![PAC met Gripper erin](https://upload.wikimedia.org/wikipedia/commons/9/95/PAC_met_Gripper_erin.JPG)
In
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 pract ...
, a port is a small medical appliance that is installed beneath the skin. A
catheter (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 oxygenated b ...
. Under the skin, the port has a
septum
In biology, a septum (Latin for ''something that encloses''; plural septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate.
Examples
Human anatomy
* Interatri ...
(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
![Portkatheter Röntgen](https://upload.wikimedia.org/wikipedia/commons/9/9f/Portkatheter_R%C3%B6ntgen.JPG)
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
![Gray576](https://upload.wikimedia.org/wikipedia/commons/e/e9/Gray576.png)
Ports are used mostly to treat
hematology
Hematology ( always spelled haematology in British English) is the branch of medicine concerned with the study of the cause, prognosis, treatment, and prevention of diseases related to blood. It involves treating diseases that affect the produc ...
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 (''ó ...
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
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 rig ...
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
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 oxygenated b ...
(usually the
jugular vein or less optimally the
subclavian vein
The subclavian vein is a paired large vein, one on either side of the body, that is responsible for draining blood from the upper extremities, allowing this blood to return to the heart. The left subclavian vein plays a key role in the absorption ...
). 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
A silicone or polysiloxane is a polymer made up of siloxane (−R2Si−O−SiR2−, where R = organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking ...
; 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 dise ...
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 it ...
. 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. Chemotherap ...
to
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 factors in patients with severe
hemophilia
Haemophilia, or hemophilia (), is a mostly inherited genetic disorder that impairs the body's ability to make blood clots, a process needed to stop bleeding. This results in people bleeding for a longer time after an injury, easy bruising, ...
.
* To withdraw (and/or return) blood to the body in patients who require frequent blood tests, and in hemodialysis patients.
* To deliver
antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...
s to patients requiring them for a long time or frequently, such as those with
cystic fibrosis
Cystic fibrosis (CF) is a rare genetic disorder that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine. Long-term issues include difficulty breathing and coughing up mucus as a result of frequent lung infections. O ...
and
bronchiectasis
Bronchiectasis is a disease in which there is permanent enlargement of parts of the bronchi, airways of the lung. Symptoms typically include a chronic cough with sputum, mucus production. Other symptoms include shortness of breath, hemoptysis, co ...
.
* 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
Bloodstream infections (BSIs), which include bacteremias when the infections are bacterial and fungemias when the infections are fungal, are infections present in the blood. Blood is normally a sterile environment, so the detection of microb ...
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 arthrit ...
coverage. Other relative contraindications are:
coagulopathy
Coagulopathy (also called a bleeding disorder) is a condition in which the blood's ability to coagulate (form clots) is impaired. This condition can cause a tendency toward prolonged or excessive bleeding (bleeding diathesis), which may occur spo ...
(abnormal coagulation), platelet count less than 50x10
9/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
![CT of port-a-cath in azygos vein](https://upload.wikimedia.org/wikipedia/commons/f/f6/CT_of_port-a-cath_in_azygos_vein.jpg)
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
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 is useful in guiding the insertion of ports.
Right
internal jugular vein (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 (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
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 (thro ...
, 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.
After the entry site is punctured with ultrasound, a guidewire is inserted with the tip of the guidewire reaching the
inferior vena cava. 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
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 rig ...
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. 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
A chest radiograph, called a chest X-ray (CXR), or chest film, is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most common film taken in med ...
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
A seat belt (also known as a safety belt, or spelled seatbelt) is a vehicle safety device designed to secure the driver or a passenger of a vehicle against harmful movement that may result during a collision or a sudden stop. A seat belt reduc ...
in case of accident when seated as the driver. Thus, there is a potential conflict by
left- and right-hand traffic
Left-hand traffic (LHT) and right-hand traffic (RHT) are the practices, in bidirectional traffic, of keeping to the left side or to the right side of the road, respectively. They are fundamental to traffic flow, and are sometimes referred to ...
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
Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's corros ...
, or
titanium
Titanium is a chemical element with the 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, resistant to corrosion in ...
* can be single chamber or dual chamber
* vary in height, width and shape.
Catheters:
* can be made of biocompatible, medical-grade
polyurethane or
silicone
A silicone or polysiloxane is a polymer made up of siloxane (−R2Si−O−SiR2−, where R = organic group). They are typically colorless oils or rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking ...
* can vary in length and diameter
For applications such as
CT scan
A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...
, high pressure infusion allowing ports are needed.
Manufacturers
The major manufacturers of ports are
AngioDynamics,
B. Braun Medical,
Bard Access Systems,
Cook Medical
Cook Group Incorporated is an American privately held company based in Bloomington, Indiana, and primarily involved in manufacturing of medical devices. It was ranked #324 in Forbes' 2008 America's Largest Private Companies. It has four main divisi ...
,
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
A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillary, capillaries. A he ...
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. An alternative site may need to be used for port placement. Puncture of the
carotid artery Carotid artery may refer to:
* Common carotid artery, often "carotids" or "carotid", an artery on each side of the neck which divides into the external carotid artery and internal carotid artery
* External carotid artery, an artery on each side of t ...
is significantly more rare, since attempts to access the nearby
jugular vein are increasingly done with
ultrasound
Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...
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: Attempts to gain access to the
subclavian vein
The subclavian vein is a paired large vein, one on either side of the body, that is responsible for draining blood from the upper extremities, allowing this blood to return to the heart. The left subclavian vein plays a key role in the absorption ...
or
jugular vein 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 substanc ...
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 (thro ...
: formation of a blood clot in the catheter may block the device irrevocably. To prevent clotting the port is flushed with
saline
Saline may refer to:
* Saline (medicine), a liquid with salt content to match the human body
* Saline water, non-medicinal salt water
* Saline, a historical term (especially US) for a salt works or saltern
Places
* Saline, Calvados, a commune in ...
and
heparin
Heparin, also known as unfractionated heparin (UFH), is a medication and naturally occurring glycosaminoglycan. Since heparins depend on the activity of antithrombin, they are considered anticoagulants. Specifically it is also used in the treatm ...
, 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: 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 each use, a
heparin
Heparin, also known as unfractionated heparin (UFH), is a medication and naturally occurring glycosaminoglycan. Since heparins depend on the activity of antithrombin, they are considered anticoagulants. Specifically it is also used in the treatm ...
lock is made by injecting a small amount of heparinized saline (an
anticoagulant
Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where the ...
) 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, 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 cyber ...
novel ''
Neuromancer'', a minor character, Peter Riviera, has a kind of medical port placed in his arm to facilitate his
recreational drug use
Recreational drug use indicates the use of one or more psychoactive drugs to induce an altered state of consciousness either for pleasure or for some other casual purpose or pastime by modifying the perceptions and emotions of the user. When a ...
.
See also
*
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 ...
*
Peripherally inserted central catheter
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 ...
or "PICC"
*
Groshong line
A Groshong line is a type of intravenous catheter used for central venous access. It can be tunneled or non-tunneled.
Application
Groshongs may be left in place for extended periods and are used when long-term intravenous therapy is needed, s ...
*
Central venous catheter
A central venous catheter (CVC), also known as a central line(c-line), central venous line, or central venous access catheter, is a catheter placed into a large vein. It is a form of venous access. Placement of larger catheters in more central ...
Notes
References
Further reading
*
External links
www.breastcancer.org: Ports for ChemoA photo-essay on what it's like to have a portAn overview of chemo ports/Portacaths
{{DEFAULTSORT:Port
Catheters
Implants (medicine)
Medical equipment
Oncology
Vascular surgical procedures