Changing Patterns in the Management of Small Bowel Fistulas Nicholas A. Halasz, MD, San Diego, California

In the past three decades the approach to the management of the patient with a small bowel fistula has undergone multiple major changes and even reversals [J--3]. Watchful waiting and pessimistic conservatism first were replaced by early, aggressive operative intervention. Then the developing expertise with skin care made immediate operation once again less critical, and when intravenous hyperalimentation became available, it permitted patients to be better prepared for operation while their skin was being protected. More recently, by further exploitation of these two modalities, spontaneous closure of fistulas has become increasingly frequent, aided and abetted by the availability of intravenous fat emulsions and elemental diets. In order to trace some of these changes and to evaluate the status quo, the following study was performed. Material and Methods A nine year period, from 1967 to 1976, was reviewed, and al\ patients treated at the University of California, San Diego Medical Center during this period with a diagnosis of small bowel fistula were evaluated. Forty-seven such patients were identified. Much of the analysis was carried out in terms of three-year periods: seventeen patients fell into the first three-year period; thirteen into the second; and seventeen into the third. Thirteen primary (spontaneous) fistulas were treated during the period of the study and thirty-four were secondary to abdominal surgical procedures. Of these thirty-four, fifteen occurred in our hospital and nineteen were referred from other institutions. The causes of the primary fistulas were radiation therapy (external, 8 patients; vaginal, 3), Crohn’s disease (3), tuberculosis (l), and trauma (1). The indications for the operative procedures which resulted in the secondary fistulas in the other From the Department of Surgery, University Hospital, Universityof California Medical Center, San Diego, San Diego, California. Reprint requests should be addressed to Nicholas A. Halasz. MD, Department of Surgery. University Hospital, University of California Medical Center. San Diego, 225 Dickinson Street, San Diego, California 92103. Presented at the Forty-Ninth Annual Meeting of the Pacific Coast Surgical Association, Newport Beach, California, February 19-22, 1976.

Volume 136, July 1978

thirty-four patients were inflammation (12), trauma (6), cancer (4), adhesive obstruction (4), and other indications (8). An attempt was made to reconstruct the course of events during the operation which led to the fistula. The results of this process outlined the putative reasons for the development of these fistulas, including anastomotic leak (ll), injury to bowel (8), abdominal closure (6), wire mesh (1)) foreign body (1)) and other or unclear causes (7). The treatment of the fistulas consisted of a mixture of medical and surgical measures and will be discussed further. In the first three-year period, 10 of 17 patients required or had operative closure(s) of their fistula. This number diminished to 5 of 13 in the second three-year period, and to 4 of 17 in the third period. This progressive diminution is statistically significant (p cO.05). Two fistulas recurred; one was closed surgically and the other, along with yet another, was left open. Both were present in heavily irradiated patients, and drained less than 100 ml per day. In the first three-year period, the mean length of hospitalization (from diagnosis of the fistula or admission with the fistula) was fifty-two days; in the last period. it was thirty-nine days. Four deaths occurred from intercurrent complications during the first two time periods. There were no deaths during the last three years of the study. Comments

Four of the primary fistulas in this series underwent spontaneous closure while being treated with decompression and hyperalimentation (intravenously, 3; orally with an elemental diet, 1). In general, it can be assumed that because of local conditions many primary fistulas will require operative intervention for closure, as they did in 9 of 13 cases in our series. It is the postoperative fistula which, theoretically at least, can be expected to close provided that one of the following features is not present: distal obstruction; local problems-cancer, granulomatous disease or infection, and mucosal eversion; or foreign body. Probably the most important cause of the perpetuation of fistulas is the eversion of the mucosa at the point of fistulization and the resultant partial or complete lining of the tract by mucosa.

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Halasz

The general approach to fistula management can be broken down into four major components: diagnostic study; skin management; gastrointestinal tract defunctionalization; and nutrition. Several points about diagnostic study deserve emphasis. The importance of obtaining records of prior treatment cannot be overemphasized, particularly in terms of reviewing operative notes and pathologic material. Radiologic evaluation should be approached in a systematic fashion. Usually it is best to initiate study with fistulography, using watersoluble contrast material so that if an abscess cavity exists or if peritoneal leakage occurs, barium does not get deposited. If a pocket or abscess is present between the bowel and the skin, suction must be applied to it and it may ultimately require surgical opening as well. If there is no abscess and no extravasation occurs from the tract into the peritoneum, a more satisfactory study can be performed using barium. With image amplification and cinematography, this contrast material is slowly instilled through the fistula, allowing evaluation of the mucosa in the area of the fistula and also localization of the level of its opening in the bowel. Once the contrast material used for the fistulogram has been eliminated, a regular gastrointestinal barium study should be performed to search for inflammatory or other conditions in the bowel and also to rule out the possible presence of obstruction. In long-standing fistulas, or when there is suspicion of some specific inflammatory, granulomatous, or neoplastic disease, biopsy of the bowel should be performed. This can be accomplished even when bowel mucosa is not exposed on the surface by the use of a cystoscope or flexible bronchoscope. Local management of the fistulous opening is aimed at the protection of the skin [4]. A secondary gain from good control is the ability to measure the output of the fistula accurately. Time is of the essence here: protection of the skin must be initiated when the remotest possibility of a fistula first arises. Silicone-based creams provide the simplest emergent protection if correctly applied; that is, worked into skin which has been carefully dried. Long-term skin protection is best achieved by the application of Stomahesive* accurately cut to fit the edges of the opening with attachment of a plastic bag to collect the effluent. In irregular defects, a paste made of karaya powder and glycerol should be used to fill in clefts and hollows to provide a flat base for the Stomahesive. In occasional, deeply seated fist&s it may be necessary to utilize a sump-suction device within the drainage bag. The key to local success is to remember that it is relatively easy to keep the skin from

