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PERIPHERAL VASCULAR DISEASE Presented by Jill Kerkman Pathophysiology Form of atherosclerosis Progressive disease May occur suddenly if an embolism occurs or when a blood clot rapidly develops in a blood vessel restricted by an atherosclerotic plaque, and the blood flow is quickly cut off. PVD is a generic term that encompasses vascular insufficiencies such as arteriosclerosis, arterial stenosis, Raynaud’s phenomenon. Peripheral arteriosclerosis is common in the elderly and is often associated with hypertension and hyperlipidemia. PVD is frequently observed in patients with CAD, diabetes, and a long-term history of smoking. Two types of PVD Functional Doesn’t have an organic cause. Doesn’t involve defects in blood vessels’ structure, usually short-term effects and come and go. Ex: Raynaud’s disease. Organic Caused by structural changes in the blood vessels, such as inflammation. Ex: Peripheral artery disease, caused by fatty buildups in arteries. How Common is PVD? Affects about 1 in 20 people over the age of 50, or 8 million people in the US. PVD is only diagnosed in 50% of the population. Symptomatic PVD carries at least a 30% risk of death within 5 years and almost 50% within 10 years, primarily due to MI (60%) or stroke (12%). Symptoms of PVD Leg or hip pain during walking (intermittent claudication). The pain stops when you rest. Numbness, tingling or weakness in the legs. Burning or aching pain in feet or toes when resting. Sore on leg or foot that won’t heal. Cold legs or feet. Color change in skin of legs or feet. Loss of hair on legs. The 5 P’s Peripheral signs of PVD are the classic 5 P’s Pulselessness Paralysis Paraesthesia Pain Pallor Paralysis and paraesthesia suggest limb- threatening ischemia and mandate prompt evaluation and consultation. Advanced PVD may manifest as mottling in a “fishnet pattern”, pulselessness, numbness, or cyanosis. Paralysis may follow, and the extremity may become cold; gangrene eventaully may be seen. Poorly healing injuries or ulcers in the extremities help provide evidence of preexisting PVD. Who is at risk for PVD? Over the age of 50 Smokers Diabetics Overweight (especially with syndrome X or hyperinsulinism) Male sex Sedentary people People who have hypertension or high cholesterol Family history of heart or vascular disease Pain Scale A subjective grading scale for PVD pain is as follows: Grade 1: Definite discomfort or pain, but only of initial or modest levels (established, but minimal). Grade 2: Moderate discomfort or pain from which the patient’s attention can be diverted, for example by conversation. Grade 3: Intense pain (short of Grade 4) from which the patient’s attention cannot be diverted. Grade 4: Excruciating and unbearable pain. How is PVD Diagnosed? Ankle-Brachial Index Test (ABI) The blood pressure in your arms and ankles is checked using a regular blood pressure cuff and a special ultrasound stethoscope called a Doppler. The pressure in your ankle is compared to the pressure in your arm to determine how well your blood is flowing. The index is determined by dividing ankle systolic BP by arm systolic BP. ABI Measurements are usually taken at rest and after standardized treadmill exercise (i.e.. For 5 min. at 2mph, 12%). A normal resting ABI is 1 or 1.1. An index of 0.9 or less indicates the presence of obstructive disease. 0.5 or less suggests multiple-level arterial disease. An ABI of less than 0.26 indicates severe, limb- threatening arterial compromise. Duplex Ultrasonography and Doppler Color-Flow Imaging Technical advances in ultrasonography have allowed reproducible measurements of blood vessels and blood flow as well as standardization of criteria for assessment of PVD. Doppler color-flow imaging are useful in localizing diseased segments, and spectral imaging can assess lesion severity. Magnetic Resonance Imaging and Angiography Useful in evaluating arterial dissection and characterizing vessel-wall morphology (including hematoma or thrombus). Computed Tomography (CT) Angiography Treatment for PVD Severe lower extremity PVD is treated initially with cardiovascular disease risk factor modification: Exercise training Medication Diet Stop Smoking Interventional Radiology Surgery Gene-Based Therapy Exercise Research has shown that regular exercise is the most consistently effective treatment for PVD. Patients who have taken part in a regular exercise program for at least 3 months have seen substantial increases in the distances they are able to walk without experiencing painful symptoms. Exercise Prescription Training Intensity Initial • Set by result of peak treadmill. • Starting exercise work load brings on claudication pain. Subsequent • Speed or grade increased if patient walks > 10 minutes. • Grade increased first if speed > 2 mph. • Speed increased first if < 2 mph. Exercise Prescription Duration Initial • 35 minutes (intermittent walking) Subsequent • Add 5 minutes every session until 50 minutes (intermittent walking) is possible Exercise Prescription Frequency 3-5 times per week. Specificity of Activity Treadmill walking is the recommended exercise. Stop Smoking On average, smokers are diagnosed with PVD as much as 10 years earlier than non- smokers. Stopping