Self-expanding metal esophageal stent with anti-reflux mechanism

An antireflux stent versus conventional stents for palliation of distal esophageal or cardia cancer: a randomized clinical study

BACKGROUND

Self-expandable metal stents placed across the esophagogastric junction for palliative treatment of malignant strictures may lead to gastroesophageal reflux and pulmonary aspiration. This study compared the effects of a Dua antireflux stent with those of a conventional stent.

METHODS

Patients with incurable cancer of the distal esophagus or gastric cardia were randomly assigned to receive an antireflux stent (n = 19) or a standard stent (n = 22) at nine Swedish hospitals during the period September 1, 2003 to July 31, 2005. Complications were recorded at clinical follow-up visits. Survival rates were assessed through linkage to the Population Register. Dysphagia, reflux symptoms, esophageal pain, dyspnea, and global quality of life were assessed as changes in mean scores between baseline and 1 month after stent insertion through validated questionnaires.

RESULTS

No technical problems occurred during stent placement in the 41 enrolled patients. Fewer patients with complications were observed in the antireflux stent group (n = 3) than in the standard group (n = 8), but no statistically significant difference was shown (p = 0.14). The survival rates were similar in the two groups (p = 0.99; hazard ratio, 1.0; 95% confidence interval, 0.5-2.0). The groups did not differ significantly in terms of studied esophageal or respiratory symptoms or quality of life. Clinically relevant improvement in dysphagia occurred in both groups. Dyspnea decreased after antireflux stent insertion (mean score change, -11), and increased after insertion of standard stent (mean score change, +21).

CONCLUSIONS

Antireflux stents may be used without increased risk of complications, mortality, esophageal symptoms, or reduced global quality of life. These results should encourage large-scale randomized trials that can establish potentially beneficial effects of antireflux stents.

Prior chemoradiotherapy is associated with a higher life-threatening complication rate after palliative insertion of metal stents in patients with oesophageal cancer

BACKGROUND

Self-expanding metal stents are used routinely to palliate dysphagia due to oesophageal cancer.

STUDY AIM

To compare the frequency of life-threatening complications after self-expanding metal stent insertion, depending on whether patients received prior chemoradiotherapy or no treatment.

PATIENTS AND METHODS

During 7 years, 116 consecutive patients were treated at a single centre in a palliative intent by insertion of self-expanding metal stent for dysphagia due to an oesophageal cancer. Patients were retrospectively separated into two groups: patients with chemoradiotherapy before self-expanding metal stent insertion (group 1, n = 56) and patients with no treatment before or after self-expanding metal stent insertion (group 2, n = 60). Life-threatening complications were compared and predictive risk factors of postprocedure complications were identified.

RESULTS

Median dysphagia was significantly improved during the first month (grade 3 to grade 1 in the two groups). Early and late major complications occurred more frequently in group 1 (23.2% vs. 3.3%; P < 0.002 and 21.6% vs. 5.1%; P < 0.02 respectively). Prior chemoradiotherapy was the only independent predictive factor of postprocedure major complications, with an odds ratio of 5.59 (CI 95% 1.7-18.1).

CONCLUSIONS

Life-threatening complications after palliative self-expanding metal stent placement seem to occur more frequently in patients with prior chemoradiotherapy. Prevention of these severe complications should be considered before stenting.

Endoscopic approaches for palliation of luminal gastrointestinal obstruction

Much of the workload of a typical gastroenterologist is devoted to screening patients for gastrointestinal malignancies. Efforts such as colorectal cancer screening via colonoscopy and endoscopic surveillance of patients with Barrett's esophagus are widespread and widely endorsed. In recent years, the armamentarium of endoscopy has broadened considerably and now affords physicians a variety of nonsurgical means to palliate malignant obstruction of the gastrointestinal tract. This article reviews endoscopic techniques to treat malignant esophageal, biliary, small bowel, and colonic obstruction.

