DOI: 10.1148/rg.231025051
(Radiographics. 2003;23:89-105.)
© RSNA, 2003
Balloon Dilation and Stent Placement for Esophageal Lesions: Indications, Methods, and Results1
Eric Therasse, MD,
Vincent L. Oliva, MD,
Edwin Lafontaine, MD,
Pierre Perreault, MD,
Marie-France Giroux, MD and
Gilles Soulez, MD
1 From the Departments of Radiology (E.T., V.L.O., P.P., M.F.G., G.S.) and Surgery (E.L.), Centre Hospitalier de l’Université de Montréal (CHUM), 3840 St Urbain St, Montreal, Quebec, Canada H2W 1T8. Recipient of a Certificate of Merit award for an education exhibit at the 2001 RSNA scientific assembly. Received March 8, 2002; revision requested April 25 and received May 24; accepted May 28. Address correspondence to E.T. (e-mail: eric.therasse.chum@ssss.gouv.qc.ca).
 |
Abstract
|
|---|
Esophageal balloon dilation and expandable stent placement are safe, minimally invasive, effective treatments for esophageal strictures and fistulas. These procedures have brought the management of dysphagia due to esophageal strictures into the field of interventional radiology. Esophageal dilation is usually indicated for benign stenoses and is technically successful in more than 90% of cases. Most patients with esophageal carcinoma are not candidates for resection; thus, the main focus of treatment is palliation of malignant dysphagia and esophagorespiratory fistulas. Esophageal stent placement, which is approved only for malignant strictures, is one of the main therapeutic options in affected patients and relieves dysphagia in approximately 90% of cases. Dedicated commercially available devices continue to evolve, each with its own advantages and limitations. Stent placement is subject to technical pitfalls, and adverse events occur following esophageal procedures in a minority of cases. Although chest pain is common and self-limited, reflux esophagitis, stent migration, tracheal compression, and esophageal perforation and obstruction require specific interventions. In many cases, these complications can be recognized and treated by the interventional radiologist with minimally invasive techniques.
© RSNA, 2003
Index Terms: Esophagus, diseases, 71.291, 71.321, 71.33 • Esophagus, grafts and prostheses, 71.1269 • Esophagus, interventional procedures, 71.1269 • Esophagus, neoplasms, 71.30 • Esophagus, stenosis or obstruction, 71.74 • Stents and prostheses, 71.1269
|
LEARNING OBJECTIVES
|
|---|
After reading this article and taking the test, the reader will be able to:
- Discuss the indications for and results of esophageal stent placement.
- Describe the insertion techniques, advantages, and limitations associated with commercially available stents.
- Recognize and manage complications that may occur following esophageal stent placement.
|
Introduction
|
|---|
Most cases of malignant dysphagia are due to esophageal carcinomas that are unresectable at presentation and for which palliation will be the focus of treatment (1). Dysphagia has long been treated with surgical and endoscopic interventions. Esophageal bougienage may be performed without guidance, and a rigid plastic stent could be inserted endoscopically with or without fluoroscopic guidance. However, crossing tight esophageal stenoses and positioning metallic stents are sometimes difficult or impossible without fluoroscopic guidance and appropriate catheter technology. Radiologists, who are already accustomed to using similar materials and techniques for vascular and nonvascular interventions, are in the ideal position to perform these interventions safely and relatively easily. Esophageal procedures should be adequately tailored to the underlying disease, and one should take advantage of the characteristics of various devices in specific situations. Although many benign strictures can be treated with balloon dilation, esophageal stent placement will be one of the main palliative options in malignant dysphagia. In addition, the radiologist should be aware of possible complications of esophageal interventions because in many cases he or she will be able to prevent or treat these complications.
In this article, we review the indications for and the methods and outcomes of balloon dilation and stent placement for esophageal strictures. We also describe various commercially available stents as well as the advantages and limitations of each stent. In addition, we discuss specific situations that require careful attention and the management of possible complications of stent insertion.
|
Indications
|
|---|
Esophageal dilation is usually indicated for benign stenoses such as rings, webs, achalasia, and strictures caused by peptic, postsurgical, postsclerotherapeutic, or corrosive injury (2). Dilation of extrinsic esophageal compression is usually ineffective. In malignant lesions, dilation is sometimes performed prior to stent insertion or can be used as a temporizing measure prior to surgery or radiation therapy, but it is generally ineffective if used alone.
Esophageal stents have been approved by the U.S. Food and Drug Administration (FDA) only for malignant strictures, whether intrinsic (esophageal carcinoma) or extrinsic (eg, lung carcinoma). The use of stents in benign lesions is plagued by a high long-term complication rate and leads to tissue hyperplasia with recurrent esophageal stenosis (3). However, good results have been reported in benign lesions with retrievable stents that are left in the esophagus for a few months (4). Covered metallic stent placement is now the primary treatment for malignant bronchoesophageal fistulas and is also accepted as the main treatment option for malignant dysphagia in patients with poor functional status who cannot tolerate radiation therapy or chemotherapy, who have advanced metastatic disease, or in whom previous therapy has failed (5).
|
FDA-approved Stents
|
|---|
There are currently three self-expandable esophageal stents approved by the FDA (Fig 1), and their characteristics are listed in Table 1 (1). All currently available esophageal stents are covered to prevent tumor ingrowth and allow treatment of fistulas, whereas their extremities are uncoated to permit anchoring and prevent migration. These stents have now completely replaced rigid plastic tubes, which were associated with a high procedural complication rate and poor palliation (5).
