MCQ Pathology Answer 33

The Correct Answer is A

The atrial repair of transposition of the great arteries—rerouting systemic and pulmonary venous blood at the atrial level—results in the right ventricle's becoming the systemic ventricle. This results in an anatomic right ventricle with abnormal geometry sustaining the afterload of a more ideally suited left ventricle.

Long-term complications of ventricular dilatation, AV valve regurgitation, and right ventricular failure have been reported in as many as 10% of patients many years following the atrial operation.

The multiple suture lines in the atrium have been associated with a high incidence of late atrial arrhythmias and a low incidence of sinus rhythm following the Mustard and Senning operations.

These complications do not appear to be as frequent with the arterial switch repair.

In addition, the complicated interatrial baffles have been associated with pulmonary or systemic venous baffle obstruction. Because the right ventricular outflow tract is not addressed during an atrial switch operation, right ventricular outflow tract obstruction is not a recognized complication following the repair. Right ventricular outflow tract and supravalvar pulmonic stenosis, however, have been reported in patients after the arterial switch repair, owing to the reconstruction of the right ventricular outflow tract in that operation.

Although progression of pulmonary arterial obstruction has rarely been reported following early repair with the atrial or the arterial switch procedure, it is an unusual complication if operation is undertaken in infancy. Delayed repair beyond age 6 months to 1 year, however, has been associated with a higher incidence of progressive development of pulmonary vascular obstructive disease.

The rapidity of the development of pulmonary vascular disease is increased by the coexistence of a VSD.

Category: Pathology MCQs