Early Obstruction of Systemic to Pulmonary Artery Shunts in Neonates and Infants

Background: Systemic-to-pulmonary shunts are technically demanding and yet are associated with a considerable risk of failure. Shunt failure may be related to stenosis with consecutive hypoxemia and eventually death. We retrospectively revised our results taken a comprehensive dataset into account to identify the impact of early shunt obstruction on survival and on which parameters may influence early shunt obstruction defined as necessity for surgical or interventional measures within 30 days after implantation.

Method: Between August 2012 and August 2022, a total of 75 consecutive patients less than 1 year of age (52 neonates; 71%) underwent shunt implantation, either isolated (n = 33; 43%) or as part of more complex procedures. Two patients with late shunt obstruction were excluded. Indication for shunt implantation was either related to univentricular palliation in 45 patients (62%) or as temporarily palliation in a biventricular setting. PTFE tubes of 3.5 mm (n = 62), 4.0 mm (n = 9) or 5 mm (n = 2) in diameter were proximally anastomosed to the ascending aorta in 20 patients, to the innominate artery in 48, and subclavian or carotid artery in 5 patients. Cardio-pulmonary bypass was applied in 57 patients (78%).

Results: Fifteen patients (76%) experienced early shunt failure due to obstruction 1 to 18 days after implantation. In 7 of 15 patients (47%) interventional treatment was applied and successfully done in 6 Children. Hospital mortality was 6/15 (40%) in patients with obstruction versus 13/58 (22%) in the remainder (p = 0.195). Shunt obstruction was not related to prematurity (p = 0.676), age at surgery (p = 0.342), gender (p = 0.379), body weight (p = 0.472), main cardiac diagnosis, or general therapy plan (biventricular vs. univentricular) (p = 0.770). It was not related to individual surgeons (0.507), the use of CPB (p = 0.840), or to a more extensive surgery other than a PDA closure (p = 0.966) or the position of the proximal shunt anastomosis (p = 0.556). There was no obstruction after DHCA (p = 0.067), packing for bleeding (p = 0.566), or ECMO (p = 0.761). In addition, “clinical status score” 1 hour of transfer to ICU defined as good-moderate impaired or poor did not reveal an impact.

Conclusion: The incidence of early shunt obstruction and associated mortality is considerable. However, even comprehensive analysis was not able to define risk factors rendering a more multifactorial etiology likely.

Publication History

Article published online:
28 January 2023