Systemic to pulmonary artery shunts

Provided by "Pediatric Heart Surgery — a reference for professionals"

Indications and pathophysiology 

The systemic to pulmonary artery shunt procedure is used in some patients with cyanotic congenital heart disease. A connection is created between a systemic artery and the pulmonary artery or one of its main branches. The connection can be direct, or more commonly, a synthetic tubular graft may be used. This results in shunting of blood from the systemic artery to the pulmonary artery. This is a palliative procedure designed to increase systemic arterial oxygen saturation by increasing blood flow to the pulmonary artery. Indications for systemic to pulmonary artery shunting include any patient with a congenital heart defect in whom pulmonary artery blood supply is inadequate and in whom complete definitive repair is otherwise contraindicated. Individuals commonly submitted for this procedure include patients with tricuspid atresia, small infants with tetralogy of Fallot who experience severe hyper- cyanotic spells, and patients with pulmonary atresia. Increasing pulmonary artery blood flow serves to increase arterial oxygen saturation, and in addition, may promote growth of the pulmonary vascular tree.

Surgical technique

The systemic-to-pulmonary artery shunt procedure is usually performed via median sternotomy or thoracotomy without the use of cardiopulmonary bypass. The modified Blalock-Taussig shunt is performed using a synthetic tube graft. One end is anastomosed to the subclavian or innominate artery and the other end to the right or left pulmonary artery. The central shunt procedure is performed using a synthetic tube graft between the aorta and the main pulmonary artery. Optimal shunt size depends upon patient size, pulmonary artery resistance, and individual anatomy.

Postoperative considerations

The postoperative course following systemic to pulmonary artery shunting is usually benign. When the procedure is performed as part of a more major operation, such as the Norwood procedure, the post- operative considerations discussed in that section would apply. Complications following the systemic to pulmonary artery shunt procedure are rare. Phrenic nerve, vagus nerve, and/or sympathetic nerve injury is rarely observed and usually resolves spontaneously. Length of hospital stay required following surgery averages 4 to 7 days