Surgical outcomes of the systemic-to-pulmonary artery shunt: risk factors of post-operative acute events and effectiveness of regulation of pulmonary blood flow with metal clips.

Objectives: The aim of this study was to analyze the risk factors for acute events after systemic-to-pulmonary shunt (SPS) and to investigate the effectiveness of pulmonary blood flow regulation with a metal clip.

Methods: The case histories of 116 patients (78 biventricular [BV] and 38 single ventricle [SV] physiology) who underwent SPS between 2010 and 2021 were retrospectively reviewed. Our strategy was to delay SPS until 1 month of age; pulmonary blood flow (PBF) regulation by partial clipping of the graft, if needed. Cases of aortic cross-clamping were excluded from this study.

Results: CPB was used in 49 (42%) patients: the median age at SPS was 1 month (2 days to 16 years), and the sternotomy approach in 65. Discharge survival was 98.3% (114/116); hospital death occurred in 1.7% due to coronary ischemia. Inter-stage mortality occurred in 1.7% (shunt thrombosis, 1; pneumonia, 1). Pre-discharge acute events occurred in 7 patients (6.0%): thrombosis 3, pulmonary over-circulation 2, and coronary ischemia 2. Multiple logistic regression analysis revealed that pulmonary atresia with intact ventricular septum (PA/IVS) (p = 0.0253) was an independent risk factor for acute events. Partial clipping of the graft was performed in 24 patients (pulmonary atresia 15) and clip removal was performed by catheter intervention in 9 patients; no coronary ischemic events and graft injury occurred in these patients.

Conclusion: Surgical outcomes after SPS were acceptable and metal clip regulation of pulmonary blood flow appears to be safe and effective. PA/IVS was still a significant risk factor for acute events.