Overall Hypothesis: Endothelin-1 (ET1) and associated dysregulation of key metabolic pathways decrease pre-operative pulmonary blood vessel development and increase post-operative pulmonary blood vessel resistance leading to decreased pulmonary blood flow in patients undergoing SCPA.
For enrolled patients, collected data will include:
* 3 mL blood sample (x2) at pre-SCPA catheterization.
* 3 mL blood samples at 2, 24, and 48 hours post-operative.
* Urine sample pre-operatively and post-operatively
* Collection of otherwise-discarded operative tissue sample from the pulmonary artery.
* Collection of clinical data, demographic data, and results of routine, post-operative hemodynamic monitoring.
