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Therapeutic Endoscopy for Strictures of the Upper ...
Therapeutic Endoscopy for Strictures of the Upper ...
Therapeutic Endoscopy for Strictures of the Upper Digestive Tract
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The most common cause of esophageal strictures are peptic strictures, resulting from reflux esophagitis. Today, with the widespread use of proton pump inhibitors, the incidence is decreasing. However, in the past, nearly 80% of esophageal strictures were associated with gastroesophageal reflux disease. Other causes are Schatzky's rings, esophageal cancer, and injury to the esophagus from surgery or other forms of treatment. Esophageal strictures can be categorized into simple and complex strictures. Esophageal strictures are symmetric or concentric, with a diameter greater than 12 mm, and easily allow passage of a diagnostic upper endoscope. Complex strictures have one or more of the following features, asymmetry, a diameter less than 12 mm, or inability to pass an endoscope. Today, endoscopic treatment of esophageal strictures is largely narrowed to three modalities, dilation therapy, stent therapy, and incisional therapy. We will systemically review each of these modalities. The primary aim of esophageal dilatation is to alleviate symptoms, permit maintenance of oral nutrition, and reduce the risk of pulmonary aspiration. Esophageal dilatation is indicated in the treatment of symptomatic obstruction of the esophagus. Obstruction may develop as a consequence of a wide range of anatomical and functional esophageal disorders. Reflux-induced strictures, malignant strictures, and akalasia are the most frequent indications. But patients with anastomotic, sclerotherapy, radiation, and corrosive-induced strictures, and those with rings and webs, may also frequently require dilatation. Patients with diffuse esophageal spasm and other motility disorders may occasionally require dilatation of the lower esophageal sphincter when conservative measures fail. Active esophageal perforation is an absolute contraindication to esophageal dilatation, as it may extend the esophageal defect and promote mediastinal contamination. Severe cardiorespiratory disease is a relative contraindication to all endoscopic procedures. The balance of risks and benefits should be individualized and carefully considered. Major bleeding is uncommon following esophageal dilatation, but is more likely in patients with severe coagulopathy and in those taking anticoagulant drugs. The procedure should be undertaken with caution in those who have suffered recent perforation or undergone recent upper gastrointestinal surgery. The risks of dilatation are likely to be greater in patients with pharyngeal or cervical deformity and in those with large thoracic aneurysms. The risks of perforation are greater during dilatation of malignant disease of the esophagus. All patients should be fasted at least 4 to 6 hours prior to procedure. Endoscopy and contrast radiology are both helpful and are often complementary. The cause of esophageal obstruction should be carefully assessed. Biopsies or brush cytology should be taken for analysis. A tissue diagnosis is desirable prior to dilatation as it will influence overall management and the estimation of perforation risk. In patients with short, simple, benign-looking strictures, however, it is common practice for biopsies to be taken and dilatation performed during the same examination. When the stricture is tight or when the endoscopic features suggest malignancy, the results of biopsies are best awaited unless the patient has absolute dysphagia. When a stricture prevents passage of the endoscope, a barium swallow examination will provide useful anatomical detail. This is helpful in patients with long, tight, or complex strictures in whom dilatation may be technically difficult and associated with greater risks. Features that may make dilatation more risky, such as angulation of the stricture, and the presence of diverticula, a hiatus hernia, or a small stomach, should also be noted. It should be remembered that patients with proximal dysphagia may be harboring conditions which increase the risk of perforation, such as a pharyngeal pouch or a post-cricoid web, and in these circumstances, endoscopy should only be undertaken by an experienced endoscopist. In patients taking oral anticoagulants, dilatation has the potential to produce bleeding, which may be difficult to control. It is therefore advisable that patients at low risk of thromboembolic events should discontinue anticoagulants prior to the dilatation. A pre-procedure prothrombin time should be performed. In patients at high risk of thromboembolic events, oral anticoagulants should again be discontinued prior to the procedure. Monitoring should be undertaken. An intravenous heparin started once oral anticoagulation becomes subtherapeutic. Heparin should be discontinued 4-6 hours before dilatation and resumed 4-6 hours thereafter. Anticoagulants are generally resumed on the night of the procedure. The limited data available suggests that aspirin and non-steroidal anti-inflammatory drugs do not increase the risk of significant bleeding after therapeutic endoscopy. In the absence of pre-existing bleeding disorders, endoscopic procedures may be performed in patients taking aspirin or other non-steroidal anti-inflammatory drugs. In three prospective studies, the rate of bacteremia after esophageal bougie dilatation was demonstrated to be 12-22%. Bacteremia may be more frequent with the dilation of malignant strictures than with benign strictures. Bacteremia may also be more frequent with the passage of multiple dilators rather than with a single dilation. However, in the 2008 ASGE guidelines, administration of prophylactic antibiotics solely to prevent infective endocarditis was not recommended based on the following evidence. The Maloney bougie is the most commonly used bougie dilator. Made of rubber and filled with mercury or tungsten, it has a tapered tip and is freely passed without a guide wire. The Savary-Gillard bougie is a tapered thermoplastic dilator and is passed over a guide wire. There are a variety of available through-the-scope balloon dilators, available in either single or multiple diameters, that may be passed with or without wire guidance. Prior to dilatation, the endoscopist should consider five points. The diameter to which the obstruction should be dilated, how quickly the dilatation should be achieved, the dilator that should be employed, the need for wire guidance or endoscopic control, and the need for radiographic screening. In patients with benign peptic strictures, the results of dilatation appear best when a luminal diameter of 13-15 mm is achieved. Large caliber dilators are advised in the treatment of patients with Schatzky's rings. In patients with malignant esophageal disease, however, large caliber dilators are best avoided, as perforation is more likely and dilatation is rarely the definite treatment. Modest dilatation, sufficient to permit biopsy or endoscopic ultrasound, or facilitate stent insertion is the safest approach. Traditionally, it has been suggested that no more than three dilators of progressively increasing diameter should be passed in a single session to reduce the risk of perforation. Several sessions were therefore often required to achieve adequate dilation. Recent experience suggests that the passage of a single large dilator or incremental dilatation in larger steps may be safely employed in many patients with