Late follow-up after venous switch operation (Mustard procedure) for simple and complex transposition of the great arteries.

Most adolescents and young adults born with complete transposition of the great arteries (TGA) and alive today are survivors of the Mustard operation. This study reports on the serial, long-term (from 10 to > 20 years) follow-up of 85 patients who underwent this operation between 1971 and 1981. Of these, 63 had simple and 22 complex TGA. The age at surgery ranged from 2 days to 17 years. The early mortality rate was 10.5% and the late mortality 9.2%. The actuarial survival rate after 15 years was 86% for simple and 64% for complex TGA. Event-free survival after 15 years was 77% for simple and 46% for complex TGA. Yearly review of electrocardiograms and, less frequently, of Holter tracings disclosed a lower mean resting heart rate and decrease over time in sinus rhythm and an increase in active arrhythmias. Fifty-two percent had resting sinus rhythm and 17% had active arrhythmias at 16 to 20 years of follow-up. Exercise stress testing in 21 patients revealed resumption of sinus rhythm during exercise but significant diminution of endurance time and peak heart rate response. Seven of the survivors (9.2%) required reoperation. Of these, 4 had severe tricuspid regurgitation following patch closure of ventricular septal defect. This study shows gratifying long-term and event-free survival for the majority of patients who underwent surgery by this venous switch procedure.