New developments in palliative therapy

Over the past 5 years, new developments in the palliative treatment of incurable cancer of the oesophagus and gastro-oesophageal junction have been introduced with the aim of palliating dysphagia and improving the survival of patients. Stent placement is currently the most widely used treatment for palliation of dysphagia from oesophageal cancer. A stent offers rapid relief of dysphagia; however, current recurrent dysphagia rates vary between 30 and 40%. Recently introduced new stent designs are likely to reduce recurrent dysphagia by decreasing stent migration and non-tumoral tissue overgrowth. Intraluminal radiotherapy (brachytherapy) has been demonstrated to compare favourably with stent placement in long-term effectiveness and safety. A disadvantage of brachytherapy, however, is that one-fifth of patients need an additional treatment because of persistent tumour growth in the oesophagus. A solution may be to administer brachytherapy not in a single fraction but in multiple fractions. Finally, efforts have been undertaken to improve survival of patients by using chemotherapy. In the future, a multimodal approach--for example by combining stent placement with chemotherapy or radiotherapy--may improve the prognosis of patients without jeopardizing their quality of life.

Palliative therapy

There are a wide variety of palliative treatments for esophageal cancer. The aim of most treatments is to maintain oral food intake, which should stabilize or even improve quality of life. Stent placement is currently the most widely used treatment modality for palliation of dysphagia from esophageal cancer. Stent placement offers a rapid relief of dysphagia, however, the rate of complications (late hemorrhage) and recurrent dysphagia (stent migration, tumor overgrowth) is relatively high. The scientific evidence to advocate the use of anti-reflux stents for the prevention of gastro-esophageal reflux is currently too low. Photodynamic therapy is mostly used in North America; however, due to the high costs of the treatment, the long-lasting side effects and the necessity of repeated treatments, it is not an ideal treatment for palliation of malignant dysphagia. Nd:YAG laser is a relatively effective and safe treatment modality, although laser treatment is also expensive, technically difficult and requiring repeated treatment sessions at 4-6 weeks intervals. Single dose brachytherapy compares favorably to stent placement in long-term effectiveness and safety. Effective treatment strategies are probably 12 Gy given in one fraction or 16 Gy given in two fractions. Palliative chemotherapy offers response rates in recent trials (including partial and complete responses) ranging from 35% to 50%. Whether palliative chemotherapy also results in a survival benefit is not established yet. For clinical trials on palliation of esophageal cancer, the measurement of quality of life is an important outcome measure. The cancer-specific EORTC QLQ-C30 and the esophageal cancer-specific EORTC-OES-18 are validated measures for establishing quality of life status. For the future, a multimodality approach with stent placement or brachytherapy in combination with chemotherapy may be indicated.

Quality improvement guidelines for placement of esophageal stents

Esophageal cancer is now the sixth leading cause of death from cancer worldwide. During the past three decades, important changes have occurred in the epidemiologic patterns associated with this disease. Due to the distensible characteristics of the esophagus, patients may not recognize any symptoms until 50% of the luminal diameter is compromised, explaining why cancer of the esophagus is generally associated with late presentation and poor prognosis. Esophageal cancer has a poor outcome, with an overall 5 year survival rate of less than 10%, and fewer than 50% of patients are suitable for resection at presentation. As a result palliation is the best option in this group of patients. The aims of palliation are maintenance of oral intake, minimizing hospital stay, relief of pain, elimination of reflux and regurgitation, and prevention of aspiration. For palliative care, current treatment options include thermal ablation, photodynamic therapy, radiotherapy, chemotherapy, chemical injection therapy, argon beam or bipolar electrocoagulation therapy, enteral feeding (nasogastric tube/percutaneous endoscopic gastrostomy), and intubation (self-expanding metal stents (SEMS) or semi-rigid prosthetic tubes) with different success and complications rates.

Endoluminal palliation

Endoluminal palliation involves the application of endoscopic techniques or devices to relieve the symptoms of malignant gastrointestinal obstruction. This is most often achieved with the use of self-expandable metal stents (SEMS). SEMS can be deployed as far distally or proximally in the gastrointestinal tract as the reach of an adult colonoscope. This article outlines the use of endoscopic techniques to provide endoluminal palliation.

