The previously used fully implantable pumps have been improved by development of additional safety options (e.g. acoustic occlusion alarm) for use in patients with PH. In the meantime, the pump (manufacturer: Tricumed GmbH, Germany, exclusively marketing rights: OMT GmbH & Co KG, 78665 Frittlingen, Germany) is offered with an option that meets the requirements for use in treating PH patients. It is based on a constant flow system that consists of gas driven micro-infusion via a chip capillary. The medication is filled into a titanium reservoir via a so-called filling septum (silicon membrane). The membrane is punctured percutaneously with a special needle by specially trained personnel for filling under aseptic conditions. Various safety options ensure a continuous flow rate of the medication and signalize any malfunctions. If catheter occlusion is signalized, the catheter can be rinsed through a second septum in the pump after a percutaneous puncture without emptying the medication reservoir. The pump is available in two sizes (20 ml or 40 ml filling volume). The flow rate set for the 20 ml pump is 1.0 ml/ 24 hours, so that refilling is required every 19 to 20 days. The flow rate set for the 40 ml pump is 2.3 ml/ 24 hours, so that refilling is required every 29 to 30 days. Initial experience with the use of this pump has shown good results for up to 3 years of use (minor complications during implantation, no pump defects in long-term usage, reliable filling under outpatient conditions).