ALU Chapter 14 Non-Cardiac Blood Vessel Disorders

One study of 5,285 individuals who underwent surgery and were followed for greater than 25 years, revealed the following predictors of mortality in all age groups:

1. age, with a relative risk of 1.62 for each 10-year increase in age 2. male sex, relative risk 1.55 3. diabetes mellitus, relative risk 1.71 4. systemic hypertension, relative risk 1.51.

Thoracic aneurysms can be classified based on their anatomic location. The four basic categories are:

1. ascending thoracic aneurysms 2. aortic arch aneurysms 3. descending aortic aneurysms 4. thoracoabdominal aneurysms.

The structural elements most common to arterial vessels consist of five separate tissue components:

1. endothelium 2. basement membrane 3. elastic tissue 4. collagen 5. smooth muscle

The main indications for utilizing angioplasty for peripheral vascular disease are:

1. persistent claudication that significantly reduces the ability of the individual to perform activities indent of daily living 2. pain at rest 3. tissue loss.

Surgical intervention is indicated with an accelerated growth rate of greater than or equal to

1.0 cm per year in aneurysms less than 5.0 cm in diameter. Surgical intervention is also indicated when end-diastolic diameter is 5.0 to 6.0 cm for an ascending aneurysm and 6.0 to 7.0 cm for a descending aneurysm, found by radiologic intervention.

Treatment is directed at preventing coronary artery aneurysms. Coronary artery aneurysms will develop in

15-25% of those affected, unless treatment, in the form of IV gamma globulin, is instituted in the early stages of the disease. Aneurysms are easily detected by transthoracic echocardiography. Smaller aneurysms usually regress over five years. Despite regression, there are case reports of young adults suffering myocardial infarction more than a decade after the initial disease.

Peripheral arterial disease can cause occlusion of all of the following vessels EXCEPT the: 1. aorta 2. vena cava 3. iliac artery 4. femoral-popliteal artery

2. vena cava

Which of the following statements regarding abdominal aortic aneurysms is/are ccorrect? A. They can be caused by atherosclerosis B. They usually develop before age 50. C. Hypertension affects aneurysmal growth 1. A only is correct. 2. B only is correct. 3. A and C only are correct. 4. A, B, and C are correct

3. A and C only are correct.

Which of the following statements regarding Wegener's granulomatosis is/are correct? A. It is a vasculitis of the large vessels. B. The majority of affected individuals are adults. C. It primarily affects the lungs and kidneys. 1. A only is correct. 2. B only is correct. 3. B and C only are correct. 4. A, B, and C are correct.

3. B and C only are correct.

The risk factor strongly linked to thromboangiitis obliterans (Buerger's disease) is: 1. genetics 2. hyperlipidemia 3. cigarette smoking 4. sedentary lifestyle

3. cigarette smoking

The smallest blood vessels in the vascular system are: 1. venules 2. arterioles 3. lymphatics 4. capillaries

4. capillaries

Risk factors for development of AAA include age over

60 years, male sex, family history, tobacco use, presence of other large vessel aneurysms, coronary artery disease, and peripheral arterial disease. Aneurysms typically expand at a rate of 0.2 to 0.3 cm per year, but 20% expand more rapidly. The most important clinical factor affecting aneurysmal growth is elevated blood pressure.

The Society for Vascular Surgery recommends surveillance of unrepaired AAA by ultrasound imaging based on aneurysm diameter.

AAA diameter (cm) - surveillance interval Less than 3.0 -- 10 years 3.0-3.9 -- 3 years 4.0-4.9 -- 1 year 5.0-5.4 -- 6 months

Small vessel

ANCA-associated: Microscopic polyangiitis (MP A), Granulomatosis with polyangiitis (GPA, Wegener's), Eosinophilic granulomatosis with polyangiitis (Churg-Strauss) Immune complex small vessel: Anti-glomerular basement membrane disease, Cryoglobulinemic vasculitis, IgA vasculitis (Henoch-Schonlein purpura), Hypocomplementemic urticarial vascultis ( anti- Clq vasculitis)

AHA Grade: 6 Criteria: Description:

All the above plus surface defect, hematoma, hemorrhage, or thrombosis Complicated lesion

Other

Associated with systemic disease: Lupus, rheumatoid, sarcoid, others Associated with probable etiology: Hepatitis C or B, syphilis, drug associated, cancer-associated

Variable vessel

Behcet's syndrome Cogan's syndrom

The level and extent of PAD can be determined by segmental limb pressures.

