Double Switch, Senning Rastelli / Nikaidoh, Corrected Transposition of the Great Arteries (cTGA), Congenitally Corrected Transposition of the Great Arteries (ccTGA), also Known as Levo-Transposition of the Great Arteries (L-TGA)
Indication and Timing
Diagnosis of the heart defect represents the indication for operation. The timing depends on the associated heart defects:
- ventricular septal defect (VSD)
- left ventricular outflow tract obstruction (LVOTO)
- tricuspid valve morphology (Ebstein-like)
- atrial appendages in relation to apex (important for the Senning operation).
As a general principle: the Senning operation is technically feasible from the age of 6 months; however, indextrocardia and situs solitus it is more difficult.
Relative contraindication to correction: patients >16 years with right ventricular (LV training difficult!) or biventricular failure, following classical correction with tricuspid valve insufficiency or LV dysfunction with mitral valve insufficiency, significant arrhythmia --> rather, candidates for heart transplantation.
At the Deutsches Herzzentrum Berlin the patients are therefore treated as follows:
With non-restricted pulmonary blood flow
Senning and arterial switch operation:
- small VSD, no heart failure: if RV function is compensated --> wait until RV function deteriorates or until mild tricuspid valve insufficiency occurs--> PA banding and if appropriate atrioseptectomy for LV training until LV pressure (muscle mass) equals RV pressure.
- small VSD and heart failure (LV not trained!): if tricuspid valve insufficiency is moderate --> first PA banding and if appropriate atrioseptectomy. If the patient becomes cyanotic: SEN + ASO.
- large VSD and heart failure: SEN-ASO at the age of 3-6 months.
With pulmonary stenosis (PS) and “committed” VSD
Senning Rastelli, with “non-committed” VSD Senning Nikaidoh:
- moderate PS and elevated or balanced lung flow: --> SEN-RAS at 6-12 months
- severe PS/pulmonary atresia --> BT shunt, in the case of cyanosis at the age of 1 year --> SEN- RAS
- by echocardiography: atrial situs, connection of the systemic and pulmonary veins, AV valves, straddling, connection of the ventricles and great arteries, morphology and diameter of the semilunar valves, localization of VSD, relationship to tricuspid, pulmonary and aortic valve, morphology of pulmonary stenosis if present, coronary anomalies.
- by heart catheterization: before complex corrective operations to evaluate the hemodynamics.
- MRI: volume and ventricular mass of the LV (cTGA).
The heart-lung machine is used. The pulmonary arteries and the upper and lower caval vein are exposed. If necessary, autologous pericardium is removed for the pulmonary artery reconstruction.
- Senning operation: opening of the atrium, separation of the pulmonary venous bafflewith GoreTex patch, tunneling of the systemic veins to the tricuspid valve, opening of the right pulmonary veins and open anastomosis with pericardium to created continuity with the mitral valve (Shumaker modification)
- arterial switch operation or Rastelli, REV or Nikaidoh operation (see TGA), if necessary VSD closure (N.B. conduction tissue has anterior course in the SLL-anatomical subtype of the ccTGA atrial-ventricular-vascular orientation).
Possible Long-Term Complications
The short- and mid-term prognosis is good. In the natural course many patients develop heartblock. In a small proportion stenosis of the intra-atrial tunnel may occur. In the long term, narrowing of the outflow tracts and insufficiency of the neo-aortic valve may be seen. Following the Rastelli operation the non-growing conduit must later be replaced.
Recommendations for Further Treatment
Close cardiological monitoring remains necessary to identify stenoses that can lead to incorrect loading of the heart. In view of the use of prosthetic material we recommend prophylactic antibiotic treatment with any procedure involving potential bacteremia in the further course.