Diseases of the COLON ¢Y RECTUM VOL. 11 july-August, 1968 No. 4 Anorectal Fistulas: Current Concepts * .RAYMOND J. JACKMAN, N[.D.'~ Rochester, Minnesota ~)IA(;NOSIS and treatment of anorectal and secondary opening, since the principles fistulas at times presents the simplest and of dealing with such a lesion have been at other times the most challenging prob- well established. lems encountered in surgery, is this sinus actually an anorectal fistula? Or does it Etiology originate elsewhere, such as in a region of Anorectal fistulas comprise 85 per cent sigmoidal diverticulitis or ileocolitis? Or of sinuses opening onto the perineum. The does it connect with an infected precoccyg- other 15 per cent result from hidradenitis eal cyst? What keeps the sinus or fistula suppurativa, pilonidal disease, and other active when the primary source has healed less common causes. There are many types over spontaneously or has been erased by of anorectal fstulas, but the one feature a previous operation? In what situations that they have in common is that they might the surgeon anticipate fecal inconti- originated inside the anus or rectum. (I nence after fistulectomy, and what can be use the past tense because the anorectal done about it? site of origin, the primary lesion, may have The purpose of this presentation is to healed over, but at one time it was present.) attempt to answer these and similar ques- All anorectal fistulas and most perianal tions that, in my opinion, have been inade- sinuses originate as abscesses. Frequently, quately answered in medical literature. I but not always, the abscess starts as infec- shall not dwell on the simple uncompli- tion in a crypt at the mucocutaneous junc- cated fistula with a definite primary source doz~. Fistu!as also may originate in a break in the continuity of the anal skin, such as =~ Presidential Address at the meeting of the Amer- ican Proctologic Society, Denver, Colorado, June 10 a fissure, or in a break in the intestinal to 13, 1968. mucosa, such as an ulcer occurring in ile- j-Mayo Clinic and Mayo Foundation: Section of Proctology. itis, ileocolitis, or ulcerative colitis. 247 248 JACKMAN Differential Diagnosis on unusual or less common causes of peri- Sometimes determination of the exact anal sinuses, but the point I wish to make nature and course of the fistulous tract has here is that a perianal sinus, ostensibly an anal fistula, for which the patient previ- to be made when the patient is under anes- ously has been operated on, should alert thesia. The exploring finger is probably of more value than any other device in one immediately to some unusual source- determining the source and course of the sometimes an infected precoccygeal cyst fistula. Frequently, the primary source can and, more frequently, regional ileitis o1 be palpated with the tip of the index finger sigmoidal diverticulitis. as a depression or an area of induration. Association of Perianal Abscesses and Bidigital examination, not uncommonly, Fistulas with Other Diseaes: The tendency will reveal a cord-like channel of indura- toward fistulization, not only anorectal but tion leading to the secondary opening. enteroenteric and so on, in ileocolitis has Anoscopic examination may reveal a drop been noted by many authors. Rawls and of pus exuding from the primary source or co-workers,5 in a study of 1,000 patients a tuft of granulation tissue. The use of with anorectal fistulas, found that 17 per the probe, until the time of operation, is cent of them had an underlying or asso- probably the least effective means of deter- ciated systemic disease. The three disorders mining the nature of the fistula and should occurring most frequently were chronic not be resorted to if it causes the patient ulcerative colitis, diabetes mellitus, and discomfort. The differential diagnosis of regional ileitis, in a study of 114 patients draining sinuses in the nether parts has with regional enteritis, Smith and 1 s have been the subject of a previous presentation 2 found that 1 per cent either had anal ab- • ~AYO CLINIC .. Fro. 1. a and b, Conversion of fistulous channel or tunnel into open ditch. ANORECTAL FISTULAS 249 scess or fistula at the time of examination or gave a history of having had such a S e lesion in the preceding three years. Seven oF 8 _ _. per cent of the patients in this group had a presenting complaint of anal fistula or abscess. The abdominal or gastrointestinal symptoms were so mild that the patients ignored them. Any young adult whose pre- senting complaint is o[ anal abscess or ano- rectal fistula should be investigated [or an underlying systemic disease, particularly [or U enteritis, enterocolitis (Crohn's disease) or ulcerative colitis. • Dd_:rn__]ing__lo .... Association of Anal Fistula with Tuber- culosis: Not too many years ago, the stu- Fro. 2. Traction applied to site of secondary dent was taught that if a