Peripheral artery occlusive disease
Encyclopedia
Peripheral vascular disease (PVD), commonly referred to as peripheral arterial disease (PAD) or peripheral artery occlusive disease (PAOD), refers to the obstruction of large arteries
not within the coronary, aortic arch
vasculature, or brain
. PVD can result from atherosclerosis
, inflammatory
processes leading to stenosis
, an embolism
, or thrombus
formation. It causes either acute or chronic
ischemia
(lack of blood supply). Often PAD is a term used to refer to atherosclerotic blockages found in the lower extremity.
PVD also includes a subset of diseases classified as microvascular diseases resulting from episodal narrowing of the arteries (Raynaud's phenomenon
), or widening thereof (erythromelalgia
), i.e. vascular spasms.
:
A more recent classification by Rutherford consists of three grades and six categories:
:
(ABPI/ABI). When the blood pressure readings in the ankles is lower than that in the arms, blockages in the arteries which provide blood from the heart to the ankle are suspected. An ABI ratio less than 0.9 is consistent with PVD; values of ABI below 0.8 indicate moderate disease and below 0.4 imply severe ischemic disease.
It is possible for conditions which stiffen the vessel walls (such as calcifications that occur in the setting of chronic diabetes) to produce false negatives usually, but not always, indicated by abnormally high ABIs (> 1.3). Such results and suspicions merit further investigation and higher level studies.
If ABIs are abnormal the next step is generally a lower limb doppler ultrasound examination to look at site and extent of atherosclerosis
. Other imaging can be performed by angiography
, where a catheter is inserted into the common femoral artery
and selectively guided to the artery in question. While injecting a radiodense
contrast agent an X-ray
is taken. Any flow limiting stenoses
found in the x-ray can be identified and treated by atherectomy
, angioplasty
or stent
ing.
Modern multislice computerized tomography (CT) scanners provide direct imaging of the arterial system as an alternative to angiography. CT provides complete evaluation of the aorta
and lower limb arteries without the need for an angiogram's arterial injection of contrast agent.
Treatment with other drugs or vitamins are unsupported by clinical evidence, "but trials evaluating the effect of folate and vitamin B-12 on hyperhomocysteinaemia
, a putative vascular risk factor, are near completion".
After a trial of the best medical treatment outline above, if symptoms remain unnacceptable, patients may be referred to a vascular or endovascular surgeon; however, "No convincing evidence supports the use of percutaneous balloon angioplasty or stenting in patients with intermittent claudication".
(ABPI). Large-vessel PAD increases mortality from cardiovascular disease significantly. PAD carries a greater than "20% risk of a coronary event in 10 years".
There is a low risk that an individual with claudication will develop severe ischemia and require amputation, but the risk of death from coronary events is three to four times higher than matched controls without claudication. Of patients with intermittent claudication, only "7% will undergo lower extremity bypass surgery, 4% major amputations, and 16% worsening claudication", but stroke and heart attack events are elevated, and the "5-year mortality rate is estimated to be 30% (versus 10% in controls)".
In the USA peripheral arterial disease affects 12–20 percent of Americans age 65 and older. Approximately 10 million Americans have PVD. Despite its prevalence and cardiovascular risk implications, only 25 percent of PAD patients are undergoing treatment.
The incidence of symptomatic PVD increases with age, from about 0.3% per year for men aged 40–55 years to about 1% per year for men aged over 75 years. The prevalence of PVD varies considerably depending on how PAD is defined, and the age of the population being studied. Diagnosis is critical, as people with PAD have a four to five times higher risk of heart attack
or stroke
.
The Diabetes Control and Complications Trial and U.K. Prospective Diabetes Study trials in people with type 1 and type 2 diabetes, respectively, demonstrated that glycemic control is more strongly associated with microvascular disease than macrovascular disease. It may be that pathologic changes occurring in small vessels are more sensitive to chronically elevated glucose levels than is atherosclerosis occurring in larger arteries.
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....
not within the coronary, aortic arch
Aortic arch
The arch of the aorta or the transverse aortic arch is the part of the aorta that begins at the level of the upper border of the second sternocostal articulation of the right side, and runs at first upward, backward, and to the left in front of the trachea; it is then directed backward on the left...
vasculature, or 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,...
