Port (medicine)

A port is more correctly known as a "totally implantable venous access device". They are also commonly referred to as a Portacath or Chemo port. Brand names include Eco Port, Clip-a-Port, SmartPort, Microport, Bardport, PowerPort, Passport, Port-a-Cath, Infuse-a-Port, Medi-Port, and Bioflo. == Structure ==

runs from the portal and is surgically inserted into a vein (usually the jugular vein, subclavian vein, or superior vena cava). Ideally, the catheter terminates in the superior vena cava, just upstream of the right atrium. This position allows infused agents to be spread throughout the body quickly and efficiently. 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, with the catheter inserted into the jugular vein. 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 other than occasional flushing to keep clear. It 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 (non-coring) 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. ==Uses==

Ports have many uses: • To deliver chemotherapy to cancer patients who must undergo treatment frequently. Chemotherapy is often toxic, and can damage skin and muscle tissue, and therefore should not be delivered through these tissues. Ports provide a solution, delivering drugs quickly and efficiently through the entire body via the circulatory system. • To deliver coagulation factors in patients with severe hemophilia. • To withdraw (and/or return) blood to the body in patients who require frequent blood tests, and in hemodialysis patients. • To deliver antibiotics to patients requiring them for a long time or frequently, such as those with cystic fibrosis and bronchiectasis. • Delivering medications to patients with immune disorders. • For treating alpha 1-antitrypsin deficiency with replacement therapy • For delivering radiopaque contrast agents, which enhance contrast in CT imaging. • To fill or withdraw fluid from the Lap-Band or Realize gastric bands used in Bariatric surgeries. • To administer analgesics to patients with chronic pain, such as cancer patients and those with sickle-cell disease ==Contraindications==

Installation of a port is absolutely contraindicated when a patient has bacteremia or sepsis. In those with contrast allergy, or allergy to food or medications, the procedure can still be carried out with prednisolone coverage. Other relative contraindications include coagulopathy (abnormal coagulation) or platelet count less than 50×109/L. However, if the port is needed urgently, platelet transfusion may be given while the procedure is ongoing on table. ==Insertion==

after insertion of a port, with a malpositioned tip in the azygos vein. of the same patient confirming the position of the port tip in the azygos vein. 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. Fluoroscopy is useful in guiding the insertion of ports. Interventional radiology Right internal jugular vein (IJV) is frequently chosen as the site of access. A 19G puncture needle is used to obtain access to the vein under ultrasound guidance. The needle should be pointed away from the common carotid artery (CCA) as the CCA just lie medially to the IJV. If there is difficult puncture, micropuncture set can be used to puncuture the vein and later switch to a bigger access system. If bilateral IJVs are thrombosed, then right external jugular vein is chosen as the puncture site. The puncture site should not be the same side as the pathological site such as breast cancer site or an area that is chosen as the potential site for radiation therapy. 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. == Models ==

There are many different models of ports. The particular model selected is based on the patient's specific medical conditions. Portals: • can be made of plastic, stainless steel, or titanium • can be single chamber or dual chamber • vary in height, width and shape. Catheters: • can be made of biocompatible, medical-grade polyurethane or silicone • can vary in length and diameter For applications such as CT scan, high pressure infusion allowing ports are needed. Manufacturers The major manufacturers of ports are AngioDynamics, B. Braun Medical, Bard Access Systems, Cook Medical, MedComp, Navilyst Medical, Norfolk Medical Products, and Smiths Medical. ==Risks and complications==

The most common complications are: catheter blockage (7.4%), and catheter-related infection (5.6%). Other complications are: malpositioning of the catheter, venous thrombosis, catheter leak or dislodgement. The common carotid artery may be injured during the puncture of the internal jugular vein as the artery lies close to the vein. This mostly due to the needle overshooting into the artery rather than the inability to recognise vein and artery under ultrasound guidance. The risk of puncture increases when the artery lies superficial to the vein and for those with short neck and obese people. However, these cases can be easily controlled using compression and it does not leave a hematoma at the site of puncture. • Age: If the device is put into a child, the child's growth means that the catheter becomes relatively shorter and will move towards the head. It may become necessary to remove or replace it. • Vascular occlusion: formation of a blood clot between the catheter and the vascular wall leading to partial or complete occlusion of the vein. The occlusion is cleared by removal of the port if possible. If not, then heparin therapy may clear the occlusion. • Intravenous drug use: If an intravenous drug user is discharged to be treated with a port in place to be treated on an outpatient basis, they may be likely to use the port improperly to inject illicit drugs. This use poses a serious risk of injury or severe infection, including of the heart lining. == Maintenance ==

To reduce damage or coring of the septum (cutting out small pieces of membrane with the needle, plugging it up), low or non coring needles are to be used. After every cycle of chemotherapy, the port should be flushed with 1:10 diluted heparin (5000 IU/ml) to prevent clot formation within the port. If the port is not used for a long time, it should be flushed with diluted heparin every two months. == Alternatives ==

Sometimes, the physical condition of the patient, especially the structure of their 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. == In popular culture ==

In the 1984 cyberpunk novel Neuromancer, a minor character, Peter Riviera, has a kind of medical port placed in his arm to facilitate his recreational drug use. == History ==

Niederhuber et al. first reported the use of totally implantable central venous port system (TICVPS) in 1982. == See also ==