Management of the single ventricle and potentially obstructive systemic ventricular outflow tract

Abstract

Multi-stage palliation is the current management strategy for the treatment of children with various single ventricle (SV) cardiac malformations. The success of this strategy depends on the presence of favorable anatomic and hemodynamic criteria. Several SV anomalies have the potential of developing systemic ventricular outflow tract obstruction (SVOTO) that might be evident early on or progress later after palliative surgeries. SVOTO could result in ventricular hypertrophy, impaired diastolic function and subendocardial ischemia with subsequent deleterious effects on the SV and disturbance of some of those criteria for a successful multi-stage palliation strategy. Careful identification of SV patients at risk of developing SVOTO and proper planning of the optimal palliation sequence beginning at the 1st stage procedure are vital factors that would affect long-term outcomes in those patients. In the current review, we describe the morphology of SV patients with potential SVOTO risk, surgical procedures that address potential or present SVOTO, and optimal timing of those procedures within the multi-stage palliation chain. We attempt to provide a treatment algorithm for various patients taking into consideration their unique anatomic and physiologic characteristics.

Keywords: Hybrid; Norwood; Pulmonary artery band; Single ventricle.

Figure 1

Left thoracotomy view of a single ventricle patient with normally related great vessels who has aortic coarctation, hypoplastic aortic arch and patent ductus arteriosus (A). The patient underwent extended end-to-end repair of aortic coarctation, ligation and division of the ductus arteriosus, and main pulmonary artery banding as a 1st stage palliation procedure (B).

Figure 2

View from a single ventricle patient with normally related great vessels at time of 2nd stage procedure following initial pulmonary artery banding. The band was removed, the main pulmonary artery was transected, the branch pulmonary arteries end was closed with a patch, and an incision at the medial side of the aorta was created (A). The patient underwent an end to side Damus-Kaye-Stansel anastomosis, supplemented with patch material, in addition to Glenn bidirectional cavopulmonary connection (B). View from a patient with single ventricle and normally related great vessels at time of 2nd stage procedure following initial pulmonary artery banding. The band was removed, the main pulmonary artery was transected at the site of the band, the aorta was transected at almost similar height above the sinotubular junction, and the branch pulmonary arteries end was closed primarily (C). The patient underwent a side to side double barrel Damus-Kaye-Stansel anastomosis, in addition to Glenn bidirectional cavopulmonary connection (D).

Figure 3

View from a single ventricle patient with ventriculo-arterial discordance who underwent ventriculotomy into the rudimentary ventricle and enlargement of the bulboventricular foramen. The dashed line indicates the safe area for enlargement while the circles demonstrate the likely site for conduction system (A). Following enlargement of the bulboventricular foramen, the ventriculotomy is closed with a patch (B).

Figure 4

View from a single ventricle patient with ventriculo-arterial discordance who underwent a Norwood-type 1st stage palliation. The main pulmonary artery and ascending aorta were transected above the sinotubular junction, the hypoplastic aortic arch was opened and the coarctation area was excised (A). The reconstruction was completed by performing a Damus-Kaye-Stansel anastomosis, arch reconstruction and augmentation with patch. The source of pulmonary blood flow is provided with an aortopulmonary shunt, or a right ventricle to pulmonary artery shunt (Not shown) (B).

Figure 5

View from a single ventricle patient with ventriculo-arterial discordance who underwent a palliative arterial switch operation as 1st stage palliation. Neo-aorta was reconstructed after coronary transfer, and a Lecompte maneuver was accomplished by placing the branch pulmonary arteries anterior to the reconstructed neo-aorta (A). The neo-pulmonary artery was reconstructed with a patch. Very often, the addition of either an aortopulmonary shunt or a pulmonary artery band is necessary. In this example, an aortopulmonary shunt is shown (B).

Figure 6

View from a single ventricle patient who underwent hybrid-type 1st stage palliation with branch pulmonary artery banding and ductal stenting (A). At time of 2nd stage surgery, the reconstruction was completed by performing a Damus-Kaye-Stansel anastomosis, arch reconstruction and augmentation with patch, pulmonary artery de-banding and augmentation, in addition to Glenn bidirectional cavopulmonary connection (B).

Figure 7

A proposed management algorithm for the treatment of single ventricle patients at potential risk of developing systemic ventricle outflow tract obstruction.