. PVD can result from atherosclerosis
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
, inflammatory
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
processes leading to stenosis
Stenosis
A stenosis is an abnormal narrowing in a blood vessel or other tubular organ or structure.It is also sometimes called a stricture ....
, an embolism
Embolism
In medicine, an embolism is the event of lodging of an embolus into a narrow capillary vessel of an arterial bed which causes a blockage in a distant part of the body.Embolization is...
, or thrombus
Thrombus
A thrombus , or blood clot, is the final product of the blood coagulation step in hemostasis. It is achieved via the aggregation of platelets that form a platelet plug, and the activation of the humoral coagulation system...
formation. It causes either acute or chronic
Chronic (medicine)
A chronic disease is a disease or other human health condition that is persistent or long-lasting in nature. The term chronic is usually applied when the course of the disease lasts for more than three months. Common chronic diseases include asthma, cancer, diabetes and HIV/AIDS.In medicine, the...
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...
(lack of blood supply). Often PAD is a term used to refer to atherosclerotic blockages found in the lower extremity.
PVD also includes a subset of diseases classified as microvascular diseases resulting from episodal narrowing of the arteries (Raynaud's phenomenon
Raynaud's phenomenon
In medicine, Raynaud's phenomenon is a vasospastic disorder causing discoloration of the fingers, toes, and occasionally other areas. This condition can also cause nails to become brittle with longitudinal ridges. Named for French physician Maurice Raynaud , the phenomenon is believed to be the...
), or widening thereof (erythromelalgia
Erythromelalgia
Erythromelalgia, also known as Mitchell's disease , acromelalgia, red neuralgia, or erythermalgia, is a rare neurovascular peripheral pain disorder in which blood vessels, usually in the lower extremities , are episodically blocked , then become hyperemic and inflamed...
), i.e. vascular spasms.
Classification
Peripheral artery occlusive disease is commonly divided in the Fontaine stages, introduced by René Fontaine in 1954 for ischemiaIschemia
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...
:
- mild pain when walking (claudicationClaudicationClaudication, literally 'limping' , is a medical term usually referring to impairment in walking, or pain, discomfort or tiredness in the legs that occurs during walking and is relieved by rest. The perceived level of pain from claudication can be mild to extremely severe. Claudication is most...
), incomplete blood vessel obstruction; - severe pain when walking relatively short distances (intermittent claudicationIntermittent claudicationIntermittent claudication is a clinical diagnosis given for muscle pain , classically in the calf muscle, which occurs during exercise, such as walking, and is relieved by a short period of rest.Claudication derives from the Latin verb claudicare, "to limp".-Signs:One of the hallmarks of arterial...
), pain triggered by walking "after a distance of >150 m in stage IIa and after <150 m in stage II-b"; - pain while resting (rest painRest painRest pain is a continuous burning pain due to ischaemia of the lower leg. It begins, or is aggravated, after reclining and is relieved by sitting or standing. Risk factors include claudication....
), mostly in the feet, increasing when the limb is raised; - biological tissue loss (gangreneGangreneGangrene is a serious and potentially life-threatening condition that arises when a considerable mass of body tissue dies . This may occur after an injury or infection, or in people suffering from any chronic health problem affecting blood circulation. The primary cause of gangrene is reduced blood...
) and difficulty walking.
A more recent classification by Rutherford consists of three grades and six categories:
- Mild claudication
- Moderate claudication
- Severe claudication
- Ischemic pain at rest
- Minor tissue loss
- Major tissue loss
Symptoms
About 20% of patients with mild PAD may be asymptomatic; other symptoms include:- ClaudicationClaudicationClaudication, literally 'limping' , is a medical term usually referring to impairment in walking, or pain, discomfort or tiredness in the legs that occurs during walking and is relieved by rest. The perceived level of pain from claudication can be mild to extremely severe. Claudication is most...
- pain, weakness, numbness, or cramping in muscles due to decreased blood flow - Sores, wounds, or ulcers that heal slowly or not at all
- Noticeable change in color (blueness or paleness) or temperature (coolness) when compared to the other limb (termed unilateral dependent rubor; when both limbs are affected this is termed bilateral dependent rubor)
- Diminished hair and nail growth on affected limb and digits.
Causes
Risk factors contributing to PAD are the same as those for atherosclerosisAtherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
:
- Smoking - tobacco use in any form is the single most important modifiable cause of PVD internationally. Smokers have up to a tenfold increase in relative risk for PVD in a dose-related effect. Exposure to second-hand smoke from environmental exposure has also been shown to promote changes in blood vessel lining (endothelium) which is a precursor to atherosclerosis.
