medicine Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pr ...

, a port is a small medical appliance that is installed beneath the skin. A

catheter In medicine, a catheter (/ˈkæθətər/) is a thin tubing (material), tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgi ...

(plastic tube) connects the port to a

vein Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenat ...

. Under the skin, the port has a septum (a silicone membrane) through which drugs can be injected and blood samples can be drawn many times, usually with less discomfort for the patient (and clinician) than a more typical "needle stick".

Terminology

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

Ports are used mostly to treat hematology and

oncology Oncology is a branch of medicine that deals with the study, treatment, diagnosis and prevention of cancer. A medical professional who practices oncology is an ''oncologist''. The name's etymological origin is the Greek word ὄγκος (''� ...

patients. Ports were previously adapted for use in

hemodialysis Hemodialysis, also spelled haemodialysis, or simply dialysis, is a process of purifying the blood of a person whose kidneys are not working normally. This type of dialysis achieves the extracorporeal removal of waste products such as creatinin ...

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 The clavicle, or collarbone, is a slender, S-shaped long bone approximately 6 inches (15 cm) long that serves as a strut between the shoulder blade and the sternum (breastbone). There are two clavicles, one on the left and one on the r ...

or collar bone, with the catheter inserted into the

jugular vein The jugular veins are veins that take deoxygenated blood from the head back to the heart via the superior vena cava. The internal jugular vein descends next to the internal carotid artery and continues posteriorly to the sternocleidomastoid mu ...

. 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

runs from the portal and is surgically inserted into a

(usually the

or less optimally the subclavian vein). Ideally, the catheter terminates in the

superior vena cava The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm) short length vein th ...

or the

right atrium The atrium ( la, ātrium, , entry hall) is one of two upper chambers in the heart that receives blood from the circulatory system. The blood in the atria is pumped into the heart ventricles through the atrioventricular valves. There are two at ...

. 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 An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dis ...

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 A Hickman line is a central venous catheter most often used for the administration of chemotherapy or other medications, as well as for the withdrawal of blood for analysis. Some types are used mainly for the purpose of apheresis or dialysis. T ...

. 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 Saline (also known as saline solution) is a mixture of sodium chloride (salt) and water. It has a number of uses in medicine including cleaning wounds, removal and storage of contact lenses, and help with dry eyes. By injection into a vein i ...

. Then, treatment will begin.

Uses

Ports have many uses: * To deliver

chemotherapy Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

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 The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...

. * To deliver

coagulation factor Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanism o ...

s 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 Alpha-1 antitrypsin deficiency (A1AD or AATD) is a genetic disorder that may result in lung disease or liver disease. Onset of lung problems is typically between 20 and 50 years of age. This may result in shortness of breath, wheezing, or an inc ...

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

When the patient has bacteremia or

sepsis Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...

, it is absolutely contraindicated for the procedure. In those with contrast allergy, or allergy to food or medications, the procedure can still be carried with

prednisolone Prednisolone is a steroid medication used to treat certain types of allergies, inflammatory conditions, autoimmune disorders, and cancers. Some of these conditions include adrenocortical insufficiency, high blood calcium, rheumatoid arthr ...

coverage. Other relative contraindications are: coagulopathy (abnormal coagulation), platelet count less than 50x10⁹/L. However, if the port is still needed urgently, the procedure can be carried out platelet transfusion when the procedure is ongoing on table.

Insertion

X-ray of port-a-cath in azygos vein - anteroposterior

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 Outpatient surgery, also known as ambulatory surgery, day surgery, day case surgery, or same-day surgery, is surgery that does not require an overnight hospital stay.The International Association for Ambulatory Surgery (IAAS) would not consider a ...

procedure in a hospital or clinic by an

interventional radiologist Interventional radiology (IR) is a medical specialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs bo ...

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 Fluoroscopy () is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope () allows a physician to see the internal structure and function ...

is useful in guiding the insertion of ports. Right

internal jugular vein The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. This vein runs in the carotid sheath with the common carotid artery and vagus nerve. It begins in the poste ...

(IJV) is frequently chosen as the site of access. A puncture needle is used to obtain access to the vein under ultrasound guidance. The needle should be pointed away from the

common carotid artery In anatomy, the left and right common carotid arteries (carotids) (Entry "carotid"
in
thrombosed, then right

external jugular vein The external jugular vein receives the greater part of the blood from the exterior of the cranium and the deep parts of the face, being formed by the junction of the posterior division of the retromandibular vein with the posterior auricular 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. After the entry site is punctured with ultrasound, a guidewire is inserted with the tip of the guidewire reaching the

inferior vena cava The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of th ...

. The proximal end of the guidewire is secured to prevent dislodgement. Then a chemoport pocket is created on the deltopectoral region at 2.5 cm below the level of

by using a scalpel. Bupivacaine with adrenaline (0.25%) is used as local anesthetic to reduce the formation of haematoma and prolong the anesthetic effect. After the pocket is created, a

trocar A trocar (or trochar) is a medical or veterinary device that is made up of an awl (which may be a metal or plastic sharpened or non-bladed tip), a cannula (essentially a hollow tube), and a seal. Trocars are placed through the abdomen during lap ...

is used insert a silicone catheter from the pocket towards the internal jugular vein puncture site. A peel-away sheath is then inserted to facilitate the insertion of the silicone catheter into the cavoatrial junction. Silicone catether insertion should be done during breath hold at inspiration. The peel-away sheath should be pinched to prevent air embolism. The proximal end of the catheter is connected to the port within the skin pocket later after irrigation of the pocket with normal saline. The port is then sutured on two sites to the underlying muscles. The tip of the catheter is checked for kinks and position using a

fluoroscope Fluoroscopy () is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging Medical imaging is the technique and process of imaging the interior of a ...