Self-expanding metal stents in the palliation of malignant dysphagia: outcome analysis in 100 consecutive patients

SUMMARY. Patients with inoperable esophageal malignancy often undergo palliative self-expanding metal stent insertion. This analysis of cases shows that although such stents provide good palliation of dysphagia, complications frequently occur. Complications reported were pain after insertion, bleeding, food bolus impaction, stent migration and increased gastroesophageal reflux. Furthermore, in patients with esophageal adenocarcinoma, survival was less if the distal end of the stent entered the stomach, rather than lying entirely within the esophagus. Reduced survival, in this group with gastroesophageal junction tumors, may be a result of increased gastroesophageal reflux leading to pulmonary aspiration. Stents incorporating an antireflux valve have been shown to reduce symptomatic gastroesophageal reflux. It may be that such valves offer a survival advantage where stent insertion ablates the function of the lower esophageal sphincter. Further studies are needed to assess the role of antireflux stents on survival in patients with gastroesophageal junction tumors.

Palliative gastroenterology

Continuous improvements in endoscopic imaging and accessories have opened up a field of interventional endoscopy. This highly technical offshoot of gastroenterology uses not just standard endoscopic techniques but also newer endoscopic ultrasound (EUS) imaging or fluoroscopic monitoring to facilitate procedures that were once performed either surgically or percutaneously, if at all. This review will update the role of these novel procedures that can be used to assist in the palliative care of patients whose malignancies involve the gastrointestinal tract. The emphasis will be on those palliative interventions that are used to overcome intestinal obstruction in the gastrointestinal tract and restore luminal patency. The role of EUS-guided celiac plexus neurolysis to assist in pain control, especially in patients with pancreatic malignancies, will also be detailed.

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Esophageal stents with antireflux valve for tumors of the distal esophagus and gastric cardia: a randomized trial

BACKGROUND

Self-expandable metal stents deployed across the gastroesophageal junction predispose to gastroesophageal reflux. The efficacy of a stent with an antireflux mechanism in preventing gastroesophageal reflux was assessed.

METHODS

Thirty patients with carcinoma of the distal esophagus or of the gastric cardia were randomized to receive either a stent with a windsock-type antireflux valve (FerX-Ella) (n = 15) or a standard open stent (n = 15) of the same design minus the valve. Gastroesophageal reflux was assessed by using standardized questionnaires and by 24-hour pH monitoring 14 days after treatment.

RESULTS

Technical problems occurred during stent placement in 3 patients: migration (n = 2) and a problem with the introducing system (n = 1). Dysphagia improved from a median score of 3 (liquids only) to 1 (eat some solid food) in the antireflux group and from 3 to 0 (solid foods) in the open stent group ( p > 0.20). Reflux symptoms were reported by 3/12 patients (25%) with an antireflux stent and by 2/14 (14%) with an open stent. In 11 patients, 24-hour pH monitoring was obtained, and increased esophageal acid exposure (normal: <4%) was present with both types of stent: median 24-hour reflux time (9 patients) with the antireflux stent was 23% vs. 10% in (2 patients) with the open stent ( p = NS). Major complications occurred in 3 patients (20%) in each group and included bleeding (n = 3), severe pain (n = 2), and aspiration pneumonia (n = 1). The main cause of recurrent dysphagia was stent migration, which occurred in 7 of the 30 patients (23%).

CONCLUSIONS

The FerX-Ella antireflux stent provided relief of dysphagia caused by malignancy of the distal esophagus and gastric cardia. However, the antireflux valve failed to prevent gastroesophageal reflux.

Surgical palliation of thoracic malignancies

Primary and metastatic thoracic malignancies are often incurable. Surgeons caring for these patients must be familiar with the options,indications, techniques, and limitations of interventions for palliative treatments in these patients. This article is an overview of the current practices for palliation of a broad spectrum of complaints relating to patients with carcinomas of the lung, esophagus,and mesothelium. The information can be used for treatment of patients with complaints secondary to less common malignancies and metastatic disease of the thorax.