uncomplicated peptic strictures. However, it should be borne in mind that these observations were uncontrolled and it would be wise to employ a cautious approach in patients with tight, tough, or complex strictures. The risk of esophageal perforation may be higher with blind passage of Maloney dilators than with Savory or TTS balloons, especially in patients with a large hiatal hernia, a torturous esophagus, or those with complex strictures. The unguided passage of weighted bougies should be restricted to the treatment of patients with simple reflux into strictures, rings, and webs. Weighted bougies are not suited for the management of tight strictures. Wire-guided dilatation gives greater assurance that the dilator is following the line of the esophageal lumen, thus reducing the risk of perforation. Routine radiological screening was previously recommended when undertaking wire-guided dilatation. But this is not essential when the anatomy is well-defined, axial alignments are maintained, and the wire passes easily into the stomach. The guide wire should be placed at least 20 to 30 cm below the lowest point of the stricture, usually in the gastrogantrum. Through the scope, balloon dilatation is performed under direct endoscopic view. Inadequate channel size and lubrication facilitate easy passage. The balloon should be centered at the tightest point of the stricture. Recommended inflation times range from 20 to 60 seconds, but the optimum time is unknown. Maximum dilating pressures vary in relation to balloon size, and range between 30 to 45 psi, but again, the optimum pressure is unknown. A graded approach to dilatation is recommended by some, with obliteration of the stricture waste seen during radiographic screening or endoscopic assessment of stricture dilatation as commonly used endpoints of success. Through the scope, balloon dilatation has the additional advantage that it allows dilatation of the proximal part of a stricture. This may be helpful when a guide wire will not pass. The use of radiographic screening gives additional assurance and control of the dilatation process. Radiographic screening is especially helpful when the stricture is torturous or complex, or associated with a large hiatus hernia or diverticula. It may also be of value when the guide wire meets with resistance during passage through the stricture, or when an adequate length of wire cannot be passed distal to the stricture. Although comparative trials are not available, the selective use of radiologic screening appears safe and effective, and is supported by extensive clinical experience. During wire-guided dilatation, it ensures that the wire has passed the stricture, that kinking of the wire has not occurred within or distal to the stricture, and that during the dilatation process, the dilator is following the line of the esophageal lumen. During balloon dilatation, it indicates whether the balloon has slipped during inflation, and whether obliteration of the stricture waste has occurred. A 26-year-old female swallows an acidic caustic solution. The patient developed dysphagia. Fifty days after caustic injury, a stricture is seen in the mid-esophagus. Bougie dilation for corrosive strictures is usually initiated at least six weeks after corrosive ingestion. Endoscopy showed a stricture approximately 8 mm in diameter. A lubricated guide wire was introduced through the accessory channel, and the tip was placed in the antrum for stability. The endoscope was withdrawn slowly in 5-10 cm increments, while simultaneously advancing the guide wire in comparable length. An 8 mm Savory-Gilliard bougie was advanced over the prepositioned guide wire to the strictured area, because the first dilation performed should be approximately the diameter of the stricture. Dilation is considered to have been performed when there is a moderate or significant amount of resistance. If there is no resistance, dilation has not been performed. Excessive force is not necessary, and should not be used. It is reasonable to follow the rule of three, performing up to three dilations that meet resistance per session. Successful dilation was accomplished in this patient with 9 and 10 mm bougies. This is a 67-year-old male who was diagnosed with early gastric cancer at the gastric cardia. Endoscopic submucosal dissection was successfully performed. However, this patient eventually developed dysphagia one month after ESD, and endoscopy showed that a stricture developed at the gastroesophageal junction. Under direct endoscopic visualization, the CRE balloon catheter is passed through the stricture. An 8-10 mm CRE balloon is advanced through the channel of the endoscope. The floppy tip was positioned across the stricture. Once in place, the CRE balloon was advanced over the guide wire, leaving one third of the balloon beyond the stricture. The CRE balloon was then inflated to 8, 9, and 10 mm for three minutes at each diameter. When to repeat dilation depends on the degree of stenosis and the success of the initial procedure. The procedure should be repeated within two weeks for high-grade strictures. A planned repeated dilation was performed in two weeks' time. We chose not to use more than two catheters during a single session. For the second dilation, 10-13.5 mm and 12-15 mm CRE balloons were used. Following dilation, the patient eventually tolerated all foods well. Patients should be closely observed after each dilation. Patients should be closely observed after esophageal dilation. Chest X-ray is not essential, but should be performed urgently in patients who develop pain, dyspnea, fever, or tachycardia. We recommended the patient to initially drink water. If the patient was awake and alert and had no evident complications, we advanced the diet carefully in a stepwise pattern. Endoscopic assessment of the stricture was performed two weeks after a single session. Benign esophageal strictures can be dilated with a Savary-Gilliard-Bougie, or TTS, balloon for up to five sessions. If the stricture is refractory to treatment, dilation with intralesional steroid injection can be attempted. Stenting is optional and should only be considered when the patient has given information. There is evidence that intralesional steroid injection prior to dilation reduces the risk of recurrent stricture formation in refractory benign esophageal strictures. However, this comes from studies with poorly defined patient populations, in which it was not clear whether the patients truly had refractory benign esophageal strictures. It also remains to be defined what the optimal injection technique and frequency is, and at what dose steroids should be injected. Regardless of the specific method of dilation, early improvement in the ability to swallow is achieved by dilation. Regardless of the specific method of dilation, early improvement in the ability to swallow is achieved in virtually all patients. However, longer term outcomes are influenced by the underlying pathologic condition. If a luminal diameter of at least 13-15 mm can be achieved, nearly all patients will be relieved of dysphagia. In patients with benign peptic strictures, a graded stepwise dilating approach between 13 and 20 mm yields relief in 85-93% of patients. Bougie-type dilators exert not only radial forces as they are passed, but also longitudinal forces as the result of a shearing effect. Longitudinal forces are not transmitted with balloon dilators because the entire dilating force is delivered radially and simultaneously over the entire length of the stenosis, rather than progressively