The Blalock-Taussig shunt is a surgical procedure to give palliation to cyanotic heart defects which are common causes of blue baby syndrome. In modern surgery, this procedure is temporarily used to direct blood flow to the lungs and relieve cyanosis while the infant is waiting for corrective surgery.
One branch of the subclavian artery or carotid artery is separated and connected with the pulmonary artery. The lung receives more blood with low oxygenation from the body. The first area of application was tetralogy of Fallot.
The procedure is no longer in use in its original form. Now a length of artificial tubing, 3 to 4 millimeters in diameter, is sewn between either the subclavian or the carotid artery and the corresponding side branch of the pulmonary artery, thus obviating the need to cut off blood supply and making it easier to regulate the blood flow to the lungs. Some centers now use a shunt directly from the right ventricle to the pulmonary artery, a Sano shunt. This is done to avoid the reduced diastolic blood flow in the coronary circulation associated with the Blalock-Taussig shunt.