Implantable port

Polyurethanes as Biomaterials. Much of the progress in cardiovascular devices can be attributed to advances in preparing biostable polyurethanes. Biostable polycarbonate-based polyurethane materials such as Corethane (9) and ChronoFlex (10) offer far-reaching capabiUties to cardiovascular products. These and other polyurethane materials offer significant advantages for important long-term products, such as implantable ports, hemodialysis, and peripheral catheters pacemaker interfaces and leads and vascular grafts. 

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. 

To use the port, the overlying skin is prepared using conventional techniques. A local anesthetic is sometimes used to decrease pain of needle insertion, though this is usually not necessary using techniques which utilize small-bore needles. A special point needle is used to puncture the implanted ports as the point of these needles is deflected so it tears the septum rather than coring it, allowing multiple entries. The septum reseals when the needle is removed. 

The primary advantages of implantable ports are no maintenance between uses other than periodic flushing with heparinized saline every 28 days to ensure patency, lower incidence of clotting and thrombosis, no dressing changes, insignificant infection incidence, unobtmsive cosmetic appearance, and no restriction on physical activity. 

Impingement nozzle, 23 179 Implantable ports, 3 720-721 Implant drug delivery, 18 711-712 Implanted species concentration, ion implantation and, 14 434 Implants... 

Venous acc s ix)rts are totally implanted ports with a self-sealing septum diat is attached to a catiieter leading to a large v sel, usually the vena cava These device are most commonly used for chemotherapy or other long-term therapy and require surgical insertion and removal. Dru are administered throu i injections made into the portal tiirough the skin. These dru are administered by die primary care provider or a registered nurse ... 

The client has had an implanted port placed to receive chemotherapy. When the nurse attempts to access the device, there is no backflow of blood and the nurse meets resistance when flushing. Which action should the nurse take to access the implanted port ... 

Flush the implanted port with 5-10 mL of normal saline. 

Schedule the client for a newly implanted port placement. 

The nurse is accessing a newly implanted port intravenous line. Which interventions should the nurse implement Rank in order of performance. 

The implanted port provides venous access for the client receiving chemotherapy... 

The client with an implanted port has completed the chemotherapy medications and is ready for discharge. Which action should the nurse take to prepare the client for discharge ... 

Urokinase is a thrombolytic. Instilling a small amonnt into the lumen of the implanted port and allowing the medication to sit in the catheter may dissolve the clot. The procedure may need to be repeated more than once to dissolve the entire clot. 

Implanted ports can be palpated through the skin to determine where the diaphragm of the port is. The nurse then places a finger on each side of the diaphragm to maintain the correct placement target. 

The diaphragm of the implanted port is designed to be punctured repeatedly over months to years. A noncoring needle (Huber) is used to prevent damage to the diaphragm. The nnrse places the needle between the fingers and inserts it until the needle strikes the back of the reservoir. 

Central venous access device Non-tunelled CVC Tunelled CVC PICC Apheresis/ haemodialysis catheter Implantable Port Peripheral venous access device Cannula Midline catheter... 

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). 

Another basic approach of CL analysis methods is that of the CL spectroscopy system (having no electron-beam scanning capability), which essentially consists of a high-vacuum chamber with optical ports and a port for an electron gun. Such a system is a relatively simple but powerful tool for the analysis of ion implantation-induced damage, depth distribution of defects, and interfaces in semiconductors. ... 

Almost 30 routes exist for administration of drugs to patients, but only a handfbl of these are commonly used in preclinical safety studies (Gad, 1994). The most common deviation from what is to be done in clinical trials is the use of parenteral (injected) routes such as IV (intravenous) and SC (subcutaneous) deliveries. Such injections are loosely characterized as bolus (all at once or over a very short period, such as five minutes) and infusion (over a protracted period of hours, days, or even months). The term continuous infusion implies a steady rate over a protracted period, requiring some form of setup such as an implanted venous catheter or infusion 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.]... 

Blanco and Samadani37 obtained a patent for the construction of a microprosessor-based insulin pump that works in a similar fashion to the Biostator. The implantable infusion device consists of a catheter, an information-transmitting sensor located in the catheter, a microprocessor, a pump, the drug reservoir, and a power source. The pump, the sensor, and the valves are connected by appropriate leads to the microprocessor. The device is implanted in the subcutaneous tissue in the chest area, and the infusion catheter is tethered intravenously to a central location, such as the right atrium. The device is inserted with the inlet port facing outward so that it may be refilled periodically by a physician. 

Epoxies can cure in deep sections and are useful in potting and deep-section sealing applications. They adhere well to different substrates and therefore are used in the general assembly of many medical devices. A clear, medical-grade, low-viscosity epoxy adhesive has proved useful in the fabrication of access ports that are implanted beneath the skin of patients who require multiple infusions.21... 

Funakubo et al. used a CFD model to evaluate 10 artificial implantable lungs [64]. Their research focused on the occurrence of thrombogenesis. They built a prototype to verify their CFD predictions. They found a correlation between predicted areas of low flow and thrombus formation. Further although nearly identical low flow velocity conditions exist at both the inlet and outlet ports, thrombus formation occurs only near the outlet port, which agreed with detailed vectorial analysis. Gartner et al. also used a CFD approach to model flow effects on thrombotic deposition on a membrane BO [67]. 

Central venous catheters are reluctantly used as blood access for hemodialysis because of safety concerns and frequent complications, for example sepsis, thrombosis, and vessel stenosis. Nevertheless, 20% or more of all patients rely on atrial catheters for chronic dialysis because of lack of other access. Potentially fatal risks related to central venous catheters include air embolism (1), severe blood loss (2), and electric shock (3). These specific risks have been substantially eliminated by the inherent design and implantation of Dialock (Biolink Corporation, USA). Dialock is a subcutaneous device consisting of a titanium housing with two passages with integrated valves connected to two silicone catheters. The system is implanted subcutaneously below the clavicle. The tips of the catheters are placed in the right atrium. The port is accessed percutaneously with needle cannulas. 

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