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In medicine, a port is a small medical appliance that is installed beneath the skin. A catheter connects the port to a vein. Under the skin, the port has a septum through which drugs can be injected and blood samples can be drawn many times, usually with less discomfort for the patient than a more typical "needle stick".
Ports are used mostly to treat hematology and oncology patients. Ports were previously adapted for use in hemodialysis patients, but were found to be associated with increased rate of infections and are no longer available in the US.
The port is usually inserted in the upper chest (known as a "chest port"), just below the clavicle or collar bone, leaving the patient's hands free.
A port is more correctly known as a "totally implantable venous access device". Brand Names include Eco Port, Clip-a-Port, SmartPort, Microport, Bardport, PowerPort, Passport, Port-a-Cath, Infuse-a-Port, Medi-Port, and Bioflo.
A port consists of a reservoir compartment (the portal) that has a silicone bubble for needle insertion (the septum), with an attached plastic tube (the catheter). The device is surgically inserted under the skin in the upper chest or in the arm and appears as a bump under the skin. It requires no special maintenance and is completely internal so swimming and bathing are not a problem. The catheter runs from the portal and is surgically inserted into a vein (usually the jugular vein or less optimally the subclavian vein). Ideally, the catheter terminates in the superior vena cava or the right atrium. This position allows infused agents to be spread throughout the body quickly and efficiently.
The septum is made of a special self-sealing silicone; it can be punctured hundreds of times before it weakens significantly. To administer treatment or to withdraw blood, a health care professional will first locate the port and disinfect the area, then access the port by puncturing the overlying skin with a Huber point needle. Due to its design, there is a very low infection risk, as the breach of skin integrity is never larger than the caliber of the needle. This gives it an advantage over indwelling lines such as the Hickman line. Negative pressure is created to withdraw blood into the vacuumized needle, to check for blood return and see if the port is functioning normally. Next, the port is flushed with a saline solution. Then, treatment will begin.
The implantation procedure itself is considered minor, and is typically performed with both local anaesthesia and moderate sedation. Patients often have post-procedure discomfort at the insertion site which is most often managed by administration of acetaminophen or a non-steroidal anti-inflammatory drug such as ibuprofen.
A port is most commonly inserted as an outpatient surgery procedure in a hospital or clinic by an interventional radiologist or surgeon, under moderate sedation. Implantation is increasingly performed by interventional radiologists due to advancements in techniques and their facile use of imaging technologies. When no longer needed, the port can be removed in the interventional radiology suite or an operating room.
Ports have many uses:
A follow-up chest radiograph can immediately detect complications associated with the procedure in the form of pneumothorax, hemothorax and malpositions of the catheter (see Risks below for further details). However, it is suggested that chest radiography is not mandatory as a routine method after fluoroscopy-guided port insertion that is mainly performed by venous cutdown.
The side of the patients' chest the port is implanted in will usually be chosen to avoid damage to the port and the veins by the seat belt in case of accident when seated as the driver. Thus, there is a potential conflict by left- and right-hand traffic as the rule of the road.
There are many different models of ports. The particular model selected is based on the patient's specific medical conditions.
Ports can be put in the upper chest or arm. The exact positioning itself is variable as it can be inserted to avoid visibility when wearing low cut shirts, and to avoid excess contact due to a backpack or bra strap. The most common placement is on the upper right portion of the chest, with the catheter itself looping through the right jugular vein, and down towards the patient's heart.
To reduce damage or coring of the septum during use, low or non coring needles are to be used. After each use, a heparin lock is made by injecting a small amount of heparinized saline (an anticoagulant) into the device, preventing development of clots within the port or catheter. In some catheter designs where there is a self-sealing valve at the far end, the system is locked with just saline. The port can be left accessed for as long as required. The port is covered in a dressing to protect the site from infection and to secure the needle in position.
If a port is used infrequently, it may be necessary to access the port, flush it with saline, and inject a new heparin lock to prevent clotting between uses.
Sometimes, the physical condition of the patient, especially the structure of his veins, does not allow for the insertion of a port. An alternative is the PICC line, despite drawbacks such as external entry point and limited lifespan of the device.
Verlauf des Autosicherheitsgurts in die Überlegungen mit einzubeziehen (to include the place of the safety belt into the planning)
Auf welcher Seite wird der Sicherheitsgurt angebracht? (which side is the safety belt)
Liegedauer von 4 Monaten
Riviera loosened and removed the elastic length of surgical tubing from his arm. 'Yes. It's more fun.' He smiled, his eyes distant now, cheeks flushed. 'I've a membrane set in, just over the vein, so I never have to worry about the condition of the needle.' 'Doesn't hurt?' [said Case] The bright eyes met his. 'Of course it does. That's part of it, isn't it?'