When lateral sinuses are discovered in this variety of phis-tulae, the lateral branches should be divided up to the main channel and a single cut made through the sphincter muscle. When the fistulous tract, or the remains of the abscess cavity, appears to extend higher than the external sphincter muscle, Goodall and Miles recommend that this portion of the tract be left uncut, the lower section made wide enough for free drainage and the portion behind the internal sphincter forced to granulate by the use of a fifty per cent. solution of nitrate of silver introduced on a cotton stick. In other cases where the lateral tracts are tortuous, and long, it is necessary sometimes to divide a portion of the sinus by inserting the director or probe as far as possible and cutting the overlying tissue, then reintroduce the director until the entire tract is divided. There are many specially constructed directors and scissors made for this purpose, but the success of the operation is dependent upon the ability of determining the true course of the fistulous tract.

Excision or division with the immediate suture of a complete fistula is well worth the attempt and if the entire tract, on account of the lateral burrowing, seems unfavorable for immediate suture, sometimes the lateral tracts may be sutured at once, and the main sinus left open for granulation In this way, much time can be saved in the subsequent healing which can do no harm in the attempt, because, if the wound is watched and infection is evident, one can immediately cut out the sutures and allow granulation in the ordinary way.

Complete External Fistula usually require very simple treatment. In some instances the introduction of the director through the sinus, and incision over its course, is sufficient to institute permanent healing.

Complete Interns! Fistula are much more difficult to operate upon because the fistulous tract is very often tortuous and may have more than one lateral branch, as well illustrated in the Y-shaped sub mucous blind internal fistula. This class of cases should be treated on the same plan as the blind external, as free drainage and a provision for subsequent treatment is secured by converting them into the complete type. A light packing of gauze should be inserted into the wound to prevent the tissue healing over and to arrest hemorrhage.

The Incomplete Internal Fistula The incomplete internal fistula is sometimes very hard to find, but fortunately they are mostly of the sub mucous type. A speculum is as a rule necessary for those high up in the rectum. They should be converted into the complete type and incised through the entire tract. If possible, avoid cutting the internal sphincter muscle.

Incomplete External Fistula The blind external fistula is best operated upon by inserting the director into the fistulous tract as far as possible and then forcing it through the rectum. This procedure makes it a complete fistula in order to ensure free drainage and to facilitate after-treatment.

General After-treatment should begin two days subsequent to the operation. An attempt to keep the wound as clean as possible should be made by the use of an abundance of mild antiseptic solutions or hot water. Tincture of iodine should be introduced on a cotton stick or toothpick and the wound swabbed with it every second day. It is an antiseptic and mild, effective stimulant. The finger should be introdiced into these wounds as far as possible for the purpose of breaking up all adhesion which are not strong enough to withstand the pressure. This will prevent the formation of a new fistulous tract by the bridging over of the tissue.

Horseshoe Fistula are probably the most difficult of the Common fistula to treat success fully, and owing to the irregularities of the sites and openings of the tracts, the technique will vary with the individual case. A general principle for operation should be to cut all the communicating sinus up to the main tract, then pass the director into the rectum and make one division of the sphincter muscle at that point.

Complicated Fistula When there are a number of openings, both in the rectum and externally, it is sometimes necessary to cut the sphincter in more than one place. Incontinence is very likely to follow this operation, but there are exceptions to this rule. In those cases which do not suffer from incontinence as the result of loss of sphincter control, there seems to be a disturbance of the nerve supply which is nearly as bad.

Fig. 46. Horseshoe fistula, diagrammatic.

Recto-vaginal Fistula are claimed by the gynecologist as part of his field of operation and from their anatomical relations might justly be so, but many of these cases are most successfully treated when a knowledge of the rectal origin form a part of the plan of treatment. This type of fistula most commonly originates from an abscess of the anterior rectal wall, the result of an ulceration due to the presence of either a proctorial, malignant, or non-malignant growth, or from pressure during a tedious labor. They may be the result of a burrowing from a pelvic abscess.

The diagnosis of either of these conditions will greatly modify the treatment. The fistulous tract may be short, straight or of some length and tortuous when due to the burrowing of an abscess. When a fistula is caused by pressure during the second stage of labor there is a loss of tissue in the recto-vaginal septum and as a result the vaginal opening will be found within three inches of the couchette

Treatment. The treatment of this type of fistula is dependent upon the cause, position and size of the openings. Should the opening be short, direct, and not too large, the result of a ruptured perineum, the application of the solid stick of nitrate of silver to the entire tract will usually prove successful. The rectum and vagina should be kept well cleaned during the treatments. If due to an ulceration, the result of a stricture, the gradual dilatation of the stricture and permitting free exit of the flatus through the rectal tube,will suffice in many instances for a cure without further treatment.