ventricle palliation course of treatment for the infant. At 4 months of age, she underwent left-sided modified Blalock-Taussig shunt, patent ductus arteriosus ligation, and atrial septectomy. At 2 years of age, shunt takedown, left bidirectional cavopulmonary shunt, and main pulmonary artery division were performed. Annual echocardiography of the patient showed that the LV size was growing too adequately to persist with the single ventricle palliation course of treatment. Via a multidisciplinary approach, we considered her LV to be suitable for biventricular repair and HTTSO was planned. The operation and postoperative course were uneventful. The patient was discharged on postoperative day 6 and went back to Kazakhstan. Conclusions: Based on our successful surgical outcome, in patients diagnosed with DORV (TGA type) or TGA with VSD, PS, and borderline LV, HTTSO after achieving adequate LV growth by single ventricle palliation may be considered a good alternative to conventional operations in patients at a high risk for initial biventricular repair.