Mini Extracorporeal Circuit for Coronary Artery Bypass Grafting: Initial Clinical and Biochemical Results

W.J. van Boven[1]; W.B. Gerritsen[1]; F.G. Waanders[1]; F.J. Haas[1]; L.P. Aarts[2]

[1] St Antonius Hospital Nieuwegein, Nieuwegein, The Netherlands [2] University Hospital Groningen, Groningen, The Netherlands

Background: The new concept of mini-extracorporeal circulation (MECC) for coronary artery bypass grafts (MCABG) consists of minimal priming volume, a heparin-coated closed circuit, a centrifugal pump, active drainage, blood cardioplegia and a cell-saving device. The potential organ protective effect of this technique during CABG is unknown. Initial clinical outcomes, oxidative stress, alveolar shunting and need for blood transfusion were investigated for MCABG patients. Subsets of these data were compared to outcomes of matched groups of patients operated conventionally (CCABG) and off-pump (OPCAB).

Methods: Data of 184 patients were gathered and analysed from a prospective observational database system. This database consists of the initial experience with the first 114 MCABG operations. Of these, the clinical outcome was investigated. In a subset of 60 MCABGs, need for transfusion was monitored and compared to 60 CCABGs. Serum concentrations of malondialdehyde (MDA), allantoin/urate ratios, shunt fractions and lung epithelium-specific proteins (CC16) were measured as biomarkers of damage during MCABG, CCABG and OPCAB (n = 30).

Results: Patient groups were similar concerning age, risk and number of distal anastomoses. Clinical outcomes are shown for MCABGs only. During MCABG, need for transfusion was significantly reduced compared to CCABG (p < 0.001). Serum concentrations of MDA and allantoin/urate ratios showed significantly reduced oxidative stress during MCABG compared to CCABG. During MCABG, F-shunts were reduced shortly after surgery. Increased concentrations of pneumoprotein CC16 were measured during CCABG compared to MCABG (data submitted).

Conclusion: Short-term clinical outcomes of MCABG patients are satisfactory. Compared to CCABG the need for transfusion is significantly reduced when a MECC is used. Oxidative stress parameters show a tendency towards improved global organ protection compared to CCABG. F-shunt fractions and CC16 concentrations suggest reduced alveolar damage during MCABG. In a prospective study, the protective effect of mini-CABG has to be confirmed.