The method of treating external rectal fistul must vary according to the direc tion and extent of the track. If the mucous membrane alone intervenes be tween the finger introduced into the bowel and a probe passed along the sinus, the channel should be transformed into a complete fistula by perforating the mu cous membrane with the probe, or with a director, at the uppermost limits of the fistulous channel. The regular operation for complete fistula is then to be per formed by dividing the intervening sep tum between the fistula and the bowel. In cases in which the sinus is directed away from the rectum, the proper course is not to divide the sphincters, but freely to enlarge the external orifice and to maintain free drainage.
The treatment of incomplete internal rectal fistuhe invariably demands opera tive interference at the earliest possible moment after a diagnosis is made, for if left alone its tendency is to burrow. The operation for this variety of fistula con sists in making it a complete fistula and in dividing the intervening structures between the bowel and the sinus. This is best performed by introducing a probe pointed director, bent at an acute angle, into the bowel, and passing the bent por tion through the internal opening. This done, the point of the probe can be felt subcutaneously and cut down upon and the remainder of the operation com pleted.
In dealing with complex fistuhgi the surgeon must be guided by the peculiari ties of each case. In operating upon a horseshoe fistula it is important to recog nize the true condition of affairs; for a careless or inexperienced observer might think that he had two separate fistulw to deal with and operate accordingly.
Immediate Suture. — In otherwise healthy subjects, a method of operating which has met with success, especially in this country, consists in the immediate suture of the wound after the fistula has been excised. The steps of the opera tion are as follow: the septum between the fistula and the bowel is divided; the entire fistulous channel and all lateral sinuses are excised; buried sutures of catgut, silk-worm gut, or of silk are then inserted beneath the wound and around its circumference at intervals of a quar ter of an inch and tied so as to bring the deep tissues together. The sutures are inserted very much in the same man ner as in the ordinary operation for ruptured perineum. The advantage of this plan is that primary union is secured and the patient recovers in a shorter time than would have been the case after one of the operations which aims to se cure union by granulations. The wound now and then becomes infected, however, probably from its proximity to the bowel and its consequent liability to infection from the entrance of fecal matter. At all events, this complication has occurred so often in my experience that I would advise extreme caution when this proced ure is employed, for if the presence of pus is not promptly recognized, the state of the patient is worse than prior to op eration.
Ligature.—There are two methods of using the ligature, which we may term the immediate and the mediate. The immediate operation has little to coin mend it. It consists in passing a silk thread through the fistula and drawing it backward and forward so as to cause it to cut its way through. The same ob
ject may be accomplished by the use of the galvanic ecraseur or of the wire ecraseur of Chassaignac. In mediate operation by the liagture either the silk ligature or an elastic one may be em ployed. If the silk be employed, it may be used in one of two ways: In both methods a short piece of silk is threaded to a silver probe bent to a curve, which is passed through the fistula and drawn out at the anus. The thread is passed through the track so that one end hangs out of the bowel and the other at the external orifice of the fistula. It is at this point that the methods diverge. One plan consists in knotting the ends loosely together and allowing the patient to go about. After a time, ranging from two to four weeks, the ligature comes away, having slowly cut through the included tissues. According to Harrison Cripps, the pathological process by which this is accomplished appears to be a gradual destruction or disintegration of the in eluded tissue, due to the ulcerative ac tion of the thread. The other plan is to tie the silk so tightly that it will com pletely cut its way through and strangu late all the tissue requiring division in an ordinary case of fistula. This method causes considerable suffering to the pa tient and has therefore been discarded in favor of the operation next to be de scribed.
Elastic Ligature. — The advocates of the elastic ligature maintain that it does not give rise to hemorrhage. This is a matter of considerable importance when the fistula penetrates deeply, and also in those rare eases of hemorrhagic di athesis, in which severe bleeding is apt to follow a trivial incision. The elastic ligature, for which we are chiefly in debted to Dittel, of Vienna, causes strangulation by the firm pressure it constantly exerts upon the included structures; it cuts its way out in a week's time or less. It is stated, by those who have had an extended experi ence with this plan of treatment, that, contrary to what might be expected, the pain attending the ulceration of the band through the tissues is slight, especially after the first twelve hours. Conse quently, this method would prove an ex cellent way of treating fistula if it were to be relied upon to effect a cure. Un fortunately, this is not the case, for it often happens that after the ligature has cut its way through, and the superficial parts have healed, the fistula remains un cured. The reason for this is to be found in the fact that the ligature has dealt with the main track only of a fistula in which exist one or more secondary chan nels or diverticula. It is, therefore, a measure to be resorted to only when there is an insuperable dread of any cut ting operation; when the fistula is un complicated with branch sinuses; in cases of deep fistula in which there is danger of wounding large vessels; in cases in which the patients are debili tated by some chronic disease; and, finally, in patients of known tmor rhagic tendency. It is a valuable adjunct to the use of the knife in dealing with cases in which a sinus runs for some dis tance along the bowel toward the supe rior pelvi-rectal space.