Medical procedures for the treatment of chronic diseases often require repeated and prolonged access to a patient's vascular system to inject therapeutic compounds and/or to obtain blood samples. Kidney dialysis, chemotherapy and other chronic treatments may have to be performed several times a week. However it is impractical and dangerous to insert and remove a catheter and a needle from the patient's vein at every session. Thus, these catheters are generally implanted semi permanently with a distal end remaining within the patient in contact with the vascular system and a proximal end remaining accessible from outside the patient's body. A port may be used to access the proximal end of the catheter from outside the body, for example, via a syringe. In many cases, such ports are implanted subcutaneously in the arm or chest to provide protection to the port while maintaining easy access thereto. Such ports typically consist of a housing with one or more wells to receive therapeutic agents.
Under certain conditions, it may be necessary to infuse therapeutic agents (e.g., chemotherapy agents) that are not compatible with one another. In some cases, the therapeutic agents are fluids that cannot be mixed together outside of the body, but which preferably are infused together. These unmixable fluids may lose their potency or may become toxic if mixed prior to infusion in the body. They are therefore kept separate until they reach the blood stream. To address this difficulty, a separate catheter may be used for each of the fluids with distal ends of the catheters (i.e., outlets) near one another. Alternatively, a multi-lumen catheter (e.g., a dual lumen catheter) may be used, with each lumen transporting a different fluid.
Providing two unmixable therapeutic fluids to a dual lumen catheter or to two separate catheters near each other presents challenges as a conventional port may not be useable to inject both fluids. Multiple. ports are generally not implanted near one another because of the surgery required to insert each port and additional complications that may arise with respect to each port. For these purposes a dual well port device having two ports formed within a single housing may be used with each port being connected to a different catheter or to a different lumen of a dual lumen catheter. However, conventional dual well port devices are larger than single port devices, and may require more extensive surgery to be placed in the patient's body. The connections between the wells and the catheter further increase the width of the dual well port, so that a larger incision is often necessary to place such a port within the patient.