Management of Tracheoesophageal Fistulas in Adults

The approach to treatment of adult patients with tracheoesophageal fistulas depends on whether the fistula is congenital or acquired in origin. Most adults have acquired tracheoesophageal fistulas, and treatment depends on whether the fistula is a result of a benign process or a malignancy, with the latter usually primary esophageal cancer. For patients with benign tracheoesophageal fistulas, treatment is almost always initially supportive followed by definitive surgical correction. In general, depending on the size and location of the tracheal aspect of the fistula, surgical therapy involves primary repair of the fistula and, if necessary, resection and reconstruction of the trachea. For patients with malignant tracheoesophageal fistulas, treatment depends on whether the patient is resectable and/or medically fit for surgical therapy. However, most patients with malignant trach-eoesophageal fistulas have advanced disease and can only be treated with palliative measures. The current standard of palliative therapy for patients with malignant tracheoesophageal fistulas is the endoscopic or radiologic placement of covered self-expanding metallic stents (SEMS), which allow closure of the fistula. All three types of commercially available covered SEMS have been used in this capacity with success. Other, less common treatment options for selected patients with malignant tracheoesophageal fistulas include chemotherapy and radiation, surgical bypass, esophageal exclusion, and fistula resection and repair.

New approach to malignant strictures of the esophagus

Primary esophageal cancer is the most common cause of malignant esophageal stricture. Prognosis and treatment outcomes vary with the stage of the disease. Endoscopic ultrasound has a high accuracy rate for local and regional staging. Surgery is curative for early cancer. Endoscopic mucosal resection, photodynamic therapy, or brachytherapy can be used with curative intent for early cancer, especially in patients with comorbid conditions precluding surgery. Unfortunately, the majority of patients with esophageal cancer present with advanced disease. The primary aim in these patients is to alleviate symptoms with a minimum of side effects and reinterventions. Palliative surgery or chemoradiotherapy can be associated with high morbidity and mortality rates. Several endoscopic techniques for palliation are available, and all have the potential of significantly improving swallowing. The choice of a particular endoscopic approach is usually determined by local expertise and characteristics of the stricture.

Balloon dilation and stent placement for esophageal lesions: indications, methods, and results

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.

Effectiveness of open versus antireflux stents for palliation of distal esophageal carcinoma and prevention of symptomatic gastroesophageal reflux

PURPOSE

To compare the effectiveness of an antireflux stent with that of a standard open stent in preventing symptoms of gastroesophageal reflux in patients with inoperable distal esophageal cancer.

MATERIALS AND METHODS

Fifty consecutive patients with inoperable distal esophageal tumors underwent placement of either a standard open or an antireflux stent across the cardia. Stents were allocated randomly before assessment of the stricture. All patients were followed up prospectively by the departmental research nurses. Technical and clinical success, reflux symptoms, complications, and reintervention rates were assessed. P values of observed differences were calculated by using the chi(2) and log-rank tests as appropriate.

RESULTS

The technical success rate was 100%. Improvement in dysphagia was identical in both groups (three points on a five-point scale). Twenty-four (96%) of 25 patients with standard open stents had symptoms of esophageal reflux; 19 (76%) of 25 required treatment. Three (12%) of 25 patients with antireflux stents reported esophageal reflux; one (4%) of 25 required treatment. This difference was significant (P <.001). There was no significant difference in survival, complications, or reintervention rate. One case of late esophageal perforation occurred in each group. One patient died of aspiration within 24 hours after insertion of a standard open stent; no procedure-related deaths occurred with the antireflux stent.

CONCLUSION

This antireflux stent is as safe and effective as the standard open stent in relieving malignant dysphagia and was successful in reducing symptomatic gastroesophageal reflux.

Esophageal cancer

Despite advances in our knowledge of esophageal cancer, 50% of patients present with incurable disease, and the overall survival after diagnosis is poor. The incidence of esophageal adenocarcinoma of the distal esophagus is rising at a rapid rate in developed countries. Recent advances in the epidemiology of esophageal cancer offer insights into preventive strategies in patients who are at risk. New developments in diagnosis may help detect the disease at an early stage. New diagnostic modalities permit more accurate staging procedures and allow appropriate selection of therapy. New studies provide more information on multimodality therapy for esophageal cancer, and new endoscopic techniques allow resection of small lesions without surgery. New stent designs provide better palliation by providing tumor ingrowth. These developments in the treatment of esophageal cancer are the focus of this review.

