3 December 2013 Last updated at 20:40 ET
The rechargeable pump sits underneath the skin and can be switched off at night
Patients at the Royal Free Hospital in London are testing a device that provides relief from a common side-effect of liver disease.
The pump siphons off excess fluid that can build up in the abdomen after liver failure and diverts it to the bladder so it can be urinated out.
A liver transplant may be the only option for patients with cirrhosis.
Doctors say the pump could buy time and may even allow the liver to recover, avoiding the need for a transplant.
“It can improve quality of life for patients and keep them out of hospital for longer”
Prof Rajiv Jalan
So far eight patients at the Royal Free have had one fitted.
The Alphapump sits beneath the skin of the abdomen and is connected to two small tubes that do the siphoning.
When patients have cirrhosis, the liver and kidneys stop working properly and fluid, known as ascites, can accumulate.
Litres of fluid can gather inside the abdominal cavity, making the patient appear pregnant as well as being painful.
Patients may have to make weekly or monthly trips to hospital to have the fluid drained.
Rajiv Jalan, professor of hepatology at University College London's institute for liver and digestive health at the Royal Free, is the doctor running the trial.
He said: "With cirrhosis, patients can accumulate litres and litres of fluid. They might need to come to hospital fortnightly to have up to 20 litres drained from their tummy.
"The pump can avoid this by draining about 15 millilitres every 15 minutes. It means they'll pass a little bit more urine but they can turn the pump off at night.
"It can improve quality of life for patients and keep them out of hospital for longer."