View larger version (57K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1a. Photographs show FDA-approved covered esophageal stents: the Ultraflex stent (a), the Wallstent II (b), and the Z-stent without anchors (shown with an antireflux valve [arrows]) (c).
|
|
View larger version (64K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1b. Photographs show FDA-approved covered esophageal stents: the Ultraflex stent (a), the Wallstent II (b), and the Z-stent without anchors (shown with an antireflux valve [arrows]) (c).
|
|
View larger version (66K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 1c. Photographs show FDA-approved covered esophageal stents: the Ultraflex stent (a), the Wallstent II (b), and the Z-stent without anchors (shown with an antireflux valve [arrows]) (c).
|
|
Ultraflex Stent
The Ultraflex stent is mounted on a delivery catheter, unprotected by a sheath, and restrained by a string that must be pulled out to release the stent. Because of the stent shortening that occurs during deployment, two delivery systems are proposed (Fig 2). Preinsertion dilation is often required because the unprotected surface of the stent and the large profile of the delivery system produce friction during advancement through tight esophageal strictures. Lubrication of the Ultraflex stent delivery system is recommended to help with insertion. Stent shortening, the poor radiopacity of nitinol, and the need to predilate tight strictures make Ultraflex stent deployment more difficult than deployment of the Wallstent. The lower radial force and greater flexibility of the Ultraflex stent are probably responsible for less postdeployment chest pain and better patient tolerance; however, the Ultraflex stent also requires more time to fully expand in comparison with other stents (6). Smooth, nontraumatic edges should offer protection against esophageal erosions and bleeding. The Ultraflex stent is also available in a 22–23-mm-diameter version for use in dilated esophagus.
View larger version (73K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2a. Drawings illustrate the delivery system of the Ultraflex stent. (a) The distal release system allows elimination of proximal foreshortening during deployment and is best suited for stent placement in the middle and upper esophagus. (b) The proximal release system allows elimination of distal foreshortening during deployment and is best suited for stent placement in the gastroesophageal junction. Arrows indicate how to release the stent by pulling out the string. (Courtesy of Microvasive/Boston Scientific, Natick, Mass.)
|
|
View larger version (72K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 2b. Drawings illustrate the delivery system of the Ultraflex stent. (a) The distal release system allows elimination of proximal foreshortening during deployment and is best suited for stent placement in the middle and upper esophagus. (b) The proximal release system allows elimination of distal foreshortening during deployment and is best suited for stent placement in the gastroesophageal junction. Arrows indicate how to release the stent by pulling out the string. (Courtesy of Microvasive/Boston Scientific, Natick, Mass.)
|
|
Wallstent
The Wallstent is mounted on a delivery catheter and covered by a sheath. Stent deployment is illustrated in Figure 3. Stent shortening occurs at both extremities and must be considered when choosing the appropriate stent length. The Wallstent is easy to deploy and is loaded in a small (18-F) sheath that allows crossing of most lesions without preinsertion dilation. The radiopacity of the stent is excellent, and deployment requires minimal traction on the sheath. The uncoated sharp filaments of the stent extremities can be traumatic but should reduce the occurrence of migration. The Wallstent has the highest radial force (more appropriate for extrinsic compression) of the FDA-approved stents and is more likely to produce postdeployment chest pain.
View larger version (156K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 3a. Photographs illustrate the delivery system of the Wallstent. (a) Wallstent before deployment. (b, c) To deploy the stent, the inner catheter (arrow in b) is held stationary while the outer sheath (arrowhead in b) is withdrawn, allowing distal to proximal stent release (c).
|
|
View larger version (101K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 3b. Photographs illustrate the delivery system of the Wallstent. (a) Wallstent before deployment. (b, c) To deploy the stent, the inner catheter (arrow in b) is held stationary while the outer sheath (arrowhead in b) is withdrawn, allowing distal to proximal stent release (c).
|
|
View larger version (140K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 3c. Photographs illustrate the delivery system of the Wallstent. (a) Wallstent before deployment. (b, c) To deploy the stent, the inner catheter (arrow in b) is held stationary while the outer sheath (arrowhead in b) is withdrawn, allowing distal to proximal stent release (c).
|
|
Z-stent
The Z-stent must be inserted into the delivery system before use (Fig 4). The Z-stent has good radiopacity, and its shortening is minimal. However, considerable traction must be applied on the outer tube to release the stent from the bulky 31-F sheath, which often requires preinsertion dilation to 12 mm. In addition, removal of the delivery system is often difficult because its tip has a tendency to catch the stent. The Z-stent has minimal flexibility, making it less appropriate for tortuous anatomic structures. The stent is available with uncoated flange ends without anchors (31-F) and with coated flange ends with anchors (24-F). The former version is also available with an antireflux valve to be used when the stent has to cross the gastroesophageal junction. This windsock-type valve, an extension of the stent polyurethane membrane 8 cm beyond the lower metal cage, is designed to invert inside the stent when gastric pressure rises above a threshold, thereby allowing patients to belch or vomit (7). The Z-stent has a higher migration rate when placed across the gastroesophageal junction (6).