- Diabetes mellitusDiabetes mellitusDiabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
- causes between two and four times increased risk of PVD by causing endothelial and smooth muscle cell dysfunction in peripheral arteries. Diabetics account for up to 70% of nontraumatic amputations performed, and a known diabetic who smokes runs an approximately 30% risk of amputationAmputationAmputation is the removal of a body extremity by trauma, prolonged constriction, or surgery. As a surgical measure, it is used to control pain or a disease process in the affected limb, such as malignancy or gangrene. In some cases, it is carried out on individuals as a preventative surgery for...
within 5 years. - DyslipidemiaDyslipidemiaDyslipidemia or dyslipidaemia is an abnormal amount of lipids in the blood. In developed countries, most dyslipidemias are hyperlipidemias; that is, an elevation of lipids in the blood, often due to diet and lifestyle. The prolonged elevation of insulin levels can lead to dyslipidemia...
(high low density lipoprotein [LDL] cholesterolCholesterolCholesterol 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...
, low high density lipoprotein [HDL] cholesterol) - elevation of total cholesterol, LDL cholesterol, and triglycerideTriglycerideA triglyceride is an ester derived from glycerol and three fatty acids. There are many triglycerides, depending on the oil source, some are highly unsaturated, some less so....
levels each have been correlated with accelerated PAD. Correction of dyslipidemia by diet and/or medication is associated with a major improvement in short-term rates of heart attack and stroke. This benefit is gained even though current evidence does not demonstrate a major reversal of peripheral and/or coronary atherosclerosis. - HypertensionHypertensionHypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
- elevated blood pressure is correlated with an increase in the risk of developing PAD, as well as in associated coronary and cerebrovascular events (heart attack and stroke). - Risk of PAD also increases in individuals who are over the age of 50, male, obese, or with a family history of vascular diseaseVascular diseaseVascular disease is a form of cardiovascular disease primarily affecting the blood vessels.Some conditions, such as angina and myocardial ischemia, can be considered both vascular diseases and heart diseases .Cigarette smoking is the major risk factor....
, heart attackMyocardial infarctionMyocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
, or strokeStrokeA 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...
. - Other risk factors which are being studied include levels of various inflammatory mediators such as C-reactive protein, homocysteineHomocysteineHomocysteine is a non-protein amino acid with the formula HSCH2CH2CHCO2H. It is a homologue of the amino acid cysteine, differing by an additional methylene group. It is biosynthesized from methionine by the removal of its terminal Cε methyl group...
.
Diagnosis
Upon suspicion of PVD, the first-line study is the ankle brachial pressure indexAnkle brachial pressure index
The Ankle Brachial Pressure Index , known more commonly as an ABI, is the ratio of the blood pressure in the lower legs to the blood pressure in the arms. Compared to the arm, lower blood pressure in the leg is an indication of blocked arteries...
(ABPI/ABI). When the blood pressure readings in the ankles is lower than that in the arms, blockages in the arteries which provide blood from the heart to the ankle are suspected. An ABI ratio less than 0.9 is consistent with PVD; values of ABI below 0.8 indicate moderate disease and below 0.4 imply severe ischemic disease.
It is possible for conditions which stiffen the vessel walls (such as calcifications that occur in the setting of chronic diabetes) to produce false negatives usually, but not always, indicated by abnormally high ABIs (> 1.3). Such results and suspicions merit further investigation and higher level studies.
If ABIs are abnormal the next step is generally a lower limb doppler ultrasound examination to look at site and extent of atherosclerosis
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
. Other imaging can be performed by angiography
Angiogram
Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins and the heart chambers...
, where a catheter is inserted into the common 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....
and selectively guided to the artery in question. While injecting a radiodense
Radiodensity
Radiodensity refers to the relative inability of electromagnetic radiation, particularly X-rays, to pass through a particular material. Radiolucency indicates greater transparency or "transradiancy" to X-ray photons...
contrast agent an X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
is taken. Any flow limiting stenoses
Stenosis
A stenosis is an abnormal narrowing in a blood vessel or other tubular organ or structure.It is also sometimes called a stricture ....
found in the x-ray can be identified and treated by atherectomy
Atherectomy
Atherectomy is a minimally invasive surgical method of removing, mainly, atherosclerosis from a large blood vessel within the body. Today, it is generally used to effectively treat peripheral arterial disease of the lower extremities...
