A limb infarction is an area of tissue death of an

arm In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...

leg A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element ca ...

. It may cause ''skeletal muscle infarction'',

avascular necrosis Avascular necrosis (AVN), also called osteonecrosis or bone infarction, is death of bone tissue due to interruption of the blood supply. Early on, there may be no symptoms. Gradually joint pain may develop which may limit the ability to move. C ...

of bones, or necrosis of a part of or an entire limb.

Signs and symptoms

Early symptoms of an arterial embolism in the arms or legs appear as soon as there is ischemia of the tissue, even before any frank infarction has begun. Such symptoms may include: A major presentation of diabetic ''skeletal muscle infarction'' is painful thigh or leg swelling.

Affected tissues

The major tissues affected are nerves and muscles, where irreversible damage starts to occur after 4–6 hours of cessation of blood supply.internetmedicin.se > Artäremboli / thrombos
Professor David Bergqvist. Reviewed by Professor lashylash. Updated 2007-11-10 Skeletal muscle, the major tissue affected, is still relatively resistant to infarction compared to the heart and brain because its ability to rely on

anaerobic metabolism Anaerobic respiration is respiration using electron acceptors other than molecular oxygen (O2). Although oxygen is not the final electron acceptor, the process still uses a respiratory electron transport chain. In aerobic organisms undergoing r ...

by glycogen stored in the cells may supply the muscle tissue long enough for any clot to dissolve, either by intervention or the body's own system for thrombus breakdown. In contrast, brain tissue (in

cerebral infarction A cerebral infarction is the pathologic process that results in an area of necrotic tissue in the brain (cerebral infarct). It is caused by disrupted blood supply ( ischemia) and restricted oxygen supply ( hypoxia), most commonly due to thromboemb ...

) does not store glycogen, and the heart (in

myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may ...

) is so specialized on aerobic metabolism that not enough energy can be liberated by lactate production to sustain its needs.

Bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

is more susceptible to ischemia, with

hematopoietic cell A blood cell, also called a hematopoietic cell, hemocyte, or hematocyte, is a cell produced through hematopoiesis and found mainly in the blood. Major types of blood cells include red blood cells (erythrocytes), white blood cells (leukocytes), ...

s usually dying within 2 hours, and other

bone cell An osteocyte, an oblate shaped type of bone cell with dendritic processes, is the most commonly found cell in mature bone. It can live as long as the organism itself. The adult human body has about 42 billion of them. Osteocytes do not divide and ...

s (

osteocyte An osteocyte, an oblate shaped type of bone cell with dendritic processes, is the most commonly found cell in mature bone. It can live as long as the organism itself. The adult human body has about 42 billion of them. Osteocytes do not divide an ...

osteoclast An osteoclast () is a type of bone cell that breaks down bone tissue. This function is critical in the maintenance, repair, and remodeling of bones of the vertebral skeleton. The osteoclast disassembles and digests the composite of hydrated pro ...

s, osteoblasts etc.) within 12–20 hours.eMedicine Specialties > Bone Infarct
Author: Ali Nawaz Khan. Coauthors: Mohammed Jassim Al-Salman, Muthusamy Chandramohan, Sumaira MacDonald, Charles Edward Hutchinson On the other hand, it has better regenerative capacity once blood supply is reestablished, as the remaining dead inorganic

osseous tissue A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

forms a framework upon which immigrating cells can reestablish functional bone tissue in optimal conditions.

Causes

Causes include: *

Thrombosis Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (t ...

(approximately 40% of cases) * Arterial embolism (approximately 40%) *

arteriosclerosis obliterans Arteriosclerosis obliterans is an occlusive arterial disease most prominently affecting the abdominal aorta and the small- and medium-sized arteries of the lower extremities, which may lead to absent dorsalis pedis, posterior tibial, and/or poplit ...

Another cause of limb infarction is ''skeletal muscle infarction'' as a rare complication of long standing, poorly controlled

diabetes mellitus Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...

Diagnosis

In addition to evaluating the symptoms described above,

angiography Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is perfor ...

can distinguish between cases caused by

(displaying abnormalities in other vessels and

collateral circulation Collateral circulation is the alternate circulation around a blocked artery or vein via another path, such as nearby minor vessels. It may occur via preexisting vascular redundancy (analogous to engineered redundancy), as in the circle of Wil ...

s) from those caused by emboli. Magnetic resonance imaging (MRI) is the preferred test for diagnosing ''skeletal muscle infarction''.

Treatment

Oxygen consumption of skeletal muscle is approximately 50 times larger while contracting than in the resting state.Cardiovascular Physiology Concepts > Myocardial Oxygen Demand
Richard E. Klabunde, PhD Thus, resting the affected limb should delay onset of infarction substantially after arterial occlusion.

Low molecular weight heparin Low-molecular-weight heparin (LMWH) is a class of anticoagulant medications. They are used in the prevention of blood clots and treatment of venous thromboembolism (deep vein thrombosis and pulmonary embolism) and in the treatment of myocardial in ...

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.''Kirurgiska åtgärder vid akut ischemi i nedre extremitet''. (Google Translate: ''Surgical measures in acute ischemia of lower extremities''.) Pekka Aho och Pirkka Vikatmaa. Finska Läkaresällskapets Handlingar (Finnish Medical Society Documents). No. 1, 2003 If results are not satisfying, another angiography should be performed.

Thrombolysis Thrombolysis, also called fibrinolytic therapy, is the breakdown (lysis) of blood clots formed in blood vessels, using medication. It is used in ST elevation myocardial infarction, stroke, and in cases of severe venous thromboembolism (massive ...

using analogs of

tissue plasminogen activator Tissue plasminogen activator (abbreviated tPA or PLAT) is a protein involved in the breakdown of blood clots. It is a serine protease () found on endothelial cells, the cells that line the blood vessels. As an enzyme, it catalyzes the conversion ...

(tPA) may be used as an alternative or complement to surgery. Where there is extensive vascular damage,

bypass surgery Bypass surgery refers to a class of surgery involving rerouting a tubular body part. Types include: * Vascular bypass surgery such as coronary artery bypass surgery, a heart operation * Cardiopulmonary bypass, a technique used in coronary artery ...

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 Fasciotomy or fasciectomy is a surgical procedure where the fascia is cut to relieve tension or pressure in order to treat the resulting loss of circulation to an area of tissue or muscle. Fasciotomy is a limb-saving procedure when used to tr ...

, opening up all four leg compartments. Because of the high recurrence rates of thromboembolism, it is necessary to administer anticoagulant therapy as well.

Aspirin Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat inc ...

and

low molecular weight heparin Low-molecular-weight heparin (LMWH) is a class of anticoagulant medications. They are used in the prevention of blood clots and treatment of venous thromboembolism (deep vein thrombosis and pulmonary embolism) and in the treatment of myocardial in ...

should be administered, and possibly

warfarin Warfarin, sold under the brand name Coumadin among others, is a medication that is used as an anticoagulant (blood thinner). It is commonly used to prevent blood clots such as deep vein thrombosis and pulmonary embolism, and to prevent st ...

as well. Follow-up includes checking peripheral pulses and the arm-leg blood pressure gradient.

Prognosis

With treatment, approximately 80% of patients are alive (approx. 95% after surgery) and approximately 70% of infarcted limbs remain vital after 6 months.

References

External links

{{DEFAULTSORT:Limb Infarction Gross pathology