MECHANISMS OF CHANGES IN RENAL HANDLING OF SODIUM FOLLOWING TRANSJUGULAR INTRAHEPATIC PORTAL-SYSTEMIC STENT-SHUNT (TIPSS)

Background and aims: Transjugular intrahepatic portosystemic stent-shu nt (TIPSS) reduces the portal pressure gradient and leads to better co ntrol of ascites. The aim of this study was to evaluate (1) changes in renal handling of sodium following TIPSS and (2) the mechanism of the se changes. Design: Prospective study. Setting: Tertiary referral cent re for liver diseases. Methods: Eighteen patients with ascites undergo ing TIPSS for recurrent variceal haemorrhage (16) (3 or more hospital admissions because of variceal haemorrhage whilst being treated endosc opically) or refractory ascites (2) were studied. Urinary sodium (UNa) , creatinine clearance (CrCl), plasma renin activity (PRA), atrial nat riuretic peptide (ANP), cyclic guanosine monophosphate (cGMP), Angiote nsin II (All) and lithium clearance (LiCl) were measured before and 3 months after TIPSS when portography was performed and the portal press ure gradient (PPC) also measured. All patients were haemodynamically s table and had received no diuretics for at least 1 week before blood s ampling. 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 L iCl were abnormal before TIPSS and improved significantly following TI PSS (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 signif icantly following TIPSS. Changes in UNa did not correlate with the Pug h score or the change in PPG. Conclusion: The results of this study sh ow that TIPSS is associated with significant improvement in UNa, CrCl, PRA, All, cGMP and LiCl. The change in UNa following TIPSS was indepe ndent of the severity of underlying liver disease or the change in PPG .