Palliation of Malignant Dysphagia and Esophageal Fistulas

Introduction

The incidence of new cases of esophageal and gastroesophageal junction (GEJ) cancer is estimated to be 450,000 per year worldwide. Esophageal cancer is the eighth most frequent malignancy and has the sixth-highest cancer-specific mortality. The estimated 5-year survival rate in Western countries is less than 20% after the diagnosis. In the past, squamous cell carcinoma (SCC) was responsible for more than 90% of cases of esophageal carcinoma, but currently, adenocarcinoma is by far the leading esophageal malignancy, representing more than 60% of overall esophageal cases. This change in the histologic trend probably comes from the modification of risk factors for esophageal cancer, with several risk factors for adenocarcinoma (such as gastroesophageal reflux disease [GERD], Barrett's esophagus, cigarette smoking, obesity, hiatal hernia, and age > 50 years) being very globally distributed. Esophageal SCC is more frequently associated with smoking and alcohol intake. In patients with head and neck cancer, the risk of developing esophageal cancer is increased 3 to 10 times, with incidence ranging from 1% to 8%. SCC is located predominantly in the upper and middle parts of the esophagus. However, there are other nonesophageal cancers that can cause dysphagia, including primary lung cancer, proximal gastric cancer, and mediastinal lymphadenopathy. Adenocarcinoma of the esophagus, on the other hand, is located primarily in the distal esophagus. The poor prognosis of esophageal cancer is mainly due to the late diagnosis of advanced neoplasia, which allows only palliative treatments. The most common clinical symptom at presentation is dysphagia; other symptoms include drooling, thoracic pain, anemia, nausea, and weight loss usually associated with severe malnutrition. Moreover, advanced esophageal neoplasia may be associated in a limited number of cases with the presence of tracheal or bronchoesophageal fistula. Thus, the main goal of the palliative measures is the treatment of dysphagia and eventually the treatment of esophagorespiratory fistulas. Significant weight loss and malnutrition as a consequence of malignant dysphagia, as well as cachexia, are predominant symptoms in esophageal neoplastic strictures. To diagnose nutritional imbalances at an early stage, the European Society for Clinical Nutrition and Metabolism (ESPEN) recommends regular evaluation of nutritional intake, weight change, and body mass index (BMI) at the time of cancer diagnosis and repeated according to the stability of the clinical situation. Esophageal stenting is currently the most effective method for this aim and is used in approximately 50% of patients with inoperable esophageal carcinoma. Tracheoesophageal or bronchoesophageal fistulas usually develop quite late in the context of advanced cancer of the esophagus, lung, or mediastinum, either as a consequence of progressive tumoral invasion or as an adverse event of cancer therapies, in particular chemoradiotherapy. Unfortunately, the clinical condition of such patients has often already significantly worsened at the time they develop a fistula, and the remaining life expectancy is quite short (within weeks to months). Rapid relief of life-threatening symptoms related to the fistula, preferably by minimally invasive treatment such as esophageal stenting, is thus of pivotal importance to improve quality of life. In this chapter, we will address the endoscopic management of malignant dysphagia due to advanced cancer that is not suitable for surgery.

Esophageal Stents

Thanks to the technologic improvements of the last 20 years, different types of stents have been introduced to the market. Multiple types of self-expandable stents are available. They differ in terms of design, luminal diameter, radial force, flexibility, and degree of shortening after deployment. Available stents can be divided in two main categories: self-expandable metal stents (SEMSs) and self-expandable plastic stent (SEPSs). SEMSs are further subdivided into fully covered (FCSEMS), partially covered (PCSEMS), or uncovered SEMS. SEMS are mainly made of nitinol, a nickel and titanium alloy. In clinical practice, covered stents (partially or full covered) are usually preferred to the uncovered ones. It has been demonstrated that covered stents may delay tumor ingrowth without increasing the risk of migration. The most common metal stents currently available are listed in Table 28.1 .

