Restenosis
Encyclopedia
Restenosis literally means the reoccurrence of stenosis
, a narrowing of a blood vessel
, leading to restricted blood flow. Restenosis usually pertains to an artery
or other large blood vessel
that has become narrowed, received treatment to clear the blockage and subsequently become renarrowed. This is usually restenosis of an artery
, or other blood vessel, or possibly a vessel within an organ
. This term is common in vascular surgery
, cardiac surgery
, and angioplasty
, all branches of medicine that frequently treat narrowing of blood vessels.
It can be defined as a reduction in the circumference of the lumen of 50% or more, and had a high incidence rate (25-50%) in patients who had undergone balloon angioplasty, with the majority of patients needing further angioplasty within 6 months.
has a long lasting beneficial effect for the patient. However in some cases, the procedure itself can cause further narrowing of the vessel, or restenosis.
Angioplasty
also called Percutaneous transluminal coronary angioplasty (PTCA
) is commonly used to treat blockages of the coronary arteries,or peripheral arteries
such as the limbs. The balloon inserted into the narrowing ‘smashes’ the cholesterol
plaques (atherosclerosis
) against the artery walls, thus widening the size of the lumen
and increasing blood flow. However the action does damage to the artery walls, and it responds by using physiological mechanisms to repair the damage. (See physiology below)
A stent
is a mesh tube-like structure often used in conjunction with angioplasty
to permanently hold open an artery
, allowing for unrestricted blood flow, or to support a weakness in the artery wall called an aneurysm
.
The artery
can react to the stent
, perceive it as a foreign body and respond by mounting an immune system
response (see physiology below) which leads to further narrowing near to or inside the stent
.
wall by angioplasty
triggers physiological response that can be divided into two stages. The first stage that occurs immediately after tissue trauma
, is thrombosis
. A blood clot forms at the site of damage and further hinders blood flow. This is accompanied by an inflammatory immune response.
The second stage tends to occur 3–6 months after surgery and is the result of proliferation of cells in the intima, a smooth muscle wall in the vessel. This is also known as Neointimal hyperplasia (NIHA)
drugs (called IIb/IIIa inhibitors) immediately after surgery greatly reduces the chance of a thrombosis
occurring.
Drug-eluting stent
s are now being trialled in Europe and the USA, as well as in Asia-Pacific. These stents are coated with pharmaceuticals that inhibit tissue growth and thus reduce the risk of restenosis from scar-tissue and cell proliferation.
There has been some success with these new stents in reducing the occurrence of restenosis, with clinical studies showing an incidence rate of 5% or lower.
, it is usually treated with more angioplasty
. Once restenosis has occurred and been treated by angioplasty
, the chances of restenosis occurring again are increased by a factor of 2.This treatment is also used if restenosis occurs at either end of the stent
.
If restenosis occurs within a stent
it may be treated with repeated angioplasty
and insertion of another stent inside the original; occasionally using a drug-eluted stent.
Alternative treatments include brachytherapy
, or intracoronary radiation. The radiation kills cells and inhibits tissue growth (similar to a patient undergoing cancer therapy).
Images of restenosis with bare-metal stent
s and drug-eluting stent
s are here .
Stenosis
A stenosis is an abnormal narrowing in a blood vessel or other tubular organ or structure.It is also sometimes called a stricture ....
, a narrowing of a blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
, leading to restricted blood flow. Restenosis usually pertains to 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....
or other large blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
that has become narrowed, received treatment to clear the blockage and subsequently become renarrowed. This is usually restenosis of 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....
, or other blood vessel, or possibly a vessel within an organ
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...
. This term is common 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...
, cardiac surgery
Cardiac surgery
Cardiovascular surgery is surgery on the heart or great vessels performed by cardiac surgeons. Frequently, it is done to treat complications of ischemic heart disease , correct congenital heart disease, or treat valvular heart disease from various causes including endocarditis, rheumatic heart...
, and angioplasty
Angioplasty
Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, the latter typically being a result of atherosclerosis. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size...
, all branches of medicine that frequently treat narrowing of blood vessels.
