Does left ventricular outflow tract obstruction influence outcome of interrupted aortic arch repair?

In previous studies left ventricular outflow tract obstruction (LVOTO) has been recognized as an important factor affecting survival and reoperation probability in patients having repair of an interrupted aortic arch (IAA).

All 72 patients who underwent operation for IAA from January 1, 1985 to June 30, 1997 were reviewed. The presence or absence of LVOTO was noted and the immediate and long-term results were analyzed.

Type A IAA was found in 23 patients and type B IAA in 49 patients. Anomalous right subclavian artery was noted in 15 patients, all of whom had type B IAA. LVOTO was identified in 36 patients before arch repair and was associated with the presence of type B IAA and anomalous right subclavian artery (p = 0.02 and 0.007, respectively). There were 2 hospital deaths (within 30 days) for a mortality of 2.8% (confidence limit [CL] = 0% to 6.6%). There were 7 late deaths over 3,737 patient-months of follow-up (9.7%, CL = 2.9% to 16.6%). Actuarial survival for the whole cohort was 84.8% (CL = 73.2% to 94.4%) at 12 years. There was 87% 10-year survival (CL = 60% to 93%) for patients with LVOTO at presentation compared with 83% (CL = 62% to 92%) for patients without LVOTO (p = 0.85, hazard function 0.87). Twenty-eight patients have required at least one reoperation. The use of conduits to restore right ventricular to pulmonary artery continuity predicted the need for reoperation (p = 0.0001). Patients with presence of a nonseptatable heart were also more likely to need reoperation (p = 0.027) when compared to the rest of the cohort. Freedom from reoperation was 47.3% (CL = 30% to 62%) at 12 years. In patients with LVOTO, freedom from reoperation (55% at 10 years, CL = 33% to 72%) was not significantly different from those patients without LVOTO at presentation (29% at 10 years, CL = 7% to 56%; p = 0.97, hazard function 0.7). Actuarial freedom from recurrent arch obstruction requiring reintervention was 82.7% (CL = 66.7% to 98.7%) at 12 years.

Neonatal complete repair of patients with IAA is possible with low mortality. LVOTO was not a significant risk factor for hospital or late death in patients having complete repair of IAA during this period. The use of conduits for right ventricular to pulmonary artery continuity and the presence of a nonseptatable heart are important risk factors for further operation and will continue to provide added morbidity to these patients.