Blood pressure cuffs are applied at various levels based on the results of ABI testing and location of the clinical symptoms of claudication. Each cuff is inflated individually, and a pressure gradient difference is determined. A 20 mmHg or greater reduction or difference in pressure between the segments along the same leg, or when compared to the same level in the opposite leg, is considered significant.

The hallmark of arterial insufficiency of the lower extremity is a decrease in the ankle-brachial index, especially after exercise. The ABI is determined through

Doppler wave ultrasound assessment received from blood pressure measurements in the arm and ankle. The index is determined by dividing ankle systolic blood pressure by arm systolic blood pressure. The test is usually performed at rest and after treadmill exercise. Completion of a standard exercise protocol without pain or symptoms virtually excludes the diagnosis of PAD. A normal ABI is >.91. An index of 0.9 or less indicates the presence of obstructive disease and 0.4 or less suggests severe disease.

AHA Grade: 1 Criteria: Description:

Isolated macrophage foam cells (MFC) which contain lipid Initial lesion

Large vessel

Takayasu arteritis Giant cell (temporal) arteritis

When seen in younger individuals, thoracic aneurysm is most often associated with

Marfan syndrome and, to a lesser degree, with connective diseases such as Ehlers-Danlos syndrome. A strong association exists between thoracic aneurysms and bicuspid aortic valve and aortic coarctation. Thirty to forty percent of those with bicuspid aortic valve also have coarctation of the aorta. ln a study of young males with bicuspid aortic valve, over half also had enlargement of the aortic root and dilatation of the ascending aorta.

AHA Grade: 3 Criteria: Description:

Numerous MFC with pools of extracellular lipid Intermediate: fatty plaque, raised fatty streak

AHA Grade: 4 Criteria: Description:

Numerous MFC with well-defined core of extracellular lipid Atheroma, fibrous plaque, or raised lesion

AHA Grade: 2 Criteria: Description:

Numerous MFC, fine particles of extracellular lipid Fatty streak

AHA Grade: 5 Criteria: Description:

Numerous MFC, well-defined core or multiple cores of extracellular lipid, reactive fibrotic cap, vascularization, or calcium Fibroatheroma, fibrous plaque, or raised lesion

Medium vessel

Polyarteritis nodosa Kawasaki disease

Single Organ

Primary central nervous system vasculitis

The definitive diagnostic tool is still angiography.

The use of contrast material in angiography increases risk to the individual and is usually reserved for severe cases of peripheral vascular disease when surgical intervention is contemplated.

PAD usually presents with gradual onset of lower extremity claudication characterized by

aching, tiredness, or burning pain, and frequently goes unrecognized for an extended period. The symptoms are usually brought on by walking and are relieved by rest. The most common presentation is calf claudication, secondary to femoral-popliteal artery atherosclerosis.

A blood test to identify the autoantibody antineutrophil cytoplasmic antibody (ANCA), and in conjunction with an

active urinary sediment, elevated ESR, unexplained anemia, and recurrent symptoms, help form the diagnosis. In cases where the ANCA is negative, a biopsy of an involved site can be needed to support a definitive 75% of diagnosis. individuals. With the Unfortunately, use of approximately immunosuppressive 50% will agents, relapse and remission develop can be active achieved disease.

General risk factors for atherosclerosis align with risk factors for cardiovascular disease. Established risk factors for atherosclerosis include

advancing age, cigarette smoking, dyslipidemia (e.g., increased non-HDL cholesterol, triglycerides, lipoprotein (a), high blood pressure, diabetes mellitus, family history of premature atherosclerosis, and evidence of inflammation [markers including high sensitivity C-reactive protein (hsCRP)]).

Vascular imaging provides the best diagnostic evidence and is often combined with

angioplasty. Corticosteroids remain the therapy of choice for management of TA. Aggressive surgical intervention has led to improved prognosis in recent years. Long-term studies found stable clinical conditions in two-thirds of patients.

The most accurate, quick, and non-invasive way to diagnose PAD is by

ankle-brachial index (ABI). The ABI is 95% sensitive and 99% specific for angiographically-measured lower extremity arterial stenosis of 50% or greater.

Takayasu 's Arteritis (TA): This large vessel vasculitis classically involves the

aortic arch and its main branches but can also involve the coronary and pulmonary vessels in half the cases. Inflammation of the vessels results in intimal thickening with subsequent stenosis and/ or aneurysm. Complete occlusion of an upper extremity artery can occur, hence the name "pulseless disease." TA affects females, usually under the age of 40 years, with higher incidence rates in the Asian population.