from its proximal to distal extent. Despite these differences, no clear advantage has been demonstrated between the two dilator types. Several clinical features are associated with outcome. For peptic strictures, a smaller lumen diameter, presence of a hiatal hernia greater than 5 cm, persistence of heartburn after dilation, and number of dilations needed for initial dysphagia relief were significant predictors of early symptomatic recurrence. A multivariate analysis revealed that a non-peptic etiology of strictures was a significant predictor of early symptomatic recurrence within one year of initial dilation. Patients with peptic strictures should be treated with proton pump inhibitors. Compared with histamine receptor antagonists, proton pump inhibitors decrease stricture recurrence and the need for repeated stricture dilation. The principal complications of esophageal dilation are perforation, bleeding, and aspiration. The perforation rate for esophageal strictures after dilation has been reported to be 0.1 to 0.4%. The risk of perforation is lower in simple strictures and higher in more complex strictures. Perforation may be more common in severe with radiation-induced strictures, and the perforation rate may be influenced by the experience level of the endoscopist. Esophageal stents can be considered in malignant esophageal obstruction and benign refractory esophageal strictures. Currently, there is no consensus on absolute contraindications for esophageal stent placement. Inadequate candidates for esophageal stenting include curable esophageal cancer without complete dysphagia, patients with uncontrolled bleeding tendency, severely ill patients with limited life expectancy, obstructive lesions of the stomach and small bowel due to peritoneal seating, or severe tracheal compression that would be made worse by esophageal stenting. Before stent placement, it may be helpful to obtain a barium esophagogram to define stricture location, length, angulations, and presence of tracheoesophageal fistulae. It can provide useful information regarding the diameter and the length of the stent to be employed. Smaller caliber endoscopes can easily pass through the stricture, offering a simple and safe evaluation of the lesion. .035 or .038 inch stiff wires are usually used, but if the stricture is extremely tight or torturous, a hydrophilic biliary guide wire preloaded through a standard biliary catheter can be used. Once the guide wire has been passed through the stricture with fluoroscopic monitoring, bougie dilation is performed to a minimal luminal diameter of 6-10 mm that will permit deployment. The choice of stent for an individual is influenced by a variety of factors, including tumor length and position, the presence of a fistula, potential airway compromise, and personal preference of the physician inserting the stent. The diameter and length of the stent should be determined after measuring and monitoring the length of the stricture using fluoroscopy or endoscopy. The length of the stent chosen should be at least 3-4 cm longer than the obstruction to allow an adequate margin of stent on either side of the obstruction. Self-expandable metallic stents are composed of a variety of metal alloys with varying shapes and sizes depending on the individual manufacturer. All stents appear to be equally effective in palliating obstructive symptoms. None of the currently available stents are small enough to pass through the endoscope. Fluoroscopy is used to confirm the length and location of the stricture. Once the length of the stricture has been determined, the length of the stent can be chosen. After determination of the stricture length and location, a guide wire is introduced through the stricture. Predilation may increase the risk of perforation. However, there is currently no consensus on how many sessions of predilation can be performed before the risk of perforation increases. If the endoscope can be passed with minimal difficulty through the obstruction, this can be attempted without predilation. Once the guide wire is in place, a pre-deployed stent is advanced over the wire into the stricture. It is important to realize that some stents are available as proximal release devices while others deploy in a distal to proximal sequence. The distal release stents are used for stent placement in the mid and upper esophagus while proximal release stents are used for the gastroesophageal release. After deployment, the endoscope is passed into the proximal portion of the stent but not through the stent to assess stent position relative to the tumor while avoiding dislodgement of the stent. This is a 67-year-old male with advanced esophageal cancer who is in a critical condition. This is a 67-year-old male with advanced esophageal cancer of the mid-esophagus. We used a partially covered ultraflex stent with distal release. The stent is constructed of a single strand of nitinol that exerts a constant gentle radial pressure while minimizing traumatic tissue compression. The low radial force of the stent seems to be useful for patients with malignant strictures that are close to the upper esophageal sphincter. Although we use an ultraflex stent, other stents can also be used in this patient. Prior to the procedure, the endoscopist should be familiar with the characteristics of each available stent. The use of stents in the proximal esophagus has traditionally been considered to be restricted because of an increased risk of complications and patient intolerance. Recently, this view has been challenged by a few small and preliminary reports. In an evaluation of 104 patients with proximal esophageal stenting, technical success, dysphagia improvement, the rate of major and minor complications, and recurrent dysphagia was not significantly different between patients with strictures within 4 cm or between 5 to 12 cm of the upper esophageal sphincter. A foreign body sensation was significantly higher in patients with strictures within 4 cm of the upper esophageal sphincter. However, stent removal was indicated in none of the patients. In other studies comparing series of stents placed in the middle distal esophagus or gastrocardia, the complication rate in proximal esophageal stenting was also comparable, with thyroid frequencies varying between 24 to 36%. This is a barium esophagogram of a 45-year-old male complaining of dysphagia with known anaplastic cancer of the thyroid gland. On the left, barium can be seen leaking through the tracheostomy site. The distal esophagus below the tracheostomy site cannot be seen, and collections of barium can be seen filling the bronchial tree. Endoscopy shows a stricture with a fistula 2 cm below the upper esophageal sphincter. We decided to deploy a cervical chew stent for palliation of symptoms and sealage of the fistula. The cervical chew stent is a covered stent with a proximal funnel to minimize foreign body sensation. After successful stent deployment, the patient's dysphagia improved, and no further leakage was observed on follow-up exams. During the last few years, stents have become increasingly used for dilating refractory benign esophageal strictures. The idea is that dilation for a prolonged period of time will ultimately reduce the risk of recurrent stricture formation. This is a 57-year-old male with an anastomotic site stricture following surgery for esophageal cancer. The stricture was refractory despite several sessions of Bujji dilation and microwave therapy. We inserted a covered self-expandable metallic stent for one week. Following removal of the