Nature of Doppler perfusion index changes in patients with colorectal cancer liver metastases.

Abstract

Occult hepatic metastases from colorectal cancer result in an increase of the ratio of arterial hepatic blood flow to total hepatic blood flow, described as the Doppler perfusion index. Whether this alteration is due to an increase in arterial blood flow or a decrease in portal venous inflow has not yet been unequivocally determined. The purpose of this study was to analyze changes in hepatic perfusion in patients with liver metastases from colorectal cancer by standardization of hemodynamic parameters to body surface area. Hemodynamic parameters (crosssectional area, blood flow, and congestive index) were measured for the common hepatic artery and portal vein with duplex color Doppler sonography in 20 patients with liver metastases and 20 healthy control subjects and evaluated relative to body surface area. No statistically significant differences in age, body surface area, cross-sectional area of the common hepatic artery, and congestion index of the common hepatic artery and portal vein were observed between control subjects and patients with liver metastases. Patients with liver metastases had significantly greater arterial hepatic blood flow and Doppler perfusion index and significantly smaller portal cross-sectional area portal blood flow as well as total liver blood flow (P <.001). This study supports the theory that the primary mechanism of alteration in liver perfusion is the reduction of portal inflow with subsequently increased arterial hepatic blood flow.