Background and Aim:
To analyse the long-term patency of coronary arteries and correlated factors in a cohort of patients undergone arterial switch (ASO) operation in our institution.
This is a retrospective study of operative and postoperative data of 191 patients who underwent ASO between 1991 and 2016. All patients underwent clinical, echocardiographic and angiographic evaluation during follow-up; dobutamine-stress and treadmill test were performed when indicated. Variables included were: complex native coronary anatomy (Yacoub types B-E), aorto-pulmonary relationship (anterior aorta vs. syde-by-syde) dimensional-mismatch, coronary reimplantation technique (direct-punch vs. trap-door technique). Univariate analysis was performed by chi-squared test and ANOVA when necessary.
191 patients have been studied by elective invasive cardiac coronary angiography after ASO at a mean time of 2.7 ± 2.1years without any significant procedure-related complication. Mean follow-up after the ASO was 12.9 ± 6.6years. Nine patients (4.7%) had angiographic signs of coronary stenosis or occlusion:8/9were asymptomatic. All details are reported in Table 1. Neither TGA anatomical features, nor coronary anatomy,nor reimplantation technique were identified as risk factors for occurrence of coronary artery obstruction (univariable analysis p values 0.159, 0.282, 0.49 respectively).
Coronary obstruction after ASO is a silent and often overlooked complication. Patients may not show any symptoms or instrumental evidence of myocardial ischemia even with severe lesions, and the ordinary non-invasive diagnostic tools could be inadequate. Routine angiographic catheterization represents a secure and effective tool for follow-up ensuring early identification of coronary disease.
In our experience, the extended mobilization of coronary ostia to avoid abnormal coronary tension/distortion, even by the excision of small conal branches, has led to low incidence of coronary obstruction. Thanks to this, neither coronary complexity is a risk factor anymore