View larger version (38K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4a. Photographs illustrate the delivery system of the Z-stent. (a) The stent is lubricated and is loaded through a funnel in the tip of the outer tube by pulling on threads (arrow). (b) The guiding tip (arrowhead) is adapted to the sheath by pulling on the other end of its shaft (arrow). (c) To deploy the stent, the locking device is pulled out and the inner catheter (arrow) is held stationary while the outer sheath (arrowhead) is withdrawn. The thread is cut and removed before retrieving the delivery system.
|
|
View larger version (43K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4b. Photographs illustrate the delivery system of the Z-stent. (a) The stent is lubricated and is loaded through a funnel in the tip of the outer tube by pulling on threads (arrow). (b) The guiding tip (arrowhead) is adapted to the sheath by pulling on the other end of its shaft (arrow). (c) To deploy the stent, the locking device is pulled out and the inner catheter (arrow) is held stationary while the outer sheath (arrowhead) is withdrawn. The thread is cut and removed before retrieving the delivery system.
|
|
View larger version (42K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4c. Photographs illustrate the delivery system of the Z-stent. (a) The stent is lubricated and is loaded through a funnel in the tip of the outer tube by pulling on threads (arrow). (b) The guiding tip (arrowhead) is adapted to the sheath by pulling on the other end of its shaft (arrow). (c) To deploy the stent, the locking device is pulled out and the inner catheter (arrow) is held stationary while the outer sheath (arrowhead) is withdrawn. The thread is cut and removed before retrieving the delivery system.
|
|
Table 2 summarizes the strengths and weaknesses of the various FDA-approved esophageal stents.
|
Esophageal Dilation and Stent Placement Methods
|
|---|
Setup and Steps
An esophageal stricture should be evaluated with esophagography or endoscopy before dilation or stent placement. The patient, who should fast beginning on the day before the procedure, is placed in the left lateral decubitus position. Adequate monitoring with oxymetry, electrocardiography, and blood pressure measurements should be performed. Oxygen should routinely be administered, and suction should be available. Sedation with intravenous administration of midazolam (1–2 mg) and fentanyl (50–100 µg) is tailored to each patient, and topical anesthesia of the pharynx is achieved with lidocaine spray. A 5-F headhunter or "hockey stick" catheter and a soft-tip Bentson guide wire are then advanced via the mouth into the esophagus under fluoroscopic guidance. The esophageal segments above the stricture are opacified before the guide wire and catheter are gently advanced across the lesion, whereas the esophageal segments below the stricture are opacified afterward. Iso-osmolar contrast medium (eg, iodixanol) is less likely to produce pulmonary edema if aspirated into the lungs and should be injected sparingly into the esophagus to prevent aspiration. Hydrophilic guide wires can be helpful in tight strictures, although they are more prone to perforate an esophageal tumor. Therefore, one should make sure that the guide wire is within the lumen before esophageal dilation or stent placement is performed. Fluoroscopy allows better monitoring of stent deployment than does endoscopy. In addition, endoscopy often cannot be performed distal to tight strictures, although it may provide better delimitation of tumor extension (Fig 5).
View larger version (158K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5a. Better delineation of tumor extension with endoscopy in a patient with esophageal carcinoma. (a) Esophagogram demonstrates adequate stent placement with a residual waist located in the midportion of the stent (arrow) due to the stricture. No obstruction is seen at the lower end of the stent (arrowhead). (b) Endoscopic image obtained 2 weeks later demonstrates malignant disease (arrows) beyond the stent.
|
|
View larger version (121K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5b. Better delineation of tumor extension with endoscopy in a patient with esophageal carcinoma. (a) Esophagogram demonstrates adequate stent placement with a residual waist located in the midportion of the stent (arrow) due to the stricture. No obstruction is seen at the lower end of the stent (arrowhead). (b) Endoscopic image obtained 2 weeks later demonstrates malignant disease (arrows) beyond the stent.
|
|
Esophageal Balloon Dilation
Balloon dilation is usually performed up to a diameter of 15–20 mm, and tight strictures require stepwise dilation that begins with a smaller balloon (8). Dilation to more than 12 mm is not required before stent insertion and may increase the complication rate. Except for rings or webs, dilation should not be performed too quickly and should not exceed the diameter of the stricture by more than 7–8 mm in a single session (Fig 6). The level of pain experienced by the patient should be monitored, and dilation to a greater diameter should not be attempted if the patient complains of moderate to severe pain.
View larger version (116K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 6a. Esophageal tear after balloon dilation. (a) Esophagogram shows an esophageal peptic stricture with a lumen 6 mm in diameter (arrow). (b) Esophagogram shows a waist (arrow) in the balloon at the beginning of inflation. (c) Esophagogram demonstrates complete dilation of the balloon to 12 mm, which is achieved over a 2-minute period. (d) Postdilation esophagogram demonstrates a small, contained esophageal laceration (arrows).
|
|
View larger version (115K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 6b. Esophageal tear after balloon dilation. (a) Esophagogram shows an esophageal peptic stricture with a lumen 6 mm in diameter (arrow). (b) Esophagogram shows a waist (arrow) in the balloon at the beginning of inflation. (c) Esophagogram demonstrates complete dilation of the balloon to 12 mm, which is achieved over a 2-minute period. (d) Postdilation esophagogram demonstrates a small, contained esophageal laceration (arrows).
|
|
View larger version (117K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 6c. Esophageal tear after balloon dilation. (a) Esophagogram shows an esophageal peptic stricture with a lumen 6 mm in diameter (arrow). (b) Esophagogram shows a waist (arrow) in the balloon at the beginning of inflation. (c) Esophagogram demonstrates complete dilation of the balloon to 12 mm, which is achieved over a 2-minute period. (d) Postdilation esophagogram demonstrates a small, contained esophageal laceration (arrows).
|
|
View larger version (123K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 6d. Esophageal tear after balloon dilation. (a) Esophagogram shows an esophageal peptic stricture with a lumen 6 mm in diameter (arrow). (b) Esophagogram shows a waist (arrow) in the balloon at the beginning of inflation. (c) Esophagogram demonstrates complete dilation of the balloon to 12 mm, which is achieved over a 2-minute period. (d) Postdilation esophagogram demonstrates a small, contained esophageal laceration (arrows).