It can be defined as a reduction in the circumference of the lumen of 50% or more, and had a high incidence rate (25-50%) in patients who had undergone balloon angioplasty, with the majority of patients needing further angioplasty within 6 months.
Causes
Usually surgery to widen or unblock a blood vesselBlood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
has a long lasting beneficial effect for the patient. However in some cases, the procedure itself can cause further narrowing of the vessel, or restenosis.
Angioplasty
Angioplasty
Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, the latter typically being a result of atherosclerosis. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size...
also called Percutaneous transluminal coronary angioplasty (PTCA
PTCA
PTCA may refer to:* Percutaneous transluminal coronary angioplasty, a type of angioplasty* Percutaneous transhepatic cholangiography...
) is commonly used to treat blockages of the coronary arteries,or peripheral arteries
Peripheral arteries
Peripheral arteries are the arteries which are farthest from the heart . In some cases blockages in the peripheral arteries may be treated with catheterization and balloon dilatation instead of surgery....
such as the limbs. The balloon inserted into the narrowing ‘smashes’ the cholesterol
Cholesterol
Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...
plaques (atherosclerosis
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
) against the artery walls, thus widening the size of the lumen
Lumen (anatomy)
A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...
and increasing blood flow. However the action does damage to the artery walls, and it responds by using physiological mechanisms to repair the damage. (See physiology below)
A stent
Stent
In the technical vocabulary of medicine, a stent is an artificial 'tube' inserted into a natural passage/conduit in the body to prevent, or counteract, a disease-induced, localized flow constriction. The term may also refer to a tube used to temporarily hold such a natural conduit open to allow...
is a mesh tube-like structure often used in conjunction with angioplasty
Angioplasty
Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, the latter typically being a result of atherosclerosis. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size...
to permanently hold open 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....
, allowing for unrestricted blood flow, or to support a weakness in the artery wall called an aneurysm
Aneurysm
An aneurysm or aneurism is a localized, blood-filled balloon-like bulge in the wall of a blood vessel. Aneurysms can commonly occur in arteries at the base of the brain and an aortic aneurysm occurs in the main artery carrying blood from the left ventricle of the heart...
.
The 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....
can react to the stent
Stent
In the technical vocabulary of medicine, a stent is an artificial 'tube' inserted into a natural passage/conduit in the body to prevent, or counteract, a disease-induced, localized flow constriction. The term may also refer to a tube used to temporarily hold such a natural conduit open to allow...
, perceive it as a foreign body and respond by mounting an immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
response (see physiology below) which leads to further narrowing near to or inside the stent
Stent
In the technical vocabulary of medicine, a stent is an artificial 'tube' inserted into a natural passage/conduit in the body to prevent, or counteract, a disease-induced, localized flow constriction. The term may also refer to a tube used to temporarily hold such a natural conduit open to allow...
.
Physiology
Damage to the blood vesselBlood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
wall by angioplasty
Angioplasty
Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, the latter typically being a result of atherosclerosis. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size...
triggers physiological response that can be divided into two stages. The first stage that occurs immediately after tissue trauma
Physical trauma
Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
, is thrombosis
Thrombosis
Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
. A blood clot forms at the site of damage and further hinders blood flow. This is accompanied by an inflammatory immune response.
The second stage tends to occur 3–6 months after surgery and is the result of proliferation of cells in the intima, a smooth muscle wall in the vessel. This is also known as Neointimal hyperplasia (NIHA)
Prevention
In the first stage of restenosis, administering anti-plateletPlatelet
Platelets, or thrombocytes , are small,irregularly shaped clear cell fragments , 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days...
drugs (called IIb/IIIa inhibitors) immediately after surgery greatly reduces the chance of a thrombosis
Thrombosis
Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
occurring.
Drug-eluting stent
Drug-eluting stent
A drug-eluting stent ' is a peripheral or coronary stent placed into narrowed, diseased peripheral or coronary arteries that slowly releases a drug to block cell proliferation. This prevents fibrosis that, together with clots , could otherwise block the stented artery, a process called restenosis...
s are now being trialled in Europe and the USA, as well as in Asia-Pacific. These stents are coated with pharmaceuticals that inhibit tissue growth and thus reduce the risk of restenosis from scar-tissue and cell proliferation.