, 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...
or 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...
ing.
Modern multislice computerized tomography (CT) scanners provide direct imaging of the arterial system as an alternative to angiography. CT provides complete evaluation of the aorta
Aorta
The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...
and lower limb arteries without the need for an angiogram's arterial injection of contrast agent.
Treatment
Dependent on the severity of the disease, the following steps can be taken:- Smoking cessationSmoking cessationSmoking cessation is the process of discontinuing the practice of inhaling a smoked substance. This article focuses exclusively on cessation of tobacco smoking; however, the methods described may apply to cessation of smoking other substances that can be difficult to stop using due to the...
(cigarettes promote PVD and are a risk factor for cardiovascular diseaseCardiovascular diseaseHeart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
). - Management of diabetes.
- Management of hypertension.
- Management of cholesterol, and medication with antiplatelet drugAntiplatelet drugAn antiplatelet drug is a member of a class of pharmaceuticals that decrease platelet aggregation and inhibit thrombus formation...
s. Medication with aspirinAspirinAspirin , also known as acetylsalicylic acid , is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. It was discovered by Arthur Eichengrun, a chemist with the German company Bayer...
, clopidogrelClopidogrelClopidogrel is an oral, thienopyridine class antiplatelet agent used to inhibit blood clots in coronary artery disease, peripheral vascular disease, and cerebrovascular disease. It is marketed by Bristol-Myers Squibb and Sanofi-Aventis under the trade name Plavix. The drug works by irreversibly...
and statins, which reduce clot formation and cholesterol levels, respectively, can help with disease progression and address the other cardiovascular risks that the patient is likely to have. - Regular exercise for those with claudication helps open up alternative small vessels (collateral flow) and the limitation in walking often improves. Treadmill exercise (35 to 50 minutes, 3 to 4 times per week) has been reviewed as another treatment with a number of positive outcomes including reduction in cardiovascular events and improved quality of life.
- Cilostazol or pentoxifylline treatment to relieve symptoms of claudication.
Treatment with other drugs or vitamins are unsupported by clinical evidence, "but trials evaluating the effect of folate and vitamin B-12 on hyperhomocysteinaemia
Hyperhomocysteinemia
Hyperhomocysteinemia or hyperhomocysteinaemia is a medical condition characterized by an abnormally large level of homocysteine in the blood....
, a putative vascular risk factor, are near completion".
After a trial of the best medical treatment outline above, if symptoms remain unnacceptable, patients may be referred to a vascular or endovascular surgeon; however, "No convincing evidence supports the use of percutaneous balloon angioplasty or stenting in patients with intermittent claudication".
- 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...
(PTA or percutaneous transluminal angioplasty) can be done on solitary lesions in large arteriesArteryArteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
, such as the femoral arteryFemoral arteryThe 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....
, but angioplasty may not have sustained benefits. - Plaque excisionAtherectomyAtherectomy is a minimally invasive surgical method of removing, mainly, atherosclerosis from a large blood vessel within the body. Today, it is generally used to effectively treat peripheral arterial disease of the lower extremities...
, in which the plaque is scraped off of the inside of the vessel wall. - Occasionally, bypassBypass (surgical)In medicine, a vascular bypass generally means an alternate or additional route for blood flow, which is created in bypass surgery, e.g. coronary artery bypass surgery by moving blood vessels or implanting synthetic tubing. Vessels frequently used for the bypass are large veins taken from the...
grafting is needed to circumvent a seriously stenosed area of the arterial vasculature. Generally, the saphenous veinSaphenous veinSaphenous vein may refer to:*Great saphenous vein*Small saphenous vein...
is used, although artificial (Gore-TexGore-TexGore-Tex is a waterproof/breathable fabric, and a registered trademark of W. L. Gore and Associates. It was co-invented by Wilbert L. Gore, Rowena Taylor, and Gore's son, Robert W. Gore. Robert Gore was granted on April 27, 1976, for a porous form of polytetrafluoroethylene with a...