. Besides that, aspiration of blood and contrast injection through the chemoport can also be used to confirm the position. The port is the closed in two layers (subcutaneous tissue is sutured first, followed by the skin). Sterile dressing is then placed on the port. The optimum site to park the tip of the catheter is at the cavo-atrial junction or with margin of error of not more than 4 cm above the junction. A follow-up on a chest radiograph can immediately detect complications associated with the procedure in the form of

pneumothorax A pneumothorax is an abnormal collection of air in the pleural space between the lung and the chest wall. Symptoms typically include sudden onset of sharp, one-sided chest pain and shortness of breath. In a minority of cases, a one-way valve i ...

hemothorax A hemothorax (derived from hemo- lood+ thorax hest plural ''hemothoraces'') is an accumulation of blood within the pleural cavity. The symptoms of a hemothorax may include chest pain and difficulty breathing, while the clinical signs may incl ...

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. 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 Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...

, stainless steel, or

titanium Titanium is a chemical element with the Symbol (chemistry), symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resista ...

* can be single chamber or dual chamber * vary in height, width and shape. Catheters: * can be made of biocompatible, medical-grade

polyurethane Polyurethane (; often abbreviated PUR and PU) refers to a class of polymers composed of organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane is produced from ...

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

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. The overall risk of arterial puncture is 0.5%. The subclavian artery can be inadvertently punctured while attempting a subclavian vein access, leading to a subcutaneous hematoma and occasionally a

pseudoaneurysm A pseudoaneurysm, also known as a false aneurysm, is a locally contained hematoma outside an artery or heart due to damage to the vessel wall. The injury goes through all the three layers of the arterial wall causing a leak, which is contained b ...

. An alternative site may need to be used for port placement. Puncture of the carotid artery is significantly more rare, since attempts to access the nearby

are increasingly done with

ultrasound Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies ...

guidance. * 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. * Mechanical failure is uncommon. Ports placed through the subclavian vein may develop "pinch-off syndrome" where the catheter fractures as it passes into the vein. Ports placed via the jugular vein do not have this problem. The catheter fragment then travels through the venous system and typically lodges in the right heart or the lungs. Many patients are asymptomatic but the mechanical failure is discovered because of an inability to flush or withdraw fluids from the port. In those instances, an interventional radiologist can usually retrieve the fragment and place a new port. *

Pneumothorax A pneumothorax is an abnormal collection of air in the pleural space between the lung and the chest wall. Symptoms typically include sudden onset of sharp, one-sided chest pain and shortness of breath. In a minority of cases, a one-way valve i ...

: Attempts to gain access to the subclavian vein or

can injure the lung, potentially causing a pneumothorax. If the pneumothorax is large enough, a

chest tube A chest tube (also chest drain, thoracic catheter, tube thoracostomy or intercostal drain) is a surgical drain that is inserted through the chest wall and into the pleural space or the mediastinum in order to remove clinically undesired substance ...

might need to be placed. In experienced hands, the incidence of this complication is about 1% when accessing the subclavian vein. When accessing the jugular vein the pneumothorax rate is virtually nonexistent. *

Thrombosis Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (t ...

: formation of a blood clot in the catheter may block the device irrevocably. To prevent clotting the port is flushed with saline and heparin, usually by a nurse or other medical professional, or someone properly trained that is a family member or the patient, once every six weeks, or more often in conjunction with administering medication. *

Vascular occlusion Vascular occlusion is a blockage of a blood vessel, usually with a clot. It differs from thrombosis in that it can be used to describe any form of blockage, not just one formed by a clot. When it occurs in a major vein, it can, in some cases, cau ...

: 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 Drug injection is a method of introducing a drug into the bloodstream via a hollow hypodermic needle, which is pierced through the skin into the body (usually intravenously, but also at an intramuscular or subcutaneous location). Intravenous t ...

: 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 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 regularly, flush it with saline, and inject a new heparin lock to prevent clotting between uses.

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 A peripherally inserted central catheter (PICC or PIC line), less commonly called a percutaneous indwelling central catheter, is a form of intravenous access that can be used for a prolonged period of time (e.g., for long chemotherapy regimens ...

, despite drawbacks such as external entry point and limited lifespan of the device.

In popular culture

In the 1984

cyberpunk Cyberpunk is a subgenre of science fiction in a dystopian futuristic setting that tends to focus on a "combination of lowlife and high tech", featuring futuristic technological and scientific achievements, such as artificial intelligence and c ...

novel ''

Neuromancer ''Neuromancer'' is a 1984 science fiction novel by American-Canadian writer William Gibson. Considered one of the earliest and best-known works in the cyberpunk genre, it is the only novel to win the Nebula Award, the Philip K. Dick Award, and ...

'', a minor character, Peter Riviera, has a kind of medical port placed in his arm to facilitate his recreational drug use.

Notes

References

External links

www.breastcancer.org: Ports for Chemo

A photo-essay on what it's like to have a port

An overview of chemo ports/Portacaths
{{DEFAULTSORT:Port Catheters Implants (medicine) Medical equipment Oncology Vascular surgical procedures