|
|
Esophageal Stent Placement
Metallic stent placement is performed under fluoroscopic guidance over a stiff (Amplatz) 260-cm guide wire. Routine predilation of the lesion is not required but will facilitate stent expansion and removal of the delivery system in cases involving narrow strictures or large delivery systems (Z-stent, Ultraflex). Esophageal stents may shorten either during (Ultraflex, Wallstent) or after (Wallstent) deployment, a factor that should be considered when choosing the stent length. Stents should never be placed across the superior esophageal sphincter (C5-C6 level). Crossing the gastroesophageal junction with the stent should be avoided if possible. The delivery system should be carefully retrieved to prevent its tip from catching on the stent. During stent placement, the site of the lesion may be identified owing to residual contrast medium (following esophagography) or with the use of anatomic landmarks such as vertebral bodies. The head should be held in hyperextension to facilitate stent insertion. The covered part of the stent (excluding the bare extremities) should cover the lesion and include a safety margin of at least 2 cm of the normal esophagus at each end. Because esophageal stents are more likely to migrate distally than proximally, a little more of the stent should be positioned above the lesion than below it. Esophageal opacification is performed after stent placement to assess stent location and exclude complications. When the stent is properly positioned, the esophageal stricture induces a "waist" at the center of the stent immediately after deployment (Fig 7).
View larger version (116K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 7a. Esophageal stent placement technique. (a) Esophagogram demonstrates a malignant stricture (arrowheads) 4 cm below the superior esophageal sphincter (arrow). (b) Esophagogram shows dilation of the stricture. (c) Esophagogram shows the expected postdeployment position of the covered portion of an Ultraflex stent (arrows). (d) Esophagogram demonstrates a stricture-induced waist in the middle of the stent (arrowheads), a finding that indicates good stent location.
|
|
View larger version (103K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 7b. Esophageal stent placement technique. (a) Esophagogram demonstrates a malignant stricture (arrowheads) 4 cm below the superior esophageal sphincter (arrow). (b) Esophagogram shows dilation of the stricture. (c) Esophagogram shows the expected postdeployment position of the covered portion of an Ultraflex stent (arrows). (d) Esophagogram demonstrates a stricture-induced waist in the middle of the stent (arrowheads), a finding that indicates good stent location.
|
|
View larger version (105K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 7c. Esophageal stent placement technique. (a) Esophagogram demonstrates a malignant stricture (arrowheads) 4 cm below the superior esophageal sphincter (arrow). (b) Esophagogram shows dilation of the stricture. (c) Esophagogram shows the expected postdeployment position of the covered portion of an Ultraflex stent (arrows). (d) Esophagogram demonstrates a stricture-induced waist in the middle of the stent (arrowheads), a finding that indicates good stent location.
|
|
View larger version (98K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 7d. Esophageal stent placement technique. (a) Esophagogram demonstrates a malignant stricture (arrowheads) 4 cm below the superior esophageal sphincter (arrow). (b) Esophagogram shows dilation of the stricture. (c) Esophagogram shows the expected postdeployment position of the covered portion of an Ultraflex stent (arrows). (d) Esophagogram demonstrates a stricture-induced waist in the middle of the stent (arrowheads), a finding that indicates good stent location.
|
|
After undergoing esophageal stent placement, patients need to modify their diet to prevent large boluses of food from becoming impacted within the stent. If a stent without a valve protrudes through the gastroesophageal junction, the patient is instructed to sleep with the head of the bed raised, and acid suppression therapy is prescribed. Those who undergo placement of a Z-stent with a valve are instructed to drink a glass of water to revert the valve (a) if they experience reflux symptoms and (b) after any events that raise intragastric pressure (eg, coughing, sneezing, vomiting) (7). Table 3 gives the standard procedures performed immediately after stent placement.
|
Specific Situations
|
|---|
Cervical Lesions
Stent insertion into the upper esophagus may cause discomfort and aspiration in the lungs if the stent is too close to or crosses the proximal esophageal sphincter. In addition, stent migration and tumor overgrowth are more likely to occur because of the short uninvolved proximal margin. Therefore, esophageal stent placement can be hazardous if the stricture is less than 3 cm from the superior esophageal sphincter (Fig 8), and use of a softer stent (Ultraflex) may be more appropriate in the upper esophagus.
View larger version (85K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 8a. Stent placement through the superior esophageal sphincter. (a) Esophagogram shows a Wallstent whose upper end (arrow) was inadvertently positioned across the superior esophageal sphincter (C5-C6 level). Stent placement was intended as treatment for a proximal esophageal stricture. The patient experienced discomfort and swallowing difficulties, with reflux of contrast medium into the maxillary sinuses (arrowheads). (b) Esophagogram demonstrates aspiration into the lungs (arrow).
|
|
View larger version (78K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 8b. Stent placement through the superior esophageal sphincter. (a) Esophagogram shows a Wallstent whose upper end (arrow) was inadvertently positioned across the superior esophageal sphincter (C5-C6 level). Stent placement was intended as treatment for a proximal esophageal stricture. The patient experienced discomfort and swallowing difficulties, with reflux of contrast medium into the maxillary sinuses (arrowheads). (b) Esophagogram demonstrates aspiration into the lungs (arrow).
|
|
Malignant Esophageal and Tracheobronchial Strictures or Fistulas
Coexisting esophageal and tracheobronchial strictures are usually caused by bronchogenic or esophageal malignancy. Because esophageal stent placement may further compress the trachea and precipitate respiratory distress, tracheobronchial stent placement should be performed first (Fig 9). Malignant disease can also result in tracheoesophageal fistulas, which require urgent intervention. The best treatment for malignant fistulas is covered esophageal stent placement. If compression of the airways is present, tracheobronchial stent placement should precede esophageal stent placement (Figs 9, 10). Treatment failure may be due to a dilated esophagus that prevents apposition of the stent to the esophageal wall. If esophageal stent placement does not close the fistula, covered stent insertion into the trachea or bronchus should be considered. Predilation of the esophageal lesion should be avoided because it could enlarge the fistula. In addition, a minimal amount of contrast medium should be injected into the esophagus during the procedure to avoid bronchial aspiration.
