| Arterial thrombosis occurs when a blood clot (thrombus) adheres to the wall of a vessel (artery) and blocks the flow of blood. A blood clot that dislodges from the artery wall and moves throughout the circulatory system is known as a thromboembolus. The occlusion of blood flow by a foreign particle (embolus) other than a blood clot within the vessel is known as an embolism.
An embolus may be any material that forms a rounded mass (bolus) and moves through the circulatory system. This can include an air bubble, bacteria, fat, or cancer cells. Regardless of its composition, an embolus or thromboembolus eventually becomes lodged in an artery that is too small to accommodate its passage. The result is partial or complete blockage (occlusion) of blood through the artery. Tissues the vessel supplies with blood may become starved for oxygen and nutrients. Individuals with arterial thrombosis or embolism often develop alternative (collateral) circulation to provide blood flow to the tissue to compensate for the loss of arterial flow. However, because it takes time for sufficient collateral circulation to develop, the loss of blood flow threatens the survival of tissues in the affected area of the body.
Depending on the area of involvement, arterial embolism or thrombus may create serious conditions that can result in permanent damage to tissues and organs. When arterial flow is interrupted, tissue death (necrosis) and decay (gangrene) are possible, and in some cases, individuals may be at risk of death.Risk: Important risk factors for arterial embolism and thrombosis may include advanced age, cigarette smoking, high blood pressure (hypertension), obesity, blood serum fat (lipid) abnormalities (i.e., high serum levels of cholesterol, triglycerides, lipoprotein (a), or apolipoprotein B or low serum levels of high-density lipoprotein cholesterol), diabetes mellitus, abnormal blood coagulation factors, and low levels of physical exercise. A combination of two or more of these risk factors may produce more than an additive increase in risk for developing arterial embolism and thrombosis. Incidence and Prevalence: The incidence of arterial embolism and thrombosis in the heart (coronary) arteries, brain (cerebral) arteries, and arteries in the trunk, arms, and legs (periphery) is of epidemic proportions in western industrialized countries. In many industrialized nations including the US, complications of arterial embolism and thrombosis (particularly as they relate to ischemic or coronary heart disease) are the leading causes of death. Approximately 550,000 Americans die each year from heart-related arterial embolism and thrombosis and about 250,000 of these individuals are female. Approximately 100,000 of all these deaths are considered premature, that is, prior to the age of average life expectancy. Although the incidence of arterial embolism and thrombosis is declining in some countries, in others, such as those in Eastern Europe, incidence rates are increasing. |
Source: Medical Disability Advisor
| History: Individuals with arterial embolism or thrombosis may complain of pain in the region of the affected blood vessel; numbness, coldness, tingling or pain in an extremity, such as an arm or leg; muscle weakness, spasms, and/or paralysis; lack of a pulse in the artery beyond the site of blockage; and paleness (pallor) or discoloration (mottling) of the skin in the affected extremity. The individual may report a recent surgery, a blood clotting disorder, stroke or cardiovascular disease, or a history of long-term intravenous therapy. Physical exam: A pulse cannot usually be felt (palpated) in the artery beyond (distal to) the site of blockage. Coldness or mottling of the affected extremity is common and muscular effects such as weakness, spasms, or paralysis may be noted. There is often a distinct line (demarcation) at the blockage with pallor or bluish color (cyanosis) distal to the occlusion. Necrosis and gangrene may be observed in the affected tissue. Tests: Laboratory and diagnostic tests are conducted to determine any underlying cause for thrombosis or embolism and to confirm presence of the obstruction. Tests may include measurement of cardiac enzymes in the blood (cardiac-specific troponin T or I, myoglobins, and creatine kinase isoenzymes). Blood cultures may be done to identify the organism responsible for an infection. Diagnostic tests include recording the electrical activity in the heart (electrocardiogram, or ECG), visualization of the blood vessels using low-energy radio waves (MRI) or x-rays following injection of a radiopaque contrast material (arteriography), or studying the structure and motion of the heart with ultrasonic waves (echocardiography). Computer-enhanced arteriography (digital subtraction arteriography) is useful for examining individuals for whom the volume of radiopaque contrast material must be kept to a minimum. A flexible fiber-optic catheter inserted directly into an artery helps visualize its interior (fiberoptic angioscopy). |
Source: Medical Disability Advisor
| Therapy may include administration of drugs that relax the blood vessels (vasodilators), enhance accessory (collateral) blood flow (serotonin antagonist, ketanserin), or reduce or prevent blood clots (antithrombotic therapy). Invasive treatments include removal of the obstruction (embolectomy) using either a flexible catheter inserted into the blood vessel or open surgery, direct administration of antithrombotic agents onto the clot in the vessel using a flexible catheter (intra-arterial thrombolysis), and cutting the nerves that stimulate blood vessels causing them to relax (lumbar sympathectomy). If necrosis and gangrene has set in an arm or leg, the limb may be amputated. |
Source: Medical Disability Advisor
| The outcome varies depending on the location of the embolism and the extent to which it affects blood supply to the surrounding area. Arterial embolism can be serious if not treated promptly and, with a 25% to 30% death rate, it may be life-threatening. The affected area can be permanently damaged with up to approximately 25% of cases requiring amputation of an affected extremity. Arterial emboli may recur even after successful treatment.