The greatest success rate for PT A has been found when it is utilized for

aortoiliac stenosis. In uncomplicated disease, the five-year patency rate is 70%. The use of intravascular stents for aortoiliac occlusive disease is usually limited to a suboptimal angioplasty result and is not routinely employed as part of the PT A procedure.

Often, the treating physician will erroneously attribute the symptoms to

arthritis, muscular pain, or aging. Misdiagnosis as an orthopedic back problem is especially common when the aortoiliac artery is involved since that causes hip, thigh, or buttock pain. Claudication can also present as the hip or leg "giving out" after a certain period of ambulation.

For example, recommendations for

ascending (thoracic) aortic or aortic root aneurysms include annual CT or MR angiography for aneurysms 3.5 to 4.4 cm and every six months for aneurysms 4.5 to 5.4 cm m size.

Most abdominal aortic aneurysms are

asymptomatic and can progress without symptoms. Diagnosis requires a high level of clinical suspicion, with imaging confirmation. Symptoms, when present, may include pain in the abdomen, back or flank and limb ischemia, which are associated with increased risk for rupture.

The two most important causes of aortic aneurysms are

atherosclerosis and cystic medial degeneration of the arterial media. Arterial aneurysms can also be caused by systemic diseases (e.g., vasculitides), trauma, and mycotic (fungal) infections.

Abdominal aortic aneurysms (AAA) are usually caused by the

atherosclerotic process of plaque formation. Plaque forming in the intima eventually starts to erode the media or muscular layer of the vessel wall, thus weakening the media with eventual aneurysmal formation. Although atherosclerosis and hypertension predispose an individual to the development of an aortic aneurysm, recent attention has focused on a genetic predisposition to an altered balance of collagen degradation and synthesis, providing a susceptible substrate on which atherosclerosis and hypertension could act to weaken the vessel wall.

Arterioles are small arteries, which lead, in turn, to

capillaries. Capillaries, the smallest blood vessels, have an endothelium but no intima. Red blood cells pass single file through the capillary bed at a very slow pace.

The ABI can be used to identify individuals with an increased risk of

cardiovascular events and total mortality. Studies show that more severe disease, as evidenced by the lower ABI value, is associated with greater risk of total mortality and cardiovascular mortality than mild disease,

AAA management includes optimal control of

cardiovascular risk factors, including smoking cessation. Smaller unrepaired AAAs may be detected on imaging done for another reason. The need for ongoing surveillance depends on size of the aneurysm. Underwriting of smaller unrepaired AAAs requires imaging reports with a description of the aneurysm and its diameter. Ideally, evidence of monitoring according to recommended intervals and serial measures should be available to assess for any aneurysm expansion. For repaired aneurysms, cardiovascular risk factor control remains important as does regular surveillance for all endovascular repairs.

In about 15%, GCA targets the large arteries, most notably the

carotid, subclavian and axillary arteries. Termed the aortic arch syndrome, this variant typically presents with claudication of the upper arms, absent pulses, paresthesia, Raynaud's phenomenon, and occasionally gangrene. Nonspecific blood tests, such as an elevated ESR, help support the clinical suspicion of GCA. A positive biopsy of the affected vessel is the procedure of choice. Corticosteroids effectively treat the symptoms of GCA with a significant concomitant reduction in the rate of blindness.

Although many aneurysms are not seen on

chest x-ray, it is a common way to identify an incidental asymptomatic aneurysm. Mediastinal widening and enlargement of the aortic knob, when seen, warrant further investigation. CT scan and MRI with contrast are the recommended imaging procedures to diagnose thoracic aneurysms.

The small and medium vessel vasculitides are a .

complex heterogeneous group of disorders that involve inflammation and destruction of blood vessel walls. This section will review the major vasculitides that affect the small and medium vessels

Smooth muscle provides the

contracting component of the vascular system that regulates vasoconstriction and dilation.

Atherosclerosis is a pathologic condition that causes

coronary, cerebral, aortic, and peripheral arterial diseases. It develops primarily in elastic arteries (e.g., aorta, carotid, and iliac arteries) and large and medium-sized muscular arteries (e.g., popliteal arteries). It begins as fatty streaks in childhood and lesions can advance with age.

