25: Management of Malignant Esophageal Fistula

Malignant esophageal fistula occurs infrequently, yet remains one of the most challenging complications encountered in thoracic oncology. It may occur in the setting of complicated esophageal cancer, presenting at an advanced stage of disease, or as a complication of treatment. The fundamental tenets of successful management of any fistula, such as relief of distal obstruction, treatment of infection, nutrition, and treatment of underlying malignancy, should be kept in mind but unfortunately are inherent to the disease process and usually overwhelming for patient and clinician. Improvements in completely covered self-expanding metallic stents (SEMSs) and associated delivery systems have dramatically changed the approach to managing esophageal fistulae, particularly involving the tracheobronchial tree. Palliation and not cure is the objective in the majority of patients afflicted with this uniformly fatal complication, which most often occurs in the setting of advanced stage disease. A multidisciplinary approach to accurate and precise diagnosis and treatment is essential.

Malignant esophageal fistula usually presents with clinical symptoms of recurrent aspiration or less commonly hemoptysis or hematemesis. An esophageal fistula may also be suspected on the basis of transmission of oral flora through the fistula tract and the development of associated infection of the body cavity or organ in communication with the esophagus, such as recurrent pneumonia, empyema, and abscess. The majority of patients will present with known locally advanced or metastatic tumor and will frequently already be undergoing treatment with chemotherapy and radiation. The diagnosis is confirmed with fluoroscopy during administration of dilute barium oral contrast followed by thin-cut computed tomography (CT), which will usually define the precise location and extent of the fistula. A small fistula may be missed on radiographic evaluation and aspiration of swallowed barium can be confused with a fistula to the respiratory tract, particularly with proximal third esophageal lesions. Flexible esophagoscopy and bronchoscopy often are required for confirmation and anatomic assessment of the suspected fistula and provide additional information needed for treatment planning in addition to the therapeutic benefit of clearing the contaminated airway.

A tracheobronchial–esophageal fistula is often visualized more easily with bronchoscopy rather than esophagoscopy, as the esophageal mucosal folds and tumor sometimes obscure the origin of the fistula. It is also important to visualize any luminal compromise of the airway from tumor compression, as this may be exacerbated with esophageal stenting.

Once the diagnosis is established, broad-spectrum antibiotics should be instituted to include coverage for gram-positive bacteria, anaerobes, and yeast. Oral intake should be withheld and alternative forms of nutrition established. The ensuing treatment plan should then be directed toward:

1. Limiting or eliminating ongoing contamination of the respiratory tract or other body cavities.

2. Draining contained foci of infection such as the pleural, peritoneal, and pericardial spaces.

3. Maintaining adequate nutrition for healing.

4. Minimizing distal obstruction.

5. Treating the cancer if feasible.

Traditionally, contamination was controlled by surgical exclusion or diversion with a cervical esophagostomy and possible placement of a gastrostomy to limit reflux contamination, along with a jejunal feeding tube. Any contaminated fluid collections identified in the mediastinum, pleural space, peritoneal cavity, or pericardium should be adequately drained percutaneously or surgically.

Partially or fully covered SEMSs are now the primary treatment option for most fistulae, and offer an attractive alternative to some of the described surgical options. It is important to remember that contaminated fluid collections still require drainage. Primary thoracoscopic debridement and decortication may prevent the need for thoracotomy. Advantages of SEMSs in the management of esophageal fistulae related to esophageal cancer include ease and expediency of deployment with essentially immediate control of ongoing contamination from both antegrade and retrograde secretions. Tumor or treatment-related stricture and associated obstruction distal to the fistula are effectively managed simultaneously with stent placement across the fistula and through the stricture or obstructed lumen of the esophagus. Oral enteral nutrition can be resumed promptly without the need for a surgically placed feeding tube. The most common clinically significant complication of SEMSs is stent migration, which is more common in the absence of stricture or partial obstruction by tumor. It is important, particularly in the absence of stricture, to maximize the diameter and length of the stent both to increase the purchase of the stent and decrease migration. As well, it is important to ensure that the length of the covered portion of the stent extends 2 to 4 cm proximal and distal to the fistula. The stent should be long enough to include any stricture, both to facilitate oral intake and minimize stent migration. More than one stent occasionally may be required. SEMSs successfully control the fistula in essentially all patients with a very low complication rate.¹

Once the diagnosis is confirmed, it is important to determine the location (proximal, middle, or distal third of the esophagus) of the fistula, its size, communication with other organs or body cavities, presence or absence of abscess cavities or effusions, and whether it is wholly contained within the mediastinum. Broad-spectrum antimicrobial coverage already should have been instituted, often even before the diagnosis is established, and the patient should be resuscitated, stabilized, and the airway secured with endotracheal intubation if necessary. Each of these components are integral to making an adequate assessment of the fistula, along with CT and endoscopy as described above, and are essential to formulating a treatment plan.

Once clinically stabilized, patients then are selected for conservative nonoperative management or surgical intervention, based on the size and location of the fistula and other associated pathology. A combined approach that is commonly employed in the operating room with anesthesia may include endoscopy with SEMS placement under fluoroscopic guidance, a surgical drainage procedure and decortication, and placement of a gastrostomy or jejunostomy tube for drainage or enteral access.

Perforations or fistulae involving the proximal third of the esophagus may be contained within the mediastinum or communicate with the airway via the membranous trachea. Fistulae that are contained within the mediastinum, depending on size, can be managed nonoperatively or by placing a closed drain in the mediastinum via a left neck incision. Caution should be exercised in placing SEMSs in the esophagus that extend proximally toward the hypopharynx as proximal migration can occur resulting in airway compromise and even asphyxiation. Proximal lesions involving the airway are better managed with a tracheal stent and a cervical drain.

