Limb infarction
Encyclopedia
A limb infarction is an area of tissue death
of an arm
or leg
. It may cause skeletal muscle infarction, avascular necrosis
of bones, or necrosis of a part of or an entire limb.
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 by glycogen
stored in the cells, which 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
) does not store glycogen, and the heart (in myocardial infarction
) is so specialized on aerobic metabolism that not enough energy can be liberated by lactate production to sustain its needs.
Bone
is more susceptible to ischemia, with hematopoietic cells usually dying within 12 hours, and other bone cell
s (osteocyte
s, osteoclast
s, osteoblast
s etc.) within 12–48 hours. On the other hand, it has better regenerative capacity once blood supply is reestablished, as the remaining dead inorganic osseous tissue
forms a framework upon which immigrating cells can reestablish functional bone tissue in optimal conditions.
Another cause of limb infarction is skeletal muscle infarction as a rare complication of long standing, poorly controlled diabetes mellitus
.
of the tissue, even before any frank infarction has begun. Such symptoms may include:
Later symptoms are closely related to infarction
of the tissue supplied by the occluded artery:
A major presentation of diabetic skeletal muscle infarction is painful thigh or leg swelling.
(displaying abnormalities in other vessels and collateral circulation
s) from those caused by emboli.
Magnetic resonance imaging
(MRI) is the preferred test for diagnosing skeletal muscle infarction.
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.
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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 main character of the medical drama House, M.D., was stricken with a limb infarction in his right quadriceps muscle. The infarction became advanced. Muscle death occurred and the doctors at the hospital tried a risky procedure in order to save his leg. The quadriceps was removed, forcing House to walk with a cane. The condition plays a large role in the development of his character. It should be noted that the injury suffered by House is a rather extreme example of limb infarction.
Infarction
In medicine, infarction refers to tissue death that is caused by a local lack of oxygen due to obstruction of the tissue's blood supply. The resulting lesion is referred to as an infarct.-Causes:...
of an arm
Arm
In human anatomy, the arm is the part of the upper limb between the shoulder and the elbow joints. In other animals, the term arm can also be used for analogous structures, such as one of the paired forelimbs of a four-legged animal or the arms of cephalopods...
or leg
Leg
Łęg may refer to the following places in Poland:*A former name for the town of Ełk *Part of the Czyżyny district of Kraków*Łęg, Pleszew County in Greater Poland Voivodeship...
. It may cause skeletal muscle infarction, avascular necrosis
Avascular necrosis
Avascular necrosis is a disease where there is cellular death of bone components due to interruption of the blood supply. Without blood, the bone tissue dies and the bone collapses...
of bones, or necrosis of a part of or an entire limb.
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.Skeletal muscle
Skeletal muscle
Skeletal muscle is a form of striated muscle tissue existing under control of the somatic nervous system- i.e. it is voluntarily controlled. It is one of three major muscle types, the others being cardiac and smooth 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 by glycogen
Glycogen
Glycogen is a molecule that serves as the secondary long-term energy storage in animal and fungal cells, with the primary energy stores being held in adipose tissue...
stored in the cells, which 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
Cerebral infarction
A cerebral infarction is the ischemic kind of stroke due to a disturbance in the blood vessels supplying blood to the brain. It can be atherothrombotic or embolic. Stroke caused by cerebral infarction should be distinguished from two other kinds of stroke: cerebral hemorrhage and subarachnoid...
) does not store glycogen, and the heart (in myocardial infarction
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
) is so specialized on aerobic metabolism that not enough energy can be liberated by lactate production to sustain its needs.
Bone
Bone
Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
is more susceptible to ischemia, with hematopoietic cells usually dying within 12 hours, and other bone cell
Bone cell
There are five types of bone cells.*Osteoblasts - These are commonly called bone-forming cells. They secrete osteoid, which forms the bone matrix. They also begin mieralization, and are unable to divide....
s (osteocyte
Osteocyte
An osteocyte, a star-shaped cell, is the most abundant cell found in compact bone. Cells contain a nucleus and a thin ring of cytoplasm. When osteoblasts become trapped in the matrix they secrete, they become osteocytes...
s, osteoclast
Osteoclast
An osteoclast is a type of bone cell that removes bone tissue by removing its mineralized matrix and breaking up the organic bone . This process is known as bone resorption. Osteoclasts were discovered by Kolliker in 1873...
s, osteoblast
Osteoblast
Osteoblasts are mononucleate cells that are responsible for bone formation; in essence, osteoblasts are specialized fibroblasts that in addition to fibroblastic products, express bone sialoprotein and osteocalcin.Osteoblasts produce a matrix of osteoid, which is composed mainly of Type I collagen...
s etc.) within 12–48 hours. On the other hand, it has better regenerative capacity once blood supply is reestablished, as the remaining dead inorganic osseous tissue
Osseous tissue
Osseous tissue, or bone tissue, is the major structural and supportive connective tissue of the body. Osseous tissue forms the rigid part of the bone organs that make up the skeletal system.-Formation:Bone tissue is a mineralized connective tissue...
forms a framework upon which immigrating cells can reestablish functional bone tissue in optimal conditions.
Causes
Causes include:- ThrombosisThrombosisThrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
(approximately 40% of cases) - Arterial embolismArterial embolismArterial embolism is a sudden interruption of blood flow to an organ or body part due to an embolus adhering to the wall of an artery and blocks the flow of blood, the major type of embolus being a blood clot...
(approximately 40%) - arteriosclerosis obliteransArteriosclerosis obliteransArteriosclerosis 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 popliteal artery pulses.It is characterized by fibrosis of...
Another cause of limb infarction is skeletal muscle infarction as a rare complication of long standing, poorly controlled diabetes mellitus
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
.