Methods of palliation of esophageal and gastric cancer

Esophageal and gastric malignancies are common worldwide. Less than half are amenable to curative treatment at the time of diagnosis because of advanced or metastatic disease. Palliation is often required for symptoms, such as dysphagia, gastrointestinal bleeding, aspiration caused by tracheoesophageal fistula, nausea and emesis secondary to gastric outlet obstruction, and malnutrition. This article reviews the gastric outlet obstruction, and malnutrition. This article reviews the medical, endoscopic, and surgical options for palliative treatment.

Stents for Esophageal Disease

Esophageal malignancies presenting with dysphagia from luminal obstruction generally are not resectable for cure, and palliative therapy is the primary focus. Self-expandable metal stents (SEMS) have replaced plastic stents as a primary mode of palliation for malignant esophageal obstruction because of the relative ease of insertion, lower initial morbidity, and larger stent diameter. Self-expandable metal stents are ideal for patients with midesophageal tumors. A majority of patients experience relief of dysphagia with SEMS and dietary modification, but the initial cost is high and early morbidity may be significant. The placement of SEMS across the gastroesophageal junction may result in free reflux that may improve with a stent containing a one-way gastric flap valve. The placement of SEMS in the cervical esophagus, although more difficult, less effective, and less well tolerated, also may be successful. Coated SEMS are a treatment of choice for individuals with tracheoesophageal fistula. Delayed complications occur in up to 40% of patients and include stent migration, bleeding, perforation, fistula formation, and occlusion. Most complications can be managed endoscopically and additional stents may be placed for tumor overgrowth. The comparison of three currently available SEMS for esophageal malignancy show no statistically significant differences with regard to ease of placement, effectiveness, complications, and mortality. The use of SEMS for patients with benign disease is still considered experimental.

Antireflux stents in tumors of the cardia

Self-expanding metal esophageal stents (SMES) are highly effective in relieving dysphagia in patients with esophageal carcinoma. As the incidence of cancer at the lower esophagus/cardia continues to increase, SMES also are being deployed across the gastroesophageal junction (GEJ). However, use of SMES in this location makes the stomach and the esophagus, in effect, a common cavity, which predisposes patients to gastroesophageal reflux (GER) and aspiration. Reflux may result from an increase in intra-abdominal pressure or it may occur passively when the patient is recumbent. Acid-suppression medications do not protect against regurgitation and aspiration. We developed a modified antireflux SMES and evaluated its efficacy in vitro, in dogs, and in 11 patients with distal esophageal/GEJ carcinoma. The modification involved extending the polyurethane coating of the stent to 8 cm below the lower edge. In dogs, significantly more reflux episodes occurred with the regular stent (mean, 197 episodes) than with the modified stent (mean, 16 episodes; P = 0.03). In patients who received the modified stent, dysphagia scores were significantly reduced (mean baseline score, 3.4; mean end point score, 1.1; P <0.001). The modified stent prevented GER while allowing belching and vomiting.

The role of oesophageal stenting in the non-surgical management of oesophageal strictures

The role of oesophageal stenting continues to evolve, with several new stents currently on the market. These stents possess anti-reflux valves, internal plastic coatings and retrievable threads. In patients with malignant dysphagia, management should ideally take place within multi-disciplinary teams such that accurate tumour staging occurs prior to treatment. Multi-modality therapy can not only improve dysphagia and response rates but may also improve survival. Several non-surgical palliative techniques are available to recanalize malignant obstruction, including oesophageal stenting. Other therapeutic modalities include the use of endoluminal laser therapy, photodynamic therapy, argon beam and bipolar electrocoagulation, ethanol injection and intracavity brachytherapy. Their use often depends on local availability and expertise. Although the initial costs of metal stents are high, the overall costs compare favourably with other forms of palliative therapy that often require multiple procedures with repeated inpatient hospitalization. Treatment of refractory benign strictures with oesophageal stents remains uncommon and several recent reports using retrievable stents appear to improve outcome, although more work is required in this area.