stent, dramatic improvement can be seen. Self-expandable metallic stents have been used with variable success in the treatment of benign strictures. However, complications of uncovered or partially covered self-expandable metallic stents include difficulty in stent extraction, development of secondary strictures, necrosis, and ulceration from the stents themselves. Therefore, it is best to avoid uncovered or partially covered self-expandable metallic stents for the treatment of benign strictures. These are the currently available stents for benign esophageal strictures. These stents all have the common feature of easy retrieval after deployment. Patients who have advanced esophageal obstruction frequently have retained secretions in the esophagus. These patients are at risk for pulmonary aspiration. Placing the patient in the left lateral decubitus position and having the assistant closely monitor and suction secretions will help prevent aspiration. Vigorous irrigation through the endoscope channel in an attempt to clear secretions and improve endoscopic visualization may also cause aspiration. Unfortunately, fluids tend to reflux proximally from the obstruction leading to aspiration. This is more likely to occur with proximal lesions. Irrigation should be avoided in patients with tracheoesophageal fistulas. Irrigation should be avoided in patients with tracheoesophageal fistulas when the endoscope is positioned near the fistula since fluid is likely to pass directly into the trachea. Finally, in those patients who have gastroesophageal junction tumors, gastric contents can reflux through the stent immediately after deployment. Thus, while in the recovery area, patients in whom a stent has been placed across the GE junction should be kept in the left lateral decubitus position or have their head elevated if placed in the supine position to prevent aspiration during this period. Airway compromise from tracheal obstruction is the most feared immediate complication of esophageal stent placement. It almost always occurs in the setting of large mediastinal masses that are in the area of the carina or more proximally located in the esophagus. Any history of recent shortness of breath or wheezing should alert the endoscopist that there may be airway compromise. In addition, the development of stridor associated with oxygen desaturation during passage of the endoscope across the stricture is a red flag. Because most patients will have a recent chest CT, a pre-procedural review with attention to the relationship of the esophagus to the mass usually will suggest some sort of tracheal narrowing in those patients at risk. Some endoscopists advocate the passage of a moderate-sized rigid dilator or inflation of a dilating balloon within the stricture as a test to see if the patient develops stridor. There is no data, however, to support this practice. To prevent stent malposition, the endoscopist must first be familiar with the stent that is to be used. Thorough knowledge of the characteristics of each stent, including the release system and the degree of foreshortening, should be taken into account before deployment. There are several options to manage stent malposition should it occur, depending on whether the stent is partially within the stricture. If it has been deployed more distally than intended, it usually can be pulled proximally by grasping the proximal edge with a raw-tooth forcep and withdrawing the endoscope. If deployed too far proximally, it is usually not possible to push the stent forward, especially if the stent is distal release. In this situation, either the stent can be removed completely with forceps, or a second stent can be placed in an overlapping fashion to cover the distal end of the stricture. Stent dislodgement usually occurs when an attempt is made to pass the endoscope through the stent lumen immediately after deployment. This step is usually unnecessary. Another case of stent dislodgement is placement of a percutaneous endoscopic gastrostomy tube after stent deployment. Perforation during deployment can be caused by the guide wire itself, application of excessive force to the endoscope during attempts to pass the stricture, or excessive dilation of the stricture. A stent should never be deployed unless the endoscopist is absolutely certain that the guide wire is interluminally placed. In this patient with a complex stricture at the EG junction following lye ingestion, CRE balloon dilation and stenting was attempted. However, guide wire passage through the stricture was difficult. This patient eventually developed pneumoperitoneum the following day. Following stent insertion, chest x-ray should be carried out to verify the position of the stent and to check for signs of perforation. Following stent placement, patients can experience varying degrees of chest pain and discomfort. This is usually controlled with simple analgesia and occasionally opiates. It is important to ascertain whether or not the chest pain is related to acid reflux. Chest x-ray should be performed to confirm the position, expansion and function of the inserted stent one and three days after stenting. In contrast to malignant esophageal strictures, stents are removed after a period of time for benign strictures of the esophagus. Although there are no available guidelines, most reports recommend a stent dwell time of 4 to 16 weeks. The most commonly anticipated early complications following esophageal stenting are bleeding, chest pain and nausea. Bleeding is almost always self-limited. Chest pain occurs very commonly and is usually controlled with simple analgesia. Nausea is an underappreciated complication. There is no way to avoid this. Although the use of scheduled anti-nausea agents for the first few days should be considered in those patients who experience more than minimal nausea in the recovery area. The most common late complications are gastroesophageal reflux, migration, reobstruction, tracheostomy and gastrointestinal infarction. Gastroesophageal reflux disease, with or without aspiration, can occur when a self-expandable metallic stent is placed across the GE junction. Gastroesophageal reflux and aspiration can be avoided by the aggressive use of proton pump inhibitors. Various stents with anti-reflux mechanisms have been developed just for the purpose of placement across the GE junction. Although the available data is limited, the use of anti-reflux stents has usually been used in the recovery area. Migration of a successfully deployed stent is a relatively common complication. Migration may occur in the case of incomplete obstruction, where the stent may not hold within the stricture. Tumor shrinkage following oncologic treatment of gastrointestinal infarction and gastrointestinal infarction may occur. Migration may occur in the case of incomplete obstruction, where the stent may not hold within the stricture. Tumor shrinkage following oncologic treatment of gastrointestinal infarction and gastrointestinal infarction may occur. Stents placed across very soft polypoid tumors and smaller diameter stents placed across the GE junction are more prone to migration. Thus, to minimize migration in this setting, it is recommended that larger diameter stents be used. The management of stent migration depends on the health of the patient, degree of dysphagia, and location of the stent. Most commonly, the stent migrates into and remains within the stomach. If the patient's performance status is poor, it is probably best to leave the stent in place. Patients who are symptomatic because of early