It is necessary to treat all excoriations or ulcerations, to cure the cystitis, and to relieve the tension of all bands of scar-tissue in the vagina that may prevent proper approximation of the edges of the opening. The phosphatic deposit should be carefully removed from the vaginal walls and the interior of the bladder with a soft sponge or cotton, and a weak solution of nitrate of silver (gr. v to ℥j) should be applied to the raw surfaces. Frequent warm sitz-baths should be administered daily. The vagina should be washed out several times a day with large quantities of sterile hot water or with a solution of boracic acid (ʒj to the pint). The urine, which is generally alkaline, should be rendered acid by the use of benzoic or boracic acid. Emmet advises the following prescription: “2 drams of benzoic acid and 3 drams of borax to 12 ounces of water, of which a tablespoonful, further diluted, should be given three or four times a day.” After the urine has become acid the dose may be reduced. Every fifth day the solution of nitrate of silver should be applied to the unhealed, excoriated surfaces. It may be necessary to pursue this treatment several weeks before the parts are brought to a healthy condition. Improvement is perceived not only in the condition of the vaginal walls and the bladder, but in the edges of the fistula, which, in place of being hypertrophied and indurated, assume a natural color and density. In case the vaginal fistula be small, the accompanying cystitis may be difficult to cure, because there is always some residual urine in the bladder. It may then be advisable, as a preparatory step, to enlarge the fistulous opening by a clean incision in the median line, in order to secure more perfect drainage. The cystitis may be kept up by the presence of a phosphatic concretion in the bladder, which may be removed in this way. It is useless to close the fistula until the cystitis is cured. In every case of vesico-vaginal fistula it is advisable to examine for vesical calculus, that the bladder may not be closed with a calculus in it. The calculus occasionally exists before the formation of the fistula, and perhaps assists in its production, the vesico-vaginal septum being squeezed between the child’s head and the calculus. Usually, however, the calculus forms as a result of the fistula. When the parts have been brought to a healthy condition the fistula should be examined with a view to the method of closure. The opening should be exposed with the Sims speculum, and the edges at opposite points should be seized with tenacula or forceps and approximated. In this way the surgeon may determine the direction in which the fistula may be closed with the least traction on the sutures. When possible, it is advisable, in order to prevent shortening of the vagina, to close the fistula in the direction of the long axis of the vagina. [Illustration: FIG. 181.--Sims’ vaginal dilator.]