Potentialities and problems of a novel bilateral ventricular assist systemwithout thoracotomy

Mechanical cardiac assistance can be critical in saving the lives of patien ts with acute cardiac failure. However, currently used methods of ventricul ar assistance require advanced technical knowledge and equipment, and only small numbers of patients can be provided with them. Our aim was to develop new cannulas to construct a less invasive biventricular assist system that would permit easy application without thoracotomy. We prepared 2 centrifug al pumps and 4 uniquely shaped cannulas and conducted experiments to invest igate the potential and problems of the system. In the first experiment, th e system was attached to 6 dogs with ventricular fibrillation to confirm wh ether our system could maintain cardiac output. In the second experiment, t he system was installed for 3 days in 3 goats, and changes in aminotransfer ases, BUN, creatinine, and plasma free hemoglobin levels were examined. In Experiment 1, it was demonstrated that the system was able to maintain circ ulation in dogs. In Experiment 2, although the flow rate of the pumps was m aintained over 3 days, increased hemolysis and deteriorating renal function were observed. Although these problems need to be solved, the system was s till helpful in the management of acute biventricular failure for short per iods and may be clinically useful in the near future.