View larger version (123K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 9a. Compression of the esophagus and trachea. (a) Computed tomographic (CT) scan shows compression of the trachea (arrow) by a mesothelioma (arrowheads). (b) Esophagogram shows extrinsic compression of the esophagus. Stents (arrows) were positioned in the trachea and right main bronchus. (c) Esophagogram obtained after esophageal stent placement demonstrates relief of esophageal obstruction.
|
|
View larger version (105K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 9b. Compression of the esophagus and trachea. (a) Computed tomographic (CT) scan shows compression of the trachea (arrow) by a mesothelioma (arrowheads). (b) Esophagogram shows extrinsic compression of the esophagus. Stents (arrows) were positioned in the trachea and right main bronchus. (c) Esophagogram obtained after esophageal stent placement demonstrates relief of esophageal obstruction.
|
|
View larger version (101K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 9c. Compression of the esophagus and trachea. (a) Computed tomographic (CT) scan shows compression of the trachea (arrow) by a mesothelioma (arrowheads). (b) Esophagogram shows extrinsic compression of the esophagus. Stents (arrows) were positioned in the trachea and right main bronchus. (c) Esophagogram obtained after esophageal stent placement demonstrates relief of esophageal obstruction.
|
|
View larger version (127K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 10a. Malignant left esophagobronchial fistula and stricture at the tracheal bifurcation. (a) Chest radiograph shows a stent that was dilated into the left main bronchus. (b) Esophagogram reveals that an esophageal stricture and a left bronchoesophageal fistula are still present after bronchial stent placement. (c) Esophagogram shows an esophageal Wallstent that was placed for treatment of the esophageal stricture and fistula. However, the Wallstent is constricted by the tumor (arrows).
|
|
View larger version (151K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 10b. Malignant left esophagobronchial fistula and stricture at the tracheal bifurcation. (a) Chest radiograph shows a stent that was dilated into the left main bronchus. (b) Esophagogram reveals that an esophageal stricture and a left bronchoesophageal fistula are still present after bronchial stent placement. (c) Esophagogram shows an esophageal Wallstent that was placed for treatment of the esophageal stricture and fistula. However, the Wallstent is constricted by the tumor (arrows).
|
|
View larger version (125K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 10c. Malignant left esophagobronchial fistula and stricture at the tracheal bifurcation. (a) Chest radiograph shows a stent that was dilated into the left main bronchus. (b) Esophagogram reveals that an esophageal stricture and a left bronchoesophageal fistula are still present after bronchial stent placement. (c) Esophagogram shows an esophageal Wallstent that was placed for treatment of the esophageal stricture and fistula. However, the Wallstent is constricted by the tumor (arrows).
|
|
Malignant Gastric and Esophageal Stenoses
Malignant gastric and esophageal stenoses are usually the result of advanced gastric carcinoma that extends to the esophagus. The standard surgical treatment, esophagojejunostomy, carries a high morbidity rate in high-risk patients. These lesions may be treated by placing a long, covered esophageal stent across both the esophageal and gastric strictures (Fig 11). If the lesion is too long, two overlapping covered stents may be implanted.
View larger version (121K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 11a. Treatment of malignant gastric and esophageal stenoses. (a) Esophagogram shows gastric carcinoma with antral (arrowheads) and distal esophageal strictures. (b) Esophagogram shows a 15-cm-long Wallstent that has been positioned across the gastroesophageal junction. The stent extends to the gastric antrum but ends before reaching the duodenal bulb (arrows).
|
|
View larger version (113K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 11b. Treatment of malignant gastric and esophageal stenoses. (a) Esophagogram shows gastric carcinoma with antral (arrowheads) and distal esophageal strictures. (b) Esophagogram shows a 15-cm-long Wallstent that has been positioned across the gastroesophageal junction. The stent extends to the gastric antrum but ends before reaching the duodenal bulb (arrows).
|
|
Postoperative Esophageal Fistulas and Strictures
Postoperative esophageal fistulas are serious complications that most often require surgical correction. If the patient is unfit for further surgery or residual cancer is present, the fistula may be closed with covered esophageal stent insertion (Fig 12). Benign strictures that develop in a surgically reconstructed esophagus are first treated with balloon dilation. These fibrotic strictures may rupture if they are dilated to the expected normal esophageal diameter in one session. Malignant strictures almost always occur at an anastomosis and are best treated with covered stent placement. Flexible stents are useful when the esophagoenteric anastomosis manifests with an angulation (Fig 13).