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breaking down, but it may be extremely difficult to heal it. Defunctionalization of the gastrointestinal tract is an essential part of management. Initially this should consist of fasting combined with effective nasogastric suction. If the fistula output can be made to decrease to less than 500 ml per day, an attempt can be made to discontinue suction to see how much of an increment in drainage this produces. When these stressed fasting patients are not treated with nasogastric suction, they should be given antacids in tablet form every few hours to protect them from peptic ulceration. If drainage through the fistulous tract increases to more than 750 ml in a fasting patient off suction, it may become worthwhile to attempt reduction of secretions by the use of propantheline, being mindful of the risk of gastric and urinary retention. Diphenoxylate with atropine may also be utilized and is easier to titrate because of its availability in liquid form. The drug dosage should be gradually increased until cycloplegia is noted, then slightly reduced to just eliminate the blurring of vision. Parenteral methantheline or atropine can be used instead of these drugs in the patient who requires continued nasogastric suction. In patients with high output fistulas (usually originating in the proximal small bowel), another measure is often helpful. This consists of passing a 2 or 3 mm polyethylene catheter into the small bowel, past the opening of the fistula. This is usually accomplished without undue difficulty by tying a finger cot containing a few milliliters of mercury to the end of the small catheter and then passing it much as one would a Miller-Abbott or Cantor tube, by positioning the patient and occasionally by utilizing fluoroscopy. The small tube can be used for two purposes. Firstly, nasogastric aspirate can be collected under refrigeration and returned through the small catheter into distal intact gastrointestinal tract. Secondly, the tube can be used for feeding. If and when a patient with a small bowel fistula has been effectively weaned from nasogastric suction and has maintained a low fistula output, it becomes appropriate to consider feeding an elemental diet by mouth, and to depend on absorption taking place prior to its reaching the (usually low) fistula in these patients [5,6]. Initial attempts are best made by giving water by mouth in increasing volumes, keeping careful track of fistula output to see how much volume the patient can tolerate prior to an increase in drainage. If the patient tolerates 50 ml or more volume per hour without increasing his fistula output, gradual replacement of the water with an elemental diet is tried. In a number of patients in our series with

The American Journal of Surgery

Management

distal fistulas, it has been possible to administer 2 or 3 liters of such feedings per day, thereby allowing discontinuation of intravenous hyperalimentation. In patients with proximal fistulas in whom a slim tube has been inserted and passed into the bowel below the fistula, elemental diets can be administered through this catheter. Problems occur somewhat more often in this group, but it is still worth trying. In general, our experience has been that aroundthe-clock administration of elemental diets using a pump or drip regulator has led to a lower incidence of diarrhea than has bolus feeding [7]. Occasionally, patients will refuse to take elemental diets by mouth. In these instances, a # 8 or # 10 infant feeding tube, or catheter of similar size, can be passed into the stomach. This will usually be well tolerated and is less objectionable to some patients than the flavor of the elemental diet. The nutritional aspects of the management of the small bowel fistulas represent the single most important advance in the last one or two decades. However, because of many excellent up-to-date reviews of this subject, it will not be discussed here in detail. Suffice it to say that intravenous hyperalimentation has become an essential part of the management of small fistulas and has permitted the healing of the majority without operation [S]. ‘The availability of a fat emulsion for intravenous use (Intralipido) in the last two years has permitted high caloric intravenous feedings without the use of central lines [9]. Although this regimen is not adequate for patients who are septic and stressed (in whom central lines and concentrated carbohydrate solutions still have to be used), for the stable patient who is simply waiting for a fistula to close, it is safer not to have to use a central line, and therefore, this method is valuable. One additional aspect of the management of small bowel fistulas must be mentioned. The occurrence of a fistula, particularly postoperatively, tends to be considered a tragedy by the surgeon, and therefore its existence tends to be denied initially. This allows for breakdown of the skin, which is not protected by denial. When the diagnosis of a fistula is inescapable, often only ad hoc measures are taken, allowing the patient to become depleted and perhaps septic. The long view, emphasizing expeditious diagnosis and a global approach to management, is often sadly lacking for days and even weeks in the management of these patients. We must learn to accept the necessity for a clear-cut therapeutic plan: to establish goals in terms of time, regarding control of the output of the fistula, closure of the fistula, and the beginning of an adequate oral intake; to establish nutritional

Volume 136, July 1978

of Small Bowel Fistulas

goals in terms of caloric intake and maintenance or gain of weight; and equally important, to establish goals rega:rding the skin around the fistula, namely to heal it and to keep it healed. It is only with such a plan that safe and expeditious resolution of this difficult problem can be accomplished. Operation for repair of the fistula is undertaken when patients do not meet these established goals because of mechanical problems, or when closure has not taken place by a reasonable time in the presence of adequate decompression and nutrition. Summary

Forty-seven patients were treated for infraduodenal small bowel fistulas over the past nine years. Thirty-four of these fistulas occurred postoperatively; the others followed trauma or radiation or were secondary to inflammatory bowel disease. A progressive diminution of operative rates (to close fistulas) was evident in each of three three-year groups, from 59 to 38 to 24 per cent (p

Changing patterns in the management of small bowel fistulas.

Changing Patterns in the Management of Small Bowel Fistulas Nicholas A. Halasz, MD, San Diego, California In the past three decades the approach to t...
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