Age dependency of regional impedance indices regardless of clinical stage in patients with cirrhosis of the liver.

PURPOSE: To prospectively assess if ageing itself induces modifications of the impedance indices (resistance and pulsatility indexes) of hepatic, splenic, superior mesenteric and renal arteries in patients with liver cirrhosis. MATERIALS AND METHODS: 78 consecutive patients with cirrhosis (41 males, 37 females, Child-Pugh score 7 [range 5 - 12]) were studied by colour-Doppler ultrasound. The resistance index (RI) and pulsatility index (PI) were determined in the main hepatic artery, intraparenchymal branches of hepatic, splenic, and renal arteries, and superior mesenteric artery; clinical data were simultaneously collected. Logistic regression analysis was performed to assess the relative impact of age, severity of liver disease and other relevant variables on the increase of impedance indices. Linear regression analysis was used to identify a coefficient to adjust RIs and PIs to age. RESULTS: Resistance and pulsatility indices of all the vessels studied except of the superior mesenteric artery showed a direct correlation with age (e. g. splenic artery RI: R = 0.520, p < 0.0001), and correlated most strongly with Child-Pugh score (e. g. right renal artery PI: R = 0.462, p < 0.0001). Age was associated independently with increased PI and RI in hepatic, splenic and renal arterial districts. In these vessels, the RI threshold of normality can be adjusted to the decade of age adding a correction of 0.03. CONCLUSION: Ageing itself induces an increase of hepatic, splenic and renal impedance indices in cirrhotic patients. The threshold of normality for these indices in cirrhosis should be adjusted according to the patients’ age.