Due to better medical care, a growing number of patients with congenital heart disease reach adulthood. A large number of these patients needs a redo cardiac surgery. No guidelines of best transfusion practice exist for this patient population. A retrospective analysis of all adult patients with congenital heart disease undergoing cardiac surgery between 2000 and 2020 will be performed. Transfusion practices and their influence on outcome at 30 days and 6 month will be evaluated.

Introduction: About 1% of newborns in Belgium have a congenital heart defect. The improvement of intra- and postoperative treatment and the development of new surgical techniques have allowed an increasing management of congenital heart pathologies, making it possible to successfully treat approximately 95% of children with these conditions. The increase in life expectancy of these children has resulted in an ever-increasing proportion of this population reaching adulthood.

Most patients with congenital heart disease, particularly cyanotic conditions, require specialized follow-up in a referral center, given the risk of late complications related to correction or palliation of the primary condition.

Reoperations in adulthood pose a number of challenges for the multidisciplinary team managing these patients: more complex surgical approach (adhesions, altered in situ anatomy, development of collateral circulation, persistence of intra- or extra-cardiac shunts...). The operative risk but also the infectious risk are clearly increased in this population.

The risk of bleeding, which is already high in cardiac surgery, particularly due to the use of extracorporeal circulation, is also increased by the re-intervention itself. This is potentially accompanied by greater exposure to allogeneic blood products, which has been associated with increased postoperative morbidity and mortality.

Various techniques have been developed to reduce the risk of bleeding in cardiac surgery, including the use of anti-fibrinolytic agents, avoidance of deep hypothermia, reduction of vascular filling to avoid excessive hemodilution, and application of a permissive hypotension and restrictive transfusion strategy. The ultimate goal of integrating these techniques into our transfusion practices is to improve patient outcomes by reducing exposure to blood products. There are currently no recommendations on good transfusion practices for the management of these patients with congenital heart disease who require cardiac re-intervention in adulthood. There are also few studies specific to this population in the current literature.

Objectives: The main objective of the study is to analyze, in our center, if the transfusion practices (measures to decrease the risk of bleeding, transfusion of red blood cells (RBCs) and/or blood derivatives), in patients who have had a re-intervention of congenital heart surgery, are determinant to reduce morbidity and mortality in the following 30 days and 6 months Type of study and design: Retrospective and descriptive study by extraction of patients who underwent cardiac surgery, at the Brugmann University Hospital, between the year 2000 to the year 2020, by analysis of the medical charts.

Patients: Grown-up congenital heart disease patients re-operated from cardiac surgery between January 2000 to December 2020.

Inclusion criteria: All patients with congenital heart disease reoperated from a new cardiac surgery under extracorporeal circulation, at Brugmann University Hospital, between the year 2000 to the year 2020.

Exclusion criteria: Patients with cardiac surgery without cardiopulmonary bypass, patients with acquired heart disease, patients who had a re-intervention due to a complication within 30 days postoperatively.

Statistical evaluation: Descriptive analyses will be used and further analyses will be performed based on preliminary results and hypotheses raised. The patients' data will be put in an anonymized file and analyzed later.

Variables to be collected: demographic data; type of procedure; personal history of the patient; clinical symptomatology; pre-op, intra-op and post-op treatment; complementary pre-, per-, and post-op examinations (radiological, laboratories), operative data (surgical procedure performed, blood loss, blood component transfusion (red blood cells, platelets, plasma), fluid balance, use of anti-fibrinolytics) ; hemodynamic monitoring (intraoperative vital parameters), duration of cardiopulmonary bypasss (CPB) time, aortic clamping time, intraoperative and postoperative complications, death, length of stay in intensive care and total length of stay.

Inclusion Criteria:

• All adult congenital heart disease patients undergoing cardiac surgery with cardiopulmonary bypass between 2000 and 2020 at Brugmann University Hospital

Exclusion Criteria:

• Off-pump cardiac surgery
• re-intervention within 30 days of cardiac surgery due to complications

All adult congenital heart disease patients undergoing cardiac surgery with cardiopulmonary bypass between 2000 and 2020 at Brugmann University Hospital