LEFT-HEART BYPASS IN THE PIG WITH A CENTRIFUGAL PUMP USING CANNULAE PREPARED FOR PERCUTANEOUS PLACEMENT

A rapid and efficient circulatory support system may save a patient in cardiogenic shock. Left heart bypass with percutaneous and trans-sept al placement of the aspiration cannula simplifies the circuit and elim inates the need for an oxygenator. In this pre-clinical study we asses sed left heart bypass support with a centrifugal pump using new cannul ae prepared for percutaneous placement (14 F arterial catheter and 16 F left atrial aspiration line) in 5 anaesthetized pigs. Animals were s upported for two hours at a mean flow of 3.2 l/min (4,033 rpm), a mean haematocrit of 29% and low heparinisation (ACT double baseline). Hemo dynamic measurements and blood samples were taken at baseline (A), 10 minutes (B), one hour (C) and 2 hours (D) on support. Results show mai ntenance of hemodynamic parameters throughout the 2 hour support perio d. Only systolic arterial and left ventricular pressure decreased by 1 2% and 20% respectively from baseline to the end of the support period with a 13% increase in cardiac output. When the pump was turned on (0 -3 l/min) there was usually a decrease in heart rate, systolic pressur e and left ventricular pressure, with unchanged cardiac output (non fa iling model). Potassium increased from 3.9 to 4.2 mmol/l (ns), and pla sma hemoglobin from 6.0 to 18.2 mg/dl (p<0.05). Thrombocytes decreased from 187 to 155 10(9)/1 (ns). In conclusion, this preclinical study d emonstrated the feasibility of an efficient left heart bypass of short duration with a centrifugal pump using cannulae prepared for percutan eous placement. Left heart bypass was well tolerated hemodynamically a nd no significant laboratory change occurred within the two hours of s upport. This opens several possibilities for the short term support of patients in cardiogenic shock and eventually also for patients submit ted to minimally invasive cardiac surgery.