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| Anatomy and classiflcntion |
In this congenital anomaly there is no direct communication between the pulmonary veins and the left atrium. All the pulmonaty veins connect to the right atrium or one of its tributaries. An ASD or large PFO (patent foramen ovale) is essential for survival. The main varieties are supracardiac (45 per cent), cardiac (25 per cent), infiacardiac (25 per cent) and mixed type (5 per cent).
Indications for Surgery
Once TAPVC is diagnosed in a neonate with symptoms, operation should be undertaken immediately. It is one of the conditions which demand surgery in the frrst few days or weeks of life and usually before six months of age. There is no palliative measure except for atrial septostoiny if in a rare case that is the only point of obstruction. Obstruction of the common pulmonary venous channel is more comlnon in the infracardiac variety necessitating very early intervention. A few individuals without obstruction survive to childhood or adult life. The degree of cyanosis is not the main indication for surgery. There is good mixing in the right atrium and so cyanosis may be minimal. When pulmonary vascular disease id suspected cardiac catheterization and assessinent of pulmonary vascular resistance is done with isoproterenol infusion. Otherwise surgery is undertaken after echocardiography.
In neonates when there is obstivction only at atrial septa1 defect, a balloon or blade septostomy is indicated. Definitive surgery is not delayed more than a few days after such a procedure.
Technique of Surgery
Corrective surgery is undertaken as an emergency procedure after diagnosis has been confirmed by two-dimensional echocardiography. The approach is through median sternotomy. The preferred technique in neonates is deep hypothermia and circulatory arrest (DHCA) and limited cardiopulmonary bypass. Ductus arteiiosus is dissected and ligated before going on bypass.
Results
Reported hospital mortality varies from 2 to 20 per cent depending on the experience of cardiac surgery center and time of presentation for surgery. Two serious post-operative complications are: (I) pulmonary hypertei~sive crisis, and(2) delayed development and progression of pulmonary vein stenosis. Children who survive the operation have excellent chances of long-teim survival.
Indications for Surgery
Once TAPVC is diagnosed in a neonate with symptoms, operation should be undertaken immediately. It is one of the conditions which demand surgery in the frrst few days or weeks of life and usually before six months of age. There is no palliative measure except for atrial septostoiny if in a rare case that is the only point of obstruction. Obstruction of the common pulmonary venous channel is more comlnon in the infracardiac variety necessitating very early intervention. A few individuals without obstruction survive to childhood or adult life. The degree of cyanosis is not the main indication for surgery. There is good mixing in the right atrium and so cyanosis may be minimal. When pulmonary vascular disease id suspected cardiac catheterization and assessinent of pulmonary vascular resistance is done with isoproterenol infusion. Otherwise surgery is undertaken after echocardiography.
In neonates when there is obstivction only at atrial septa1 defect, a balloon or blade septostomy is indicated. Definitive surgery is not delayed more than a few days after such a procedure.
Technique of Surgery
Corrective surgery is undertaken as an emergency procedure after diagnosis has been confirmed by two-dimensional echocardiography. The approach is through median sternotomy. The preferred technique in neonates is deep hypothermia and circulatory arrest (DHCA) and limited cardiopulmonary bypass. Ductus arteiiosus is dissected and ligated before going on bypass.
Results
Reported hospital mortality varies from 2 to 20 per cent depending on the experience of cardiac surgery center and time of presentation for surgery. Two serious post-operative complications are: (I) pulmonary hypertei~sive crisis, and(2) delayed development and progression of pulmonary vein stenosis. Children who survive the operation have excellent chances of long-teim survival.
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