Late outcome after arterial switch operation for complete transposition of great arteries with left ventricular outflow tract obstruction

BACKGROUND: Long-term follow-up of patients who underwent arterial switch operation for complete transposition of great arteries with anatomic left ventricular outflow tract obstruction (LVOTO) has rarely been brought into the focus. METHODS: Of 299 patients who underwent an arterial switch operation between January 1991 and January 2001, 23 patients had anatomic LVOTO. Age ranged from 4 days to 18 years (median 90 days) and weight ranged from 2.6 to 35 kg (median 4.3 kg). Surgical management included arterial switch operation, closure of ventricular septal defect wherever indicated, and excision of LVOTO. RESULTS: Among patients with preoperative LVOTO there were 2 early deaths and 8 patients had mild neoaortic regurgitation at the time of discharge. Follow-up ranged from 8 months to 9 years (mean 60 +/- 12 months). In 4 patients who had mild neoaortic regurgitation at discharge, the regurgitation progressed to moderate or severe degree after a follow-up of 22 to 72 months. In 1 patient mild mitral regurgitation present at the time of discharge progressed to severe mitral regurgitation. This patient subsequently underwent double valve replacement. CONCLUSIONS: Presence of preoperative anatomical LVOTO in patients undergoing arterial switch operation predicts high incidence of postoperative neoaortic regurgitation.