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Those unsuitable for surgery may receive thrombolytics. In the past, streptokinase was the main thrombolytic chemical. More recently, drugs such as tissue plasminogen activator, urokinase, and anisterplase have been used in its place. Mechanical methods of injecting the thrombolytic compounds have improved with the introduction of pulsed spray catheters—which allow for a greater opportunity for patients to avoid surgery. Pharmacological thrombolysis requires a catheter insert into the affected area, attached to the catheter is often a wire with holes to allow for a wider dispersal area of the thrombolytic agent. These agents lyse the ischemia-causing thrombus quickly and effectively. However, the efficacy of thrombolytic treatment is limited by hemorrhagic complications. Plasma fibrinogen level has been proposed as a predictor of these hemorrhagic complications. However, based on a systemtic review of the available literature until January 2016, the predictive value of plasma is unproven.
Oxygen consumption of skeletal muscle is approximately 50 times larger while contracting than in the resting state. Thus, resting the affected limb should delay onset of infarction substantially after arterial occlusion.
Low molecular weight heparin is used to reduce or at least prevent enlargement of a thrombus, and is also indicated before any surgery. In the legs, below the inguinal ligament, percutaneous aspiration thrombectomy is a rapid and effective way of removing thromboembolic occlusions. Balloon thrombectomy using a Fogarty catheter may also be used. In the arms, balloon thrombectomy is an effective treatment for thromboemboli as well. However, local thrombi from atherosclerotic plaque are harder to treat than embolized ones. If results are not satisfying, another angiography should be performed.
Thrombolysis using analogs of tissue plasminogen activator (tPA) may be used as an alternative or complement to surgery. Where there is extensive vascular damage, bypass surgery of the vessels may be necessary to establish other ways to supply the affected parts.
Swelling of the limb may cause inhibited flow by increased pressure, and in the legs (but very rarely in the arms), this may indicate a fasciotomy, opening up all four leg compartments.
Because of the high recurrence rates of thromboembolism, it is necessary to administer anticoagulant therapy as well. Aspirin and low molecular weight heparin should be administered, and possibly warfarin as well. Follow-up includes checking peripheral pulses and the arm-leg blood pressure gradient.
The primary intervention in acute limb ischaemia is emergency embolectomy using a Fogarty Catheter, providing the limb is still viable within the 4-6h timeframe. Other options include a vascular bypass to route blood flow around the clot.
Cilostazol or pentoxifylline can improve symptoms in some. Cilostazol may improve walking distance for people who experience claudication due to peripheral artery disease, but there is no strong evidence to suggest that it improves the quality of life, decreases mortality, or decreases the risk of cardiovascular events.
Treatment with other drugs or vitamins are unsupported by clinical evidence, "but trials evaluating the effect of folate and vitamin B-12 on hyperhomocysteinemia, a putative vascular risk factor, are near completion".
Treatment is aimed at controlling symptoms and improving the interrupted blood flow to the affected area of the body.
Medications include:
- Antithrombotic medication. These are commonly given because thromboembolism is the major cause of arterial embolism. Examples are:
- Anticoagulants (such as warfarin or heparin) and antiplatelet medication (such as aspirin, ticlopidine, and clopidogrel) can prevent new clots from forming
- Thrombolytics (such as streptokinase) can dissolve clots
- Painkillers given intravenously
- Vasodilators to relax and dilate blood vessels.
Appropriate drug treatments successfully produces thrombolysis and removal of the clot in 50% to 80% of all cases.
Antithrombotic agents may be administered directly onto the clot in the vessel using a flexible catheter ("intra-arterial thrombolysis"). Intra-arterial thrombolysis reduces thromboembolic occlusion by 95% in 50% of cases, and restores adequate blood flow in 50% to 80% of cases.
Surgical procedures include:
- Arterial bypass surgery to create another source of blood supply
- Embolectomy, to remove the embolus, with various techniques available:
- Thromboaspiration
- Angioplasty with balloon catheterization with or without implanting a stent Balloon catheterization or open embolectomy surgery reduces mortality by nearly 50% and the need for limb amputation by approximately 35%.
- Embolectomy by open surgery on the artery
If extensive necrosis and gangrene has set in an arm or leg, the limb may have to be amputated. Limb amputation is in itself usually remarkably well tolerated, but is associated with a substantial mortality (~50%), primarily because of the severity of the diseases in patients where it is indicated.