View larger version (166K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 12a. Postoperative esophageal fistulas. (a) Esophagogram obtained following left pneumonectomy for lung cancer shows an irregular cavity (arrow) that arises from the left side of the esophagus. (b) Esophagogram demonstrates a covered Wallstent that has been positioned across the fistula. Residual contrast medium (arrows) from esophagography performed prior to stent placement remains trapped in the cavity.
|
|
View larger version (138K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 12b. Postoperative esophageal fistulas. (a) Esophagogram obtained following left pneumonectomy for lung cancer shows an irregular cavity (arrow) that arises from the left side of the esophagus. (b) Esophagogram demonstrates a covered Wallstent that has been positioned across the fistula. Residual contrast medium (arrows) from esophagography performed prior to stent placement remains trapped in the cavity.
|
|
View larger version (134K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 13a. Malignant postoperative anastomotic stricture. (a) Esophagogram obtained 1 year after gastrectomy shows a malignant stricture at the esophagojejunal anastomosis (arrow). (b) Esophagogram shows a Wallstent that successfully relieved the stricture, even though the stent is almost perpendicular to the jejunum.
|
|
View larger version (155K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 13b. Malignant postoperative anastomotic stricture. (a) Esophagogram obtained 1 year after gastrectomy shows a malignant stricture at the esophagojejunal anastomosis (arrow). (b) Esophagogram shows a Wallstent that successfully relieved the stricture, even though the stent is almost perpendicular to the jejunum.
|
|
|
Outcomes
|
|---|
In benign strictures, balloon dilation is technically successful in more than 90% of cases, functional success is achieved in 86%–90%, and about one-third of patients require repeat dilation (8). Dilation of esophageal webs or rings will give the best results. The outcome is not as favorable in radiation-induced strictures, with a functional success rate of 66% and a higher restenosis rate of 42% (8). Relief of malignant dysphagia with balloon dilation is only transient, and dysphagia caused by external compression of the esophagus does not generally respond to dilation (2).
Dysphagia is relieved in approximately 90% of patients who undergo esophageal stent placement (5). These results are superior to those of radiation therapy and chemotherapy for the relief of dysphagia, and metallic stents have been shown to provide better palliation than plastic stents, with fewer acute complications (5,8). Improvement of dysphagia after metallic stent placement is less important in cases of extrinsic compression than in cases of esophageal cancer. Successful closure of tracheo- or bronchoesophageal fistulas can be achieved in 70%–100% of patients (8). Treatment failure occurs more frequently when the esophagus is dilated and the fistula is close to the superior esophageal sphincter.
|
Complications
|
|---|
Approximately 0.5%–2% of patients die as a direct result of expandable stent placement (5). Patients who were previously treated with radiation therapy or chemotherapy have a higher rate of life-threatening complications (perforation, bleeding, tracheoesophageal fistulas) and a higher mortality rate after stent insertion (1,5). Overall, the reintervention rate after esophageal stent placement is approximately 25% (1).
Chest pain is frequently encountered after stent insertion and is more prominent when the stent is placed in the upper esophagus and with stents having a high radial force (eg, the Wallstent). The symptoms are well controlled with medication and gradually disappear within days.
Reflux Esophagitis and Aspiration
Esophageal carcinoma is often the late result of chronic gastroesophageal reflux. In such cases, relief of dysphagia by means of esophageal stent placement will sometimes be associated with recurrent gastroesophageal reflux. Esophagitis and aspiration are even more likely to occur when the stent is positioned across one of the esophageal sphincters (Fig 14). These conditions can be prevented with careful stent positioning, use of a stent with an antireflux valve, or strict antireflux precautions and aggressive acid suppression therapy when the stent is positioned across the gastroesophageal junction.
View larger version (110K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 14a. Reflux esophagitis. (a) Endoscopic image obtained after placement of a stent across the gastroesophageal junction shows normal-colored mucosa above the stent. (b) Endoscopic image obtained 3 months later demonstrates severe esophagitis (note the redness of the mucosa) that resulted from gastroesophageal reflux. Tumor overgrowth is also apparent (arrowheads).
|
|
View larger version (129K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 14b. Reflux esophagitis. (a) Endoscopic image obtained after placement of a stent across the gastroesophageal junction shows normal-colored mucosa above the stent. (b) Endoscopic image obtained 3 months later demonstrates severe esophagitis (note the redness of the mucosa) that resulted from gastroesophageal reflux. Tumor overgrowth is also apparent (arrowheads).
|
|
Stent Migration
Stent migration occurs in 0%–35% of patients and occurs more frequently when the stent is positioned across the gastroesophageal junction (9). It can also be due to (a) shrinkage of the tumor from chemotherapy or radiation therapy, (b) stent malposition, or (c) overdilation of the lesion before stent placement. There is no evidence that surgically removing a stent that has completely migrated into the stomach is safer than leaving it in situ, unless it causes symptoms (10). Recurrent dysphagia caused by stent migration may be treated with placement of an additional stent. Ultraflex stents are soft enough to be retrieved via the mouth without major trauma if they can be snared in the stomach under endoscopic or fluoroscopic guidance. If partial migration has occurred, placement of an additional stent may also prevent further migration (Fig 15).
View larger version (99K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 15a. Stent migration. (a) Esophagogram shows that an Ultraflex stent (arrows) positioned through a gastroesophageal lesion has migrated upward in the esophagus. (b) Esophagogram shows the extent of the lesion (arrows) near the distal end of the stent (arrowhead). (c) Esophagogram demonstrates a Wallstent that has been positioned through the lesion and overlaps the distal end of the Ultraflex stent.
|
|
View larger version (131K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 15b. Stent migration. (a) Esophagogram shows that an Ultraflex stent (arrows) positioned through a gastroesophageal lesion has migrated upward in the esophagus. (b) Esophagogram shows the extent of the lesion (arrows) near the distal end of the stent (arrowhead). (c) Esophagogram demonstrates a Wallstent that has been positioned through the lesion and overlaps the distal end of the Ultraflex stent.
|
|
View larger version (167K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 15c. Stent migration. (a) Esophagogram shows that an Ultraflex stent (arrows) positioned through a gastroesophageal lesion has migrated upward in the esophagus. (b) Esophagogram shows the extent of the lesion (arrows) near the distal end of the stent (arrowhead). (c) Esophagogram demonstrates a Wallstent that has been positioned through the lesion and overlaps the distal end of the Ultraflex stent.