Adventitia, the outermost

covering of the vessel wall, consists of a mixture of collagen, elastic tissue, smooth muscle, nerve fibers, vasa vasorum, and lymphatic vessels that accommodate lymphatic flow to nourish and remove metabolic waste products from the vessel wall.

Pharmacologic therapy has a well-established role in the treatment of PAD. Antiplatelet agents, such as aspirin and dipyridamole,

decrease claudication with ambulation and increase resting limb blood flow. Clopidogrel (and ticlopidine, which is not available in U.S.), both inhibitors of platelet aggregation, modestly increase walking distance. Cilostazol, a phosphodiesterase inhibitor, suppresses platelet aggregation and induces vasodilatation. Pentoxifylline (Trental@) is approved for treatment of intermittent claudication and appears to increase pain-free walking by up to 67% in most studies.

Physical exam of an affected limb often reveals

decreased pulses, atrophic changes of the skin, decreased capillary refilling, loss of hair, discoloration of the skin, and vascular bruits. While vascular bruits can indicate the presence of disease, they do not cone late with its severity. The posterior tibial pulse (found behind the ankle bone) is always present in individuals who do not have PAD. Any decrease in or absence of this pulse is the most reliable clinical sign of the presence of PAD.

Veins have larger

diameters, larger lumens, and thinner, more distensible walls making the venous system capable of holding approximately two-thirds of the total blood in the body. In the extremities, where blood flows against gravity, a system of valves prevents reverse flow or pooling of blood

Surveillance of unrepaired TAA with serial imaging is recommended, with

echocardiography, computed tomographic (CT) angiography, or magnetic resonance (MR) angiography. Imaging modality choice depends on aneurysm location, ideally using the same technique (and center) serially for optimal comparison.

The vascular system is further subdivided into

elastic arteries (the aorta and major pulmonary arteries), muscular arteries (the renal and femoral arteries), arterioles, and capillaries. Elastic arteries contain large amounts of elastic tissue, which enables them to distend and recoil during systole and diastole to help propel blood.

Elastic tissue encompasses the

endothelium and basement membrane. Collagen (a major protein of the white fibers of connective tissue, cartilage, and bone) resists stretching and thereby prevents over-distention of the vasculature.

MRl and MRA are widely used techniques for

evaluating the blood vessels of the vascular system, especially when surgical intervention is contemplated. Magnetic resonance techniques are very sensitive and specific in evaluating arterial wall morphology and possible dissection.

The endothelium is comprised of a

flat layer of endothelial cells lining the entire vascular system. Below the endothelium is the basement membrane, composed of various proteins and polysaccharides that serve as a support structure and transport medium for various materials.

PTA is utilized traditionally for

focal, short segment occlusions. More recently, technology allows PT A to be applied to more extensive disease segments. It can also be used in individuals who are poor surgical candidates.

When employed for femoral-popliteal occlusive disease, the restenosis rate is

greater than 50% at two years in some studies, making femoropopliteal surgical bypass a more appropriate choice of intervention. Stenting also carries a high restenosis rate and has not been shown to improve outcome.

Complications from PTA include direct arterial injury leading to

groin hematoma (2 to 4% ), pseudoaneurysm (0.3 to 2%), or arteriovenous fistula (0.1 to 0.3%). The actual dilatation of the vessel can result in distal embolization (2%), thrombotic occlusion (2%), and rarely, arterial rupture.

Making the diagnosis of PAD with symptoms of claudication requires careful

history taking, with special attention to differentiating true claudication from pseudoclaudication due to lumbar canal stenosis. True claudication is manifested by pain when walking a certain distance that is relieved when the individual stops. It does not occur while the individual is merely standing. With pseudoclaudication, pain persists when standing and can necessitate sitting or changing position to obtain relief.

Treatment modalities

include lifestyle, medical, and surgical interventions. Medical treatment is also directed at reducing the major morbidity and mortality of co-morbid conditions, especially cardiovascular and cerebrovascular disease. Surgical intervention is usually reserved for severe cases that are not responsive to risk factor modification, exercise, and drug therapy.

Gray scale imaging is used to assess the

morphology of the vessel, to determine the presence of plaque, and to assess the characteristics of the plaque. Color flow imaging is useful in evaluating subtotal occlusion of blood vessels and aneurysms and localizing areas of stenosis.

