3 The procedure
3.1 Subcutaneous implantation of a battery-powered catheter drainage system is done with the patient under general anaesthesia, usually 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 moves fluid from the peritoneal cavity (via the first catheter) into the bladder (via the second catheter). Fluid is eliminated through normal micturition. The pump is programmed to move preset volumes of ascites to the bladder. The pressure sensors prevent it from over-distending the bladder.
3.2 A clinician programmes the pump wirelessly by an external handheld 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 collects pump data, which are then downloaded to a computer for review by the clinician.