Portosystemic Shunt Ligation in Cats

A portosystemic shunt is an irregular connection between the blood vessel that carries blood from the gastrointestinal tract to the liver (portal vein) and for systemic circulation. In a feline without a portosystemic shunt, blood toxins are removed when the blood passes through the intestine to the liver. Unfortunately for a cat with a portosystemic shunt, the liver is bypassed and the toxins cannot be removed from the blood. Over time, the lack of detoxification causes toxin buildup within the body. The veterinarian may attempt to treat the condition medically, but portosystemic shunt ligation is the treatment of choice whenever possible. Portosystemic shunt ligation in cats is the act of tying off the abnormal shunt vessel. The procedure is technically challenging and your veterinarian may refer your cat to an ACVS board-certified veterinary surgeon. 

The veterinarian will first identify the shunt and measure the portal vein pressure to determine if a portosystemic shunt ligation is possible. Excessively high portal hypertension or low portal hypertension can result in death if ligation is completed. If the portal hypertension is regular, the vet can proceed to conducting the surgery. 

In a portosystemic shunt ligation surgery, the veterinary surgeon will tie off the abnormal shunt vessel. The vet surgeon may complete this act through the use of an intravenous embolic coil, an injection of specialized glue material, or a suture-type material. The act of wrapping material around the vessel will cause an inflammatory response, which will force the vessel to slowly close over a period of months.

The goal of a portosystemic shunt ligation procedure in cats is to aid the liver in carrying out normal functions more efficiently, by allowing more blood to flow through the liver organ. The prognosis for a portosystemic shunt ligation in cats is generally excellent. 

The feline will be hospitalized for a period of time following the portosystemic shunt ligation surgery. During this time the feline will be given intravenous fluids and pain medications. For the next four to five months, the feline will be fed a low protein diet and given oral antibiotics, as well as, lactulose. Lactulose is a cathartic, which aids in the expulsion of fecal matter. Follow-up bile acid exams and portal scintigraphy tests should be completed to monitor the functionality of the shunt. 

Portosystemic shunt ligation in cat can cost a cat owner anywhere from $2,000 to $5,000. Recovery medications and a prescribed diet should also be considered when configuring the total cost of a portosystemic shunt ligation surgery. Ask your veterinarian for an estimated cost of the surgery, including recovery medications and follow-up examinations. 

Complications following a portosystemic shunt ligation in cats are possible. If the material used to close the shunt was ineffective, the shunt may reopen or fail to close despite tying off the vessel. Improper blood circulation is also a possibility as closure of the vessel may lead to decreased blood circulation to other organs (highly unlikely). Lastly, on rare occasions, a cat may develop seizures in response to the treatment. 

Portosystemic shunts can be either congenital, meaning the cat was born with the shunt, or acquired, which means the shunt develop under certain circumstances. Only acquired portosystemic shunts can be prevented and this condition is usually the result of a secondary problem in the liver. Trauma and disease are usually to blame for an acquired portosystemic shunt in cats.