satiety caused by the stent should be offered stent removal. If the patient experiences recurrent dysphagia, stent removal and placement of a new stent can be tried. Before attempting to retrieve a migrated stent, one should first consider the design of the stent. Reobstruction can occur from several mechanisms, including food impaction, tumor overgrowth or ingrowth, and tissue hyperplasia. Diet education is needed for prevention of stent reobstruction due to food impaction. Reobstruction by tumor ingrowth, overgrowth, or tissue hyperplasia is managed best with placement of a new stent within the previous one. Tracheoesophageal fistulas, as a result of the ends of the stent eroding through the wall, is beyond the control of the endoscopist. This complication can be managed by placing another covered self-expandable metallic stent or a self-expandable plastic stent within the initial stent. The risk of tracheoesophageal fistulas may be greater in patients who have received radiation therapy. Delayed bleeding can be fatal and is largely beyond the control of the endoscopist because it is usually tumor-related or caused by prior treatment with chemoradiation. Other notable causes of bleeding occurs when the distal end of the stent has been placed too far into the stomach, such that it impacts the greater curvature, forming a mechanical ulcer. Overall, the benefits of stenting in malignant esophageal strictures is well-established. The technical success rate is 90-100%. Over 90% of patients show improvement of dysphagia, and the mean improvement in dysphagia score is 1.28-2.5. Although there are various complications that occur in varying frequency, chest pain is the most common immediate complication, and tumor overgrowth is the most common delayed complication. Previous radio or chemotherapy may be associated with increased risk of developing complications. Causes of recurrent dysphagia include stent migration, stent occlusion by tumor in and overgrowth, or food impaction. In an outcome analysis of 338 patients with esophageal or gastrocardiac cancer who were treated with either small or large diameter stents, relief of dysphagia was equal, regardless of the stent diameter. However, there was a significant increase of recurrent dysphagia in patients who inserted small stents compared to large stents. This study provides us some insight regarding the choice of stents in the management of malignant dysphagia. The ultraflex stent is the most commonly used stent for palliation of malignant esophageal cancer. However, in a recent study, the NITES stent showed a significant improvement in the rate of stent migration and food impaction. The self-expandable plastic polyflex stent showed a significant lower rate of tumor ingrowth and food impaction. These are the published results of self-expandable metallic stents and self-expandable plastic stents for benign strictures. For self-expandable metallic stents, the most common indication was achalasia, followed by caustic and post-radiation strictures. Early on, uncovered stents were used. However, recently partial or fully covered stents are used more frequently. The stent dwell time varied, and in some studies, the stent was not removed during the study period. Migration and hyperplastic growth were the most common complications, and long-term effects were seen in less than 50% of patients. The most common indication for self-expandable plastic stents was anastomotic strictures, followed by peptic and caustic strictures. All published studies used the polyflex stent. In contrast to self-expandable metallic stents, hyperplastic growth rarely occurred. However, the migration rate was 47%, and less than 50% of patients showed long-term effects. The results of stenting for benign strictures are disappointing so far, with long-term clinical resolution of the stricture achieved in less than 50% of patients. This is mainly due to hyperplastic tissue growth and stent migration. New stent designs are therefore needed for this indication. Most of the strictures after esophagectomy are thought to result from ischemia of the proximal gastric tube, with a smaller proportion related to fistulas or technical difficulties in the creation of the anastomosis. The reported instance of benign postoperative gastroesophageal anastomotic strictures varies widely from 5 to 55%. Anastomotic strictures generally present symptomatically 2 to 3 months postoperatively. Anastomotic strictures are generally difficult to treat. Some reports indicated a higher median number of dilations required, and many series recognized a subset of 10% of patients who required repeated treatment sessions due to refractory strictures. Although bougie or balloon dilations have been used most commonly, other endoscopic treatment modalities have been described, including steroid injection, electroincision, and temporary placement of a polyester-silicon self-expanding stent. Of these modalities, electroincision has seen the most attention of late and has shown promising results. If the stricture is non-responsive to dilation therapy, incisional therapy should be considered for Schatzky's rings and anastomotic strictures. Prior to electroincision, a barium esophagogram should be obtained. The length of the stricture is an important predictor of treatment outcome. Strictures longer than 1 cm have a less certain treatment effect. Endoscopy and biopsies should also be performed to rule out malignancy. There are several modalities available for electroincision. For incisional therapy with the needle knife, multiple longitudinal incisions around the circumference of the stricture are performed. The electrosurgical unit uses a blended current with a cutting power of 120 watts. This is a patient with previous esophagectomy for esophageal cancer. A long, complex anastomotic stricture is observed on endoscopy. Radial incisions are made around the stricture using the needle knife. The number and radial position of the incisions were chosen to completely open the rim of the stricture. We recommend that the incisions be made around the incision. The number and radial position of the incisions were chosen to completely open the rim of the stricture. Weeks after electroincision, dramatic improvement of the stricture can be seen on follow-up endoscopy. The isotome, or IT knife, are also used for electroincision. The isotome, which has a semi-oval shaped tip of epoxide, or an insulated tip knife, can prevent unintentional injury during incision. A transparent hood allows direct visualization while ensuring the safety margin. An electrosurgical unit was used with a pure cutting current at a power output setting of 40 watts. This clip shows electroincision using the isotome for an anastomotic stricture of the esophagus. The tip of the transparent hood is positioned just proximal to the stricture. Under direct vision through a transparent hood to ensure the safety margin, radial incisions parallel to the longitudinal axis of the esophagus were carefully performed by pulling up the isotome. The procedure was terminated when the endoscope could easily pass the stricture without resistance. EMCT is not a commonly used modality, however it has been used in incisional therapy for anastomotic strictures refractory to dilation therapy. The microwave tissue coagulator is set at a coagulation current of 50 watts for a duration of 5 seconds. Ball or needle type electrodes are contacted with the stricture in a radial direction. A simple short anastomotic stricture is seen in a patient who underwent esophagectomy for esophageal