Of course, an ideal stent that can perfectly fit all clinical situations does not exist. However, all available covered metal stents meet some of the criteria required to palliate malignant dysphagia and to provide temporary relief from refractory esophageal strictures. Some FCSEMS and plastic stents are also approved for temporary stenting in patients with benign recurrent or refractory esophageal strictures.

Management of Nonoperable Esophageal Malignancy

The European Society of Gastrointestinal Endoscopy (ESGE) guidelines suggest:

• Placement of PCSEMSs or FCSEMSs for palliative treatment of malignant dysphagia over laser therapy, photodynamic therapy, and esophageal bypass.

• For patients with longer life expectancy, brachytherapy can be considered a valid alternative, or used in addition, to stenting in esophageal cancer patients with malignant dysphagia. Brachytherapy may provide a survival advantage and possibly a better quality of life compared to SEMS placement alone.

• Esophageal SEMS placement is the preferred treatment for sealing tracheoesophageal or bronchoesophageal fistulas.

• The use of concurrent external radiotherapy and esophageal stent treatment is not recommended.

• SEMS placement is also not recommended as a bridge to surgery or prior to preoperative chemoradiotherapy because it is associated with a high incidence of adverse events, and alternative satisfactory options, such as placement of a feeding tube, are available.

Techniques of Stent Placement

Stent placement should be performed in the endoscopic room by an experienced endoscopist, preferably under deep sedation and fluoroscopy control, and with the support of personnel who are familiar with stent placement and related devices, such as guidewires and catheters. The length and diameter of the stent should be adequately chosen before stent placement according to stricture size and length: stent length should be 2 cm longer than the distal and proximal border of the neoplasia. Marking of proximal tumor borders is of paramount importance to properly deploy the stent under fluoroscopic control. Some experts prefer to use internal markers as clips or submucosal injection of Lipiodol (Guerbet, Villepinte, France) to achieve a better radiological identification of tumor localization. After proper definition of stricture characteristics (length, size, borders), a super-stiff steel guidewire, such as the Savary guidewire (Cook Medical, Bloomington, IN), is introduced through the stricture under fluoroscopic guidance, with the distal tip placed deeply into the stomach. Occasionally, in cases of very tight strictures, an endoscopic retrograde cholangiopancreatography (ERCP)-like technique with catheters and hydrophilic guidewires may be required to safely cannulate the stricture and advance the guidewire down into the stomach. In such a case the hydrophilic guidewire is then replaced with a stiffer one (i.e., Amplatz, Boston Scientific, Marlborough, MA), which is better able to support the proper advancement of the stent catheter through the stricture. Once the stent is advanced through the esophagus over the guidewire, it should be released slowly and carefully under fluoroscopic and/or endoscopic visualization. Stent deployment can also be performed under pure endoscopic control with results that are comparable in terms of efficacy and safety to stents released under fluoroscopic control. In such a case, a small-caliber scope is usually advanced alongside the stent catheter and used to monitor stent deployment, keeping it a few centimeters proximal to the stricture. At the end of the procedure, contrast medium may be injected through the working channel of the scope to confirm the correct positioning of the stent and to exclude complications, such as perforation. After the procedure, the patient should be closely observed in the recovery room to quickly diagnose early procedural-related complications such as hemorrhage, aspiration, perforation, and respiratory failure.

Once immediate complications are excluded, it is possible to restart feeding with fluids and then progressively with semisolids. A special mention should be made on the positioning of the stent in esophageal cancers located close to the upper esophageal sphincter (UES) ( Fig. 28.1 ). These tumors represent only 7% to 10% of all esophageal carcinomas. However, they are considered the most difficult to treat because of possible complications such as aspiration pneumonia and proximal migration, as well as the complaint of foreign body sensation and quite relevant local pain in some cases. Several studies have shown that treatment with stents is possible without major complications compared with middle/distal esophageal tumors. In these cases, it is better to perform the procedure under endoscopic and fluoroscopic control using a stent with proximal deployment to allow a more precise release and placement.