Early treatment is essential to keep the affected limb viable. The treatment options include injection of an anticoagulant, thrombolysis, embolectomy, surgical revascularisation, or amputation. Anticoagulant therapy is initiated to prevent further enlargement of the thrombus. Continuous IV unfractionated heparin has been the traditional agent of choice.
If the condition of the ischemic limb is stabilized with anticoagulation, recently formed emboli may be treated with catheter-directed thrombolysis using intraarterial infusion of a thrombolytic agent (e.g., recombinant tissue plasminogen activator (tPA), streptokinase, or urokinase). A percutaneous catheter inserted into the femoral artery and threaded to the site of the clot is used to infuse the drug. Unlike anticoagulants, thrombolytic agents work directly to resolve the clot over a period of 24 to 48 hours.
Direct arteriotomy may be necessary to remove the clot. Surgical revascularization may be used in the setting of trauma (e.g., laceration of the artery). Amputation is reserved for cases where limb salvage is not possible. If the patient continues to have a risk of further embolization from some persistent source, such as chronic atrial fibrillation, treatment includes long-term oral anticoagulation to prevent further acute arterial ischemic episodes.
Decrease in body temperature reduces the aerobic metabolic rate of the affected cells, reducing the immediate effects of hypoxia. Reduction of body temperature also reduces the inflammation response and reperfusion injury. For frostbite injuries, limiting thawing and warming of tissues until warmer temperatures can be sustained may reduce reperfusion injury.
After a trial of the best medical treatment outline above, if symptoms persist, patients may be referred to a vascular or endovascular surgeon. The benefit of revascularization is thought to correspond to the severity of ischemia and the presence of other risk factors for limb loss such as wound and infection severity.
- Angioplasty (PTA, or percutaneous transluminal angioplasty) can be done on solitary lesions in large arteries, such as the femoral artery, but angioplasty may not have sustained benefits. Patency rates following angioplasty are highest for iliac arteries, and decrease with arteries towards the toes. Other criteria that affect outcome following revascularization are length of lesion, and number of lesions. There does not appear to be long term advantages or sustained benefit to placing a stent following angioplasty in order to hold the narrowing of the superficial femoral artery open.
- Atherectomy, in which the plaque is scraped off of the inside of the vessel wall (albeit with no better results than angioplasty).
- Vascular bypass grafting can be performed to circumvent a diseased area of the arterial vasculature. The great saphenous vein is used as a conduit if available, although artificial (Gore-Tex or PTFE) material is often used for long grafts when adequate venous conduit is unavailable.
- When gangrene has set in, amputation is required to prevent infected tissues from causing sepsis a life-threatening illness.
- Thrombolysis and thrombectomy are used in cases of arterial thrombosis or embolism.
Nitroglycerin can be used immediately to widen the coronary arteries and help increase blood flow to the heart. In addition, nitroglycerin causes peripheral venous and artery dilation reducing cardiac preload and afterload. These reductions allow for decreased stress on the heart and therefore lower the oxygen demand of the heart's muscle cells.
Antiplatelet drugs such as aspirin and clopidogrel can help reduce the progression of atherosclerotic plaque formation, as well as combining these with an anticoagulant such as a low molecular weight heparin.
Treatment is varied depending upon the nature of the case. In severe cases, coronary artery bypass surgery is performed to redirect blood flow around the affected area. Drug-eluting stents and thrombolytic drug therapy are less invasive options for less severe cases.
How well a patient does depends on the location of the clot and to what extent the clot has blocked blood flow. Arterial embolism can be serious if not treated promptly.
Without treatment, it has a 25% to 30% mortality rate. The affected area can be permanently damaged, and up to approximately 25% of cases require amputation of an affected extremity.
Arterial emboli may recur even after successful treatment.
Warfarin and vitamin K antagonists are anticoagulants that can be taken orally to reduce thromboembolic occurrence. Where a more effective response is required, heparin can be given (by injection) concomitantly. As a side effect of any anticoagulant, the risk of bleeding is increased, so the international normalized ratio of blood is monitored. Self-monitoring and self-management are safe options for competent patients, though their practice varies. In Germany, about 20% of patients were self-managed while only 1% of U.S. patients did home self-testing (according to one 2012 study). Other medications such as direct thrombin inhibitors and direct Xa inhibitors are increasingly being used instead of warfarin.
