Clinical implications of acute shunt thrombosis in paediatric patients with systemic-to-pulmonary shunt re-interventions

PURPOSE

Systemic-to-pulmonary shunts are used as a source of pulmonary blood flow in palliated Congenital Heart Disease in neonates and young infants. Shunt thrombosis, often requiring shunt interventions during index hospitalisation, is associated with poor outcomes. We hypothesised that extensive use of perioperative pro-coagulant products may be associated with shunt thrombosis.

METHODS

Children (≤18 years) undergoing systemic-to-pulmonary shunts with in-hospital shunt reinterventions between 2016 and 2020 were reviewed retrospectively. Perioperative associations to shunt thrombosis were examined by univariate logistic regression and Wilcoxon rank sum tests as appropriate. Cox and log transformed linear regression were used to analyse postoperative ventilation duration, length of stay, and cost.

RESULTS

Of 71 patients requiring in-hospital shunt intervention after systemic-to-pulmonary shunts, 10 (14%) had acute shunt thrombosis, and among them five (50%) died. The median age was four (interquartile range: 0-15) months. There were 40 (56%) males, 41 (58%) had single ventricle anatomy, and 29 (40%) were on preoperative anticoagulants. Patients with acute shunt thrombosis received greater volume of platelets (p = 0.04), cryoprecipitate (p = 0.02), and plasma (p = 0.04) postoperatively in the ICU; experienced more complications (p = 0.01) including re-exploration for bleeding (p = 0.008) and death (p = 0.02), had longer hospital length of stays (p = 0.004), greater frequency of other arterial/venous thrombosis (p = 0.02), and greater hospital costs (p = 0.002).

CONCLUSIONS

Patients who develop acute shunt thrombosis receive more blood products perioperatively and experience worse hospital outcomes and higher hospital costs. Future research on prevention/early detection of shunt thrombosis is needed to improve outcomes in infants after systemic-to-pulmonary shunt surgery.

Blood and Blood Product Conservation: Results of Strategies to Improve Clinical Outcomes in Open Heart Surgery Patients at a Tertiary Hospital Are Maintained 4 Years after Initiation

Blood product usage is an important outcome for patients undergoing cardiac surgery. In 2015, our center made a concerted effort with multiple departments to focus on reducing transfusion rates in surgical patients requiring cardiopulmonary bypass (CPB). Specific changes included an upgrade of the oxygenator in mid-2015 and, in early 2016, implementation of a hemostasis management system (HMS) that used heparin dose-response titration assays for heparin and protamine management. A retrospective chart review demonstrated significant decreases in the quarterly average of patients receiving packed red blood cells (PRBCs) from a baseline of 26.7% to 22.7% following the oxygenator upgrade (p = .021) and from 22.7% to 8.8% following implementation of the HMS (p = .0017). Platelet usage decreased from an average of 50.5% during the baseline and oxygenator upgrade periods to 22.2% following implementation of the HMS (p < .0001). Usage of fresh frozen plasma (FFP) decreased from an average of 28.2% of cases during the baseline and oxygenator upgrade periods to 10.4% during 2016, and cryoprecipitate usage decreased from 38.5% to 15.4%. Heparin usage averaged 56,903 units before implementation of the HMS, decreasing to an average of 43,796 units following HMS implementation (p < .0001). During the same time periods, protamine usage averaged 340.3 mg and 183.2 mg, respectively. Because improvements achieved during quality initiatives may revert back to their pre-intervention state once the assessment period is over, we performed a second retrospective analysis to determine whether the improvements achieved were maintained during the 48 months following the initial study. During 2017-2020, quarterly average usage of blood products was as follows: PRBCs, 11.9%; platelets, 14.7%; FFP, 6.2%; and cryoprecipitate, 11.5%. Quarterly, average use of heparin and protamine were 31,556 ± 2,757 units and 189 ± 113 mg, respectively. These findings indicate that the improvements achieved were not limited to the duration of the initial quality initiative.