Developmental disorders

III./4.7.: Treatment

III./4.7.1.: Pharmaceutical treatment options

• - treatment of cardiac insufficiency;

• - in case of ductus-dependent circulation maintaining patency of a ductus arteriosus with prostaglandins;

• - endocarditis prophylaxis.

III./4.7.2.: A Forms of surgical interventions and postoperative nuances

There are numerous anatomic variants which belong to the umbrella term of DORV. There is no integrated treatment protocol that could be used for all patients. In general the goal of primary correction is to avoid palliative solutions like in case of other heart defects. Diagnosis if established constitutes the indication of surgery, as no spontaneous improvement is anticipated in DORV. Nowadays neonatal surgical intervention is recommended independent of the forms of DORV.

III./4.7.2.1.: Forms of surgical interventions

Palliative surgery

Pulmonary branding constitutes a surgical technique when a thinning collar is placed around the main trunk of the pulmonary artery. This latter procedure is performed on neonates showings imminent signs of overloaded lungs and congestive cardiac insufficiency with subaortic or subpulmonary VSD to avoid pulmonary hypertension. Taussig-Bing anomaly requires Blalock-Henlon-surgery (atrioseptectomy) to increase blood mixing. Atrioseptectomy is required for mitral valve insufficiency with hypo plastic left ventricle syndrome as well. Systemo-pulmonary shunt is required for sever pulmonary stenosis which can be postponed until later. Aortic isthmus-stenosis requires surgery but may be postponed until younger ages.

Reconstructive surgeries

The aim of reconstructive surgery is to create biventricular circulation, to create continuity of left the ventricle and the aorta and the right ventricle and the pulmonary trunk, in addition to the correction of accompanying anomalies. In case of subaortic VSD and double committed VSD intraventricular tunnel is created (intraventricular vascular tunnel, Rastelli technique) in between the left ventricle and the aortic root. In case of subpulmonary septum defect surgery is substantially more complex. In case of Taussig-Bing anomaly (subpulmonary VSD) long intraventricular tunnel can be created in between the left ventricle and the aorta, is technically feasible. Further solution provided by intraventricular tunneling in between the left ventricle and the pulmonary artery (building of TGA), and completed by the closure of VSD-t and arterial switch (Jatene) or Senning surgery.

Another solution is provided by Rastelli-type surgery with extracardial conduit. Alternative solution is represented by Nikaidoh-surgery (aortic translocation with reconstruction of outflow direction of the right ventricle). Kawashima procedure provides another alternative to correct Taussig-Bing-anomaly, which is a bidirectional Glenn-procedure based on functional modification, which later followed by a Fontan- procedure. In case of Fallot IV patching or homografting might represent solution for intraventricular tunneling and pulmonary stenosis. In case distance is significant in between VSD and the great vessels, (double committed or remote [uncommitted] VSD) intraventricular splitting is not feasible. A Fontan procedure is performed in such cases.

III./4.7.2.2.: Postoperative course

In cases of DORV circulatory disconnection provides favorable clinical and hemodynamic results. Long term prognosis requires further evaluation.

Postoperative conditions, problems, and complications

Residual stenosis of right ventricular outflow may persist: parasternal systolic murmur on the left side in II and III intercostal space. Patch plasty may result diastolic murmur related to pulmonary insufficiency. Left ventricular outflow obstruction systolic murmur is heard on the left side in 3rd intercostal space parasternally, or on the mid-section of the upper third of the sternum. Systolic murmur right after the 1st sound may manifest as results of residual VSD; large residuum may manifest as circulatory insufficiency.

Reoperation may be required for (i) residual stenosis of right ventricular outflow, (ii) conduit stenosis in between the right ventricle and the pulmonary artery, (iii) left ventricular outflow obstruction (e.g. fibromuscular subaortic stenosis; following detachment of intraventricular circulation developmental arrest of VSD constituting the entry of intraventricular tunnel etc.). Arrhythmias may appear (i) complete right bundle branch block, (ii) 3rd degree AV block (sudden death is imminent without pacemaker activity in these cases), (iii) ventricular arrhythmia.

Postoperative follow-up

Severity of disease may indicate regular postoperative follow ups. Postoperative endocarditis prophylaxis is required due to morphological changes of valvular systems. Life-long antiarrhythmic medication is required in cases of ventricular arrhythmias. Follow-up physical evaluation, chest X-ray, echocardiography, stress EKG is required on at least annual basis. MRI offers great assistance in precise patient follow-up.Currently corrective surgeries performed in younger ages hopefully will help to decrease frequency of ventricular tachycardia and sudden cardiac death.