Splenic infarction can be induced for the treatment of such conditions as portal hypertension or splenic injury. It can also be used prior to splenectomy for the prevention of blood loss.
Thrombolysis is the pharmacological destruction of blood clots by administering thrombolytic drugs including recombitant tissue plasminogen activator, which enhances the normal destruction of blood clots by the body's enzymes. This carries an increased risk of bleeding so is generally only used for specific situations (such as severe stroke or a massive pulmonary embolism).
Options include:
- Medications alone (an antiplatelet drug (or drugs) and control of risk factors for atherosclerosis).
- Medical management plus carotid endarterectomy or carotid stenting, which is preferred in patients at high surgical risk and in younger patients.
- Control of smoking, high blood pressure, and high levels of lipids in the blood.
The goal of treatment is to reduce the risk of stroke (cerebrovascular accident). Intervention (carotid endarterectomy or carotid stenting) can cause stroke; however, where the risk of stroke from medical management alone is high, intervention may be beneficial. In selected trial participants with asymptomatic severe carotid artery stenosis, carotid endarterectomy reduces the risk of stroke in the next 5 years by 50%, though this represents a reduction in absolute incidence of all strokes or perioperative death of approximately 6%. In most centres, carotid endarterectomy is associated with a 30-day stroke or mortality rate of < 3%; some areas have higher rates.
Clinical guidelines (such as those of National Institute for Clinical Excellence (NICE) ) recommend that all patients with carotid stenosis be given medication, usually blood pressure lowering medications, anti-clotting medications, anti-platelet medications (such as aspirin or clopidogrel), and especially statins (which were originally prescribed for their cholesterol-lowering effects but were also found to reduce inflammation and stabilize plaque).
NICE and other guidelines also recommend that patients with "symptomatic" carotid stenosis be given carotid endarterectomy urgently, since the greatest risk of stroke is within days. Carotid endarterectomy reduces the risk of stroke or death from carotid emboli by about half.
For people with stenosis but no symptoms, the interventional recommendations are less clear. Such patients have a historical risk of stroke of about 1-2% per year. Carotid endarterectomy has a surgical risk of stroke or death of about 2-4% in most institutions. In the large Asymptomatic Carotid Surgery Trial (ACST) endarterectomy reduced major stroke and death by about half, even after surgical death and stroke was taken into account. According to the Cochrane Collaboration the absolute benefit of surgery is small. For intervention using stents, there is insufficient evidence to support stenting rather than open surgery, and several trials, including the ACST-2, are comparing these 2 procedures.
There are also surgical procedures for removal of a thrombus (thrombectomy).
With treatment, approximately 80% of patients are alive (approx. 95% after surgery) and approximately 70% of infarcted limbs remain vital after 6 months.
In last decade, similar to myocardial infarction treatment, thrombolytic drugs were introduced in the therapy of cerebral infarction. The use of intravenous rtPA therapy can be advocated in patients who arrive to stroke unit and can be fully evaluated within 3 h of the onset.
If cerebral infarction is caused by a thrombus occluding blood flow to an artery supplying the brain, definitive therapy is aimed at removing the blockage by breaking the clot down (thrombolysis), or by removing it mechanically (thrombectomy). The more rapidly blood flow is restored to the brain, the fewer brain cells die. In increasing numbers of primary stroke centers, pharmacologic thrombolysis with the drug tissue plasminogen activator (tPA), is used to dissolve the clot and unblock the artery.
Another intervention for acute cerebral ischaemia is removal of the offending thrombus directly. This is accomplished by inserting a catheter into the femoral artery, directing it into the cerebral circulation, and deploying a corkscrew-like device to ensnare the clot, which is then withdrawn from the body. Mechanical embolectomy devices have been demonstrated effective at restoring blood flow in patients who were unable to receive thrombolytic drugs or for whom the drugs were ineffective, though no differences have been found between newer and older versions of the devices. The devices have only been tested on patients treated with mechanical clot embolectomy within eight hours of the onset of symptoms.
