Modular Miniaturised Perfusion Circuits. From In Vitro Study to “Universal Heart Lung Machine”

Conventional Cardiopulmonary Bypass (cCPB) is a trigger of systemic inflammatory response, hemodilution, coagulopathy, and organ failure. Miniaturised extra corporeal circulation (MECC) has the potential to reduce these deleterious effects. Safety concerns have been one of the main reasons opposing a wider acceptance of miniaturised perfusion circuits and impeding their wider applicability. Even centers with extensive experience have limited their use to simple coronary artery bypass (CABG). Following an extensive experience with MECC and a multitude of modifications that have negligated safety concerns we have set out to employ the Reservoir Optional Minimized Perfusion Circuit (ROCsafe, Terumo Europe, Leuven, Belgium) as a universal heart lung machine for all cardiac procedures. In the present series, we reported our experience From January 2013 to December 2013 with a total of 113 cardiac surgical procedures. Thereof 100 operations were done using the ROCsafe. Excluding procedures done under circulatory arrest or with the potential need for circulatory arrest, the ROCsafe was employed in 88% of surgeries. These included 62 operations classified as simple surgical operations (CABG, Aortic valve replacement (AVR) and CABG +AVR) with a mean bypass time of 85±28 min. and a mean clamping time of 55±24 min. and 38 operations classified as complex operations (including 15 re-interventions) with a mean bypass time of 141 ±59 min. and a mean clamping time of 97±42 min. Of the simple procedures 82% were non elective, 10% of patients had an EF<30% and the majority had an impaired renal function. Of the complex procedure 37% were urgent, 15% had an EF <30% and the majority had an impaired renal function. Retrograde autologous priming was used in all cases, blood cardioplegia was used in simple cases while crystalloid cardioplegia was used in most complex cases but drained via the right atrium. The cannulation technique was tailored to the needs of each procedure with special emphasis on avoidance of bleeding or air leaks. The 30 day mortality amounted to 5% in simple procedures, the patients who died having had a mean log Euroscore of 36%. The 30 day mortality of the complex cases was 2, 6% while their cumulative log Euroscore was>600%, no patient with a log Euroscore <40% having died. Postoperative atrial fibrillation occurred in 13% of simple cases and 16% of complex cases while Optimum outcome defined as freedom of all complications and blood transfusions was achieved in 52% and 42% respectively.