cancer. Electroincision using EMCT was performed. Tissue coagulation is performed in a radial direction until the tissue comprising the stricture ring shows a white color. Patients should be closely observed after electroincision. Chest x-ray is not essential but should be performed urgently in patients who develop pain, dyspnea, fever, or tachycardia. Therapeutic endoscopy should be considered urgently in patients who develop hematmesis, melina, or tachycardia. We recommended the patient drink water when awake and alert and without evident complications. Clinical evaluation and follow-up endoscopy should be performed at least one month after the procedure. The overall safety experience with electroincision of anastomotic strictures has been favorable, but data is still limited. Restricture may occur after incisional treatment, usually in long-segment strictures. In a recent report, the restricture rate for strictures less than 1 cm was 4%, in contrast to 66.7% for long-segment strictures. Clinical entities that can result in gastric outlet obstruction generally are categorized into two groups, benign and malignant. The major benign causes of gastric outlet obstruction are peptic ulcer disease, gastric polyps, ingestion of caustics, pyloric stenosis, congenital duodenal webs, gallstone obstruction, pancreatic pseudocysts, and besores. Pancreatic cancer is the most common malignancy causing gastric outlet obstruction. Outlet obstruction may occur in 10-20% of patients with pancreatic cancer. Other tumors that may obstruct the gastric outlet include ampullary cancer, duodenal cancer, cholangiocarcinomas, and gastric cancer. Metastasis to the gastric outlet also may be caused by other primary tumors. Traditionally, treatment of benign gastric outlet obstruction has been surgical. In high-risk patients, medical therapy was considered. However, obstruction persisted in more than 50% and necessitated surgical intervention. With the advances in endoscopic techniques and through the scope of balloon dilating catheters, endoscopic balloon dilation has emerged as the most effective first-line therapy in most patients and in those who are at a high risk for surgery. Balloon dilation for benign gastric outlet obstruction is especially useful in the treatment of obstruction related to peptic ulcer disease. Prior to endoscopy, the patient should be fasted for at least 8-12 hours. During standard upper endoscopy, the stomach and pyloric channel are carefully examined for the presence of active or chronic ulcers. A large-channel gastroscope will allow for suction and removal of retained secretions. Multiple biopsies should be taken from the ulcer edges and gastric mucosa to exclude malignancy and helicobacter pylori, respectively. The pyloric or duodenal stricture is assessed for the degree of stenosis by measuring its luminal diameter in reference to the outer diameter of the endoscope and by the ability to advance the endoscope through the stricture into the distal duodenum. Currently, there are a number of commercially available balloon dilators of different sizes and lengths. The most commonly used are the controlled radial expansion, wire-guided balloon dilators. These balloons are designed to deliver three distinct pressure control diameters with a high degree of radial vector force at any given pressure. The tip is flexible and minimizes the risk of perforation. When fluoroscopy is not utilized, dilation is performed under direct endoscopic guidance. This is an 86-year-old female complaining of nausea and early satiety. Endoscopy showed a large amount of remnant food and a pyloric stricture. The endoscope was enabled to pass through the pyloric ring. Under direct endoscopic guidance, the CRE balloon catheter is passed through the stricture. An 8-10 mm CRE balloon is advanced through the channel of the endoscope. The floppy tip is positioned across the stricture. Once in place, the CRE balloon is advanced over the guide wire, leaving one-third of the balloon beyond the stricture. The CRE balloon is then inflated to 8, 9, and 10 mm for three minutes at each diameter. When to repeat dilation depends on the degree of stenosis and the success of the initial procedure. The procedure should be repeated within two weeks for high-grade strictures. A planned repeat dilation was performed in two weeks' time. We decided not to use more than two catheters during a single session. 10-13.5 and 12-15 mm CRE balloons were used for the second dilation. Balloon dilation allowed for passage of the endoscope into the duodenum, and for biopsies of a duodenal ulcer. Patients should be closely observed after gastric outlet dilation. We recommended the patient initially drink water if the patient was awake and alert, and had no complications such as bleeding or perforation. We started a liquid diet one day after dilation, and then advanced the diet carefully in a stepwise pattern. The procedure is repeated in one to two weeks, until obstructive symptoms improve. Helicobacter pylori should be eradicated if present, and ulcer disease should be aggressively treated to prevent recurrence. A recent study evaluated the outcome of TTS balloon dilation in 72 patients with gastric outlet obstruction secondary to various causes. Immediate symptomatic relief was achieved in 80% of patients, and sustained relief was seen in 70% of patients. The mean diameter of the stricture increased from 6 mm before dilation to 16 mm after dilation. Perforation occurred in two patients, and bleeding occurred in one patient. In gastric outlet obstruction related to peptic ulcers, overall success rates for endoscopic dilations were up to 85%, with complications of perforation and bleeding occurring in fewer than 10% of cases. Failure was primarily associated with long duodenal strictures, or the inability to place the balloons, Perforations were most often seen when using balloons reaching 18 mm in diameter. Endoscopic balloon dilation is now widely accepted as the first-line therapy for benign gastric outlet obstruction. Unfortunately, recurrence of the stricture may develop, especially if the endoscopist only focuses on fixing the stricture without resolving the underlying problems. A retrospective analysis of endoscopic balloon dilation for caustic-induced chronic gastric outlet obstruction showed promising results. After a mean of 5.8 sessions, 39 of 41 patients remained symptom-free. The endoscopic balloon dilation was a success, and the endoscopic balloon dilation was a success. The endoscopic balloon dilation was a success, After a mean of 5.8 sessions, 39 of 41 patients remained symptom-free for 18 to 58 months. These results suggest that endoscopic balloon dilation may be a safe, effective, and long-lasting alternative to surgery for caustic-induced gastric outlet obstruction. Malignant gastric outlet obstruction is a common complication of advanced pancreatic cancer. It occurs in 10 to 15% of patients with pancreatic cancer and manifests as a stricture of the proximal duodenum. Clinical presentations include early satiety, nausea, vomiting, and gastric distention. Until recently, the management of this complication consisted of surgical gastroenteric bypass with or without an associated biliary bypass. Over the past decade, the endoscopic deployment of self-expanding metal stents has emerged as a new option for restoration of enteric patency. Gastroduodenal stents can be considered in symptomatic patients with malignant gastric outlet obstruction. Stent treatment should be indicated in patients with incurable cancer. Before placement of