Reasons for Failure of Systemic-to-Pulmonary Artery Shunts in Neonates.

BACKGROUND: Systemic-to-pulmonary artery shunt placement is an established palliative procedure for congenital heart disease. Although it is thought to be a simple operation, it is associated with significant morbidity and mortality. METHODS: Data for all neonates who underwent surgery for a systemic-to-pulmonary artery shunt between 2000 and 2016 were reviewed. The study endpoints were shunt failure and shunt-related mortality. Shunt failure was defined as a shunt dysfunction because of thrombosis or stenosis requiring intervention or reoperation; shunt mortality was defined as death because of a shunt dysfunction. RESULTS: A total of 305 shunts (central shunt, n = 135; Blalock-Taussig shunt, n = 170) were implanted in 280 patients. The median patients' age at the time of surgery was 9 days (1-31 days). The median shunt size was 3.5 mm (3-4 mm). Twenty-four patients (8%) were diagnosed with a shunt failure, with a median time of 7 days (0-438 days). Freedom from shunt failure at 1 year was 91.6% ± 2%. A shunt-related mortality was ascertained for 12 patients (4%). Freedom from shunt-related mortality at 1 year was 96% ± 1%. Perioperative platelet transfusion (p = 0.01), central shunt (p = 0.02), 3-mm shunt size (p = 0.02), and postoperative extra corporeal membrane oxygenation (ECMO) (p < 0.01) were identified as risk factors for shunt failure. Platelet transfusion (p = 0.04) and postoperative ECMO (p < 0.01) were further identified as risk factors for shunt mortality. CONCLUSION: Based on these data, we recommend implanting a modified Blalock-Taussig shunt of at least 3.5 mm in neonates. Perioperative platelet transfusion and postoperative ECMO increase the risk of shunt failure.

Risk Factors for Failure of Systemic-to-Pulmonary Artery Shunts in Biventricular Circulation.

Systemic-to-pulmonary artery shunt placement is an established palliative procedure for congenital heart disease, but it is associated with high morbidity and mortality. Data of all patients with biventricular circulation who underwent systemic-to-pulmonary artery shunt implantation between 2000 and 2016 were reviewed. Endpoints of the study were shunt failure and shunt-related mortality. Shunt failure was defined as any shunt dysfunction requiring intervention or reoperation. Shunt-related mortality was defined as death due to shunt dysfunction. A total of 217 shunts (central shunt, n = 131, Blalock-Taussig shunt, n = 86) were implanted in 178 patients. The median age of the patients was 98 days [1 day to 1.2 years]. Corrective surgery was performed at a median time of 0.6 years [3 months to 7 years] after shunt placement. Shunt failure was diagnosed in 21 patients (9.6%) at a median time of 14.6 days [0 days to 2 years]. Causes of shunt failure were stenosis (n = 11; 5%) and thrombosis (n = 10; 4.6%). The rate of freedom from shunt failure was 89.9 ± 2.6% at 1 year, the rate of shunt-related mortality was 3% (n = 5), and the rate of freedom from shunt-related mortality at 1 year was 97.5 ± 1%. Platelet transfusion was required in 43 patients (20%), all for postoperative thrombocytopenia. Perioperative platelet transfusion (p = 0.03) and shunt size of 3 mm (p = 0.03) were identified as risk factors for shunt failure. Shunt size of 3 mm was also identified as a risk factor for shunt-related mortality. The ideal shunt size in patients with biventricular circulation requiring a systemic-to-pulmonary artery shunt is 3.5 mm or larger. Platelet transfusion increases the risk of shunt failure and should be avoided. Type of shunt and diagnosis have no influence on morbidity or mortality after shunt placement.