smoking now is the single most important thing you can do to halt the progression of PVD or prevent it in the future. Medications Drugs that lower cholesterol or control high blood pressure. Decrease blood viscosity. Trental, Persantine, or Coumadin Antiplatlet agents: their primary long-term benefit is reduction in cardiovascular events and mortality. ASA doses of 75 to 325mg QD have shown protective benefits. Ticlid and Plavix also have shown promise in disease prevention and in therapy after vascular intervention. Interventional Radiology Treatments Angioplasty Stents Thrombolytic Therapy Stent-Grafts Gene-Based Therapy The field of molecular genetics has provided new understanding of vascular physiology and pathology and has opened exciting frontiers in the treatment of PVD. Direct gene transfer by intramuscular injection of DNA encoded with vascular growth factors has resulted in growth of new vessels and collateral circulation in chronically occluded lower extremity arterial vessels. Surgical Treatments for PVD Thrombectomy Bypass Grafts Aneurysms Most common lethal peripheral vascular abnormality. An artery whose diameter is 1.5 times the normal. Aortic aneurysms are caused by weakening of the artery walls due to atherosclerosis. The weakened walls balloon out, forming an aneurysm. When blood pumps from the heart through the aorta, it places pressure on the aneurysm walls. Over time, the aneurysm can get bigger and bigger, until eventually it may rupture. Aortoiliac Occlusive Disease Typically involves the distal abdominal aorta as well as the common and external iliac arteries. Aortobifemoral bypass with a prosthetic graft has been the traditional treatment of choice for aortoiliac occlusive disease since the 1960’s. The operative morbidity and mortality are in the 2% range, and long-term patency exceeds 90%. Superficial Femoral Occlusive Disease Presents with symptoms of claudication of the calf and sole of the foot. Usually improves as collateral circulation develops. Best treatment initially is antiplatelet therapy in combination with a vigorous exercise program. Tibial Artery Disease Distal atherosclerotic disease involving the tibioperoneal trunk and the tibial vessels is the most difficult to treat and leads to the greatest morbidity and tissue loss. ABI is typically less than 0.4 before rest pain develops, and any value less than 0.3 almost always results in ischemic tissue loss. Upper Extremity Disease Atherosclerotic disease involving the arms is almost always limited to the larger proximal vessels and rarely involves the brachial, radial, or ulnar arteries. Although these patients have no symptoms, they can have a large discrepancy in BP between the left and right arms. Always prudent to measure BP in both arms. Thrombosis A thrombus, or blood clot, within a blood vessel. Normally, a blood clot forms to prevent bleeding but a thrombus is an abnormal blood clot in the vessel when it is not even punctured. The clotting process may be encouraged by the buildup of fatty acids on the vessel walls. Thrombosis in the vein may cause pain and swelling. Deep Venous Thrombosis A blood clot in a deep vein. May form on the valves within the vein, and may subsequently increase in size to totally occlude the vein. Sometimes parts of the clot may break off and travel in the bloodstream to the lungs and cause serious health problems (pulmonary embolism). DVT is perhaps the most dangerous problem. Patients with DVT have a 30 to 40% risk of recurrence later in life. Phlebitis Inflammation of the leg veins. Two types: Inflammation of the veins on the surface of the leg (more common). Inflammation of the deep veins of the leg. Phlebitis is caused by an infection or injury. Can cause a blood clot to form and this clot can then embolize and result in pulmonary embolism. This is the worst thing that can happen if you have phlebitis. Pulmonary Embolism An embolus is a clot or any other piece of material that is carried around in the blood. Pulmonary embolism is where the embolus gets stuck in a vessel going to the lungs. The only way a clot can go to a vessel in the lungs is if it passes through the heart and is pumped out of the pulmonary artery. So, the closer the clot is to the heart, the more likely to get a pulmonary embolism. Varicose Veins Caused because either the blood flow is too slow making the vein pile up with blood or the valve in the vein is not working well so the blood falls down due to gravity and piles up in the veins of the legs. Sclerotherapy: Irritant chemical is injected into the veins, causing them to scar and seal off. This “detours” the blood to nearby healthier veins. Stripping: Procedure used to remove larger varicose veins. Parts of the vein can be removed or tied off, or the entire vein can be removed. Surgery continues to play an important role in the management of peripheral vascular disease. Revascularization procedures provide excellent outcomes for many patients at risk for loss of a limb or seriously impaired quality of life. Although endovascular techniques are now being used for managing many vascular problems, the traditional surgical approaches still offer well-documented benefits.
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