Congenital pulmonary stenosis may range from isolated valvar stenosis to complete alresia with intact venliicular septum. They may be present in the neonatal period associated with lesions of tlicuspid valve, light ventricle or coronary arteiies. Isolated pulmonary valvar stenosis that is not critical usually presents at an older age. The valve moiphology may vary fi-orn thickened tii leaflet valve with coinmissural fusion to a dysplastic valve with narrow annulus. Associated infundibular steilosis may also be present.
Indications for Surgery
Interventional treatment is required for all neonates presenting with critical pullnonary valvar stenosis. This call be achieved percutaneously except when there is severe pulmonary annular hypoplasia (Z value of - 4 or less). Such a case will require open pulmonary valvotomy and trans annular patching under cardio-pulmonary bypass. When there is severe reduction in the size of RV, a systemic to pul~nonary shunt is combined with this procedure. Ultimately they will need a Fontan like operation at about two years.Less critical pulmonary slenosis may present in an infant, child or adult. Severe stenosis will have feattures of right heart failure and cyanosis due to right to left shunting at atria level. Children presenting after infancy may have mild, moderate or severe obstruction. When right ventricular peak systolic pressure is less than 50 mm of Hg ancl RV-PA gradient less lhan 25 min of Hg, they will have normal life expectancy and except for periodic follow-up, no intervention is required. RV peak pressure less than 80 mm ofHg and peak gradient less than 50 mm of Hg come in the category of moderate pulnlon~uy stenosis. They require closer follow-up and intervelllion if the condition progresses. Patients presenting with gradients more that 50 m n of I-Ig and peak RV pressure more than 80 mm should have intervention.
Technique of Operation
Percutaneous balloon valvotomy is the procedure of choice at any age. If this is not feasible, open surgical valvotomy is recommended. This is usually done under cardio pullnonary bypass.The approach is through a median sternotomy and institution of cardio pulino~lary bypass with ascending aortic and bicaval cannulation. Moderate hypothermia to 28 OC and cardioplegia are used. Pulillonary trunk is opened vertically and valve inspectcd. All the Lhree commissures are incised up to the annulus. Adherent commissures are separated from pulmonary arterial wall and incised. When the cusps are thick and obstructive, valvectomy is also performed to give better opening. In case there is infundibular narrowing it can be excised from right atrium, pulmonary artery or by ventriculotomy. Pulmonary annular narrowing is treated by transannular patching with pericardium or PTFE patch. Systemic- pulmonary shunling is done if the right ventricle is hypoplastic.
Results
Early mortality for open pulmonary valvolomy in neonates varies between 6 and 10 per cent. For infants and children, surgical mortality approaches 0 per cent. Risk is higher when there is severe RV hypoplasia or severe right ventricular failure. Re-operation may be required in about 4 per cent of cases when followed for 10 years. '
Indications for Surgery
Interventional treatment is required for all neonates presenting with critical pullnonary valvar stenosis. This call be achieved percutaneously except when there is severe pulmonary annular hypoplasia (Z value of - 4 or less). Such a case will require open pulmonary valvotomy and trans annular patching under cardio-pulmonary bypass. When there is severe reduction in the size of RV, a systemic to pul~nonary shunt is combined with this procedure. Ultimately they will need a Fontan like operation at about two years.Less critical pulmonary slenosis may present in an infant, child or adult. Severe stenosis will have feattures of right heart failure and cyanosis due to right to left shunting at atria level. Children presenting after infancy may have mild, moderate or severe obstruction. When right ventricular peak systolic pressure is less than 50 mm of Hg ancl RV-PA gradient less lhan 25 min of Hg, they will have normal life expectancy and except for periodic follow-up, no intervention is required. RV peak pressure less than 80 mm ofHg and peak gradient less than 50 mm of Hg come in the category of moderate pulnlon~uy stenosis. They require closer follow-up and intervelllion if the condition progresses. Patients presenting with gradients more that 50 m n of I-Ig and peak RV pressure more than 80 mm should have intervention.
Technique of Operation
Percutaneous balloon valvotomy is the procedure of choice at any age. If this is not feasible, open surgical valvotomy is recommended. This is usually done under cardio pullnonary bypass.The approach is through a median sternotomy and institution of cardio pulino~lary bypass with ascending aortic and bicaval cannulation. Moderate hypothermia to 28 OC and cardioplegia are used. Pulillonary trunk is opened vertically and valve inspectcd. All the Lhree commissures are incised up to the annulus. Adherent commissures are separated from pulmonary arterial wall and incised. When the cusps are thick and obstructive, valvectomy is also performed to give better opening. In case there is infundibular narrowing it can be excised from right atrium, pulmonary artery or by ventriculotomy. Pulmonary annular narrowing is treated by transannular patching with pericardium or PTFE patch. Systemic- pulmonary shunling is done if the right ventricle is hypoplastic.
Results
Early mortality for open pulmonary valvolomy in neonates varies between 6 and 10 per cent. For infants and children, surgical mortality approaches 0 per cent. Risk is higher when there is severe RV hypoplasia or severe right ventricular failure. Re-operation may be required in about 4 per cent of cases when followed for 10 years. '
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