a stent, the life expectancy of the patient should be considered first. When life expectancy is relatively long, surgical bypass is preferred. In patients with a very short life expectancy, best supportive care is the optimal choice. Contraindications to gastroduodenal stent placement include known or suspected enteral ischemia or perforation, the inability to pass a guide wire across the stricture, and the usual endoscopic contraindications. Although not absolutely necessary, it is helpful to obtain a radiographic contrast study to assess the anatomy, length of the stricture, and degree of obstruction, especially in cases where it is unclear if the obstruction is functional. Coexistent biliary obstruction is commonly present since it typically develops earlier than gastric outlet obstruction. If there is known or impending biliary obstruction, an expandable middle biliary stent should be placed before the duodenal stent because it is difficult to obtain biliary triaxis once a duodenal stent has been placed across the papula. A percutaneous transhepatic approach may be required to treat a biliary obstruction that develops after duodenal stent placement. To prevent aspiration of gastric contents during procedure, endoscopic suction and removal of retained gastric content prior to stent insertion is essential. The patient should be placed in the left lateral decubitus or prone position. A prone position allows for better anatomic view under fluoroscopy. The supine position should be avoided because of the risk of aspirating retained gastric contents. Prior to procedure, an adequate endoscope should be chosen with consideration of the delivery catheter system and location of the obstruction. If the wall flex stent is planned to be used, an endoscope with a therapeutic working channel greater than 3.7 mm is required to allow passage of the 10 French delivery system. When stents are placed beyond the proximal or second portion of the duodenum, a therapeutic adult colonoscope is usually required. The use of fluoroscopy is highly recommended but not strictly required for proper stent placement. Fluoroscopy allows identification of contrast dye to delineate the stricture, defying its length and geometry, both of which greatly aid in the selection of stent type and size. Use of fluoroscopy during deployment helps to ensure proper position and may minimize misdeployments or other complications. If the endoscope passes easily through the lesion, a 0.035 inch guide wire with a floppy tip is placed through the endoscope channel. If the endoscope cannot be passed easily through the lesion, a hydrophilic biliary guide wire preloaded through standard biliary accessories can be used to traverse the stricture. Uncovered self-expandable metallic stents are now widely used for the palliation of malignant gastric outlet obstruction. Nevertheless, a number of complications have also been observed with self-expandable metallic stents. Most frequently, stent obstruction caused by tumor ingrowth, mucosal hyperplasia, tumor overgrowth, or food impaction. Covered stents were designed to prevent the former two problems, which are caused by the inward growth of tumorous or hyperplastic tissue across the interstices of the stent mesh. Previous studies indicated that although covered self-expandable metallic stents are beneficial in reducing the rate of obstruction, they may have a greater tendency to migrate. However, supporting evidence for the efficacy of covered self-expandable metallic stents is lacking. In a recent retrospective comparison of uncovered and covered self-expandable metallic stents in 60 patients with malignant gastric outlet obstruction, covered stents were comparable with uncovered stents in terms of feasibility and complications, but were associated with an increased need for repeated interventions. The choice of stent is influenced by a variety of factors, including tumor length and position, angulation, and personal preference. In malignant gastric outlet obstruction, angulation should be specially considered because the proximal and distal aspects of the stent should conform to the natural curves of the stomach and duodenum. Stents should be 3-4 cm longer than the underlying structure. At present, uncovered stents appear to be more suitable in the palliation of gastric outlet obstruction because uncovered stents are less prone to re-intervention. However, these results require confirmation in larger randomized trials. Currently, there are two stents approved by the Food and Drug Administration for palliation of malignant gastroduodenal obstruction, the duodenal wall flex and colonic duodenal wall stent. Outside of the U.S., a variety of self-expandable metallic stents designed for gastroduodenal use are available. These include the T-type stent and Haneroenteral stent. Fluoroscopy is used to confirm the length and location of the stricture. The stent should be 3-4 cm longer than the underlying stricture. For guide wire access, a .035-inch stiff guide wire is commonly used under fluoroscopic guidance. In difficult situations where the lumen is hard to locate or pass through, a round-tipped cannula with contrast injection helps with guide wire insertion. There is no need to traverse or predilate the stricture prior to procedure. Before advancing the pre-deployed stent over the guide wire, the extension tube of the delivery system should be primed with abundant saline for a smooth delivery. The endoscope should be reduced to a relatively straight position to allow the distal portion of the stent to pass through the stricture. Once the position of the stent is confirmed, deployment is performed in a slow and cautious manner. While deploying, the position of the stent frequently needs adjustment as it has a tendency to slip distally from the anticipated delivery site. The endoscope should not routinely be passed through the stent lumen to check for patency as the stent could take some time to achieve full deployment. This is a 67-year-old female with advanced gastric cancer. We used a duodenal wall stent for palliation of gastric outlet obstruction. A stiff guide wire was inserted across the obstruction site using fluoroscopy and the stent was advanced over the guide wire into the stricture. Looping of the endoscope makes it difficult to pass the stent through the operating channel. It is easier to deploy and adjust the stent when the endoscope is straightened and as close to the stricture as possible. When deploying, the endoscopist should adjust the stent position as it frequently slips distally from the delivery site. Recently reported clinical results were similar between endoscopic and fluoroscopic stent placement. However, in one study, the technical success rate under fluoroscopic guidance was significantly different depending on the site of the obstruction. Fluoroscopic stent placement at the site of duodenal obstruction and anastomotic regions were technically more difficult than the peripyloric region. This is due to loop formation of the stent delivery system in the distended stomach, the curved configuration of the duodenal C-loop, and the anatomic difficulties after surgery. Perforation during deployment can be caused by application of excessive force to the endoscope during attempts to pass the stricture, pre- or post-dilation of the stricture, or inappropriate use of the guide wire. This shows delayed perforation 15 days after duodenal stenting. Sharp proximal stent barbs are seen to be embedded in the proximal duodenal bulb. Delayed perforation is largely out of the endoscopist's