Mechanisms of changes in renal handling of sodium following transjugular intrahepatic portal systemic stent-shunt (TIPSS)

Background and aims: Transjugular intrahepatic portosystemic stent-shunt (TIPSS) reduces the portal pressure gradient and leads to better control of ascites. The aim of this study was to evaluate (1) changes in renal handling of sodium following TIPSS and (2) the mechanism of these changes. Design: Prospective study. Setting: Tertiary referral centre for liver diseases. Methods: Eighteen patients with ascites undergoing TIPSS for recurrent variceal haemorrhage (16) (3 or more hospital admissions because of variceal haemorrhage whilst being treated endoscopically) or refractory ascites (2) were studied. Urinary sodium (UNa), creatinine clearance (CrCl), plasma renin activity (PRA), atrial natriuretic peptide (ANP), cyclic guanosine monophosphate (cGMP), Angiotensin II (All) and lithium clearance (LiCl) were measured before and 3 months after TIPSS when portography was performed and the portal pressure gradient (PPC) also measured. All patients were haemodynamically stable and had received no diuretics for at least 1 week before blood sampling. Results: Improvement in ascites was achieved in ail patients in whom TIPSS was inserted successfully (reduction in PPC to <12 mmHg). PPG was reduced from a mean of 19 (+/- 6) to 8.8 (+/- 3.4) mmHg (P<0.001). Urinary sodium and creatinine clearance improved significantly following TIPSS (P<0.001, P<0.001, respectively). PRA, All, cGMP and LiCl were abnormal before TIPSS and improved significantly following TIPSS (P<0.007, P<0.001, P<0.001 and P<0.01, respectively). ANP was not significantly different from normal controls and did not change significantly following TIPSS. Changes in UNa did not correlate with the Pugh score or the change in PPG. Conclusion: The results of this study show that TIPSS is associated with significant improvement in UNa, CrCl, PRA, All, cGMP and LiCl. The change in UNa following TIPSS was independent of the severity of underlying liver disease or the change in PPG.