First clinical experience with a high-capacity implantable infusion pump for continuous intravenous chemotherapy

Purpose: To evaluate the efficiency of a new high-capacity pump for systemic venous chemotherapy and to verify the quality of implantation by interventional radiology staff. Methods: A total of 47 infusion pumps with a 60-ml reservoir and variable flow rates (2, 6, 8, or 12 ml/24 hr) were implanted by radiologists in 46 patients with solid tumor metastases requiring treatment with a single, continuously infused cytostatic agent. The reservoir was refilled transcutaneously, usually once weekly. The flow accuracy of the pump was assessed from actual drug delivery recorded on 34 patients over a minimum observation period of 180 days. Results: No early complications occurred in any of the 47 implants in 46 patients. A total of 12 (25.53%) complications occurred between 3 and 24 months after implantation. Seven (14.90%) of these were due to the external design of the pump, while five (10.63%) were related to the central venous catheter. In the 34 patients available for pump evaluation (follow-up of at least 180 days), the system was used for a total of 14,191 days (range 180-911 days, mean 417.38 days), giving an overall complication rate of 0.84 per 1000 days of operation. The mean flow rate accuracy was 90.26%. Conclusion: The new implantable pump showed good flow rate accuracy and reliable operation. The pump-related complications were related to its external design and have now been corrected by appropriate modifications. From a radiologic and surgical viewpoint, the venous implantation procedure is identical to that of conventional vascular access devices and can be performed by radiologists familiar with these techniques. The current limitations lie in the high cost of the pump and, for certain drugs, the short time between refills.