In certain selected cases of fistulæ I am in the habit of endeavoring to effect a cure by stimulating the sinus and allowing free drainage of the secretions, so as to avoid the use of the knife. To accomplish satisfactory results with this mode of treatment, the following indications should be borne in mind: 1, that the external orifice be perfectly free; 2, that the sinus be kept clean, so as to prevent putrefactive changes; 3, that an effort be made to excite a healthy action in the fistulous channel; and 4, that the parts be kept as quiet as possible.
To meet the first indication, it is necessary to dilate the outer opening of the fistula with sponge or sea-tangle tents: but better still for this purpose are the Lee's Antiseptic Slippery-Elm Tents (Fig. 25).[[46]] These are made of selected slippery-elm bark, and compressed under high pressure. Owing to their non-irritant and demulcent properties, I find them superior to other tents.
Fig. 25—Slippery-Elm Tent (large size).
The second indication (that the sinus be kept clean, so as to prevent putrefactive changes) is best carried out by the use of peroxide of hydrogen. I have cured some cases of fistula in ano by means of injections into the sinus of peroxide of hydrogen alone, being careful to keep the external opening free, and treating the patient daily until healing occurred. I am in the habit of using Marchand's preparation, undiluted. It is injected into the sinus by means of a long, flexible silver canula (Fig. 26) attached to a hypodermatic syringe.
Fig. 26—Flexible Silver Canula.
Other antiseptics may be employed for the same purpose, such as bichloride of mercury (1 to 2000), or carbolic acid (1 to 80), but I much prefer the peroxide of hydrogen.
The third indication (to excite a healthy action in the sinus) can be met in one of a number of ways. In the first place, before applying such remedies it will be well to obtund the sensibility of the channel by an injection into the sinus of a four-per-cent. solution of cocaine. This may be accomplished by using the same syringe and canula that are used for cleansing the fistula.
If the wall of the sinus is somewhat indurated, it is better to insert a small, flexible curette (Fig. 27) and scrape the wall of the fistula along its entire length. The sinus is now prepared for some one of the various stimulating substances which have been recommended for this purpose. Among these may be mentioned peroxide of hydrogen; nitrate of silver, fused, or in solution (thirty to sixty grains to the ounce); sulphate of copper in solution (ten grains to the ounce); carbolic acid mixed with equal parts of glycerine and water.