) material is often used for large tracts when the veins are of lesser quality. - Rarely, sympathectomySympathectomyA Sympathectomy is a procedure during which at least one sympathetic ganglion is removed.An example is endoscopic thoracic sympathectomy....
is used - removing the nerves that make arteries contract, effectively leading to vasodilatation. - When gangreneGangreneGangrene is a serious and potentially life-threatening condition that arises when a considerable mass of body tissue dies . This may occur after an injury or infection, or in people suffering from any chronic health problem affecting blood circulation. The primary cause of gangrene is reduced blood...
of toes has set in, amputationAmputationAmputation is the removal of a body extremity by trauma, prolonged constriction, or surgery. As a surgical measure, it is used to control pain or a disease process in the affected limb, such as malignancy or gangrene. In some cases, it is carried out on individuals as a preventative surgery for...
is often a last resort to stop infected dying tissues from causing septicemia. - Arterial thrombosis or embolism has a dismal prognosis, but is occasionally treated successfully with thrombolysisThrombolysisThrombolysis is the breakdown of blood clots by pharmacological means. It is colloquially referred to as clot busting for this reason...
.
Guidelines
Several different guideline standards have been developed, including:- TASC II Guidelines*
*
*
- ACC/AHA Guidelines
Prognosis
Individuals with PAD have an "exceptionally elevated risk for cardiovascular events and the majority will eventually die of a cardiac or cerebrovascular etiology"; prognosis is correlated with the severity of the PAD as measured by the Ankle brachial pressure indexAnkle brachial pressure index
The Ankle Brachial Pressure Index , known more commonly as an ABI, is the ratio of the blood pressure in the lower legs to the blood pressure in the arms. Compared to the arm, lower blood pressure in the leg is an indication of blocked arteries...
(ABPI). Large-vessel PAD increases mortality from cardiovascular disease significantly. PAD carries a greater than "20% risk of a coronary event in 10 years".
There is a low risk that an individual with claudication will develop severe ischemia and require amputation, but the risk of death from coronary events is three to four times higher than matched controls without claudication. Of patients with intermittent claudication, only "7% will undergo lower extremity bypass surgery, 4% major amputations, and 16% worsening claudication", but stroke and heart attack events are elevated, and the "5-year mortality rate is estimated to be 30% (versus 10% in controls)".
Epidemiology
The prevalence of peripheral vascular disease in the general population is 12–14%, affecting up to 20% of those over 70; 70%–80% of affected individuals are asymptomatic; only a minority ever require revascularisation or amputation. Peripheral vascular disease affects 1 in 3 diabetics over the age of 50.In the USA peripheral arterial disease affects 12–20 percent of Americans age 65 and older. Approximately 10 million Americans have PVD. Despite its prevalence and cardiovascular risk implications, only 25 percent of PAD patients are undergoing treatment.
The incidence of symptomatic PVD increases with age, from about 0.3% per year for men aged 40–55 years to about 1% per year for men aged over 75 years. The prevalence of PVD varies considerably depending on how PAD is defined, and the age of the population being studied. Diagnosis is critical, as people with PAD have a four to five times higher risk of heart attack
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
or 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...
.
The Diabetes Control and Complications Trial and U.K. Prospective Diabetes Study trials in people with type 1 and type 2 diabetes, respectively, demonstrated that glycemic control is more strongly associated with microvascular disease than macrovascular disease. It may be that pathologic changes occurring in small vessels are more sensitive to chronically elevated glucose levels than is atherosclerosis occurring in larger arteries.
See also
- Chronic venous insufficiencyChronic venous insufficiencyChronic venous insufficiency or CVI is a medical condition where the veins cannot pump enough oxygen-poor blood back to the heart. It is sometimes referred to as an "impaired musculovenous pump", this is due to damaged or "incompetent" valves as may occur after deep vein thrombosis or phlebitis...
- Vascular myelopathyVascular myelopathyVascular myelopathy refers to an abnormality of the spinal cord in regards to its blood supply. The blood supply is complicated and supplied by two major vessel groups: the posterior spinal arteries and the anterior spinal arteries—of which the Artery of Adamkiewicz is the largest...
- Chronic cerebrospinal venous insufficiencyChronic cerebrospinal venous insufficiencyChronic cerebrospinal venous insufficiency is a term developed by Italian researcher Paolo Zamboni in 2008 to describe compromised flow of blood in the veins draining the central nervous system...
External links
- "Peripheral Arterial Disease" at the National Heart, Lung and Blood Institute