The cautery apparatuses are represented by the hot iron and the galvano-cautery. The cautery irons are of various shapes, the extremity being pointed, flat, or olivary. The size varies according to the locality where it is to be used, very large irons being requisite for large surfaces to avoid rapid cooling.
These irons are heated over a lamp, gas, or a Bunsen burner. Fiirst's apparatus is a good one for heating small irons. Latterly Paquelm's thermo-ccutery has displaced other forms. Its shape is convenient and the requisite degree of heat may be secured and maintained as long as is desired.
The objection to these apparatuses is that they must be applied in the heated state to the desired site, and the cautery irons rapidly lose their heat and must be frequently renewed. In consequence it is only excep tionally that the cervical canal is patent enough to permit of the use of the cautery in the uterine cavity, and on account of the' dvantages of the galvano-cautery it is to-day used in preference wherever possible. First recommended by Hiiter, in 1845, the galvano-cautery was used success ively by Crussell, John Marshall, IIarding, Waite, Hilton, Nelaton, Leroy d'Etiolles, Amussat, Ellis, and Middeldorpff still further popularized its use, and his instrument, with slight modifications, has re mained the most efficient. Middeldorpff used the Bunsen elements (zinc and carbon). Bruns preferred the zinc-iron combination; the most compact instrument is the Dawson battery, which consists of zinc and platinum, and which has the advantage of not becoming polarized. We have reason to expect that in the near future the manufacture of convenient accumulators will do away with all the disadvantages resulting from the use of the batteries at present in vogue.
Instead of the cautery irons, round or sharp applicators of porcelain are used, or else the knife-shaped or pointed galvano-cautery instru ments. The disadvantages frbm the use of the galvano-cautery in com parison with the cautery iron are the cost of the apparatus, the frequently required cleansing and filling of the cells, the fact that the current is liable to sudden interruption, or at least to alteration in intensity, and further in that its action is circumscribed. The majority of these objec tions do not hold when the instrument is of correct construction, although it is still true that it is difficult to maintain an even degree of heat, and to prevent changes during the operation. On the other hand, the advan tages of the galvano-cautery, such as the obtaining of the highest possible I It.gt.tio of heat, the ability to exactly limit the action, the fact that the uppliontor may be placed cold at the desired site and gradually heated, t host+ nro so manifest that the apparatus deserves a place in the armamen tariiiin of every gynecologist.
The e utery should only be used after careful exposure and isolation of the part to be acted upon. For this purpose the tubular specula are the best, either those constructed of horn, ivory, wood, hard rubber; the double specula which are kept cool by a current of water, interfere with the field of vision. In case duck-bill or valvular specula are used, then the projecting portion of the mucous membrane must be protected by depressors, or by cotton, etc., packed against it. An irrigator filled with cold water should be always ready, in order that an injection may at once be administered if the patient complain of burning. For the pro tection of adjacent organs, when, for instance, the pedicle of an ovarian cyst is burnt through, flat, broad, clamps or fo.ceps (Baker Brown) have been devised. An exposed surface may be surrounded by a wall of wet cotton, or else by a wet sponge.
After thorough cleansing of the surface to be cauterized, the heated iron is applied to it for a few seconds, or it is carried directly into the cavity which is to be cauterized. The superficial layer of epithelium is at once destroyed, and by longer action an adherent, brown slough, a few lines thick, surrounded by a red, slender zone, is formed. In case we desire to penetrate more deeply, a number of irons must be used in suc cession, or else the thermo- or the galvano-cantery must act for some time, in order to burn through the slough, which limits the extension of the heat. In case during the application hemorrhage occurs, then before the use of a second iron the blood must be carefully wiped away. At the end of the procedure, or when it is of long duration, while it is in force, cold water should be injected until the burning sensation has disappeared.
Slight losses of substance heal under the scab, but generally this is shed with suppuration and the passage of broken-down parti3les within six to fourteen days, and a granulating wound is left which frequently only cicatrizes at the end of a number of weeks.
Cauterization of small ulcers and growths on the cervix may be per formed on outpatients; but in case of deeper cauterization of larger growths the patient should stay in bed for two to three days, and the local reaction more quickly passes away. This precaution is all the more necessary when the interior of the uterus has been cauterized, or when with the separation of the slough hemorrhage is to be anticipated.