Bypass (surgical)
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 vascular bypass generally means an alternate or additional route for blood flow
Blood flow
Blood flow is the continuous running of blood in the cardiovascular system.The human body is made up of several processes all carrying out various functions. We have the gastrointestinal system which aids the digestion and the absorption of food...

, which is created in bypass surgery, e.g. coronary artery bypass surgery
Coronary artery bypass surgery
Coronary artery bypass surgery, also coronary artery bypass graft surgery, and colloquially heart bypass or bypass surgery is a surgical procedure performed to relieve angina and reduce the risk of death from coronary artery disease...

 by moving blood vessels or implanting synthetic tubing. Vessels frequently used for the bypass are large 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 taken from the patient's leg. When and where possible, however, an artery
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....

 is cut from one place and reconnected to another artery, which supplies a region that needs the blood supply more than the original site. Generally the blood flow in the receiving vessel is temporarily interrupted or reduced while the bypass is connected. To create a bypass to a critical artery, the connection can be made while blood is flowing through the receiving vessel with the ELANA operating technique.

Types of bypass surgeries

There are several different types of bypass surgeries:
  • Heart bypass surgery is performed when the arteries that bring blood
    Blood
    Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

     to the heart muscle (coronary arteries) become clogged by plaque
    Plaque
    Plaque or placque may refer to:* Commemorative plaque, a flat ornamental plate or tablet fixed to a wall, used to mark a significant event, person, etc.* Memorial Plaque, issued to next-of-kin of dead British military personnel after World War I...

    . Such condition may lead to chest pain or heart attack.

  • A bypass may be performed on peripheral arteries with occlusive disease. For example, a femoral-popliteal bypass might be used if the femoral artery
    Femoral artery
    The femoral artery is a general term comprising a few large arteries in the thigh. They begin at the inguinal ligament and end just above the knee at adductor canal or Hunter's canal traversing the extent of the femur bone....

     was occluded.

  • The cerebral artery bypass surgery is performed to reroute blood flow around a blocked or damaged artery to improve or restore blood flow to an oxygen-deprived (ischemic) area of the brain.


When several arteries are blocked and thus several bypasses are needed the procedure is called multiple bypass. The number of bypasses needed does not increase the surgery's risks which depend on the patient's overall health. Weight and diabetes are examples of possible risks.

Care after bypass surgery

Part of the recovery after any bypass surgery includes regular visits to a physician to monitor the patient's recovery. These visits gradually decrease as the patient's health improves.

Coronary artery bypass

In the case of coronary artery bypass, patients stay in the hospital for four to six days and sometimes longer. Once the patient leaves the hospital the recovery time
Healing
Physiological healing is the restoration of damaged living tissue, organs and biological system to normal function. It is the process by which the cells in the body regenerate and repair to reduce the size of a damaged or necrotic area....

 can vary greatly. Some patients start feeling normal after one month, while others may still experience problems up to six months after the procedure.

During the first twelve weeks after the procedure patients are advised to avoid heavy lifting as well as activities such as playing golf
Golf
Golf is a precision club and ball sport, in which competing players use many types of clubs to hit balls into a series of holes on a golf course using the fewest number of strokes....

, tennis
Tennis
Tennis is a sport usually played between two players or between two teams of two players each . Each player uses a racket that is strung to strike a hollow rubber ball covered with felt over a net into the opponent's court. Tennis is an Olympic sport and is played at all levels of society at all...

, or swimming
Swimming (sport)
Swimming is a sport governed by the Fédération Internationale de Natation .-History: Competitive swimming in Europe began around 1800 BCE, mostly in the form of the freestyle. In 1873 Steve Bowyer introduced the trudgen to Western swimming competitions, after copying the front crawl used by Native...

 while the sternum completely heals.

Since the coronary artery bypass does not represent a cure for coronary artery diseases, doctors recommend lifestyle changes that include quitting smoking, making diet
Diet (nutrition)
In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...

 changes, getting regular exercise, and lowering stress
Stress (biology)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...

.