PAD is a marker for systemic disease of atherosclerosis and confers sharply

increased risks for coronary, cerebrovascular, and renovascular disease. Ten-year cardiovascular disease mortality in patients is 6.6 times that in age-matched controls. Estimates of cerebrovascular disease prevalence range from 0.5% to 52%, depending on the method of detection.

Vasculitis is a group of rare diseases with

inflammation of the blood vessels. Causes are generally unknown although some are secondary to other diseases. Information at time of underwriting should include specific diagnosis, symptoms, and treatment. Vasculitis may be associated with high mortality and morbidity risk.

Giant cell arteritis (GCA) is characterized by

inflammatory changes in one of the branches of the aorta, occurring almost exclusively in individuals older than 50 years. The disease incidence increases progressively with age and is higher in females. GCA is also known as temporal arteritis because extracranial branches of the carotid branches are targeted preferentially. ln 80-90% of individuals, vasculitis is detected in the extracranial tree, most often in the superficial temporal, vertebral, ophthalmic, and posterior ciliary arteries.

Leriche syndrome is a clinical syndrome characterized by

intermittent claudication, impotence, and decreased or absent femoral pulses. This syndrome usually correlates with narrowing of the distal aorta.

Vessels above a certain lumen diameter generally consist of three defined layers: the

intima, media, and adventitia.

The first phase,

intimal thickening with accumulation of lipid-filled macrophages (called foam cells), is followed by lipid accumulation in and around cells to produce the fatty streak. Fatty streaks transition into atherosclerotic plaques and these plaques can then develop a well-defined lipid core covered by a fibrous cap. Advanced lesions may have a necrotic lipid core with calcification, and more advanced lesions may also have hemorrhage.

In general, endovascular repair is associated with

less short-term (i.e., 30-day) morbidity and mortality compared to conventional surgical repair. However, endovascular repair is also associated with higher re-intervention rates and with an ongoing risk for rupture and the need for indefinite imaging surveillance.

Segmental Volume Plethysmography is used in conjunction with segmental

limb pressures to locate the level of disease. A transducer detects volume change in a limb as a pneumatic cuff is placed at various levels and then inflated. The volume change is converted into a pressure pulse wave. Variations in the contour of the pressure pulse wave reflect disease severity. In severe disease, the amplitude of the wave is blunted or flattened.

An aneurysm is a

localized, abnormal dilatation of a blood vessel. When an aneurysm is bounded by the components of the vessel wall, it is considered a true aneurysm. Atherosclerotic, syphilitic, and congenital vascular aneurysms are considered true aneurysms. In contrast, a false aneurysm is a breach in the vascular wall leading to an extravascular hematoma that freely communicates with the vessel lumen.

Thoracic aneurysms occur most commonly in the sixth and seventh decades of life and are twice as likely to occur in

males. Thoracic aneurysms are commonly seen in atherosclerotic vessels, and the most common risk factor associated with thoracic aneurysms is hypertension, seen in approximately 60% of cases.

Most individuals with PAN have a vasculitis neuropathy in the form of a

mononeuritis multiplex (MM) that produces symptoms of foot drop or wrist drop. The classic symptom of postprandial periumbilical pain or "intestinal angina" is a hallmark of the disease. Anemia, thrombocytosis, high erythrocyte sedimentation rate (ESR), and microscopic hematuria are common. The diagnosis of PAN requires a tissue biopsy or an angiogram demonstrating microaneurysms. Sural nerve biopsy can be highly diagnostic when MM is suspected. Immunosuppression in the form of corticosteroids and cyclophosphamide (Cytoxan®) can affect a remission or cure in one-third of cases treated.

Polyarteritis nodosa (PAN) is a prime example of a medium vessel vasculitis (MVV) affecting the arteries that contain

muscular walls. The damage caused by inflammation leads to aneurysmal formation. PAN usually begins with nonspecific symptoms that can include malaise, fatigue, fever, and weight loss, though it can take weeks to months to clearly manifest itself as a vasculitis. The organ systems most involved are skin, peripheral nerves, gastrointestinal tract, and kidneys.

Classic constitutional symptoms of

myalgias, fever, malaise, weight loss, and anorexia are often misdiagnosed as infection. Eventually, clinical patterns of ischemia become apparent based on the pattern of involved arteries. Carotid and vertebral artery involvement can cause dizziness, tinnitus, syncope, stroke, and visual disturbances. Inflammation and stenosis of the subclavian arteries would present with arm claudication, pulselessness, and discrepant blood pressures. Aortitis (inflammation of the aorta) can lead to aortic regurgitation and ischemic coronary disease.

