The Blalock-Hanlon procedure is a palliative surgical operation used to treat cyanotic congenital heart defects, particularly transposition of the great arteries (TGA), where oxygen-poor and oxygen-rich blood are improperly circulated. This procedure involves creating an atrial septal defect (a hole in the wall separating the heart's two upper chambers) to allow mixing of oxygen-poor blood from the right atrium and oxygen-rich blood from the left atrium. By enabling this mixing, the procedure increases the oxygen content of blood pumped to the body, providing temporary relief from cyanosis (a bluish discoloration of the skin due to low oxygen levels). The Blalock-Hanlon procedure is typically used as a short-term solution in infants who are not immediately candidates for corrective surgery, such as an arterial switch. It is often performed when other options, such as balloon atrial septostomy, are not feasible or effective. The procedure is considered palliative, as it does not correct the underlying congenital heart defect but helps stabilize the patient until definitive treatment can be performed. Symptoms that lead to the need for the Blalock-Hanlon procedure include severe cyanosis, difficulty breathing, poor feeding, and failure to thrive in newborns with transposition of the great arteries or other cyanotic heart conditions. These symptoms occur due to insufficient oxygenation of the blood. By creating a passage between the atria, the Blalock-Hanlon procedure helps improve oxygenation and temporarily alleviates symptoms, allowing the child to grow stronger in preparation for more permanent surgical intervention, such as an arterial switch or other corrective procedures.
