Stenosis

A stenosis (from Ancient Greek στενός, "narrow") is an abnormal narrowing in a blood vessel or other tubular organ or structure. It is also sometimes called a stricture (as in urethral stricture).[3]

Stricture as a term is usually used when narrowing is caused by contraction of smooth muscle (e.g. achalasia, prinzmetal angina); stenosis is usually used when narrowing is caused by lesion that reduces the space of lumen (e.g. atherosclerosis). The term coarctation is another synonym,[4] but is commonly used only in the context of aortic coarctation.

Restenosis is the recurrence of stenosis after a procedure.

Stenosis
Other namesStenoses
Bronchial stenosis CT
CT scan of a bronchial stenosis (arrow) that resulted from tracheobronchial injury
Pronunciation

Types

The resulting syndrome depends on the structure affected.

Examples of vascular stenotic lesions include:

The types of stenoses in heart valves are:

Stenoses/strictures of other bodily structures/organs include:

Causes

Diagnosis

Stenoses of the vascular type are often associated with unusual blood sounds resulting from turbulent flow over the narrowed blood vessel. This sound can be made audible by a stethoscope, but diagnosis is generally made or confirmed with some form of medical imaging.

See also

References

Notes

  1. ^ OED 2nd edition, 1989, as /stɪˈnəʊsɪs/.
  2. ^ Entry "stenosis" in Merriam-Webster Online Dictionary.
  3. ^ "Dorlands Medical Dictionary:stenosis". www.mercksource.com. Retrieved 2010-05-05.
  4. ^ "coarctation" at Dorland's Medical Dictionary

External links

Aortic stenosis

Aortic stenosis (AS or AoS) is the narrowing of the exit of the left ventricle of the heart (where the aorta begins), such that problems result. It may occur at the aortic valve as well as above and below this level. It typically gets worse over time. Symptoms often come on gradually with a decreased ability to exercise often occurring first. If heart failure, loss of consciousness, or heart related chest pain occurs due to AS the outcomes are worse. Loss of consciousness typically occurs with standing or exercise. Signs of heart failure include shortness of breath especially when lying down, at night, or with exercise, and swelling of the legs. Thickening of the valve without narrowing is known as aortic sclerosis.Causes include being born with a bicuspid aortic valve, and rheumatic fever. A bicuspid aortic valve affects about one to two percent of the population. As of 2014 rheumatic heart disease mostly occurs in the developing world. A normal valve may also harden over the decades. Risk factors are similar to those of coronary artery disease and include smoking, high blood pressure, high cholesterol, diabetes, and being male. The aortic valve usually has three leaflets and is located between the left ventricle of the heart and the aorta. AS typically results in a heart murmur. Its severity can be divided into mild, moderate, severe, and very severe, distinguishable by ultrasound of the heart.Aortic stenosis is typically followed using repeated ultrasound scans. Once it has become severe, treatment primarily involves valve replacement surgery, with transcatheter aortic valve replacement (TAVR) being an option in some who are at high risk from surgery. Valves may either be mechanical or bioprosthetic, with each having risks and benefits. Another less invasive procedure, balloon aortic valvuloplasty (BAV), may result in benefit, but for only a few months. Complications such as heart failure may be treated in the same way as in those with mild to moderate AS. In those with severe disease a number of medications should be avoided, including ACE inhibitors, nitroglycerin, and some beta blockers. Nitroprusside or phenylephrine may be used in those with decompensated heart failure depending on the blood pressure.Aortic stenosis is the most common valvular heart disease in the developed world. It affects about 2% of people who are over 65 years of age. Estimated rates were not known in most of the developing world as of 2014. In those who have symptoms, without repair the chance of death at five years is about 50% and at 10 years is about 90%. Aortic stenosis was first described by French physician Lazare Rivière in 1663.

Atherosclerosis

Atherosclerosis is a disease in which the inside of an artery narrows due to the build up of plaque. Initially, there are generally no symptoms. When severe, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney problems, depending on which arteries are affected. Symptoms, if they occur, generally do not begin until middle age.The exact cause is not known. Risk factors include abnormal cholesterol levels, high blood pressure, diabetes, smoking, obesity, family history, and an unhealthy diet. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. The narrowing of arteries limits the flow of oxygen-rich blood to parts of the body. Diagnosis is based upon a physical exam, electrocardiogram, and exercise stress test, among others.Prevention is generally by eating a healthy diet, exercising, not smoking, and maintaining a normal weight. Treatment of established disease may include medications to lower cholesterol such as statins, blood pressure medication, or medications that decrease clotting, such as aspirin. A number of procedures may also be carried out such as percutaneous coronary intervention, coronary artery bypass graft, or carotid endarterectomy.Atherosclerosis generally starts when a person is young and worsens with age. Almost all people are affected to some degree by the age of 65. It is the number one cause of death and disability in the developed world. Though it was first described in 1575, there is evidence that the condition occurred in people more than 5,000 years ago.