Drug treatments produce removal (lysis) of the obstruction in 50% to 80% of all cases. Removal of the obstruction using a flexible catheter or open surgery reduces mortality by nearly 50% and the need for limb amputation by approximately 35%. Intra-arterial thrombolysis reduces the blockage produced by a blood clot by 95% in 50% of cases, and restores adequate blood flow in 50% to 80% of cases. Lumbar sympathectomy is usually used only in extreme cases; however, up to 50% reported a favorable response to this treatment. Limb amputation itself is usually remarkably well-tolerated, but carries considerable (~50%) mortality primarily because of the severity of the diseases associated with this procedure. |
Source: Medical Disability Advisor
| Rehabilitation programs are individualized under the supervision of a physician. Individuals may be encouraged to walk independently outside the supervised program.
For individuals who have had a limb surgically amputated, rehabilitation begins in the first few days following surgery. Partial weight bearing may begin in the first postoperative week after the first surgical dressing change has confirmed the integrity of the wound. Following discharge from the hospital, individuals with any type of amputation should try to become as independent as possible with crutches or other aids. In the case of below-knee amputation, quadriceps-setting exercises should be encouraged. Individuals with above-knee amputations may require the use of a walker on a permanent basis. |
Source: Medical Disability Advisor
| Possible complications of arterial embolism and thrombosis depend on the site of the obstruction. In all cases, there is reduced blood flow (ischemia) to the tissues supplied by the artery. If the obstruction is in a coronary vessel, death of the heart muscle (infarction) can occur and possibly result in heart failure and death. Blockage of an artery that supplies blood to the brain may result in a stroke. Blockage of arteries that supply other organs, arms, or legs may result in necrosis and gangrene. Amputation may be required. In all cases, survival is questionable if left untreated. |
Source: Medical Disability Advisor
| Anxiety level often increases in individuals who have experienced arterial embolism or thrombosis and a less stressful job situation may be required. Individuals may also require certain measures to promote blood circulation in affected tissues, such as positional changes of the extremities on a routine basis; ankle, knee, wrist, or arm flexion exercises every few hours; and a warm environment. The individual may experience impaired physical mobility and strength following thromboembolism and strenuous or sustained physical activity may need to be restricted. |
Source: Medical Disability Advisor
| If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case. Regarding diagnosis:
- Does individual have a history of cigarette smoking, hypertension, obesity, diabetes mellitus, abnormal blood coagulation factors, and low levels of physical exercise?
-
Does individual also have a history of blood serum fat (lipid) abnormalities, such as high levels of cholesterol, triglycerides, lipoprotein (a), or apolipoprotein B—or low levels of high-density lipoprotein cholesterol?
-
Has individual had recent surgery or stroke or undergone long-term intravenous therapy?
-
Were cardiac enzymes in the blood, such as cardiac-specific troponin T or I, myoglobins, and creatine kinase isoenzymes measured?
-
Were blood cultures done to identify the organism responsible for an infection?
-
Was electrocardiogram (ECG), echocardiogram, MRI, arteriography, or fiberoptic angioscopy done?
-
Did tests reveal the underlying cause for and presence of the obstruction? Was the blockage partial or complete?
Regarding treatment:
- Was individual given medication to relax the blood vessels (vasodilators), enhance accessory (collateral) blood flow (serotonin antagonist, ketanserin), or reduce or prevent blood clots (antithrombotic therapy)?
-
Was medication sufficient to resolve the thrombus/embolus?
-
Did individual require removal of the obstruction (embolectomy) using either a flexible catheter inserted into the blood vessel or open surgery?
-
Was administration of antithrombotic agents onto the clot in the vessel using a flexible catheter (intra-arterial thrombolysis) required?
-
Were nerves that stimulate blood vessels cut, causing the blood vessels to relax (lumbar sympathectomy)?
-
Has necrosis and gangrene occurred in an arm or leg? Did the limb require amputation?
-
Did any complications arise after required surgery?
Regarding prognosis:
- What was the location of the embolism and to what extent was blood supply to the area affected?
-
Was treatment received promptly?
-
Was any permanent damage done to the affected area as a result of the blockage?
-
Is individual compliant with all medication regimens?
-
Was surgical intervention required? What type of surgery was done?
-
Would individual benefit from any other surgical options?
-
Were arteries that supply the heart and brain affected? If so, did individual experience myocardial infarction or stroke?
-
Did necrosis and gangrene occur?
-
Was amputation required? If so, would individual benefit from counseling to cope with the physical and emotional aspects of amputation?
|
Source: Medical Disability Advisor
| Coffman, David. "Peripheral Vascular Disease." Textbook of Primary Care Medicine. Eds. J. Noble and H. L. Greene. 3rd ed. St. Louis: Mosby-Year Book, Inc., 2001. 629-630. MD Consult. Elsevier, Inc. 19 May 2005 <http://home.mdconsult.com/das/book/47334204-2/view/959?sid=368479569>. |
Source: Medical Disability Advisor
| Feedback |
| Send us comments, suggestions, corrections, or anything you would like us to hear. If you are not logged in, you must
include your email address, in order for us to respond. We cannot, unfortunately, respond to every comment.
If you are seeking medical advice, please contact your physician. Thank you! |
Send this comment to:
Sales
Customer Support
Content Development
|
|
| |
|
|
|
|
|
This publication is designed to provide accurate and authoritative information in
regard to the subject matter covered. It is published with the understanding that
the author, editors, and publisher are not engaged in rendering medical, legal,
accounting or other professional service. If medical, legal, or other expert assistance
is required, the service of a competent professional should be sought. We are unable to respond to requests for advice.
Any Sales inquiries should include an email address or other means of
communication.
|