RESULTS: Between September 2010 and April 2015 more than 36 patients were implanted and followed up. As previously reported no intraoperative complications were observed. During follow-up of more than 63 patient-years only 5 surgical interventions in 4 patients became necessary 2, 4, 8 and 28 months after implantation. While a catheter-kinking was managed with local anesthesia the other interventions required general anesthesia. One pump had to be refixed after rupture of fixation at the fascia, another patient was revised for possible catheter occlusion; the mechanically damaged part was replaced. A catheter loop due to non coaxial implantation required a complete catheter replacement in a second session. One pump had to be replaced as substantial weight loss led to rotation of the pump that made refill nearly impossible. Despite a seroma that resolved without surgical intervention after the pump replacement no complications were observed.