2 The condition, current treatments and procedure
2.1 Ascites is a common complication of cirrhosis of the liver. Build-up of fluid causes the abdomen to swell and may lead to discomfort, difficulty breathing, fatigue, nausea and poor appetite.
2.2 Treatment is usually diuretics and advice about dietary sodium restriction. For refractory ascites, treatment options include large-volume paracentesis, albumin infusion and insertion of a transjugular intrahepatic portosystemic shunt. These procedures may be used to support a patient who is waiting for a liver transplant.
2.3 Subcutaneous automated low-flow pump implantation for refractory ascites is usually done under general anaesthesia, typically through 3 small incisions in the abdominal wall. A battery-powered pump with internal pressure sensors is implanted on the right side above the belt line. One catheter connects the pump to the peritoneal cavity, and another connects it to the urinary bladder. The pump and both catheters are secured with sutures to prevent migration. The pump removes fluid from the peritoneal cavity through the first catheter, and puts it into the bladder through the second catheter. The fluid is eliminated through normal micturition. The pump is programmed to remove pre-set daily volumes of fluid, and the pressure sensors prevent it from over-distending the bladder.
2.4 A clinician programs the pump wirelessly using an external hand-held charging device, according to the needs of the patient (based on previous large-volume paracentesis requirements, observed accumulation of ascites and body weight). The hand-held device is also used by the patient to charge the pump wirelessly, by holding it above the pump for about 30 minutes each day. The hand-held device collects data sent by the pump, which are downloaded to a computer for review by the clinician. Anonymised data are sent to the manufacturer, which sends a report to the clinician with a detailed analysis of the data and any recommendations.
2.5 The aim of the procedure is to avoid the accumulation of fluid, abdominal swelling and accompanying complications.