Levels and goals of amputation
Prosthetics and limb reattachment
The term amputation refers to the complete or partial severance of a limb or other body part. Surgical amputations may be performed because of an injury, congenital (birth) defect, infection, or vascular disease. It is performed to remove diseased tissue caused by such problems as arteriosclerosis, bone cancer, burns, and frostbite, or to relieve pain when a body part has been severely crushed. Amputation is performed to remove tissue that no longer has an adequate blood supply; to remove malignant tumors; and because of severe trauma to the body part.
Approximately 80% of all surgical amputations are performed on the lower limbs, such as the leg or foot. Artificial limbs (prosthetics) are often used to restore complete or partial functioning, such as walking, after amputation. About 100, 000 amputations are performed in the United States each year. More than 90% of the amputations are due to blood circulatory complications of diabetes, and most of these operations involve the legs. Children are susceptible to crushing bone injuries that result in amputation from such common household items as automobile doors and playground equipment. Adults have limbs amputated as the result of the improper use of such equipment as table saws and hydraulic wood splitters.
Amputations can be either planned or as an emergency procedure. Injury and arterial embolisms are the main reasons for emergency amputations. Amputations cannot be performed on patients with uncontrolled diabetes mellitus, heart failure, or infection. Patients with blood clotting disorders are also not good candidates for amputation.
Although surgical amputations date back at least to the time of Greek physician Hippocrates (c. 460– c. 375 BC), amputating limbs to save lives did not become widespread until the sixteenth century. Many of the advances in amputation surgery were made by military surgeons during the course of wars. In 1529, French military surgeon Ambroise Paré (1510–1590) rediscovered the use of ligation, in which a thread-like or wire material is used to tie off, or constrict, blood vessels. This surgical technique, which stops the flow of blood from a severed vein, greatly reduces the patient’s chances of bleeding to death and helped to make amputation a viable surgical approach.
The introduction of the tourniquet, in 1674, further advanced surgical amputation. Essentially, a tourniquet is a circling device that is wrapped around the limb above the area to be amputated and then twisted to apply pressure to stop the flow of blood.
In 1867, Joseph Lister’s (1827–1912) introduction of antiseptic techniques to surgery further advanced amputation. Antiseptics, such as iodine and chloride, reduced the chances of infection by inhibiting the growth of infectious agents such as bacteria. Other advances at this time included the use of chloroform and ether as anesthetics to reduce pain and keep the patient unconscious during surgery.
Reasons for amputation
The reasons for surgical amputations can be classified under four major categories: trauma, disease, tumors, and congenital defects. Amputations resulting from trauma to the limb are usually the result of physical injury, for example, from an accident; thermal injury due to a limb being exposed to extreme hot or cold temperatures; or infections, such as gangrene. Certain diseases, such as diabetes mellitus and vascular disease, may also lead to complete or partial amputation of a limb. Vascular disease is a leading cause of amputation in people over 51 years of age. The development of either malignant or nonmalignant tumors may also lead to amputation. Finally, congenital deficiencies, such as absence of part of an arm or leg or some other deformity, may be severe enough to require amputation, particularly if the defect interferes with the individual’s ability to function.
Levels and goals of amputation
In determining how much of a limb to amputate, the surgeon must take several factors into consideration. When dealing with amputation due to disease, the surgeon’s first and most important goal is to remove enough of the appendage or limb to insure the elimination of the disease. For example, when amputating to stop the spread of a malignant tumor, the surgeon’s objective is to remove any portion of the limb or tissue that may be infected by the malignancy.
Other considerations in determining the level of amputation include leaving enough of a stump so that an artificial limb (prosthesis) may be attached in a functional manner. As a result, whenever possible, the surgeon will try to save functioning joints like knees and elbows.
Further goals of amputation surgery include leaving a scar that will heal well and is painless, retaining as much functioning muscle as possible, successfully managing nerve ends, achieving hemostasis (stopping the flow of blood) in veins and arteries through ligation, and proper management of remaining bone.
Prosthetics and limb reattachment
The use of artificial limbs or prosthetics most likely dates back to prehistoric human’s use of tree limbs and forked sticks for support or replacement of an appendage. In 1858, a copper and wood leg dating back to 300 BC was discovered in Italy. In the fifteenth century, a knight who had lost a hand in battle could acquire an iron replacement. Recent medical, surgical, and engineering advances have led to the development of state-of-the-art prosthetics, some of which can function nearly as well as the original limb. For example, some individuals who lose a leg may even be able to run again with the aid of a modern prosthetic device.
Recent advances have also led to more and more accidentally amputated limbs being successfully reattached. Depending on a number of factors, including the condition of the limb and how long it has been severed, full functional ability may be regained. In a notorious case that occurred in 1993, a man’s severed penis was reattached with full functional ability.
Recently, surgeons have developed techniques to reattach severed limbs that were once impossible to reattach. Some of these limbs include ears, fingers, hands, and toes. The surgery to reattach such limbs is called microsurgery due to the fact that the surgeon uses a microscope to attach tiny nerves, blood vessels, and tendons.
A baffling medical phenomenon associated with amputation is the amputee’s perception of a phantom limb. In these cases, which are quite common among amputees, the amputees will perceive their amputated limb as though it still exists as part of their body. This phantom limb may be so real to an amputee that he or she may actually try to stand on a phantom foot or perform some task such as lifting a cup with a phantom hand. Although amputees may feel a number of sensations in a phantom limb, including numbness, coldness, and heat, the most troubling sensation is pain. Approximately 70% of all amputees complain of feeling pain in their phantom limbs. Such pain ranges from mild and sporadic to severe and constant.
Although it probably is related to the central nervous system, the exact cause of the phantom limb phenomenon is unknown. Theories on the origin of the phantom limb phenomenon include impulses from
Congenital— A condition or disability present at birth.
Ligature— The use of thread or wire to tie off blood vessels.
Tourniquet— A device used to stop blood flow.
Trauma— A severe injury.
remaining nerve endings and spontaneous firing of spinal cord neurons (nerve cells). More recent studies indicate that the phenomenon may have its origin in the brain’s neuronal circuitry.
Treatments for phantom limb pain include excision (cutting out) of neuromas (nodules that form at the end of cut nerves), reamputation at a higher point on the limb, or operation on the spinal cord. Although success has been achieved with these approaches in some cases, the patient usually perceives pain in the phantom limb again after a certain interval of time.
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