control. Although the prevention of delayed perforation is difficult, to minimize perforation, the middle end of the stent should be kept in the antrum for more proximal tumors. In more distal tumors, the endoscopist should attempt to deploy the stent in a manner that the distal end is not in a curved area and not impacted into the wall. Management of delayed perforation, should it occur, is usually surgical. Malposition occurs in most cases when the endoscopist is not familiar with the stent device. In the case of the wall flex stent, the endoscopist should keep the endoscope tip several centimeters proximal to the stricture and maintain the proximal end of the stent at this position. Because this stent is released distally, the stent must be pulled back frequently during deployment, as it slips distally from the endoscopist as it shortens. The endoscopist should also be aware that the bare metal wires are not endoscopically visible through the delivery sheath until the stent has deployed partially. At this point, the stent may be positioned too far distally than desired. Therefore, the endoscopist needs to communicate with the assistant during deployment, and stent deployment should proceed in a slow manner. It is also worth noting that the stent will continue to shorten after the procedure until it fully expands. Therefore, if only one centimeter or less is beyond one or both margins of the tumor at the time of complete deployment, the stent is likely to be too short when fully expanded several days later. Following stent insertion, x-rays should be carried out to verify the position of the stent and to check for signs of perforation. Following stent placement, patients can experience varying mild abdominal pain or discomfort while the stent is still in the process of expanding. This is usually controlled with simple analgesia. Follow-up x-rays to confirm position, expansion, and function of the inserted stent should be performed one and three days after stenting. Migration is a rare event following placement of the enteral wall stent because the stent is completely uncovered. Thus, if a stent migrates, it is likely that there is not a significant stricture. Finding minimal to no stricture or finding that a therapeutic channel endoscope easily passes through the stricture suggests that mechanical obstruction may not be the cause of the clinical findings of a dilated and fluid-filled stomach. Gastroparesis or peritoneal seeding may be the cause for the patient's symptoms. Obstruction by food is less likely to occur than with esophageal stents. Nonetheless, patients should be instructed to consume a low-fiber diet to reduce the risk of food infection within the stent. Reobstruction by tumor ingrowth, overgrowth, or tissue hyperplasia is best managed with the placement of a new stent within the previous one. If pre-evaluation of co-existent biliary obstruction precedes stent insertion, obstructive jaundice rarely occurs following placement of gastroduodenal uncovered stents. This 71-year-old male with inoperable advanced gastric cancer underwent stenting with an uncovered self-expandable metallic stent for gastric outlet obstruction. The initial abdominal CT scan showed mild intrahepatic duct dilation. After deployment of the uncovered stent, the patient's obstructive symptoms improved. However, two weeks later, he developed jaundice. An ultrasonography showed severe intrahepatic duct dilation. The patient eventually underwent percutaneous transhepatic biliary drainage. As in this case, obstructive jaundice following an uncovered stent for gastric outlet obstruction is mainly due to overlooked co-existing biliary obstruction rather than the stent itself. Obstruction of the papilla by the stent itself has been reported and managed with ABC trimming of the stent. Delayed bleeding is likely to be caused by the tumor. Delayed bleeding is likely to be caused by the tumor. Although the same mechanism that leads to delayed perforation may lead to ulcer formation and bleeding. Therefore, the same approach to prevent that complication also may prevent bleeding. Tumor-related bleeding may be managed by embolization. Broken stents are a very rare complication. The cause is unknown. However, it may be related to gastric acid, mechanical stress, defective stent material, or thermal strain occurring after APC or laser therapy. The management of a broken stent is removal and reinsertion of a new stent. Technical success rates for self-expandable metallic stents and malignant gastric outlet obstruction are generally over 90%. Technical failure results from large mass lesions with ulceration, massive gastric dilation, post-surgical anatomy, or alternative symptoms. A comprehensive review of 32 case series, including 606 patients unable to take oral intake, reported successful stent deployment in 97% of patients. And oral intake was possible in all successful cases, with 87% of patients capable of eating at least a mechanical soft diet. No differences between stent placement and gastrogygenostomy were found in technical success, early and late major complications, and persisting symptoms. Initial clinical success was higher after stent placement. Recurrent obstructive symptoms were more common after stent placement. Hospital stay was prolonged after gastrogygenostomy compared to stent placement. Self-expandable metallic stent placement seems to be associated with an improved quality of life and decreased length of hospital stay, making it a superior treatment option. According to a systematic review of 32 case series regarding gastrogygenostenting, there are no procedure-related mortalities. Severe complications such as bleeding and perforation were observed in 7 patients. Stent migration was reported in 5% of patients, and stent obstruction occurred in 18% of patients, mainly due to tumor infiltration.
Video Summary
Esophageal strictures can be caused by various factors such as reflux esophagitis, Schatzky's rings, esophageal cancer, and surgery. Endoscopic treatment options include dilation therapy, stent therapy, and incisional therapy. The primary goal of esophageal dilatation is symptom relief and to allow for oral nutrition. Endoscopic treatment should be individualized based on the patient's condition. Prophylactic antibiotics are generally not recommended for infectious endocarditis prevention following dilatation. Bougie, Savary-Gilliard, and through-the-scope balloon dilators are commonly used. Different types of endoscopic modalities like needle knife, Isotone, and microwave coagulation therapy can be used for incisional therapy. Patients should be closely monitored post-procedure for complications such as bleeding, perforation, and aspiration. Treatment also varies for gastric outlet obstruction with options including endoscopic balloon dilation, and gastroduodenal stent placement. Self-expandable metallic stents are commonly used for palliation of gastric outlet obstruction. Complications such as bleeding, migration, and perforation should be closely monitored and managed accordingly. In conclusion, endoscopic treatments are effective options for managing esophageal strictures and gastric outlet obstructions, each with its own benefits and potential complications that need to be carefully considered.
Keywords
Esophageal strictures
Dilation therapy
Stent therapy
Incisional therapy
Oral nutrition
Endoscopic modalities
Complications
Gastric outlet obstruction
Endoscopic balloon dilation
Stent placement
Self-expandable metallic stents
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