Esophageal fistulae of the middle or distal third of the esophagus may involve the airway, one or both pleural spaces, the pericardium, the peritoneum, or the aorta (Fig. 25-1). These are best managed in the operating room with anesthesia and with supplies and equipment available, including flexible esophagogastroscope, flexible bronchoscope, thoracoscope, fluoroscopy, and a variety of sizes of completely covered SEMSs for the esophagus and airway. The presence of an esophageal– aortic fistula is usually a premorbid event; however, endoluminal aortic stenting may be considered to salvage these patients. In patients awaiting planned surgical resection following neoadjuvant chemoradiation, occasionally a heroic attempt at resection may allow urgent palliation if combined with an endograft or open aortic replacement. This should only be contemplated if the patient is in excellent condition; in the era of endografting, this would be the preferred primary approach.

SEMSs are available in the United States from several different manufacturers and may be uncovered, partially covered, or fully covered. Fully covered stents are most appropriate in the management of malignant esophageal fistulae as they more effectively prevent ongoing leak from the esophagus and disrupt communication through the fistula tract. Fully covered SEMSs, as opposed to partially covered stents, are less prone to tissue ingrowth and thereby more easily removed or repositioned, but consequently also more prone to migration. Flexible esophagoscopy (Fig. 25-2A,B) should be performed in the operating room with fluoroscopy and a variety of lengths of large diameter SEMSs available. The fistula is visualized endoscopically and the proximal and distal extent marked with internal or external surface radiopaque marker under fluoroscopic guidance. The stent should be at least 4 cm longer than the desired area to be covered, which should include the entire length of the fistula and any tumor or stricture associated with, or distal to, the fistula (Fig. 25-3). If an obstructing tumor or stricture is present, it must be dilated to an internal diameter of 6 to 10 mm to permit passage of the predeployed stent delivery system. It is important to avoid overdilating the stricture as this may exacerbate the fistula as well as facilitate stent migration. It is important to attempt to limit the extent of the stent distally that resides across the lower esophageal sphincter and in the stomach, as this can promote reflux and aspiration and potentially lead to obstruction or ulceration through contact with the opposing gastric wall. If the CT scan suggests the presence of bulky tumor adjacent to the trachea posing a potential risk for external tracheal compression, then consideration should be given to placing a tracheal stent before placing an esophageal stent.

Decortication of the contaminated pleural space, including unroofing of any mediastinal abscess protruding into the pleural space (but contained by mediastinal pleura) and drainage of contaminated pleural or pericardial effusions, can usually be accomplished with video-assisted thoracoscopy. Routine drains should be placed as with any infected closed space. Rarely, consideration for an end esophagostomy should be entertained if the patient is becoming septic, although the long-term outcome from these situations is dismal.

If prolonged delay in resuming oral nutrition is anticipated because of complicating factors, such as pneumonia or respiratory compromise requiring mechanical ventilation, then a surgically placed feeding tube should be considered before leaving the operating room.

Not less than 24 hours following placement of the stent or as soon as the patient is capable of swallowing oral contrast, an esophagram is obtained to confirm proper seating of the stent and seal of the fistula as evidenced by absence of contrast leak. If no contrast leak is detected, oral liquids are resumed and the patient is advanced to a mechanical soft diet. Leaks due to migration or improper seating of the stent due to enfolding of the proximal stent may be corrected by endoscopic repositioning or occasionally require removal and replacement of the stent. Potential stent migration can be easily monitored with routine chest radiographs. After sufficient time for healing has passed, usually 4 to 6 weeks, the stent is removed in the operating room under general anesthesia and healing confirmed by endoscopy. If incomplete healing is suspected, the stent is replaced and managed accordingly. If the fistula is closed, then a confirmatory contrast esophagram is obtained within 48 hours and if negative for leak the patient is discharged home on a mechanical soft diet.²

Experience and expected outcomes in the management of malignant esophageal fistulae are mostly anecdotal, as no large series exist. Attempting to extrapolate results from the management of iatrogenic perforations or other etiologies of perforation or fistula formation provides little insight into expected results with this uncommon complication of esophageal cancer and its treatment. Confounding factors include malnutrition and compromised immunity, both of which affect healing and infection control, and the presence of luminal obstruction. All of these factors would be expected to impact a complicated open surgical repair or diversion and drainage procedure with its attendant morbidity and mortality to the same or greater degree as the contemporary recommendation described in this chapter. In this regard, improvements in completely covered SEMSs and associate delivery systems have dramatically changed the approach to managing esophageal fistulae. Older series report a median survival of 2 to 6 months following development of malignant esophageal fistula, regardless of treatment. Utilizing SEMS for fistula management to (1) rapidly and effectively control the leak and associated contamination, (2) provide rapid return of enteral nutrition, and (3) manage infection with antimicrobial agents and a minimally invasive approach to drainage, appears to provide the least morbid and most effective palliation for this uniformly fatal complication, and in most instances, is a better alternative to direct surgical intervention.

As noted above, these cases represent an almost uniformly fatal scenario. Older series, where this complication was managed by routine exclusion and diversion, describe extremely high perioperative morbidity and mortality. The current options utilizing SEMSs are much more attractive as they do not have the procedure-related complications experienced with prior approaches (including “palliative esophagectomy”). In this author's experience, the only time an open procedure with possible resection and reconstruction should be considered is when the patient has completed neoadjuvant therapy, is doing well clinically, and suddenly presents acutely with either a perforation or airway or vascular fistula. Despite this possible scenario, a recognition that these “heroic” approaches have an extremely high morbidity and mortality should always lead the surgeon to be less than sanguine toward an open direct surgical approach.