What is Indications for Operation Single Ventricle Physiology ?
The operation is indicated in patients with single ventricle physiology. Fontan operation is also indicated in patients with concordant or discordant atrio ventricular connection in whom and ventricle is too small or dysplastic. Fontan type correction is also indicated even when there are two adequate ventricles but cannot he separated because of complex overriding AV valves (straddling AV valves), relationship of VSDs and great arteries.
If the right ventricle is hypoplastic (less than 30 per cent of normal) two- ventricle correction not advisable.
As mentioned earlier; a staged Fontan operation will have to be carried out, First stage pallintion depends and whether the pulmonary flow is inadequate or excessive. Inadequate pulmonary flaw leads to severe cyanosis and the palliative procedure is systemic pulmonary artery shunt (Modified Blalock-Taussig shunt). Presence of severe cyanosis (SA02 less than 70-75 per cent) and duct dependency we indications for shunt.
In cases with excessive pulmonary flaw, palimony trunk banding is done early in life. Raised palimony artery pressure and pulmonary vascular disease makes then unsuitable far Fortuna type correction. When pulmonary blood flow is large enough to produce heart failure, pulmonary trunk banding should not be delayed.
It is ideal to do banding at 3& or 4& week of life. When the operation is done earlier the palimony regression would not have occurred and band may need tightening later on.