Cauterization (or cauterisation, or cautery) is a medical practice or technique of burning a part of a body to remove or close off a part of it. It destroys some tissue in an attempt to mitigate bleeding and damage, remove an undesired growth, or minimize other potential medical harm, such as infections when antibiotics are unavailable.
The practice was once widespread for treatment of wounds. Its utility before the advent of antibiotics was said to be effective at more than one level:
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.
The main forms of cauterization used today in the first world are electrocautery and chemical cautery—both are, for example, prevalent in the removal of unsightly warts. Cautery can also mean the branding of a human, either recreational or forced.
c. 1400, from Old French cauteriser, from Late Latin cauterizare "to burn or brand with a hot iron", from Greek καυτηριάζειν > kauteriazein, from καυτήρ, kauter, "burning or branding iron", and καίω, "I burn" (cf caustic).
Cauterization was used to stop heavy bleeding, especially during amputation. The procedure was simple: a piece of metal was heated over fire and applied to the wound. This caused tissues and blood to heat rapidly to extreme temperatures, causing coagulation of the blood and thus controlling the bleeding, at the cost of extensive tissue damage.
Cautery is described in the Hippocratic Corpus. Abu Al-Qasim Al-Zahrawi developed techniques and instruments for cauterization and described them in his book Al-Tasrif and these continued to influence medical world for five centuries. 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. 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 (or cutting through soft tissue) using heat conduction from a metal probe heated by electric current. The procedure stops bleeding from small vessels (larger vessels being ligated). Electrocautery applies high frequency alternating current by a unipolar or bipolar method. It can be a continuous waveform to cut tissue, or intermittent to coagulate tissue.
In unipolar cauterization, the physician contacts the tissue with a single small electrode. The circuit's exit point is a large surface area, such as the buttocks, to prevent electrical burns. The amount of heat generated depends on size of contact area, power setting or frequency of current, duration of application, and waveform. Constant waveform generates more heat than intermittent. Frequency used in cutting the tissue is higher than in coagulation mode.
Bipolar electrocautery passes the current between two tips of a forceps-like tool. It has the advantage of not disturbing other electrical body rhythms (such as the heart) and also coagulates tissue by pressure. Lateral thermal injury is greater in unipolar than bipolar devices.
Electrocauterization is preferable to chemical cauterization, because chemicals can leach into neighbouring tissue and cauterize outside of intended boundaries. Concern has also been raised regarding toxicity of the surgical smoke electrocautery produces. This contains chemicals that, through inhalation, may harm patients or medical staff.
Ultrasonic coagulation and ablation systems are also available.
Many chemical reactions can destroy tissue, and some are used routinely in medicine, most commonly to remove small skin lesions such as warts or necrotized tissue, or for hemostasis. Because chemicals can leach into areas not intended for cauterization, laser and electrical methods are preferable where practical. Some cauterizing agents are:
Even if the nose is not bleeding at the time, a physician may cauterize it to prevent future bleeding. Cauterization methods include burning the affected area with acid, hot metal, or lasers. Such a procedure is naturally quite painful. Sometimes, a physician uses liquid nitrogen as a less painful alternative, though it is less effective. A physician may apply cocaine in the few countries that allow it for medical use. Cocaine is the only local anesthetic that also produces vasoconstriction, making it ideal for controlling nosebleeds.
More modern treatment applies silver nitrate after a local anesthetic. The procedure is generally painless, but after the anesthetic wears off, there may be pain for several days, and the nose may run for up to a week after this treatment.
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. This method of circumcision resulted in several infants having their penises missed, with at least seven male children being reassigned as female.