AHA Grade: 0 Criteria: Description:

normal artery normal tissue

Peripheral arterial disease (PAD) is an

occlusive disease of the aorta, the iliac arteries, and the arteries of the lower extremities Prevalence is estimated at about 10 million Americans.

Exercise appears to reduce

red blood cell aggregation, improve muscle metabolism, improve endothelial function, reduce local inflammation, and can induce vascular angiogenesis (formation of new blood vessels), all mechanisms that can improve symptoms of claudication.

Modification of diet -

primarily by reducing saturated fat intake and increasing fresh fruits and vegetables -has been shown to benefit PAD. In particular, the Mediterranean diet, which consists of mainly plant-based nutrition with a high percentage of fresh fruits, legumes, vegetables, omega 3 fatty acids (fish), and monounsaturated fats such as olive oil, shows correlation with improved vascular and cardiovascular health.

Intervention, including percutaneous .

procedures or surgical bypass, can be used for individuals with significant claudication. Major advancements in percutaneous procedures, such as percutaneous transluminal angioplasty (PT A), balloon angioplasty, and stenting, have resulted in dramatic increase in these procedures in recent years. A landmark study, published in 1993, showed no significant difference in outcome between angioplasty and surgical bypass for peripheral disease after a median follow-up of four years

Historically, physicians have been taught to look for the classic "5 Ps" on physical exam:

pulselessness, paralysis, paranesthesia, pain, and pallor. These signs can be applicable in more advanced disease but are not sensitive enough to make a diagnosis early in the disease process.

Imaging six months after the initial diagnosis to ensure the stability of the aneurysm diameter and extent is recommended. Further imaging is

recommended annually if there is no expansion or extension or modified to more frequent surveillance with instability or based on etiology, site, and diameter of the aneurysm at presentation.

Diabetes mellitus was the only predictor of

recurrence of symptoms or progression of disease. Aspirin therapy prior to surgery and life-long aspirin therapy after surgery is recommended. The addition of dipyridamole can provide additional benefit in the prevention of graft failure.

Persistent symptoms and complications such as

recurrent epistaxis, mucosal ulcerations, nasal septal perforation, and nasal deformity, usually lead to more extensive evaluation. Pulmonary infiltrates are present in 50% of cases. Seventy-five percent of individuals will eventually develop glomerulonephritis.

The major complication of AAA is

rupture, which is associated with high operative mortality. Elective AAA repair is most effective to prevent rupture. In general, elective repair is indicated for asymptomatic AAA of 5.5 cm diameter or more, AAA that is rapidly expanding and AAA associated with peripheral artery disease that is being re-vascularized. Intervention is individualized and can be either endovascular or open surgical repair.

Asymptomatic AAAs are often detected by

screening or as an incidental finding on imaging done for other reasons. A pulsatile abdominal mass, discovered on physical exam or by the individual, is often the first indication of an aneurysm. As an aneurysm enlarges, the individual may experience abdominal, flank, or back pain. Abdominal ultrasound and computed tomography (CT) are excellent imaging modalities used to identify aneurysms. Magnetic resonance imaging (MRI) can also be used.

The lymphatic system is a

separate vessel system and is responsible for carrying excess fluid from the tissue spaces back to the bloodstream.

Surgical bypass and graft placement in occlusive disease are also used to relieve persistent claudication and improve the level of activities of daily living, but it is generally reserved for more

severe disease. Individuals who benefit the most from elective surgical revascularization are generally under 70 years of age, nondiabetic, and have little evidence of disease distal to the primary lesion. Of note, individuals under 40 years of age with aggressive atherosclerotic disease had a 71 % failure rate for initial vascularization and averaged a 10-year mortality rate of 31 % after initial surgery.

GCA presents with two major symptomatic complexes:

signs of vascular insufficiency resulting from impaired blood flow and signs of systemic inflammation. Individuals complain of throbbing, sharp or dull headaches, usually severe enough to prompt an evaluation. Typically, they notice temporal tenderness.

The intima is a

single layer of endothelial cells on the innermost section of the vessel wall.

Cardiovascular risk factor modification -

smoking cessation, lipid-lowering therapy, and control of blood pressure, blood sugar, and weight -is an important cornerstone for management of PAD. Individuals who stop cigarette smoking reduce progression of disease, reduce risk of amputation, and improve symptoms of limb ischemia at rest.

