Hello there, it all depends on what the case documentation states.
However for what yp ur describing your partially correct we would code
36481, and 75885 for this case.
Diagnostic Portography for diagnosis of Portal Vein hypertension is typically performed via Percutaneous Transhepatic Portography hemodynamic evaluation with wedged pressure measurements etc we would code the catheter placement with 36481- Percutaneous Portal Vein Catheterization.
75885- Percutaneous transhepatic portography with hemodynamic evaluation, radiological supervision and interpretation
A Selective Hepatic Veno gram may also be performed to diagnosis and measure portal vein pressures, don't get them confused if the physician selectively accesses the Hepatic vein(s) and performs wedged or free Hepatic Venography with wedged pressure measurements we instead code
36012- 2nd order or higher catheterization, vein.
75889-Hepatic venography, wedged or free, with hemodynamic evaluation, radiological supervision and interpretation
Always remember dont confuse Hepatic venography and Portal Vein catheterization code 36481 is non selective and the Portal Vein is directly accessed by insertion of a needle from the skin through the liver with contrast injection and then puncture into portal vein and finally place the catheter from that access.