The purpose of this clinical research study is the design of a novel modular hybrid system extracorporeal circulation circuit for open heart procedures that could easily be converted from a closed to a semi-closed circuit according to the indication. This could expand the potential of minimal extracorporeal circulation and could ultimately become the new standard circuit in performing every type of cardiac surgery.

Development of cardiopulmonary bypass circuit (heart-lung machine) is considered as a landmark breakthrough in cardiac surgery, greatly promoting treatment of cardiovascular diseases. Since 1953, when the first operation under cardiopulmonary bypass was performed and for almost 6 decades, little progress has been made in the direction of improving cardiopulmonary bypass technology. However, evolution is feasible. The proposed research project challenges the traditional belief that conventional cardiopulmonary bypass should be considered as "state of the art" technology by deducting solid evidence towards extended use of the novel minimal extracorporeal circulation circuit, which is related to an improved outcome through multiple studies. Research methodology is based on analyzing laboratory and clinical data obtained through implementing the standard and the novel technology. In order to provide solid evidence on the comparative effectiveness of both therapies, it combines analysis of clinical and laboratory data with data related to cost and quality of life. Thus, it assesses novel technology from a global perspective and the evidence obtained would be considered robust.

The ultimate purpose of the research proposal is the design of a modular hybrid system, that could easily convert from form a closed to a semi-closed circuit according to the indication, that could expand the potential of minimal extracorporeal circulation and could ultimately become the new standard circuit in performing every type of cardiac surgery. The term modular refers to an additionally mounted, clamped-off venous reservoir which allows to run the system as an open circuit in case of anticipated volume loss (ie bleeding, complex procedures, long bypass run). This measure follows the proverb 'always expect the unexpected' and offers the clinical practitioner an additional safety margin in case of unexpected intraoperative events. Unique design of this circuit would offer the opportunity of reducing cost, while at the same time improving clinical outcome. Preliminary design of this circuit, performed in our institution, is presented schematically in the appendix. After completion of the study protocol the designed circuit will be patented.

Our institution has already performed extensive research and has gained international reputation as a training centre on minimal extracorporeal circulation. Design of such a circuit could promote further research funded by the medical industry. Considering the number of cardiac surgical procedures performed every day worldwide, this evolution is greatly ambitious and could be characterized as a major breakthrough in the field of cardiac surgery opening up new horizons in the field of cardiovascular research. It would also exert a positive effect on global healthcare affecting lives of millions of people suffering from cardiovascular disease.

Inclusion Criteria:

• Any heart disease that requires open heart surgery under extracorporeal circulation

Exclusion Criteria:

• Beating heart surgery
• Age more than 80 years