Symptoms
Early symptoms of an arterial embolism in the arms or legs appear as soon as there is ischemiaIschemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...
of the tissue, even before any frank infarction has begun. Such symptoms may include:
- Coldness in a leg, arm, hand or fingers
- Decreased or no pulse in an arm or leg beyond the site of blockage
- Pain in the affected area
- Muscle spasm in the affected area
- Numbness and tingling in an arm or leg
- Paleness (pallorPallorPallor is a reduced amount of oxyhaemoglobin in skin or mucous membrane, a pale color which can be caused by illness, emotional shock or stress, stimulant use, lack of exposure to sunlight, anaemia or genetics....
) of the skin of the arm or leg - Muscle weaknessMuscle weaknessMuscle weakness or myasthenia is a lack of muscle strength. The causes are many and can be divided into conditions that have true or perceived muscle weakness...
of an arm or leg, possibly to the grade of paralysisParalysisParalysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...
Later symptoms are closely related to infarction
Infarction
In medicine, infarction refers to tissue death that is caused by a local lack of oxygen due to obstruction of the tissue's blood supply. The resulting lesion is referred to as an infarct.-Causes:...
of the tissue supplied by the occluded artery:
- BlisterBlisterA blister is a small pocket of fluid within the upper layers of the skin, typically caused by forceful rubbing , burning, freezing, chemical exposure or infection. Most blisters are filled with a clear fluid called serum or plasma...
s of the skin in the affected area - Shedding of skin (desquamationDesquamationDesquamation , also called skin peeling, is the shedding of the outermost membrane or layer of a tissue, such as the skin.-Skin:Normal, nonpathologic desquamation of the skin occurs when keratinocytes, after moving apically over about 14 days, are individually shed unnoticeably...
) - Skin erosion (ulceration)
- Discoloration (mottling, cyanosisCyanosisCyanosis is the appearance of a blue or purple coloration of the skin or mucous membranes due to the tissues near the skin surface being low on oxygen. The onset of cyanosis is 2.5 g/dL of deoxyhemoglobin. The bluish color is more readily apparent in those with high hemoglobin counts than it is...
or darkening) of the skin following necrosis. The discoloration usually has a distinct demarcation at the blockage.
A major presentation of diabetic skeletal muscle infarction is painful thigh or leg swelling.
Diagnosis
In addition to evaluating the symptoms described above, angiography can distinguish between cases caused by arteriosclerosis obliteransArteriosclerosis 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 popliteal artery pulses.It is characterized by fibrosis of...
(displaying abnormalities in other vessels and collateral circulation
Collateral circulation
Collateral circulation is when an area of tissue or an organ has a number of different pathways for blood to reach it. This is often as a result of anastamoses - branches formed between adjacent blood vessels....
s) from those caused by emboli.
Magnetic resonance imaging
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
(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. Thus, resting the affected limb should delay onset of infarction substantially after arterial occlusion.Low molecular weight heparin
Low molecular weight heparin
In medicine, low-molecular-weight heparin is a class of medication used as an anticoagulant in diseases that feature thrombosis, as well as for prophylaxis in situations that lead to a high risk of thrombosis....
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
Thrombolysis
Thrombolysis is the breakdown of blood clots by pharmacological means. It is colloquially referred to as clot busting for this reason...
using analogs of tissue plasminogen activator
Tissue plasminogen activator
Tissue plasminogen activator 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 of plasminogen to plasmin, the major enzyme responsible for clot breakdown...
(tPA) may be used as an alternative or complement to surgery.
Where there is extensive vascular damage, bypass surgery
Coronary artery bypass surgery
Coronary artery bypass surgery, also coronary artery bypass graft surgery, and colloquially heart bypass or bypass surgery is a surgical procedure performed to relieve angina and reduce the risk of death from coronary artery disease...
of the vessels may be necessary to establish other ways to supply the affected parts.
Fasciotomy
Fasciotomy or fasciectomy is a surgical procedure where the fascia is cut to relieve tension or pressure . Fasciotomy is a limb-saving procedure when used to treat acute compartment syndrome. It is also sometimes used to treat chronic compartment stress syndrome...
, opening up all four leg compartments
Fascial compartments of leg
On the human body, the limbs can be divided into segments, such as the arm and the forearm of the upper limb, and the thigh and the leg of the lower limb. If these segments are cut transversely, it is apparent that they are divided into multiple sections. These are called fascial compartments, and...
.
Because of the high recurrence rates of thromboembolism, it is necessary to administer anticoagulant
Anticoagulant
An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...
therapy as well. Aspirin
Aspirin
Aspirin , also known as acetylsalicylic acid , is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. It was discovered by Arthur Eichengrun, a chemist with the German company Bayer...
and low molecular weight heparin
Low molecular weight heparin
In medicine, low-molecular-weight heparin is a class of medication used as an anticoagulant in diseases that feature thrombosis, as well as for prophylaxis in situations that lead to a high risk of thrombosis....
should be administered, and possibly warfarin
Warfarin
Warfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood...
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.Popular culture
Gregory HouseGregory House
Gregory House, M.D., or simply referred to as House, is a fictional antihero and title character of the American television series House, played by Hugh Laurie. He is the Chief of Diagnostic Medicine at the fictional Princeton-Plainsboro Teaching Hospital, where he leads a team of diagnosticians...
, the main character of the medical drama House, M.D., was stricken with a limb infarction in his right quadriceps muscle. The infarction became advanced. Muscle death occurred and the doctors at the hospital tried a risky procedure in order to save his leg. The quadriceps was removed, forcing House to walk with a cane. The condition plays a large role in the development of his character. It should be noted that the injury suffered by House is a rather extreme example of limb infarction.