出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/07/12 21:36:23」(JST)
The medical practice or technique of cauterization is the burning of part of a body to remove or close off a part of it in a process called cautery, which destroys some tissue, in an attempt to mitigate damage, remove an undesired growth, or minimize other potential medical harmful possibilities such as infections, when antibiotics are not available.[1] The practice was once widespread for treatment of wounds. Its utility before the advent of antibiotics was effective on several levels:
Cautery was historically believed to prevent infection, but current research shows that cautery actually increases the risk for infection by causing more tissue damage and providing a more hospitable environment for bacterial growth.[2]
Actual cautery is a term referring to the metal device, generally heated to a dull red glow, that is applied to produce blisters, to stop bleeding of a blood vessel, and other similar purposes.[3]
The main forms of cauterization used today in the first world are electrocautery and chemical cautery—where both are, for example, prevalent in the removal of unsightly warts. Cautery can also mean the branding of a human, either recreational or forced.
Cauterization was used to stop heavy bleeding, especially during amputations. This form of medical work was first discovered by Andreas Vesalius, Belgian Renaissance scientist. The procedure was simple: a piece of metal was heated over fire and applied to the wound. This would cause tissues and blood to heat rapidly to extreme temperatures in turn causing coagulation of the blood thus controlling the bleeding, at the cost of extensive tissue damage.
Cautery is described in the Hippocratic Corpus.[4] The cautery was employed for almost every possible purpose in ancient times: as a counter-irritant, as a haemostatic, as a bloodless knife, as a means of destroying tumours, etc.[5] Later, special medical instruments called cauters were used to cauterize arteries. The technique of ligature of the arteries as an alternative to cauterization was later improved and used more effectively by Ambroise Paré.
Electrocauterization is the process of destroying tissue using heat conduction from a metal probe heated by electric current. The procedure is used to stop bleeding from small vessels (larger vessels being ligated) or for cutting through soft tissue. High frequency alternating current is used in electrocautery in unipolar or bipolar fashion. It can be continuous waveform (cuts the tissue) or intermittent type (coagulates the tissue). In unipolar type, the tissue to be coagulated/cut is to be contacted with small electrode, while the exit point of the circuit is large in surface area, as at the buttocks, to prevent electrical burns. Heat generated depends on size of contact area, power setting or frequency of current, duration of application, waveform. Constant waveform generates more heat than intermittent one. Frequency used in cutting the tissue is set higher than in coagulation mode. Bipolar electrocautery establishes circuit between two tips of and is used like forceps. It has the advantage of not disturbing other electrical rhythms of body (as in heart) and also acts to coagulate tissue by pressure. Lateral thermal injury is greater in unipolar devices than bipolar ones.[6]
Electrocauterization is preferable to chemical cauterization because chemicals can leach into neighbouring tissue and cauterize outside of the intended boundaries.[7] Concerns have also been raised regarding the toxicity of surgical smoke produced by electrocautery. This has been shown to contain chemicals which may cause harm by inhalation by the patients, surgeon, or operating theatre staff.[8]
Ultrasonic coagulation and ablation systems are also available.
Many chemical reactions can destroy tissue and some are used routinely in medicine, most commonly for the removal of small skin lesions (i.e., warts or necrotized tissue) or hemostasis. The disadvantages are that chemicals can leach into areas where cauterization was not intended. For this reason, laser and electrical methods are preferable, where practical. Some cauterizing agents are:
If a person has been having frequent nose bleeds, it is most likely caused by an exposed blood vessel in their nose. Even if the nose is not bleeding at the time, it is cauterized to prevent future bleeding. The different methods of cauterization include burning the affected area with acid, hot metal, or lasers. Such a procedure is naturally quite painful. Sometimes liquid nitrogen is used as a less painful alternative, though it is less effective. In the few countries that permit the use of cocaine for medicinal purposes, it is occasionally used topically to make this procedure less uncomfortable; cocaine being the only local anesthetic which also produces vasoconstriction[citation needed], making it ideal for controlling nosebleeds. More modern treatment uses silver nitrate, a local anesthetic is applied and the procedure is generally painless. The nose may run for up to a week after the procedure.
In countries that practice hudud (or hudood) as the legal penal code, cauterization may be used to prevent death due to severe loss of blood.
Cauterization has been used for the circumcision of infants in the United States and Canada. The College of Physicians and Surgeons of Manitoba advises against its use in neonatal circumcision.[9] This method of circumcision resulted in several infants losing their penises, with at least seven male children being reassigned as female.[10][11][12][13][14][15]
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