Shunt (medical)
Encyclopedia
In medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

, a shunt is a hole or a small passage which moves, or allows movement of fluid
Bodily fluid
Body fluid or bodily fluids are liquids originating from inside the bodies of living people. They include fluids that are excreted or secreted from the body as well as body water that normally is not.Body fluids include:-Body fluids and health:...

 from one part of the body
Human anatomy
Human anatomy is primarily the scientific study of the morphology of the human body. Anatomy is subdivided into gross anatomy and microscopic anatomy. Gross anatomy is the study of anatomical structures that can be seen by the naked eye...

 to another. The term may describe either congenital or acquired shunts; and acquired shunts (sometimes referred to as iatrogenic shunts) may be either biological or mechanical.
  • Cardiac shunt
    Cardiac shunt
    Cardiac shunts is when the blood flow follows a pattern in the heart that deviates from the normal circuit of the circulatory system. It may be described as right-left, left-to-right or bidirectional, or as systemic-to-pulmonary or pulmonary-to-systemic. The direction may be controlled by left...

    s may be described as right-to-left, left-to-right or bidirectional, or as systemic-to-pulmonary or pulmonary-to-systemic.

  • Cerebral shunt
    Cerebral shunt
    Cerebral shunts are commonly used to treat hydrocephalus, the swelling of the brain due to excess buildup of cerebrospinal fluid . If left unchecked, the cerebral spinal fluid can build up leading to an increase in intracranial pressure which can lead to intracranial hematoma, cerebral edema,...

    : In cases of hydrocephalus
    Hydrocephalus
    Hydrocephalus , also known as "water in the brain," is a medical condition in which there is an abnormal accumulation of cerebrospinal fluid in the ventricles, or cavities, of the brain. This may cause increased intracranial pressure inside the skull and progressive enlargement of the head,...

     and other conditions that cause chronic increased intracranial pressure
    Intracranial pressure
    Intracranial pressure is the pressure inside the skull and thus in the brain tissue and cerebrospinal fluid . The body has various mechanisms by which it keeps the ICP stable, with CSF pressures varying by about 1 mmHg in normal adults through shifts in production and absorption of CSF...

    , a one-way valve is used to drain excess cerebrospinal fluid
    Cerebrospinal fluid
    Cerebrospinal fluid , Liquor cerebrospinalis, is a clear, colorless, bodily fluid, that occupies the subarachnoid space and the ventricular system around and inside the brain and spinal cord...

     from the brain
    Brain
    The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

     and carry it to other parts of the body. This valve usually sits outside the skull
    Human skull
    The human skull is a bony structure, skeleton, that is in the human head and which supports the structures of the face and forms a cavity for the brain.In humans, the adult skull is normally made up of 22 bones...

    , but beneath the skin
    Skin
    -Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...

    , somewhere behind the ear
    Ear
    The ear is the organ that detects sound. It not only receives sound, but also aids in balance and body position. The ear is part of the auditory system....

    .

  • Lumbar-peritoneal shunt
    Lumbar-peritoneal shunt
    A lumbar-peritoneal shunt is a type of cerebral shunt.-Lumbar-peritoneal shunt:A shunt is described as a tube, catheter or "surgically created anastomosis" and is designed to bypass or redirect bodily fluids from one point in the body to another....

    : In cases of chronic increased intracranial pressure
    Intracranial pressure
    Intracranial pressure is the pressure inside the skull and thus in the brain tissue and cerebrospinal fluid . The body has various mechanisms by which it keeps the ICP stable, with CSF pressures varying by about 1 mmHg in normal adults through shifts in production and absorption of CSF...

     such as Idiopathic intracranial hypertension
    Idiopathic intracranial hypertension
    Idiopathic intracranial hypertension , sometimes called by the older names benign intracranial hypertension or pseudotumor cerebri , is a neurological disorder that is characterized by increased intracranial pressure in the absence of a tumor or other diseases...

     and Hydrocephalus
    Hydrocephalus
    Hydrocephalus , also known as "water in the brain," is a medical condition in which there is an abnormal accumulation of cerebrospinal fluid in the ventricles, or cavities, of the brain. This may cause increased intracranial pressure inside the skull and progressive enlargement of the head,...

    , a tube or shunt with or without a one-way valve is used to drain the excess cerebrospinal fluid
    Cerebrospinal fluid
    Cerebrospinal fluid , Liquor cerebrospinalis, is a clear, colorless, bodily fluid, that occupies the subarachnoid space and the ventricular system around and inside the brain and spinal cord...

     from the brain
    Brain
    The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

     and transport it to the peritoneal cavity, which is a cavity located in the abdomen area of the body. This shunt
    Shunt
    Shunt may refer to:* Shunt - a hole or passage allowing fluid to move from one part of the body to another* Shunt - a device allowing electrical current to pass around a point in a circuit...

     is usually inserted in between two of the vertebrae in the lumbar and punctures the cerebrospinal fluid sack or lumbar subarachnoid space, it then runs beneath the skin
    Skin
    -Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...

     to the peritoneal cavity, where it is eventually drained away by the normal bodily fluid drainage system. For an example of a Lumbar-peritoneal/Lumboperitoneal shunt.

