Effects of transjugular intrahepatic portosystemic shunt (TIPS) on blood volume distribution in patients with cirrhosis.

Background: Cirrhosis is accompanied by portal hypertension with splanchnic and systemic arterial vasodilation, and central hypovolaemia. A transjugular intrahepatic portosystemic shunt (TIPS) alleviates portal hypertension, but also causes major haemodynamic changes.

Aims: To investigate effects of TIPS on regional blood volume distribution, and systemic haemodynamics.

Methods: Thirteen cirrhotic patients had their regional blood volume distribution determined with gamma-camera technique before and after TIPS. Additionally, we measured systemic haemodynamics during liver vein and right heart catheterization. Central and arterial blood volume (CBV) and cardiac output (CO) were determined with indicator dilution technique.

Results: After TIPS, the thoracic blood volume increased (+10.4% of total blood volume (TBV), p<0.01), whereas the splanchnic blood volume decreased (-11.9% of TBV, p<0.001). CO increased (+22%, p<0.0001), and systemic vascular resistance decreased (-26%, p<0.001), whereas CBV did not change. Finally, right atrial pressure and mean pulmonary artery pressure increased after TIPS (+50%, p<0.005; +40%, p<0.05, respectively).

Conclusions: TIPS restores central hypovolaemia by an increase in thoracic blood volume and alleviates splanchnic vascular congestion. In contrast, CBV seems unaltered. The improvement in central hypovolaemia is therefore based on an increase in thoracic blood volume that includes both the central venous and arterial blood volume. This is supported by an increase in preload, combined with a decrease in afterload.