Implantable devices for chemotherapy: access and delivery.

Abstract

S INCE the initial access to the vascular system was introduced in 1943 and the first electronic control of infusion rate was used in 1969, vascular access devices and infusion pumps have continued to become more convenient and efficient. lv2 Having an entirely closed system between infusions is highly desirable when an indwelling catheter is present. For this reason, innovations of implantable systems are ongoing. So far, four implantable types of drug delivery systems have been devised. 3 These include implantable pellets and capsules, rate-specified pharmaceuticals, and passive and active implantable infusion devices. This paper will address the last two types of systems. Passive implantable infusion systems are devices that lack an intrinsic power source.3 They provide access but need some type of pump for infusion. Two systems used for chemotherapy are the Ommaya reservoir, which provides access to the cerebrospinal fluid, and vascular access ports, which provide access to the circulation and body cavities. In contrast, active implantable infusion devices contain an intrinsic power source that permits long-term in vivo operation, and they have a reservoir with some means of replacing the infusate.3 There are two pumps currently in clinical use with widely divergent modes of operation. Each of these types of devices are described in reference to placement, care, possible complications, and nursing responsibilities. Guidelines for evaluating the systems and areas for research concerning their use are identified.