Angioplasty and stenting have begun to be looked at as possible viable options in treatment of acute cerebral ischaemia. In a systematic review of six uncontrolled, single-center trials, involving a total of 300 patients, of intra-cranial stenting in symptomatic intracranial arterial stenosis, the rate of technical success (reduction to stenosis of <50%) ranged from 90-98%, and the rate of major peri-procedural complications ranged from 4-10%. The rates of restenosis and/or stroke following the treatment were also favorable. This data suggests that a large, randomized controlled trial is needed to more completely evaluate the possible therapeutic advantage of this treatment.
If studies show carotid stenosis, and the patient has residual function in the affected side, carotid endarterectomy (surgical removal of the stenosis) may decrease the risk of recurrence if performed rapidly after cerebral infarction. Carotid endarterectomy is also indicated to decrease the risk of cerebral infarction for symptomatic carotid stenosis (>70 to 80% reduction in diameter).
In tissue losses that are not immediately fatal, the best course of action is to make every effort to restore impairments through physical therapy, cognitive therapy, occupational therapy, speech therapy and exercise.
After an AMI, people should be treated to prevent LVT formation. Aspirin plus an oral anticoagulant such as warfarin are suggested for individuals at risk for thromboembolic events. Anticoagulants are also shown to reduce the risk of embolisms when a thrombus is already formed. Heparin, an injectable, fast-acting anticoagulant, is effective in high doses for preventing LVT formation after AMI.
Typically, tissue plasminogen activator may be administered within three to four-and-a-half hours of stroke onset if the patient is without contraindications (i.e. a bleeding diathesis such as recent major surgery or cancer with brain metastases). High dose aspirin can be given within 48 hours. For long term prevention of recurrence, medical regimens are typically aimed towards correcting the underlying risk factors for lacunar infarcts such as hypertension, diabetes mellitus and cigarette smoking. Anticoagulants such as heparin and warfarin have shown no benefit over aspirin with regards to five year survival.
Patients who suffer lacunar strokes have a greater chance of surviving beyond thirty days (96%) than those with other types of stroke (85%), and better survival beyond a year (87% versus 65-70%). Between 70% and 80% are functionally independent at 1 year, compared with fewer than 50% otherwise.
Occupational Therapy and Physical Therapy interventions are used in the rehabilitation of lacunar stroke. A physiotherapy program will improve joint range of motion of the paretic limb using passive range of motion exercises. When increases in activity are tolerated, and stability improvements are made, patients will progress from rolling to side-lying, to standing (with progressions to prone, quadruped, bridging, long-sitting and kneeling for example) and learn to transfer safely (from their bed to a chair or from a wheel chair to a car for example). Assistance and ambulation aids are used as required as the patient begins walking and lessened as function increases. Furthermore, splints and braces can be used to support limbs and joints to prevent complications such as contractures and spasticity. The rehabilitation healthcare team should also educate the patient and their family on common stroke symptoms and how to manage an onset of stroke. Continuing follow-up with a physician is essential so that the physician may monitor medication dosage and risk factors.
The goal of treatment is to prevent the development or continuation of neurologic deficits. Treatments include observation, anticoagulation, stent implantation and carotid artery ligation.
The largest clinical trial performed, CREST, randomized patients at risk for a stroke from carotid artery blockage to either open surgery (carotid endarterectomy) or carotid stent placement with embolic protection. This trial followed patients for 4 years and found no overall difference in the primary end point of both treatment arms (myocardial infarctions, any perioperative strokes or ipsilateral strokes within 4 years, or death during procedure). Patients assigned to the surgical arm experienced more perioperative myocardial infarctions compared to the stenting group; however, the difference was not statistically significant (6.8% vs or 7.2% HR for stenting is 1.1 CI 0.81-1.51 P value 0.51) whereas patients assigned to the carotid stent arm experienced more periprocedural strokes compared to endarteretomy (6.4% vs 4.7% HR for stenting 1.5 P-0.03). There was no mortality difference and no difference for major (disabling) strokes between surgery and stenting. It was noted that there did seem to exist an age cutoff where below 75 years old endarterectomy provided more positive outcomes and over 75 stenting offered a better risk profile. However, it should be noted that the CREST trial was not designed for subgroup analysis and thus not powered enough to draw any statistically significant conclusions. A later study published in 2013 evaluated how these perioperative complications affect long-term survival. This study showed that experiencing a stroke within the first year conferred a two-fold lower survival rate (Hazard Ratio(HR) 6.6 [CI 3.7-12]) than those who experienced a perioperative myocardial infarction at two years post intervention (HR 3.6 [CI 2-6.8]). This difference in mortality, however, converges and becomes negligible at 5 years (HR 2.7 [CI 1.7-4.3] vs HR 2.8 [CI 1.8-4.3]). A 2010 study found benefits (reduced strokes) from carotid endarterectomy in those without symptoms who are under 75.
