A standard text mentions doing a TIPS for ascites only if medical treatment or removing fluid through a needle has not been successful. The standard medical treatment would be to restrict salt and water, and if that doesn't cause the excess fluid to be excreted, to give spironolactone. If spironolactone alone doesn't do the job, a diuretic such as furosemide is added. In difficult cases a different kind of shunt called a peritoneovenous shunt may be considered. This is a tube with a one way valve connecting the peritoneal space where the fluid is collecting to a systemic vein.
Fluid goes from the abdomen into the blood, and is then excreted by the kidneys.
The one-way valve prevents blood from flowing back into the peritoneal space. These techniques are usually tried before a TIPS is placed because a TIPS can produce serious complications. In about thirty to fifty percent of cases the shunt closes down within a year. Although the peritoneovenous shunt can also close down and require revision, it does not increase the risk of encephalopathy. Because of this complication, you should certainly talk with your father's doctors about the other treatments being pushed to the limit before proceeding with the TIPS, since as far I can tell, your father has not had bleeding from varices.