Peripheral vascular disease restricts the flow of blood through the vessels beyond the heart. Circulation disorders in these vessels, which carry oxygen and other nutrients to vital organs and tissues, are most often caused by atherosclerosis (also called hardening of the arteries), a progressive disease process caused when plaque (composed of fat, cholesterol, and other substances) is deposited on the inner wall of the artery.
Over time, the inside diameter of the artery narrows (called stenosis), and blood flow through the artery is reduced or stopped. Plaque commonly forms in the iliac arteries (lower abdomen) and the femoral and popliteal arteries (legs).
Blocked arteries cannot supply an adequate amount of oxygen-rich blood to the working muscles. When this blockage occurs in the arteries to the legs, the result is cramp-like pain in the hips, thighs, or calves, often severe enough to limit walking. This pattern of pain, which is relieved with rest, is called intermittent claudication.
Rest pain, as the name implies, occurs during rest rather than during exercise. Sometimes lowering the legs will provide relief as gravity forces more blood to the foot.
Gangrene - death of the tissue - can occur when blood circulation is so severely restricted that the legs do not receive the nutrients they need to survive. Without treatment, the entire foot or part of the leg may be lost to disease.
Other symptoms of peripheral vascular disease in the lower extremities include:
Because other conditions may cause these symptoms, a thorough examination is necessary.
When symptoms appear, a general physical examination is the first step of the evaluation. Other tests will help the doctor determine whether the patient might benefit from peripheral vascular treatment (intervention).
Many techniques can be used to increase the flow of blood through the arteries. The latest interventions for treating vascular disease can be done quickly. Most patients can expect a short hospital stay and early return to normal activities. Devices now available include lasers, atherectomy, balloon catheters, stents and endoluminal grafts. These new technologies remove or displace the plaque that blocks blood flow to the lower extremity. During these procedures, dye is injected at certain times and X-rays are taken to determine whether the artery has been opened adequately. If it hasn't, the treatment will be continued or repeated.
If the blockage is composed of very hard calcified material, it may be resistant to any of these interventions. Bypass or detour of the blockage using a vein or synthetic graft may then be necessary.
Thrombolytics: If blood clots are the suspected cause of the blockage, strong, clot-busting drugs called thrombolytics are used first. A catheter is guided to the site of the blockage in the artery. The thrombolytic drug is infused through the catheter until the clot is dissolved. Periodic X-rays with dye are taken to monitor this treatment. Depending on the progress, the catheter may be advanced so the drug is deposited directly on the clot.
Mechanical Thrombectomy and Embolectomy: A procedure for removing blood clots (thrombus) from an artery or graft with a balloon catheter. A deflated balloon attached to a catheter is passed through the artery beyond the clot and inflated.It is then pulled back through the artery, scooping the blood clot away as it passes back .Sometimes the procedure is performed using a special catheter which agitates the clot while thrombolytic drugs are injected into it.
Balloon Angioplasty: This is now the most common method used for opening an obstructed artery. A guide wire is first passed through the narrowed part of the artery. A deflated balloon, attached to a catheter (a thin, flexible tube), is passed along the guide wire through the vessel to the area of narrowing.
The balloon is then inflated and deflated, sometimes more than once and often in more than one location. This flattens the plaque against the vessel wall, increasing the size of the opening in the artery. Balloon angioplasty may be the only treatment needed, or it can be used along with one or more of the other options.
Laser Angioplasty: Uses an excimer laser to clear, or ablate, arterial blockages and improve blood flow. Laser angioplasty is minimally invasive and is similar to balloon angioplasty. A laser catheter emits ultraviolet light to remove the blockage by evaporating the plaque. Ultraviolet light is much cooler than infrared ("hot") lasers so it reduces the risk of damage to the surrounding tissue.
If there are multiple blockages, the laser catheter is moved from blockage to blockage. Once all the blockages are ablated, the catheter is withdrawn and X-ray contrast dye is injected into the blood vessel, allowing the physician to assess the results of the procedure. Additional balloon angioplasty may be undertaken at this point. The laser angioplasty procedure generally takes one to two hours followed by one to two days of recovery in the hospital for most patients.
Atherectomy: An atherectomy catheter has a small rotating cutter at its tip that either cuts or pulverizes plaque that is blocking an artery.
Stents: If an artery that has been opened should close or re-narrow during or after the procedure, a stent may be inserted to hold the vessel open. This tiny, expandable device is made of metal and mounted on a deflated balloon attached to a catheter. When the catheter is in position at the site of the blockage, the balloon is inflated and the stentis expanded. The balloon catheter is then removed, allowing blood to flow through the artery again. The expanded stent, which looks like a rolled piece of fence, remains in place permanently.
Endoluminal Graft (ELG): An endoluminal graft is a combination of synthetic graft and a metal stent. It is inserted nonsurgically with a catheter through an artery in the groin area. Once the blockage has been cleared by thrombolysis, atherectomy, or angioplasty, the physician will position the ELG using X-ray and ultrasound images projected on a television monitor then expand the graft to affix it in place. By lining the inside of the artery with a graft, the ELG allows normal blood flow.
Endarterectomy: The surgeon can make an incision in the artery and pull out the plaque that is causing the blockage. The opening in the artery is then closed with sutures. Removal of the plaque by this method is called an endarterectomy. It is most commonly performed in the neck on the carotid arteries leading to the brain to prevent strokes.
Another common site for endarterectomy is the groin area where the deep and superficial arteries divide. Removing the plaque allows other devices to be advanced to blockages lower in the leg.
Bypass: As a last resort, a narrowed or blocked section of an artery can be detoured or bypassed with grafts. A graft may be synthetic, or it may be a natural vein taken from another part of the body, most often the leg. One end of the graft is attached to an artery above the blocked area, and the other to an artery below the blockage. Blood then travels from the artery above, through the bypass graft, and to the artery below the blockage, where it circulates to the lower part of the leg and foot.
Biomedical research and genetic interven-tions potentially offer promising new treatments for peripheral vascular disease.
The treatment options for the management of peripheral vascular disease are only the first step in restoring good health. They do not cure the underlying condition that caused the problem to develop. Further medical evaluation, treatment, and changes in lifestyle to reduce risk factors for the heart and blood vessel disease are essential. These changes may include exercising, adopting a healthy diet, controlling blood pressure and weight, lowering cholesterol levels in the blood, and not smoking. Making these lifestyle changes may slow the progression of cardiovascular disease.
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