Carotid artery stenosis

Carotid artery stenosis is a narrowing or constriction of any part of the carotid arteries, usually caused by atherosclerosis.

Esophageal stricture

A benign esophageal stricture, or peptic stricture, is a narrowing or tightening of the esophagus that causes swallowing difficulties.

Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a condition in which a portion of the heart becomes thickened without an obvious cause. This results in the heart being less able to pump blood effectively. Symptoms vary from none to feeling tired, leg swelling, and shortness of breath. It may also result in chest pain or fainting. Complications include heart failure, an irregular heartbeat, and sudden cardiac death.HCM is most commonly inherited from a person's parents. It is often due to mutations in certain genes involved with making heart muscle proteins. Other causes may include Fabry disease, Friedreich's ataxia, and certain medications such as tacrolimus. It is type of cardiomyopathy, a group of diseases that primarily affects the heart muscle. Diagnosis often involves an electrocardiogram, echocardiogram, and stress testing. Genetic testing may also be done.Treatment may include the use of beta blockers, diuretics, or disopyramide. An implantable cardiac defibrillator may be recommended in those with certain types of irregular heartbeat. Surgery, in the form of a septal myectomy or heart transplant, may be done in those who do not improve with other measures. With treatment, the risk of death from the disease is less than one percent a year.HCM affects about one in 500 people. Rates in men and women are about equal. People of all ages may be affected. The first modern description of the disease was by Donald Teare in 1958.

Intravascular ultrasound

Intravascular ultrasound (IVUS) is a medical imaging methodology using a specially designed catheter with a miniaturized ultrasound probe attached to the distal end of the catheter. The proximal end of the catheter is attached to computerized ultrasound equipment. It allows the application of ultrasound technology, such as piezoelectric transducer or CMUT, to see from inside blood vessels out through the surrounding blood column, visualizing the endothelium (inner wall) of blood vessels in living individuals.The arteries of the heart (the coronary arteries) are the most frequent imaging target for IVUS. IVUS is used in the coronary arteries to determine the amount of atheromatous plaque built up at any particular point in the epicardial coronary artery. Intravascular ultrasound provides a unique method to study the regression or progression of atherosclerotic lesions in vivo.

The progressive accumulation of plaque within the artery wall over decades is the setup for vulnerable plaque which, in turn, leads to heart attack and stenosis (narrowing) of the artery (known as coronary artery lesions). IVUS is of use to determine both plaque volume within the wall of the artery and/or the degree of stenosis of the artery lumen. It can be especially useful in situations in which angiographic imaging is considered unreliable; such as for the lumen of ostial lesions or where angiographic images do not visualize lumen segments adequately, such as regions with multiple overlapping arterial segments. It is also used to assess the effects of treatments of stenosis such as with hydraulic angioplasty expansion of the artery, with or without stents, and the results of medical therapy over time.

Laryngotracheal stenosis

Laryngotracheal stenosis refers to abnormal narrowing of the central air passageways. This can occur at the level of the larynx, trachea, carina or main bronchi.

In a small number of patients narrowing may be present in more than one anatomical location.

Meatal stenosis

Urethral meatal stenosis or urethral stricture is a narrowing (stenosis) of the opening of the urethra at the external meatus , thus constricting the opening through which urine leaves the body from the urinary bladder.

Mitral valve stenosis

Mitral stenosis is a valvular heart disease characterized by the narrowing of the orifice of the mitral valve of the heart.

Pulmonary valve stenosis

Pulmonary valve stenosis (PVS) is a heart valve disorder. Blood going from the heart to the lungs goes through the pulmonary valve, whose purpose is to prevent blood from flowing back to the heart. In pulmonary valve stenosis this opening is too narrow, leading to a reduction of flow of blood to the lungs.While the most common cause of pulmonary valve stenosis is congenital heart disease, it may also be due to a malignant carcinoid tumor. Both stenosis of the pulmonary artery and pulmonary valve stenosis are forms of pulmonic stenosis (nonvalvular and valvular, respectively) but pulmonary valve stenosis accounts for 80% of pulmonic stenosis. PVS was the key finding that led Jacqueline Noonan to identify the syndrome now called Noonan syndrome.

Pyloric stenosis

Pyloric stenosis is a narrowing of the opening from the stomach to the first part of the small intestine (the pylorus). Symptoms include projectile vomiting without the presence of bile. This most often occurs after the baby is fed. The typical age that symptoms become obvious is two to twelve weeks old.The cause of pyloric stenosis is unclear. Risk factors in babies include birth by cesarean section, preterm birth, bottle feeding, and being first born. The diagnosis may be made by feeling an olive-shaped mass in the baby's abdomen. This is often confirmed with ultrasound.Treatment initially begins by correcting dehydration and electrolyte problems. This is then typically followed by surgery. Results are generally good both in the short term and in the long term. Some treat the condition without surgery by using atropine.About one to two per thousand babies are affected. Males are affected about four times more often than females. The condition is very rare in adults. The first description of pyloric stenosis was in 1888 with surgery management first carried out in 1912 by Conrad Ramstedt. Before surgical treatment most babies died.