Cerebral artery bypass

After cerebral artery bypass, patients can return to normal activities after two to four weeks. Patients are encouraged to take short walks and gradually increase them. However, lifting weight, house work and yard work should be avoided. Also, patients are prescribed narcotic pain killers for a period of two to four weeks.

Normally a follow up visit with the neurosurgeon is scheduled for two to four weeks after surgery.

ELANA

Excimer laser assisted nonocclusive anastomosis (ELANA) is a technique in vascular surgery
Vascular surgery
Vascular surgery is a specialty of surgery in which diseases of the vascular system, or arteries and veins, are managed by medical therapy, minimally-invasive catheter procedures, and surgical reconstruction. The specialty evolved from general and cardiac surgery...

 and neurosurgery
Neurosurgery
Neurosurgery is the medical specialty concerned with the prevention, diagnosis, treatment, and rehabilitation of disorders which affect any portion of the nervous system including the brain, spine, spinal cord, peripheral nerves, and extra-cranial cerebrovascular system.-In the United States:In...

 to create a bypass without interrupting blood supply in the recipient blood vessels. This is a significant advance because the interruption of blood supply to those blood vessels (i.e., in the brain or heart) could cause a stroke or a rupture of the aneurysm.

The ELANA technique is a subtle modification of existing methods to establish a connection between blood vessels (anastomosis
Anastomosis
An anastomosis is the reconnection of two streams that previously branched out, such as blood vessels or leaf veins. The term is used in medicine, biology, mycology and geology....

) to create a bypass in or to the brain. The only real differences involve how the recipient artery
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....

 is opened. In conventional techniques the recipient artery is temporarily interrupted (occluded with clips) and opened using microscissors or scalpel
Scalpel
A scalpel, or lancet, is a small and extremely sharp bladed instrument used for surgery, anatomical dissection, and various arts and crafts . Scalpels may be single-use disposable or re-usable. Re-usable scalpels can have attached, resharpenable blades or, more commonly, non-attached, replaceable...

 while in the ELANA technique blood flow is not interrupted and the opening (arteriotomy
Arteriotomy
Arteriotomy is a medical term for an opening or cut of an artery wall. Also called arterotomy. Used mainly in :vascular surgery.Either a transverse or a longitudinal incision can be made....

) is created with radiation from a 308nm Excimer Laser delivered through a catheter inserted in the vessel that will become the bypass while blood continues to flow through the artery that receives the bypass. This subtle difference, however, is very important for the safety of the procedure and eliminates the risk of ischemia
Ischemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...

 to the regions supplied by the artery receiving the bypass. The technique is most valuable in neurosurgery, as brain cell
Neuron
A neuron is an electrically excitable cell that processes and transmits information by electrical and chemical signaling. Chemical signaling occurs via synapses, specialized connections with other cells. Neurons connect to each other to form networks. Neurons are the core components of the nervous...

s are particularly sensitive to the lack of blood supply (ischemia
Ischemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...

) that would be caused by traditional methods of bypass creation. The bypasses created with the help of the ELANA can be to one of the major arteries in the brain (extracranial to intracranial EC-IC bypass) or between two arteries in the brain (intracranial to intracranial).

Surgeons are creating such a bypass mainly as a step in the treatment of patients with unclippable and uncoilable giant aneurysms or tumors at the skull base or to treat patients at risk of stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...

 who can not be treated otherwise.

The ELANA technique has been extensively described in medical literature. It was developed in 1993 by Cornelis A.F. Tulleken, professor of neurosurgery at the University Medical Center Utrecht
Utrecht (city)
Utrecht city and municipality is the capital and most populous city of the Dutch province of Utrecht. It is located in the eastern corner of the Randstad conurbation, and is the fourth largest city of the Netherlands with a population of 312,634 on 1 Jan 2011.Utrecht's ancient city centre features...

, the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

, to find a way to treat patients with a bypass to a major cerebral artery without the risk of cerebral ischemia during the procedure. The surgery of some patients has been reported upon in the media e.g., in The New York Times
The New York Times
The New York Times is an American daily newspaper founded and continuously published in New York City since 1851. The New York Times has won 106 Pulitzer Prizes, the most of any news organization...

in December 2006.
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