Hemodynamic measurement in liver transplantation. Piggyback versus conventional techniques

The piggyback technique in venous outflow tract reconstruction has been proposed as an alternative to the conventional technique in liver transplantation. Maintaining caval flow during the anhepatic phase with hemodynamic stability is regarded as one of the main advantages of this method. Between November 1994 and November 1998, the piggyback technique was used in 47 patients in our Center. Hemodynamic measurements during the operation showed hyperdynamic circulation with an increase in cardiac output (9.3+/-3.5 L/min) and the calculated cardiac index (5.0+/-1.9 L/min/m2). There was a statistically significant increase in heart rate and a decrease in systolic arterial pressure, cardiac output (CO) and cardiac index (CI) during inferior vena cava clamping ( simulated conventional technique). Only a non-significant decrease in CO and CI was observed during the partial clamp on the inferior vena cava (piggyback technique). Out of those two techniques, piggyback proved to be a safer approach to venous outflow tract reconstruction from the hemodynamic point of view.