Andersons pediatric cardiology 1858

catheterization with angiography found no detectable differences in immediate and short-term postoperative outcomes, albeit in selected patients.211 Table 71.8 Important Elements of the Pre-Superior Cavopulmonary Connection Evaluation Hemodynamics Systemic blood flow Pulmonary blood flow Pulmonary artery pressure Atrial pressure/end-diastolic pressure Systemic and pulmonary vascular resistance Pressure gradients: atrial septum, pulmonary arteries, pulmonary veins, atrioventricular valve, ventricular outflow tract, aortic arch Valvar regurgitant fraction Anatomy Superior vena cava Pulmonary arteries Ventricular outflow tract Aortic arch Other Ventricular function Atrioventricular valve regurgitation Venovenous collaterals (potential) Aortopulmonary collaterals Modality Cath, CMR Cath, CMR Cath Cath Cath Cath, CMR, echo CMR Cath, CMR, CT, echo Cath, CMR, CT, echo Cath, CMR, CT, echo Cath, CMR, CT, echo Cath, echo, CMR Cath, echo, CMR Cath, CMR, CT Cath, CMR, CT Cath, Cardiac catheterization; CMR, cardiac magnetic resonance; CT, computed tomography; echo, echocardiography Surgical Strategies The most common anatomy encountered is a patient with levocardia and a single right superior vena cava In this setting two strategies are commonly employed to achieve a connection between the superior vena cava and the confluent pulmonary arteries The simplest is the bidirectional Glenn shunt (Fig 71.9) (Video 71.2).212 The superior vena cava is transected at its insertion into the right atrium and an anastomosis is constructed between the superior vena cava and the proximal right pulmonary artery This is generally done on cardiopulmonary bypass and includes cannulation of the superior vena cava and right atrium; but if adequate pulmonary blood flow can be maintained during the procedure and the branch pulmonary arteries do not require patch augmentation, the procedure can be done off bypass Another option is the hemi-Fontan (Fig 71.10) This is a more extensive procedure and requires cardiopulmonary bypass and aortic cross-clamping with cardioplegia The pulmonary arteries are connected widely to the superior vena cava and the cephalad portion of the right atrium A patch separating the superior cavopulmonary anastomosis from inferior portion of the right atrium completes the procedure The decision between a bidirectional Glenn shunt and a hemi-Fontan is primarily based on institutional experience and the preference for the third-stage procedure The hemi-Fontan allows for straightforward construction of a lateral tunnel Fontan, whereas the bidirectional Glenn shunt is better suited for an extracardiac Fontan Data from The Single Ventricle Reconstruction Trial show that the bidirectional Glenn was performed much more often than the hemi-Fontan (73% vs 27%) Although mortality and hospital length of stay were similar for both procedures, the hemi-Fontan had a lower complication and reintervention rate at 1 year.13,213 Transient sinus node dysfunction is more common after the hemi-Fontan operation, and the longer-term prevalence of sinus node dysfunction is similar with either type of SCPC.214–216 FIG 71.9 The bidirectional Glenn shunt is a form of superior cavopulmonary anastomosis in which the superior vena cava is divided at the insertion into the right atrium and an anastomosis is constructed with a proximal branch pulmonary artery In general additional arterial sources of pulmonary blood flow such as a systemic-to-pulmonary artery shunt are divided (From Jonas RA The intra/extracardiac conduit Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2011;14:11–18.) FIG 71.10 The hemi-Fontan procedure is another form of superior cavopulmonary anastomosis The superior caval vein is not divided; instead, an anastomosis is constructed between the superior caval vein