Renal artery stenosis

Renal artery stenosis is the narrowing of one of the renal arteries, most often caused by atherosclerosis or fibromuscular dysplasia. This narrowing of the renal artery can impede blood flow to the target kidney, resulting in renovascular hypertension – a secondary type of high blood pressure. Possible complications of renal artery stenosis are chronic kidney disease and coronary artery disease.

Spinal stenosis

Spinal stenosis is an abnormal narrowing of the spinal canal or neural foramen that results in pressure on the spinal cord or nerve roots. Symptoms may include pain, numbness, or weakness in the arms or legs. Symptoms are typically gradual in onset and improve with bending forwards. Severe symptoms may include loss of bladder control, loss of bowel control, or sexual dysfunction.Causes may include osteoarthritis, rheumatoid arthritis, spinal tumors, trauma, Paget's disease of the bone, scoliosis, spondylolisthesis, and the genetic condition achondroplasia. It can be classified by the part of the spine affected into cervical, thoracic, and lumbar stenosis. Lumbar stenosis is the most common followed by cervical stenosis. Diagnosis is generally based on symptoms and medical imaging.Treatment may involve medications, bracing, or surgery. Medications may include NSAIDs, acetaminophen, or steroid injections. Stretching and strengthening exercises may also be useful. Limiting certain activities may be recommended. Surgery is typically only done if other treatments are not effective, with the usual procedure being a decompressive laminectomy.Spinal stenosis occurs in as many as 8% of people. It occurs most commonly in people over the age of 50. Males and females are affected equally often. The first modern description of the condition is from 1803 by Antoine Portal. Evidence of the condition, however, dates back to Ancient Egypt.

Stenosis of uterine cervix

Cervical stenosis means that the opening in the cervix (the endocervical canal) is more narrow than is typical. In some cases, the endocervical canal may be completely closed. A stenosis is any passage in the body that is more narrow than it should typically be.

Transient ischemic attack

A transient ischemic attack (TIA) is a brief episode of neurological dysfunction caused by loss of blood flow (ischemia) in the brain, spinal cord, or retina, without tissue death (infarction). TIAs have the same underlying mechanism as ischemic strokes. Both are caused by a disruption in blood flow to the brain, or cerebral blood flow (CBF). The definition of TIA was classically based on duration of neurological symptoms. The current widely-accepted definition is called "tissue-based" because it is based on imaging, not time. The American Heart Association and the American Stroke Association (AHA/ASA) now define TIA as a brief episode of neurological dysfunction with a vascular cause, with clinical symptoms typically lasting less than one hour, and without evidence of infarction on imaging.TIA causes the same symptoms associated with stroke, such as weakness or numbness on one side of the body. Numbness or weakness generally occur on the opposite side of the body from the affected hemisphere of the brain. A TIA may cause sudden dimming or loss of vision, difficulty speaking or understanding language, slurred speech, and confusion.

TIA and ischemic stroke share a common cause. Both result from a disruption in blood flow to the central nervous system. In ischemic stroke, symptoms generally persist beyond 7 days. In TIA, symptoms typically resolve within 1 hour. The occurrence of a TIA is a risk factor for eventually having a stroke. Both are associated with increased risk of death or disability. Recognition that a TIA has occurred is an opportunity to start treatment, including medications and lifestyle changes, to prevent a stroke.

While a TIA must by definition be associated with symptoms, a stroke may be symptomatic or silent. In silent stroke, also known as silent cerebral infarct (SCI), there is permanent infarction present on imaging, but there are no immediately observable symptoms. An SCI often occurs before or after a TIA or major stroke.

Tricuspid valve stenosis

Tricuspid Valve Stenosis is a valvular heart disease that narrows the opening of the heart's tricuspid valve. It is a relatively rare condition that causes stenosis-increased restriction of blood flow through the valve.

Valvular heart disease

Valvular heart disease is any cardiovascular disease process involving one or more of the four valves of the heart (the aortic and bicuspid valves on the left side of heart and the pulmonary and tricuspid valves on the right side of heart). These conditions occur largely as a consequence of aging, but may also be the result of congenital (inborn) abnormalities or specific disease or physiologic processes including rheumatic heart disease and pregnancy.Anatomically, the valves are part of the dense connective tissue of the heart known as the cardiac skeleton and are responsible for the regulation of blood flow through the heart and great vessels. Valve failure or dysfunction can result in diminished heart functionality, though the particular consequences are dependent on the type and severity of valvular disease. Treatment of damaged valves may involve medication alone, but often involves surgical valve repair (valvuloplasty) or replacement (insertion of an artificial heart valve).

Cardiovascular disease (vessels) (I70–I99, 440–456)
Arteries, arterioles
and capillaries
Veins
Arteries or veins
Blood pressure

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