Atrial Switch Repair

Mustard and Senning Operations

• It was first described by Senning in 1959.
• In 1964, Mustard published his experience with the atrial switch.
• This operation became popular due to an increase in survival of over 90%.
• Both of these procedures "correct" the physiologic abnormality of the TGA by forming a baffle within the atria in order to switch the flow of blood at inflow level. As a consequence the heart and lungs will be in series.
• The Mustard Operation consist of an atrial septectomy and placement of a baffle that directs caval blood to the mitral valve, allowing the pulmonary veins to drain into the tricuspid valve. The baffle is created from pericardium or synthetic material.
• The Senning operation, utilized right atrial wall and atrial septal tissue (without the use of extrinsic materials), to create the baffle or wall of the caval tunnel in order to achieve the same goal as in Mustard.
• The early mortality rate for both procedures is low, between 1 and 10%
• The long-term outcome is affected by late complications such as atrial arrhythmia (with the highest incidence of more than 50% within 10 years), and a late right ventricular (systemic ventricular) dysfunction (approximately 10%).
• The Senning repair is becoming more promising than Mustard due to the better long term outcomes in terms of venous obstruction and atrial haemodynamics. However, the procedure of choice for treatment of patients with d-TGA is the Arterial Switch or Jatene Operation.