patient was found opening and consequent retraction at primary to have an anorectal fistula, one should source. This procedure usually gives a clue to the location of the primary lesion. look for a focus of tuberculosis elsewhere in the body, either pulmonary or gastro- intestinal. This teaching no longer holds true. In fact,, many patients previously Association of Anal Fistula with Cancer: considered ito have intestinal tuberculosis Cancer developing in or near chronic drain- probably had gramdomatous ileocolitis. ing sinuses, although uncommon, has been Since the advent of chemotherapeutic drugs reported many times. In such instances the and antibiotics--para-aminosalicylic acid, fistulas usually will have been present for isonicotinic acid, streptomycin, and so on- many years, it is generally contended that the incidence of tuberculosis, while still a irritation plays an important part in the public health problem, has declined mark- development of certain cancers. Perhaps edly. This is particularly true of anorectal the carcinogenic mechanism in the case of tuberculosis and tuberculous fistula. In an anal fistula is the long-continued drainage. article published in 1939, Buie, Smith, and Kline and co-workers4 reported five cases Ia reported the results of an intensive study of long-term anal fistula in which a carci- of 600 patients with anal fistula. O[ these noma developed later. They collected 20 patients, 11.5 per cent were found to have other similar cases from medical literature, tuberculosis some place in the body. Using and concluded that the difficuhy in diag- guinea pig inoculation and histologic study nosis of this complication of anal fistula of the excised fistulous tracts, we deter- resuhed mainly from the insidious nature mined that about 8 per cent o£ anal fistulas of the tumor and the masking effect of the were tuberculous, and that in most of these symptoms of the fistula on the early symp- cases there was an active or healed pulmo- toms of cancer. Or the 25 tumors, 44 per nary focus. I am certain that the per- cent were mucus-producing adenocarci- centage of tuberculous fistulas would be nomas of low-grade malignancy. In one of much iess ~oday. During the past two their five cases from this ciinic, the paden~ years ] have diagnosed definitely only one had had a fistula-in-ano for 47 years before case of tuberculous fistula. "The diagnosis an adenocarcinoma was detected. A radical was confirmed by guinea pig inoculation surgical operation is indicated for carci- and histopathologic study. noma superimposed on a fistula. 250 JACKMAN io/~ ir~to incLl ".. , :/ ., " .'.';i' ,,i:: . ,z:. ,: /'v " .r' \,7'?'¢< ~ " .'<" " "", ~ ' ~" ?.5", '~ aC,_ _- lhc. 3. Operation for rectovaginal listula. Undercutting rectovaginaI scptum mobilizes it sufficiently so that it can bc pulled down and sutured to the inner border of the external sphincter after d~min has been placed beneath the septum ani.l out through the fistulous tract. (Fr(;m Jackman, R. J.: Rectovaginal and anovaginal [istulas: A surgical pl'oceduxe for treatment of certain types. J. Iowa Med. Soc. 42:435-4-10 [Sept.] 1952. With permission of the Iowa Medical Society.) General Aspects of Treatment mary out through the secondary opening; The use of antibiotics in the treatment the overlying tissue is incised, converting of anorectal ab:~cesses and fistulas is not the fistulous channel or tunnel into an open advisable because usually incision and ditch; and debridement o1! the wound mar- gins is accomplished (Fig. 1). drainage has to be carried out anyway. Ahhough Escherichia coli, the usual offend- Obviously there are many deviations ing organism, is vulnerable to tetracycline, trom the "straightforward" fistula, and com- administration of this antibiotic will not binations of two or more fistulas may resolve the problem and operation will be occnr, but the basic aim of surgical treat- necessary regardless. If the abscess is the ment in all cases is to establish adequate initial sign of a true fistula, which it usu- drainage. I)uring the operative procedure, ally is, a primary source inside the anus or the surgeon must ask himself, "vVill the rectum continues to exist and is not affected drainage be satisfactory when the tone of by any antibiotic. the muscle returns or will there be over- The basic principle involved in all oper- hanging ledges or pockets that will inter- ations for anorectal ab~cess or fistula is that fere with drainage? if the latter appears satisfactory drainage must be established. more likely, steps must be taken to correct On the [ace of it this sounds simple, but this by debriding the margins more exten- the operations for fistula may be extremely sively or by incising muscle. d~bficult and the convalescence prolonged. Finding the Primary Source of the ~.~s- On the other hand, such operations may tula: Sometimes this may be difficult.