Hemodynamic effects of portal triad clamping in humans.

The hemodynamic effects of portal triad clamping (PTC) were studied in 48 adult patients scheduled for elective liver resection. Prior to hepatic resection the effects of a short period of PTC (3-5 min) were evaluated in all 48 patients: mean arterial pressure increased 21%, whereas pulmonary capillary wedge pressure and cardiac index decreased 10 and 17%, respectively. Systemic vascular resistance increased 48%. In 34 patients a liver resection was performed during PTC and hemodynamic measurements were repeated throughout the duration of liver ischemia, which ranged from 14 to 68 min. Hemodynamic changes occurred in the first 3 min and persisted thereafter. After releasing the clamp, hemodynamic parameters returned to initial values in 3 min. These results confirm that PTC does not induce the cardiovascular collapse in humans that it does in common laboratory animals and demonstrate that humans tolerate PTC for periods up to 1 hr.