Limb infarction
A limb infarction is an infarction 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.
Affected tissues
Skeletal muscle, the major tissue affected, is actually considerably resistant to infraction 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) doesn't 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[1].
Bone, on the other hand, is more susceptible to ischemia, with hematopoietic cell usually dying within 12 hours, and other bone cells (osteocytes, osteoclasts, osteoblasts etc.) within 12-48 hours.[2] 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.[2]
Causes
Causes include:
- Thrombosis (approximately 40%[3] of cases)
- Arterial embolism (approximately 40%[3])
Another cause of limb infarction is skeletal muscle infarction as a rare complication of long standing, poorly controlled diabetes mellitus.[4]
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:
- Coldness in a leg, arm, hand or fingers[5][6]
- Decreased or no pulse in an arm or leg beyond the site of blockage[5][6]
- Pain in the affected area[5][6]
- Muscle spasm in the affected area[5]
- Numbness and tingling in an arm or leg[5][6]
- Paleness (pallor)[6][5] of the skin of the arm or leg
- Muscle weakness of an arm or leg,[5][6] possibly to the grade of paralysis[6]
Later symptoms are closely related to infarction of the tissue supplied by the occluded artery:
- Blisters of the skin in the affected area[5]
- Shedding of skin (desquamation)[5]
- Skin erosion (ulceration)[5]
- Discoloration (mottling[6], cyanosis[6] or darkening[5]) of the skin following necrosis. The discoloration usually has a distinct demarcation at the blockage.[6]
A major presentation of diabetic skeletal muscle infarction is painful thigh or leg swelling.[4]
Diagnosis
In addition to evaluating the symptoms described above, angiography can distinguish between cases caused by arteriosclerosis obliterans (displaying abnormalities in other vessels and collateral circulations) from those caused by emboli.[7]
Magnetic resonance imaging (MRI) is the preferred test for diagnosing skeletal muscle infarction.[4]
Treatment
Oxygen consumption of skeletal muscle is approximately 50 times larger while contracting than in the resting state.[8] 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.[7]
In the legs, below the inguinal ligament, percutaneous aspiration thrombectomy is a rapid and effective way of removing thromboembolic occlusions.[9] Balloon thrombectomy using a Fogarty catheter may also be used.[7]. In the arms, balloon thrombectomy is an effective treatment for thromboemboli as well.[10] However, local thrombi from atherosclerotic plaque are harder to treat than embolized ones.[7] If results are not satisfying, another angiography should be performed.[7]
Thrombolysis using analogs of tissue plasminogen activator (tPA) may be used as an alternative or complement to surgery.[7]
Because of the high recurrence rates of thromboembolism, it seems necessary to administer anticoagulant therapy as well.[10]
Prognosis
With treatment, approximately 80 of patients are alive[7] (approx. 95% after surgery[7]) and approximately 70 percent of infarcted limbs remain vital after 6 months.[7]
References
- ^ Ganong, Review of Medical Physiology, 22nd Edition.Specialized form of muscle that is peculiar to the vertebrate heart.p81
- ^ a b eMedicine Specialties > Bone Infarct Author: Ali Nawaz Khan. Coauthors: Mohammed Jassim Al-Salman, Muthusamy Chandramohan, Sumaira MacDonald, Charles Edward Hutchinson
- ^ a b Campbell WB, Ridler BM, Szymanska TH (1998). "Current management of acute leg ischaemia: results of an audit by the Vascular Surgical Society of Great Britain and Ireland". Br J Surg. 85 (11): 1498–503. doi:10.1046/j.1365-2168.1998.00906.x. PMID 9823910.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ a b c Grigoriadis E, Fam AG, Starok M, Ang LC (2000). "Skeletal muscle infarction in diabetes mellitus". J. Rheumatol. 27 (4): 1063–8. PMID 10782838.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ a b c d e f g h i j k MedlinePlus > Arterial embolism Sean O. Stitham, MD and David C. Dugdale III, MD. Also reviewed by David Zieve, MD. Reviewed last on: 5/8/2008. Alternative link: [1]
- ^ a b c d e f g h i j MDGuidelines > Arterial Embolism And Thrombosis From The Medical Disability Advisor by Presley Reed, MD. Retrieved on April 30, 2010
- ^ a b c d e f g h i 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
- ^ Cardiovascular Physiology Concepts > Myocardial Oxygen Demand Richard E. Klabunde, PhD
- ^ Oğuzkurt L, Ozkan U, Gümüş B, Coşkun I, Koca N, Gülcan O (2010). "Percutaneous aspiration thrombectomy in the treatment of lower extremity thromboembolic occlusions". Diagn Interv Radiol. 16 (1): 79–83. doi:10.4261/1305-3825.DIR.2654-09.1. PMID 20044798.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ a b Magishi K, Izumi Y, Shimizu N (2010). "Short- and long-term outcomes of acute upper extremity arterial thromboembolism". Ann Thorac Cardiovasc Surg. 16 (1): 31–4. PMID 20190707.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link)