Blood samples were obtained from an arterial line that was required for the planned surgical procedure. Samples were centrifuged to yield platelet poor plasma (PPP), stored at -80 degrees Celsius and utilized for the clot analysis. Clot degradation was determined by degradation kinetic study. Blood samples were collected at four time points:1) baseline sample within 24 hours of surgery and after induction of anesthesia prior to CPB; 2) after termination of CPB and transfusion of platelets and either cryoprecipitate or fibrinogen (within 1 hour of separation from bypass; 3) upon arrival to the ICU; 4) 24 hours post-operatively. The primary outcome is to examine differences in clot degradation between study arms at 24 hours post-surgery.

This analysis includes the Intent to Treat Population, which is comprised on all participants regardless of if they completed the study per protocol.

Blood samples will be obtained from an arterial line that is required for the planned surgical procedure. They will be centrifuged to yield platelet poor plasma (PPP), stored at -80 degrees Celsius and utilized for the clot analysis. Strength will be assessed by rheology and atomic force microscopy (AFM).

Unfortunately, due to the required amount of blood necessary for triplicates of the primary outcome, there was not enough blood to examine clot strength. Due to the small amount of blood collected from neonates the samples were used for the outcome measures with the highest priority and the amount of remaining blood was not sufficient to assess clot strength.

Blood samples will be obtained from an arterial line that is required for the planned surgical procedure. They will be centrifuged to yield platelet poor plasma (PPP), stored at -80 degrees Celsius and utilized for the clot analysis. Polymerization will be determined by thrombin-initiated turbidity/absorbency curves.

Due to the maximum allowable blood to be taken from a neonate, there was not enough remaining blood available to examine clot polymerization kinetics. In order to carry out the degradation assay on neonatal fibrinogen, the study team improved the assay they originally intended to use and no longer did polymerization assays as part of the degradation assay. Due to the change in the degradation assay, the team was not able to collect additional blood for the clot polymerization kinetics assay.

Clot structure is assessed by examination of images of clot fibrin fiber alignment. Quantification of clot fiber alignment was achieved through the application of an automated algorithm based on a fast Fourier transform that measures the alignment of the fibers, as well as visual inspection. A reference range has not been established for neonates, however, higher values indicate more dense clot structure.

This analysis includes the Intent to Treat Population.

Blood product transfusion requirements were obtained from electronic medical records. An increased transfusion requirement indicates increased interoperative bleeding, thus, lower values are preferable.

This analysis includes the Intent to Treat Population.

Transfusion requirements within the first 24 hours of surgery were obtained from electronic medical records.

The recording of transfusions in the intensive care unit (ICU) changed in the middle of this study and therefore transfusions were not consistently documented by the clinical staff, thus, the study investigators decided to not collect information about transfusions up to 24 hours after surgery from medical records as data could not be reliably analyzed.

Post-operative bleeding was recorded by 24 hour chest tube output. Higher values indicate greater post-operative bleeding.

This analysis includes the Intent to Treat Population.

Mechanical ventilation time was obtained from medical records. Higher values indicate increased need for mechanical ventilation.

This analysis includes the Intent to Treat Population.

Length of ICU stay was obtained from medical records. A shorter ICU stay indicates a favorable state of health.

This analysis includes the Intent to Treat Population.

Length of hospital stay was obtained from medical records. A shorter hospital stay indicates a favorable state of health.

This analysis includes the Intent to Treat Population.

Adverse events within seven days of surgery were obtained from medical records.

This analysis includes the Intent to Treat Population.

The number of events of clinically significant postoperative thrombosis that required treatment were obtained from medical records.

This analysis includes the Intent to Treat Population.

Blood samples were obtained from an arterial line that was required for the planned surgical procedure. The samples were centrifuged to yield platelet poor plasma (PPP), stored at -80 degrees Celsius and utilized for the clot analysis. ELISA was used to measure coagulation factors at each time point. Normal fibrinogen plasma values are between 0.5 to 15 mcg/mL.

This analysis includes the Intent to Treat Population.

Blood samples were obtained from an arterial line that was required for the planned surgical procedure. The samples were centrifuged to yield platelet poor plasma (PPP), stored at -80 degrees Celsius and utilized for the clot analysis. ELISA was used to measure coagulation factors at each time point. The reference range for thrombin plasma level is 0.000313 to 0.02 mcg/mL.

This analysis includes the Intent to Treat Population.

Blood samples were obtained from an arterial line that was required for the planned surgical procedure. The samples were centrifuged to yield platelet poor plasma (PPP), stored at -80 degrees Celsius and utilized for the clot analysis. ELISA was used to measure coagulation factors at each time point. The reference range for FXIII plasma level is 0.000469 to 0.03 mcg/mL.

This analysis includes the Intent to Treat Population.

Blood samples were obtained from an arterial line that was required for the planned surgical procedure. The samples were centrifuged to yield platelet poor plasma (PPP), stored at -80 degrees Celsius and utilized for the clot analysis. ELISA was used to measure coagulation factors at each time point. Lower values may indicate an increased risk of excessive bleeding.

This analysis includes the Intent to Treat Population.