  • A Peritoneovenous shunt
    Peritoneovenous shunt
    A peritoneovenous shunt is a shunt which drains peritoneal fluid from the peritoneum into veins, usually the internal jugular vein or the superior vena cava...

    : (also called Denver shunt) is a shunt
    Shunt (medical)
    In medicine, a shunt is a hole or a small passage which moves, or allows movement of fluid from one part of the body to another. The term may describe either congenital or acquired shunts; and acquired shunts may be either biological or mechanical.* Cardiac shunts may be described as...

     which drains peritoneal fluid
    Peritoneal fluid
    Peritoneal fluid is a liquid that is made in the abdominal cavity to lubricate the surface of the tissue that lines the abdominal wall and pelvic cavity and covers most of the organs in the abdomen.- External links :...

     from the peritoneum
    Peritoneum
    The peritoneum is the serous membrane that forms the lining of the abdominal cavity or the coelom — it covers most of the intra-abdominal organs — in amniotes and some invertebrates...

     into vein
    Vein
    In the circulatory system, veins are blood vessels 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 blood to the heart...

    s, usually the internal jugular vein
    Internal jugular vein
    The two internal jugular veins collect the blood from the brain, the superficial parts of the face, and the neck.-Path:On both sides and at the base of the brain, the inferior petrosal sinus and the sigmoid sinus join to form the internal jugular vein...

     or the superior vena cava
    Superior vena cava
    The superior vena cava is truly superior, a large diameter, yet short, vein that carries deoxygenated blood from the upper half of the body to the heart's right atrium...

    . It is sometimes used in patients with refractory ascites
    Ascites
    Ascites is a gastroenterological term for an accumulation of fluid in the peritoneal cavity.The medical condition is also known as peritoneal cavity fluid, peritoneal fluid excess, hydroperitoneum or more archaically as abdominal dropsy. Although most commonly due to cirrhosis and severe liver...

    . It is a long tube with a non-return valve running subcutaneously from the peritoneum to the internal jugular vein in the neck, which allows ascitic fluid to pass directly into the systemic circulation


Possible Complications
  1. Infection
  2. Superior vena caval thrombosis
  3. pulmonary edema
  4. bleeding from varices
  5. DIC(Disseminated intravascular coagulopathy)

  • Pulmonary shunt
    Pulmonary shunt
    A pulmonary shunt is a physiological condition which results when the alveoli of the lung are perfused with blood as normal, but ventilation fails to supply the perfused region. In other words, the ventilation/perfusion ratio is zero...

    s exist when there is normal perfusion
    Perfusion
    In physiology, perfusion is the process of nutritive delivery of arterial blood to a capillary bed in the biological tissue. The word is derived from the French verb "perfuser" meaning to "pour over or through."...

     to an alveolus, but ventilation
    Ventilation (physiology)
    In respiratory physiology, ventilation is the rate at which gas enters or leaves the lung. It is categorized under the following definitions:-Sample values:...

     fails to supply the perfused region.

  • A portosystemic shunt
    Portosystemic shunt
    A portosystemic shunt , also known as a liver shunt, is a bypass of the liver by the body's circulatory system. It can be either a congenital or acquired condition....

     (PSS), also known as a liver shunt, is a bypass of the liver
    Liver
    The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

     by the body's circulatory system
    Circulatory system
    The circulatory system is an organ system that passes nutrients , gases, hormones, blood cells, etc...

    . It can be either a congenital or acquired condition. Congenital PSS is an uncommon condition in dogs and cats, found mainly in small dog breeds such as Miniature Schnauzer
    Miniature Schnauzer
    The Miniature Schnauzer is a breed of small dog of the Schnauzer type that originated in Germany in the mid-to-late 19th century. Miniature Schnauzers developed from crosses between the Standard Schnauzer and one or more smaller breeds such as the Poodle and Affenpinscher.The breed remains one of...

    s and Yorkshire Terrier
    Yorkshire Terrier
    The Yorkshire Terrier is a small dog breed of terrier type, developed in the 19th century in the county of Yorkshire, England to catch rats in clothing mills. The defining features of the breed are its size, to , and its silky blue and tan coat...

    s, and in cats such as Persians, Himalayan
    Himalayan (cat)
    The Himalayan cat is a breed of long-haired cat identical in type to the Persian, with the exception of its blue eyes and its point coloration, which were derived from the crossing of the Persian with the Siamese...

    s, and mix breeds. Acquired PSS is also uncommon and is found in older dogs with liver disease causing portal hypertension
    Portal hypertension
    In medicine, portal hypertension is hypertension in the portal vein and its tributaries.It is often defined as a portal pressure gradient of 10 mmHg or greater.-Causes:Causes can be divided into prehepatic, intrahepatic, and posthepatic...

    , especially cirrhosis
    Cirrhosis
    Cirrhosis is a consequence of chronic liver disease characterized by replacement of liver tissue by fibrosis, scar tissue and regenerative nodules , leading to loss of liver function...

    .

  • A portacaval shunt
    Portacaval shunt
    A portacaval shunt is a treatment for high blood pressure in the liver. A connection is made between the portal vein, which supplies 75% of the liver's blood, and the inferior vena cava, the vein that drains blood from the lower two-thirds of the body...

    / portal caval shunt is a treatment for high blood pressure in the liver.

  • Vesicoamniotic shunting procedure
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