Splenic Doppler impedance indices: Influence of different portal hemodynamic conditions

Abstract

impedance indices significantly decreased compared The spleen plays a pivotal role in the pathogenesis with other cirrhotic patients (RI and PI P õ .0001). In and maintenance of portal hypertension. Few data exist patients who underwent liver transplantation, splenic about splenic hemodynamics evaluated by duplex soimpedance indices were the same as those in controls. nography in this condition. Twenty-six normal subjects, In 23 of the 52 patients surgically treated (surgical shunt 207 patients with portal hypertension of various causes, or liver transplantation), impedance indices were evaluand in different splenoportal hemodynamic conditions, ated both before and after surgical treatment. All these and 31 patients with liver transplantation were evalupatients showed a decrease in splenic impedance indices ated. In each patient the splenic resistive index (RI (RI and PI, P õ .0001) after surgical treatment. RI and Å peak systolic 0 end diastolic velocity/peak systolic ve-PI values were higher in patients with large esophageal locity) and pulsatility index (PI Å peak systolic 0 end varices as compared with patients without or with small diastolic velocity/mean velocity) were measured. In 17 varices (P õ .02 and P õ . The introduction of duplex Doppler ultrasonography and PI were significantly higher in cirrhotic patients with hepatopetal portal flow compared with controls (P (DDU) has been an important breakthrough in the õ .0001), and even higher in cirrhotic patients with por-evaluation of splanchnic hemodynamics. This new tal vein thrombosis (P õ .004 and P õ .001 in comparison technique is being widely used, particularly for the aswith RI and PI values of cirrhotic patients). In patients sessment of portal hypertension. 1,2with noncirrhotic portal vein thrombosis, splenic impedSince the introduction of DDU, new splanchnic heance indices were higher than those in controls (RI and modynamic parameters of portal hypertension have PI P õ .0001). Cirrhotic patients who underwent surgery been introduced: at first portal blood flow velocity and for the therapy of portal hypertension showed splenic the congestion index of the portal vein, 1,3-6 and more recently, the arterial hemodynamic parameters, i.e., the so-called impedance or resistance indices. and, therefore, the measurement of these indices could Received June 29, 1995; accepted December 1, 1995. be useful from a pathophysiological point of view.

Doppler study of mesenteric, hepatic, and portal circulation in alcoholic cirrhosis: Relationship between quantitative doppler measurements and the severity of portal hypertension and hepatic failure

“…The same mechanism has been 4,1998 hypothesized to explain that splenic artery RI did not decrease in cirrhosis despite the increase in splenic blood flow caused by splenic enlargement. 28 In conclusion, our study demonstrates that in patients with alcoholic cirrhosis, only portal vein blood velocity and flow, but neither HA nor SMA RI, exhibit a significant correlation with HVPG and with the severity of liver failure. However, because of the scattering of the data, the quantitative measurement of portal velocity or flow has a limited utility in predicting either hepatic venous gradient or severity of liver failure in an individual patient.…”

Hemodynamic Features of Doppler Ultrasonography in Patients With Portal Hypertension

“…For instance, increased Doppler impedance indices of hepatic and splenic arteries have been described in previous studies. 3,4 Haag et al 5 used the congestion index (CI) of the portal vein, which is defined as the ratio of crosssectional area to a portal flow velocity exceeding 0.1 cm/s -1 to diagnose PHT. Other methods used to diagnose PHT include the liver vascular index (LVI), 3 the hepatic buffer index (HBI) proposed by Iwao et al, 6 and the portal hypertension index (PHI).…”

Reliability of the estimation of total hepatic blood flow by Doppler ultrasound in patients with cirrhotic portal hypertension

“…Portal blood velocity was calculated as time averaged maximum velocity multiplied by 0.57, assuming the portal velocity profile as parabolic, as previously reported [13,14]. Similarly, hepatic artery velocity was calculated as time averaged maximum velocity multiplied by 0.62, as previously reported [7,8].…”

“…Portal blood flow (PBF) and hepatic artery blood flow (HABF) were obtained by multiplying the portal vein cross-sectional area, assuming a circular shape of the portal vein and hepatic artery section, by the mean velocity of blood flow in the vessel [10,13,14] according to the following formula:…”