Stenosis
Other names	Stenoses
CT scan of a bronchial stenosis (arrow) that resulted from tracheobronchial injury
Pronunciation	/stəˈnoʊsɪs/[1][2]

Stenosis (from Ancient Greek στενός (stenós) 'narrow') is the abnormal narrowing of a blood vessel or other tubular organ or structure such as foramina and canals. 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).^[4] The term coarctation is another synonym,^[5] but is commonly used only in the context of aortic coarctation.^[6][7]

Restenosis is the recurrence of stenosis after a procedure.^[8]

Examples

Examples of vascular stenotic lesions include:

• Intermittent claudication (peripheral artery stenosis)
• Angina (coronary artery stenosis)
• Carotid artery stenosis which predispose to (strokes and transient ischaemic episodes)^[9]
• Renal artery stenosis

Types

In heart valves

The types of stenoses in heart valves are:

• Pulmonary valve stenosis, which is the thickening of the pulmonary valve, therefore causing narrowing
• Mitral valve stenosis, which is the thickening of the mitral valve (of the left heart), therefore causing narrowing
• Tricuspid valve stenosis, which is the thickening of the tricuspid valve (of the right heart), therefore causing narrowing
• Aortic valve stenosis, which is the thickening of the aortic valve, therefore causing narrowing

Elsewhere

Stenoses/strictures of other bodily structures/organs include:

• Pyloric stenosis (gastric outflow obstruction)
• Lumbar, cervical or thoracic spinal stenosis
• Subglottic stenosis (SGS)
• Tracheal stenosis
• Obstructive jaundice (biliary tract stenosis)
• Bowel obstruction
• Phimosis
• Non-communicating hydrocephalus due to aqueductal stenosis
• Stenosing tenosynovitis
• Atherosclerosis
• Esophageal stricture
• Achalasia
• Prinzmetal angina
• Vaginal stenosis
• Meatal stenosis

Causes

• alcohol
• atherosclerosis
• birth defects
• calcification
• diabetes
• headbanging
• iatrogenic
• infection
• inflammation
• ischemia
• neoplasm
• smoking
• ureteral
• urethral

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 (such as ultrasound).^[10]