Implantable vascular access port

FIGURE 17-2 Schematic representation of an implantable vascular access port that can be used with PCA. The port can be connected to a PCA pump via a percutaneous needle, and a catheter leads from the port to a large central vein. [From Knox LS. Crit Care Nurse. 1987 7 71 with permission.]... 

FIGURE 20.11 An implantable vascular access port is shown. The port is accessed through the skin via needle and is lesilioit enough to allow hundreds of punctures and infusions before needing to be replaced. 

Impla.nta.ble Ports. The safest method of accessing the vascular system is by means of a vascular access device (VAD) or port. Older VAD designs protmded through the skin. The totally implanted ports are designed for convenience, near absence of infection, and ease of implantation. Ports allow dmgs and fluids to be deUvered directiy into the bloodstream without repeated insertion of needles into a vein. The primary recipients of totally implanted ports are patients receiving chemotherapy, bolus infusions of vesicants, parenteral nutrition, antibiotics, analgesics, and acquired immune disease syndrome (AIDS) medications. 

Many different types of venous-access devices are available. Peripherally inserted central venous catheters (PICCs), which can be made of PU or silicone, are inserted into a vein in the arm rather than in the neck or chest. Nontunneled CVCs are shortterm catheters, made of PU or silicone as well, inserted into the internal jugular, subclavian, or femoral vein. Tunneled CVCs are long-term catheters implanted surgically under the skin. One end of the catheter remains outside the skin and the exit site is typically located in the chest. Passing the catheter under the skin helps to reduce the infection risk and provides stability. Implantable ports are similar to tunneled catheters but are left completely under the skin. They consist in small devices, made of plastic or titanium, inserted beneath the skin and connected to a catheter allowing vascular access. Under the skin, the port has a septum through which drugs can be injected and blood samples can be withdrawn. 

Blood Access Devices. An investigational device called the Osteoport system allows repeated access to the vascular system via an iatraosseous iafusion directiy iato the bone marrow. The port is implanted subcutaneously and secured iato a bone, such as the iUac crest. Medications are adrninistered as ia any conventional port, but are taken up by the venous sinusoids ia the marrow cavity, and from there enter the peripheral circulation (8). 

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