The muscular arteries are mainly comprised of

smooth muscle cells and control blood flow to the periphery and major organs. These arteries are capable of constricting and dilating to allow varying degrees of blood flow to certain tissues according to their needs. Muscular arteries are major regulators of systemic blood pressure.

This combination of slow movement and thin capillary walls is ideally suited for the exchange of

substances between the tissues and blood. Blood eventually passes into the post-capillary venules and, sequentially, through the collecting venules and the small, medium, and large veins, thus transporting the blood back to the right side of the heart via the vena cavae.

The vascular system consists of three highly specialized components:

the arterial, venous, and lymphatic systems.

On exam, the involved vessels are

thickened, tender and, at times, nodular. Pulses are reduced or absent. Vision loss is a serious complication and can occur when the ophthalmic artery is involved. Loss of vision is sudden, painless, and usually permanent. Amaurosis fugax, or fleeting visual blurring, can precede partial or total blindness. About one half of individuals experience claudication with prolonged talking or chewing.

Lymphatics are

thin-walled, endothelial-lined channels that collect excess fluid in the tissue (i.e., interstitial tissue fluid) and inflammatory cells, transporting them back to the blood.

The disease affects mainly the

tibial and radial arteries, leading to vascular insufficiency. Later complications include chronic ulcerations and gangrene of the fingers and toes. Clinically, in contrast to atherosclerosis, individuals experience significant pain at rest, reflecting the small vessel and neural involvement. Angiography demonstrates smooth, tapered, segmental lesions. Abstinence from tobacco use in the early stages of the disease often prevents further attacks or the development of late complications.

The venous system is responsible for

transporting deoxygenated blood back to the heart and lungs.

Consistent exercise, primarily

walking, improves exercise tolerance and symptoms of lower extremity vascular disease. A meta-analysis showed the significant delay in onset of claudication. Consistent exercise training that lasted at least 30 minutes and was performed three times a week proved most beneficial.

Exercise treadmill testing is utilized in individuals with

typical symptoms of claudication with normal resting ABI measurements. ABI is measured at one-minute intervals for five minutes after exercise. Exercise induces a systolic pressure gradient across the area of stenosis resulting in a fall in the ABI in recovery.

The quality of ultrasound testing of the

vascular system and evaluating blood flow through vessels has improved greatly in recent years. Ultrasound methods include gray-scale imaging, Doppler pulse and continuous-wave spectral imaging, and Doppler color flow imaging.

Kawasaki syndrome (KS), an acute

vasculitis of childhood, is the number one cause of acquired heart disease among children in the United States and Japan. It is a systemic vasculitis that has a predilection for the coronary arteries. Morbidity and mortality most often are due to cardiac sequelae in the form of coronary aneurysms. The peak incidence is at age two years and younger and the syndrome recurs in 2-4% of cases. KS begins with prolonged fever accompanied by rash, conjunctival injection, and oral lesions. Arthritis may be present 10 to 14 days after the onset of fever, as is periungual desquamation (i.e., peeling of the skin around the fingertips).

Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis (WG), is a

vasculitis of the small and medium vessels, affects approximately one in 20,000-30,000 people. Most individuals are adults, and the disease is not gender specific. WG affects primarily the lungs and kidneys, but that is not overtly apparent early in the course of the disease. Most individuals initially seek care for recurrent upper or lower respiratory symptoms usually attributed to asthma or infection.

Thromboangiitis obliterans, a

vasculitis strongly linked to cigarette smoking, is characterized by segmental, thrombosing, acute and chronic inflammation of small and medium vessels. Most individuals have a hypersensitivity to intradennally injected tobacco extracts. Historically a disease of males who were heavy smokers, it is increasingly reported in females, reflecting smoking increases. The disease usually begins before age 35.

As aneurysms grow, they can impinge on adjacent structures such as a blood

vessel or ureter or erode into a vertebral body. The risk of rupture is directly related to the size of the aneurysm. Risk varies from zero for a small AAA (less than 4.0 cm in diameter) to 1 % per year for aneurysms measuring 4.0 to 4.9 cm in diameter, 11 % per year for aneurysms between 5.0 and 5.9 cm in diameter, and 25% per year for those larger than 6.0 cm.

Media refers to the middle section of the

vessel wall and consists of smooth muscle cells surrounded by collagen and elastic tissue.

The arterial system consists of

vessels of varying size and carries oxygenated blood to the tissues of the body after it leaves the heart.