|
|
Esophageal Perforation
The risk of perforation following balloon dilation is approximately 3%, but this risk increases in narrow fibrotic strictures (caustic, malignant, radiation-induced). Esophageal perforation or fistulization may occur following stent insertion in 0%–8% of cases (9). Perforation may be due to overzealous catheter or guide wire manipulations or to preinsertion dilation or may supervene later as a result of erosion of the esophageal wall by the stent. Perforation occurs more frequently in tumors that were previously treated with chemotherapy, radiation therapy, or laser therapy. Diagnosis of perforation is usually obvious, being based on the visualization of pneumothorax, pneumomediastinum, or extravasation of contrast medium above or below the diaphragm. Esophageal perforation during the intervention should be recognized immediately. Sealing of the perforation with a covered stent and administration of antibiotics are the first and least invasive treatment options and should be initiated without delay (Fig 16).
View larger version (141K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 16a. Esophageal perforation. (a) Esophagogram obtained following radiation therapy and chemotherapy shows a necrotic esophageal carcinoma with ulceration (arrow). (b) Esophagogram shows a catheter that has perforated the esophagus during an attempt to position the catheter across the lesion. Contrast medium is seen around the spleen (arrows). The catheter was subsequently repositioned in the true lumen of the esophagus. (c) Esophagogram shows a Wallstent that was positioned across the gastroesophageal lesion. Antibiotics were administered, and despite the presence of pneumoperitoneum (arrow), the patient underwent no further intervention and was discharged free of dysphagia 4 days later.
|
|
View larger version (139K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 16b. Esophageal perforation. (a) Esophagogram obtained following radiation therapy and chemotherapy shows a necrotic esophageal carcinoma with ulceration (arrow). (b) Esophagogram shows a catheter that has perforated the esophagus during an attempt to position the catheter across the lesion. Contrast medium is seen around the spleen (arrows). The catheter was subsequently repositioned in the true lumen of the esophagus. (c) Esophagogram shows a Wallstent that was positioned across the gastroesophageal lesion. Antibiotics were administered, and despite the presence of pneumoperitoneum (arrow), the patient underwent no further intervention and was discharged free of dysphagia 4 days later.
|
|
View larger version (150K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 16c. Esophageal perforation. (a) Esophagogram obtained following radiation therapy and chemotherapy shows a necrotic esophageal carcinoma with ulceration (arrow). (b) Esophagogram shows a catheter that has perforated the esophagus during an attempt to position the catheter across the lesion. Contrast medium is seen around the spleen (arrows). The catheter was subsequently repositioned in the true lumen of the esophagus. (c) Esophagogram shows a Wallstent that was positioned across the gastroesophageal lesion. Antibiotics were administered, and despite the presence of pneumoperitoneum (arrow), the patient underwent no further intervention and was discharged free of dysphagia 4 days later.
|
|
Obstruction
Stent obstruction with recurrent dysphagia may be due to tumor progression, reactive hyperplasia, or food impaction. Tumor ingrowth should notoccur with use of covered stents, but tumor overgrowth may occur in 4%–18% of cases (9). Insufficient tumor coverage during stent insertion or due to stent migration or stent shortening (Fig 17) are contributing factors, although tumor overgrowth may also be due to rapidly infiltrating tumors. Tumor overgrowth may be treated with ablative therapies (eg, laser or photodynamic therapy) or with additional stent placement. Benign reactive hyperplasia, fibrosis, or granulation tissue may obstruct the stent in up to 30% of cases (11). The radiographic and endoscopic appearances of these benign processes may be indistinguishable from those of tumor overgrowth, but identifying the specific process is not important because the treatment is the same. Food obstruction appears as multiple filling defects within and above the stent lumen and is usually treated endoscopically. Patients should also be reminded to avoid large boluses of food and drink plenty of fluids with meals. Food obstruction must be differentiated from stent migration (ie, movement of the stent to another location) and from tumor overgrowth, which occurs at the stent extremities.
View larger version (119K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 17a. Tumor overgrowth. (a) Esophagogram shows a Wallstent that was placed for treatment of a malignant stricture at the esophagojejunal anastomosis. The covered portion of the stent (arrowhead) was positioned only 2 cm above the lesion, which induces a waist in the stent (arrow). (b) Esophagogram obtained 6 months later shows stent shortening associated with limited stent coverage of the lesion, which led to tumor overgrowth through the bare stent extremity (arrow). (c) Spot radiograph demonstrates balloon dilation. (d) Esophagogram shows a second Wallstent that was positioned through the stricture.
|
|
View larger version (113K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 17b. Tumor overgrowth. (a) Esophagogram shows a Wallstent that was placed for treatment of a malignant stricture at the esophagojejunal anastomosis. The covered portion of the stent (arrowhead) was positioned only 2 cm above the lesion, which induces a waist in the stent (arrow). (b) Esophagogram obtained 6 months later shows stent shortening associated with limited stent coverage of the lesion, which led to tumor overgrowth through the bare stent extremity (arrow). (c) Spot radiograph demonstrates balloon dilation. (d) Esophagogram shows a second Wallstent that was positioned through the stricture.
|
|
View larger version (113K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 17c. Tumor overgrowth. (a) Esophagogram shows a Wallstent that was placed for treatment of a malignant stricture at the esophagojejunal anastomosis. The covered portion of the stent (arrowhead) was positioned only 2 cm above the lesion, which induces a waist in the stent (arrow). (b) Esophagogram obtained 6 months later shows stent shortening associated with limited stent coverage of the lesion, which led to tumor overgrowth through the bare stent extremity (arrow). (c) Spot radiograph demonstrates balloon dilation. (d) Esophagogram shows a second Wallstent that was positioned through the stricture.