There has been some success with these new stents in reducing the occurrence of restenosis, with clinical studies showing an incidence rate of 5% or lower.
Treatment
If restenosis occurs without a stentStent
In the technical vocabulary of medicine, a stent is an artificial 'tube' inserted into a natural passage/conduit in the body to prevent, or counteract, a disease-induced, localized flow constriction. The term may also refer to a tube used to temporarily hold such a natural conduit open to allow...
, it is usually treated with more angioplasty
Angioplasty
Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, the latter typically being a result of atherosclerosis. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size...
. Once restenosis has occurred and been treated by angioplasty
Angioplasty
Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, the latter typically being a result of atherosclerosis. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size...
, the chances of restenosis occurring again are increased by a factor of 2.This treatment is also used if restenosis occurs at either end of the stent
Stent
In the technical vocabulary of medicine, a stent is an artificial 'tube' inserted into a natural passage/conduit in the body to prevent, or counteract, a disease-induced, localized flow constriction. The term may also refer to a tube used to temporarily hold such a natural conduit open to allow...
.
If restenosis occurs within a stent
Stent
In the technical vocabulary of medicine, a stent is an artificial 'tube' inserted into a natural passage/conduit in the body to prevent, or counteract, a disease-induced, localized flow constriction. The term may also refer to a tube used to temporarily hold such a natural conduit open to allow...
it may be treated with repeated angioplasty
Angioplasty
Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, the latter typically being a result of atherosclerosis. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size...
and insertion of another stent inside the original; occasionally using a drug-eluted stent.
Alternative treatments include brachytherapy
Brachytherapy
Brachytherapy , also known as internal radiotherapy, sealed source radiotherapy, curietherapy or endocurietherapy, is a form of radiotherapy where a radiation source is placed inside or next to the area requiring treatment...
, or intracoronary radiation. The radiation kills cells and inhibits tissue growth (similar to a patient undergoing cancer therapy).
Images of restenosis with bare-metal stent
Bare-metal stent
Bare-metal stent is a vascular stent without a coating . It is a mesh-like tube of thin wire. The first stents licenced for use in cardiac arteries were bare metal - often 316L stainless steel...
s and drug-eluting stent
Drug-eluting stent
A drug-eluting stent ' is a peripheral or coronary stent placed into narrowed, diseased peripheral or coronary arteries that slowly releases a drug to block cell proliferation. This prevents fibrosis that, together with clots , could otherwise block the stented artery, a process called restenosis...
s are here .
See also
- StentStentIn the technical vocabulary of medicine, a stent is an artificial 'tube' inserted into a natural passage/conduit in the body to prevent, or counteract, a disease-induced, localized flow constriction. The term may also refer to a tube used to temporarily hold such a natural conduit open to allow...
- Drug-eluting stentDrug-eluting stentA drug-eluting stent ' is a peripheral or coronary stent placed into narrowed, diseased peripheral or coronary arteries that slowly releases a drug to block cell proliferation. This prevents fibrosis that, together with clots , could otherwise block the stented artery, a process called restenosis...
- AngioplastyAngioplastyAngioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, the latter typically being a result of atherosclerosis. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size...
- Images of restenosis with bare-metal stentBare-metal stentBare-metal stent is a vascular stent without a coating . It is a mesh-like tube of thin wire. The first stents licenced for use in cardiac arteries were bare metal - often 316L stainless steel...
s and drug-eluting stentDrug-eluting stentA drug-eluting stent ' is a peripheral or coronary stent placed into narrowed, diseased peripheral or coronary arteries that slowly releases a drug to block cell proliferation. This prevents fibrosis that, together with clots , could otherwise block the stented artery, a process called restenosis...
s are here .
External links
- British Heart Foundation-Angioplasty http://www.bhf.org.uk/living_with_a_heart_condition/treatment/angioplasty.aspx
- American Heart Association-Stenting http://www.americanheart.org/presenter.jhtml?identifier=4721