Congenital left ventricular outflow tract obstruction

Congenital obstruction of the left ventricular outflow tract remains a significant problem. Obstruction may involve the subvalvar, valvar or supravalvar portion of the aortic valve complex. Congenital valvar stenosis presenting in the neonatal period represents a spectrum of disorders ranging from the hypoplastic left heart syndrome to almost normal hearts. Preoperative echocardiography may allow the selection of infants who are suitable for biventricular repair, with the therapeutic options including open valvotomy and balloon valvotomy, but the determination of the optimal method of treatment will require long term follow up data. Subvalvar obstruction may be discrete or diffuse, and the extent will determine the appropriate therapy. Discrete membranes may be managed by a simple excision while diffuse involvement of the subvalvar region may require a more extensive reconstructive procedure such as the Konno procedure. Supravalvar aortic stenosis is the least common form of aortic stenosis and may be associated with abnormalities of the pulmonary arteries. Treatment is often palliative rather than corrective with all types of congenital left ventricular outflow tract obstruction, and many patients will require reoperations, especially those with valvar and subvalvar obstruction. The lack of long term follow up data for patients treated in the neonatal period makes the choice of an optimal therapy difficult. New methods of valve replacement such as the pulmonary autograft may improve long term results.