Arterial switch procedure

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The arterial switch procedure, also known as the Jatene switch procedure, is an intervention designed to correct D-transposition of the great arteries (D-TGA) at the level of the aorta and main pulmonary artery. It is generally preferred over atrial switch procedures for simple D-TGA due to improved outcomes .

Rationale

Complete transposition of the great vessels chiefly causes mortality from either hypoxia (in the absence of an intracardiac shunt) or progressive heart failure (if hypoxia is avoided due to the presence of a mixing lesion, e.g. VSD) . Thus, the goal of corrective procedures is to address these two problems.

While hypoxia may be palliated by creating artificial interatrial shunt (transvenous septostomy), patients with D-TGA soon develop heart failure and pulmonary vascular disease with bronchopulmonary collateral formation .

The idea of the arterial switch procedure is to redirect blood flow in order to more closely simulate normal physiology. Specifically, the right ventricular flow is redirected into the pulmonary arteries, and the left ventricular flow is redirected to the systemic circulation.

Arterial switch procedures were developed to overcome problems with the earlier atrial switch procedures, such as the Senning repair or Mustard repair. The atrial switch procedures are associated with late development of atrial arrhythmias, eventual right ventricular failure and tricuspid regurgitation, and (rarely) pulmonary hypertension and baffle obstruction and/or leaking .

Procedure

The surgical technique may vary according to specific anatomic variation.

General steps include the following :

  • the aorta and pulmonary arteries are exposed, and multiple cardiovascular cannulations are performed in order to initiate a cardiopulmonary bypass
  • the aorta and pulmonary artery are transected, the latter proximal to the bifurcation
  • the left and right coronary arteries are then resected together with a small patch ("button") of aorta surrounding the origin. The coronary arteries are implanted to the neoaorta (formerly the main pulmonary artery)
  • transected great vessels are switched, creating neoaorta and neopulmonary trunk
    • proximal transected pulmonary trunk is shifted posterior to the branch pulmonary arteries (the "Lecompte maneuver") and anastomosed to the distal aorta, forming a neoaorta
    • proximal transected aorta is patched (e.g. pericardial patch) at the site of coronary artery explantation. Subsequently, this is anastomosed to branch pulmonary arteries, forming a neopulmonary trunk
  • the atrial septal defect or septostomy lesion is repaired via a right atrial incision

    • The manifestations of congenital heart disease often lie along a spectrum, and modifications of the basic arterial switch procedure are possible to accommodate the correction of other abnormalities. One such example is the Rastelli procedure, which helps simultaneously correct VSD and LVOT obstruction.

    The arterial and atrial switches have been combined to correct L-transposition in a double switch procedure.

    Complications

    Complications of arterial switch procedure include:

    • the most common complication encountered in the arterial switch procedure is supravalvular pulmonary stenosis at the anastomotic site
    • dilatation of the neoaortic root has been encountered, but abnormal valve function is uncommon and thus the significance is unclear
    • coronary artery stenosis, which may result in sudden death or myocardial infarction

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