<\/span><\/h2>\nGangrene is the located<\/span> death of body tissue. Dry gangrene is due to prolonged ischemia<\/span> (heart attack<\/span>) or inadequate oxygenation or lack of blood flow. Ischemia affecting proximal<\/span> blood vessels<\/span> it usually affects the lower extremities. Ischemia of the peripheries can cause gangrene of the fingers and toes.<\/p>\n\n<\/span>Peripheral gangrene due to ischemia<\/span><\/h5>\n<\/section>\n\n\n
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Dry gangrene due to ischemia<\/p>\n
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Dry gangrene due to ischemia<\/p>\n
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Dry gangrene due to ischemia<\/p>\n<\/p><\/div>\n<\/section>\n
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<\/span>What are the first signs of ischemia?<\/span><\/h2>\nProximal severe acute<\/span> Ischemia presents as a pale, paralyzed, pulseless limb. This is a surgical emergency because it can progress to extensive gangrene if the obstruction is not cleared quickly.<\/p>\nDistal<\/span> peripheral<\/span> vascular<\/span> the blockage appears as blue, gray, or purple patches, blisters, or ulcers<\/span> at the end of the digits<\/span>. See blue tip syndrome<\/span>.<\/p>\nIschemia at other sites can also result in localization necrosis<\/span> of the skin and deeper tissues.<\/p>\n\n<\/span>Peripheral ischemia<\/span><\/h5>\n<\/section>\n\n\n
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<\/span>What Causes Ischemia?<\/span><\/h2>\nIschemia is due to an acute or chronic<\/span> interruption in blood supply and is often due to a combination of both.<\/p>\nAcute ischemia can be due to:<\/p>\n
\n- Embolism<\/li>\n
- Acute arterial<\/span> thrombosis<\/span>\n<\/li>\n
- Vascular trauma<\/span>\n<\/li>\n
- Calciphylaxis<\/li>\n
- Extreme cold injury (frostbite)<\/li>\n
- \nInfection<\/span>-related disseminated<\/span> intravascular<\/span> coagulopathy<\/span> or purple<\/span> fulminants<\/li>\n<\/ul>\n
<\/span>Emboli<\/span><\/h3>\nEmboli are particles that flow through the bloodstream until they lodge in an arterial junction or narrowing. Emboli can be composed of:<\/p>\n
\n- \nCholesterol<\/span> Dislodged from the heart (80%) or a large artery (aorta, iliac vessel)<\/li>\n
- Tumor<\/span><\/li>\n
- Infectious particles<\/li>\n
- Fat shed during an operation<\/li>\n
- Strange objects.<\/li>\n<\/ul>\n
Large emboli lodge in the bifurcation of the femoral artery (43%), the iliac arteries (18%), the aorta (15%), and the popliteal<\/span> arteries (15%). The little ones are deposited on the fingers and toes, palms and soles of the feet.<\/p>\nVascular obstruction may also be due to hyperviscosity<\/span> syndromes or abnormal circulating proteins such as cryoglobulins or macroglobulins.<\/p>\n<\/span>Thrombosis<\/span><\/h3>\nThrombosis is a blood clot that arises within a blood vessel<\/span>. Predisposing factors include:<\/p>\n\n- Septicemia<\/span><\/span><\/li>\n
- \nHypotension<\/span> (low blood pressure)<\/li>\n
- Low cardiac output<\/li>\n
- An aneurysm (a bulge in the wall of a weakened artery)<\/li>\n
- \nAortic<\/span> dissection (a division in the wall of the aorta)<\/li>\n
- Bypass graft (a surgical procedure)<\/li>\n
- \nAtherosclerotic<\/span> narrowing of the artery.<\/li>\n<\/ul>\n
Whatever the primary<\/span> Cause of ischemia, thrombosis due to slow blood flow can make it worse.<\/p>\nChronic ischemia can be due to:<\/p>\n
\n- Peripheral arterial disease<\/li>\n
- \nVenous<\/span> insufficiency.<\/li>\n<\/ul>\n
<\/span>Peripheral arterial disease<\/span><\/h3>\nChronic peripheral arterial disease is most often due to atherosclerosis<\/span>. This is a buildup of cholesterol, fibrin<\/span> and other proteins within the arterial wall, causing the vessel to narrow and eventually become completely blocked. This process is also called obliterative arteriosclerosis.<\/p>\nRisk factors for peripheral arterial disease include:<\/p>\n
\n- \nHypertension<\/span> (hypertension)<\/li>\n
- Hyperlipidemia (high fats in the blood)<\/li>\n
- Diabetes<\/li>\n
- Cardiovascular disease including myocardial infarction, atrial fibrillation, valve disease<\/li>\n
- \nCerebrovascular<\/span> disease including stroke, transient ischemic<\/span> attack<\/li>\n
- Of smoking<\/li>\n
- \nAutoimmune<\/span> diseases: vasculitis<\/span>, arthritis<\/span>coagulopathy<\/li>\n
- \nMalignancy<\/span> (Cancer<\/span>)<\/li>\n<\/ul>\n
Peripheral arterial disease can also be caused by:<\/p>\n
\n- \nConnective tissue<\/span> disease, including systemic<\/span> sclerosis<\/span>\n<\/li>\n
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Buerger's disease (obliterative thromboangitis).<\/li>\n<\/ul>\n
<\/span>Venous insufficiency<\/span><\/h3>\nVeins may fail to remove blood from tissues due to valve dysfunction<\/span> (varicose veins) and obstruction by deep vein thrombosis (DVT) or thrombophlebitis. High pressure within the veins (venous hypertension) results in the movement of proteins and fibrin into the Soft fabric<\/span>. This leads to fibrosis<\/span>, dysfunctional<\/span> capillary<\/span> fat formation and necrosis (lipodermatosclerosis). When severe, these processes can cause ischemia and gangrene.<\/p>\n<\/span>Clinical characteristics of vascular obstruction.<\/span><\/h2>\nSigns of peripheral vascular disease depend on which tissues are ischemic and their severity. A patient may present with:<\/p>\n
\n- \nClaudication<\/span> (intermittent pain in the leg)<\/li>\n
- Pain at rest<\/li>\n
- Shiny, thin, dry, pale and cold skin.<\/li>\n
- Fragile nail<\/span>\n<\/li>\n
- The most advanced disease can be revealed by livedo<\/span> reticularis (network appearance)<\/li>\n
- Bad healing and ulceration<\/span> (most often leg ulcers)<\/li>\n
- Gangrene: an area of gray or black necrotic<\/span> (dead) tissue.<\/li>\n<\/ul>\n
<\/span>Investigations in a patient with ischemia or dry gangrene.<\/span><\/h2>\nWhen a patient has peripheral ischemia or gangrene of unknown cause, a complete physical examination is performed to evaluate the vascular system, including the heart and peripheral pulses. An electrocardiogram (ECG) assesses heart function. Blood pressure is measured with Doppler ultrasound<\/span> of both lower extremities and both upper extremities to calculate the ankle brachial index (ABI).<\/p>\n