DORV with subaortic VSD (VSD type DORV) 

• In DORV with subaortic VSD oxygenated blood flows from the right ventricle to the pulmonary arteries due to its lower resistance as occurs in usual VSD (Fig.3, video 1)
  
  
• Diagnosis is typically through the use of CUS
• Advanced imaging may be required in complex cases with associated anomalies (Fig.4)
  
• Treatment consists of closure of the VSD using a patch or baffle to redirect from the left ventricle to the aorta. Follow-up of complications can be performed with CMR (Fig.5, video 2)
  
  

DORV with subaortic VSD and pulmonary stenosis (TOF type DORV) 

• In DORV with subaortic VSD and pulmonary stenosis there is flow of non-oxygenated blood to the aorta due to high pulmonary resistance which results in cyanosis. This pathophysiology is analogous to that of TOF (Fig.6, video 3 and 4)
  
  
  
• Diagnosis is typically made using CUS, with advanced imaging rarely being necessary
• Treatment typically involves closing the VSD with a patch and opening the right ventricular outflow tract, like standard TOF management. Postoperative follow-up is typically conducted using CMR, akin to the postoperative management of TOF (Fig 7, video 5)
  
  

DORV with subpulmonary VSD (transposition type or Taussig-Bing anomaly) 

• In DORV with subpulmonary VSD, due to the abnormal position of the semilunar valves non-oxygenated blood flows predominantly to the aorta and oxygenated flow from the left ventricle to the pulmonary artery. Patients are cyanotic but, opposed to usual D-transposition of the great vessels, they are not dependent on ductus patency (blood can mix in the VSD) (Fig 8, video 6)
  
  
• Diagnosis is based in CUS, but advanced imaging is not uncommon for assessing semilunar valves patency and associated anomalies. In cases of pulmonary valve stenosis, patients show less or no cyanosis due to pulmonary resistance.
• Coronary artery assessment (with CCT, CMR or angiography) can be necessary to avoid myocardial infarction in cases with abnormal coronary anatomy (6)
• Surgery is aimed to restore separate pulmonary and systemic circulation by means of arterial switch procedure as in common D-transposition (Fig. 9)
  
  . When favorable anatomy, re-direction of the left ventricular flow to the aorta with a pericardial patch (Rastelli procedure) can be performed avoiding associated risk to coronary re-implantation. In patients with unfavorable anatomy univentricular correction can be the only choice (Fig.10)
  

DORV with doubly committed VSD (

• It is very uncommon, representing the least common type of DORV.
• Pathophysiology, imaging and surgical approach vary in function of the position of the great vessels and associated anomalies, including a wide range of approaches from patch closure of the VSD to univentricular correction Fig.11)
  

DORV with uncommitted VSD 

• The pathophysiology of DORV with uncommitted VSD is highly variable. The distance and status of the VSD to the semilunar valves, the position of the great vessels and the associated anatomic anomalies make diagnosis and management of this type of DORV a complicated task (Fig.12)
  
• Diagnosis initially relies on CUS. However, this group of DORV patients require usually advanced imaging studies in the preoperative setting, most frequently CCT due to its availability, speed and safety in the neonatal period
• Relevant aspects to be assessed in the preoperative examination include:
  • Position and status (e.g. stenosis, atresia) of the semilunar valves
  • Size of the VSD and distance to the semilunar valves
  • Size and shape of the cardiac chambers, especially the ventricles
  • Ductus arteriosus patency and position, particularly important for ductus dependent malformations
  • Aortic arch position and diameter (hypoplasia, coarctation)
  • Pulmonary arteries size and position and presence of mayor aortopulmonary collateral arteries (MAPCAs)
  • Pulmonary venous connections
  • Other cardiac and non-cardiac anomalies (heterotaxy syndromes, bronchopulmonary malformations, etc.)
• Volume rendered images and 3D printing are needed in many instances for a comprehensive understanding of the anatomy for surgeons and interventional cardiologists (Fig. 13)
  
• Treatment encompasses a range of surgical interventions. Biventricular correction is the optimal approach (7) (8). However, in select cases, it becomes imperative to resort to univentricular correction, which encompasses the Glenn and Fontan procedures. Postoperative imaging follow-up is typically conducted using (Fig. 14, video 7)