Various studies have investigated the use of anticoagulation to suppress blood clot formation in cerebral venous sinus thrombosis. Before these trials had been conducted, there had been a concern that small areas of hemorrhage in the brain would bleed further as a result of treatment; the studies showed that this concern was unfounded. Clinical practice guidelines now recommend heparin or low molecular weight heparin in the initial treatment, followed by warfarin, provided there are no other bleeding risks that would make these treatments unsuitable. Some experts discourage the use of anticoagulation if there is extensive hemorrhage; in that case, they recommend repeating the imaging after 7–10 days. If the hemorrhage has decreased in size, anticoagulants are started, while no anticoagulants are given if there is no reduction.
The duration of warfarin treatment depends on the circumstances and underlying causes of the condition. If the thrombosis developed under temporary circumstances (e.g. pregnancy), three months are regarded as sufficient. If the condition was unprovoked but there are no clear causes or a "mild" form of thrombophilia, 6 to 12 months is advised. If there is a severe underlying thrombosis disorder, warfarin treatment may need to continue indefinitely.
Thrombolysis (removal of the blood clot with "clot buster" medication) has been described, either systemically by injection into a vein or directly into the clot during angiography. The 2006 European Federation of Neurological Societies guideline recommends that thrombolysis is only used in patients who deteriorate despite adequate treatment, and other causes of deterioration have been eliminated. It is unclear which drug and which mode of administration is the most effective. Bleeding into the brain and in other sites of the body is a major concern in the use of thrombolysis. American guidelines make no recommendation with regards to thrombolysis, stating that more research is needed.
Raised intracranial pressure, if severe or threatening vision, may require therapeutic lumbar puncture (removal of excessive cerebrospinal fluid), medication (acetazolamide), or neurosurgical treatment (optic nerve sheath fenestration or shunting). In certain situations, anticonvulsants may be used to try to prevent seizures. These situations include focal neurological problems (e.g. inability to move a limb) and focal changes of the brain tissue on CT or MRI scan. Evidence to support or refute the use of antiepileptic drugs as a preventive measure, however, is lacking.
Treatment includes supportive care with analgesics and anti-inflammatory agents. Exercise should be limited as it increases pain and extends the area of infarction. Symptoms usually resolve in weeks to months, but fifty percent of sufferers will experience relapse in either leg.
Dressler syndrome is best treated with high dose aspirin. In some resistant cases, corticosteroids can be used but are not preferred (avoided) in first month due to the high frequency of impaired ventricular healing leading to increased rate of ventricular rupture. NSAIDs though once used to treat Dressler syndrome, are less advocated and should be avoided in patients with ischemic heart disease. One NSAID in particular, indomethacin, can inhibit new collagen deposition thus impairing the healing process for the infarcted region. NSAIDS should only be used in cases refractory to aspirin. Heparin in Dressler syndrome should be avoided because it can lead to hemorrhage into the pericardial sac leading to tamponade. The only time heparin could be used with pericarditis is with coexisting acute MI in order to prevent further thrombus formation.
Keeping blood pressure below 140/90 mmHg is recommended. Anticoagulation can prevent recurrent ischemic strokes. Among people with nonvalvular atrial fibrillation, anticoagulation can reduce stroke by 60% while antiplatelet agents can reduce stroke by 20%. However, a recent meta-analysis suggests harm from anticoagulation started early after an embolic stroke. Stroke prevention treatment for atrial fibrillation is determined according to the CHA2DS2–VASc score. The most widely used anticoagulant to prevent thromboembolic stroke in patients with nonvalvular atrial fibrillation is the oral agent warfarin while a number of newer agents including dabigatran are alternatives which do not require prothrombin time monitoring.
Anticoagulants, when used following stroke, should not be stopped for dental procedures.
If studies show carotid artery stenosis, and the person has a degree of residual function on the affected side, carotid endarterectomy (surgical removal of the stenosis) may decrease the risk of recurrence if performed rapidly after stroke.