|
|
View larger version (116K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 17d. Tumor overgrowth. (a) Esophagogram shows a Wallstent that was placed for treatment of a malignant stricture at the esophagojejunal anastomosis. The covered portion of the stent (arrowhead) was positioned only 2 cm above the lesion, which induces a waist in the stent (arrow). (b) Esophagogram obtained 6 months later shows stent shortening associated with limited stent coverage of the lesion, which led to tumor overgrowth through the bare stent extremity (arrow). (c) Spot radiograph demonstrates balloon dilation. (d) Esophagogram shows a second Wallstent that was positioned through the stricture.
|
|
Other Complications
Severe bleeding may occur in 0%–6% of patients (9) and may be due to vessel erosion caused by the tumor or by the stent struts. Angiographic evaluation may be performed in cases of severe bleeding because endovascular treatment (eg, embolization, exclusion of arterial fistula with stent-graft insertion) may stop the hemorrhage.
Valve dysfunction may result from use of the Z-stent with an antireflux valve: Gas bloating may be experienced after meals, and stent obstruction may occur secondary to twisting of the valve. This can be corrected endoscopically by cutting off the antireflux membrane with a heat probe (7).
Tracheal compression is an infrequent complication of esophageal stent placement (Fig 18). Esophageal stent placement should be avoided if CT or bronchoscopy demonstrates tracheal compression or if balloon dilation causes respiratory distress. Acute tracheal compression can be treated with immediate removal of the esophageal stent or with tracheal stent placement.
View larger version (106K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 18a. Tracheal compression. (a) CT scan obtained before stent placement demonstrates a proximal esophageal cancer but no tracheal compression. (b) CT scan obtained following esophageal stent placement demonstrates moderate tracheal compression.
|
|
View larger version (98K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 18b. Tracheal compression. (a) CT scan obtained before stent placement demonstrates a proximal esophageal cancer but no tracheal compression. (b) CT scan obtained following esophageal stent placement demonstrates moderate tracheal compression.
|
|
|
Conclusions
|
|---|
Esophageal balloon dilation and stent placement are safe, minimally invasive, effective treatments for esophageal strictures and fistulas. Metallic stents are generally reserved for palliation of malignant diseases, whereas balloon dilation is usually indicated in benign strictures. Metallic stents have completely replaced rigid plastic tubes, and those that are currently available have different characteristics that may make a particular stent more appropriate in specific situations. Adverse events will occur in a minority of cases following these procedures, and many of these complications can be diagnosed and managed by the interventional radiologist with minimally invasive techniques.
|
Footnotes
|
|---|
Abbreviation: FDA = Food and Drug Administration
|
References
|
|---|
- Adler DG, Baron TH. Endoscopic palliation of malignant dysphagia. Mayo Clin Proc 2001; 76:731-738.[Abstract]
- Reed CE. Pitfalls and complications of esophageal prosthesis, laser therapy, and dilation. Chest Surg Clin N Am 1997; 7:623-636.[Medline]
- Song HY, Park SI, Do YS, et al. Expandable metallic stent placement in patients with benign esophageal strictures: results of long-term follow-up. Radiology 1997; 203:131-136.[Abstract/Free Full Text]
- Song HY, Jung HY, Park SI, et al. Covered retrievable expandable nitinol stents in patients with benign esophageal strictures: initial experience. Radiology 2000; 217:551-557.[Abstract/Free Full Text]
- Baron TH. Expandable metal stents for the treatment of cancerous obstruction of the gastrointestinal tract. N Engl J Med 2001; 344:1681-1687.[Free Full Text]
- Nevitt AW, Kozarek RA, Kidd R. Expandable esophageal prostheses: recognition, insertion techniques and positioning. AJR Am J Roentgenol 1996; 167:1009-1013.[Free Full Text]
- Dua KS, Kozarek R, Kim J, et al. Self-expanding metal esophageal stent with anti-reflux mechanism. Gastrointest Endosc 2001; 53:603-613.[CrossRef][Medline]
- Morgan R, Adam A. Use of metallic stents and balloons in the esophagus and gastrointestinal tract. J Vasc Intervent Radiol 2001; 12:283-297.[Medline]
- Wang MQ, Sze DY, Wang ZP, Wang ZQ, Gao YA, Dake MD. Delayed complications after esophageal stent placement for treatment of malignant esophageal obstruction and esophagorespiratory fistulas. J Vasc Intervent Radiol 2001; 12:465-474.[Medline]
- De Palma GD, Iovino P, Catanzano C. Distally migrated esophageal self-expanding metal stents: wait and see or remove? Gastrointest Endosc 2001; 53:96-98.[CrossRef][Medline]
- Mayoral W, Fleischer D, Salcedo J, Roy P, Al-Kawas F, Benjamin S. Nonmalignant obstruction is a common problem with metal stents in the treatment of esophageal cancer. Gastrointest Endosc 2000; 51:556-559.[Medline]
This article has been cited by other articles:
|
|
|
|
 
G. S. Anderson, M. S. Levine, S. E. Rubesin, I. Laufer, G. G. Ginsberg, and M. L. Kochman
Esophageal stents: findings on esophagography in 46 patients.
Am. J. Roentgenol.,
November 1, 2006;
187(5):
1274 - 1279.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. B. Hunter, M. S. Taljanovic, P. H. Tsau, W. G. Berger, and J. R. Standen
Medical Devices of the Chest
RadioGraphics,
November 1, 2004;
24(6):
1725 - 1746.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
LEARNING OBJECTIVES
