Ventricular assist systems: experience in Japan with Toyobo pump and Zeon pump

Two types of ventricular assist systems have been approved for use by the Japanese government.

The two government-approved ventricular assist systems, the Toyobo pump (National Cardiovascular Center type) and the Zeon pump (Tokyo University type), were applied to 219 patients in Japan as of October 20, 1994.

Adult-sized were used in 211 patients and pediatric ones in 8 patients. Left ventricular assist systems was performed in most cases (82.6%). The predominant indication was failure to be weaned from cardiopulmonary bypass (65.8%). The duration of ventricular assist system application ranged from 1 hour to 70 days, and the mean was 7.3 days, excluding the patients with cardiomyopathy. The weaning rate was 48.8% and the survival rate was 25.6%. Main causes of death were heart failure including unrecoverable heart failure and multiple organ failure. In 12 cardiomyopathy patients, Toyobo pumps were applied as left ventricular assist systems. Support duration was from 13 days to 192 days (ongoing). One patient was bridged to transplantation successfully and 1 was weaned after 3 months of support.

From these data, the Toyobo pump and the Zeon pump are useful for short-term support for acute, profound heart failure. The Toyobo pump also may provide sufficient support as a bridge to transplantation for the medium term.