Esophageal cancer has an incidence that varies between 12,000 and 18,000 new cases/year. Unfortunately, the overall survival for esophageal cancer is dismal because patients usually present when symptomatic with dysphagia and/or weight loss, by which time the tumor has metastasized. The symptoms from an obstructing esophageal tumor can have a significant impact on quality of life. Fortunately, palliative treatment options of limited risk are available which can improve swallowing, allow for continued oral intake, and help prevent aspiration.
Options for palliating the patient with dysphagia from advanced, unresectable esophageal cancer include stenting, photodynamic therapy (PDT), cryoablation, laser ablation, and chemoradiation. Of these, the therapies that are most widely used in the United States are esophageal stenting and PDT. Cryoablation is a newer modality that has gained popularity. These therapies are the focus of this discussion. As a group, these therapies will improve dysphagia and provide patients with the ability to consume an oral diet with some modification.
Historically, stenting to relieve malignant strictures of the esophagus involved the use of plastic stents. Prior to the invention of self-expanding stents, these required placement via either a pulsion technique (forcing the stent through the obstruction after dilation) or via a traction technique requiring a laparotomy and gastrostomy.1,2
Fortunately, self-expanding metal stents (SEMSs) have simplified palliation and the older stents are rarely used. The SEMS can be placed under endoscopic and fluoroscopic guidance. This approach does not require general anesthesia (although this may be preferable) or aggressive dilation of the malignant stricture prior to stent deployment. The stent itself is embedded within the tumor. Consequently, the likelihood of migration is decreased. The benefits of SEMSs over the earlier plastic stents have been examined in a clinical trial, demonstrating similar improvement in dysphagia scores using both techniques but absence of early complications among patients treated with SEMSs. In this trial, there was 20% early morbidity and 16% mortality among patients treated with plastic stents.3
In general, over 85% of patients achieve immediate palliation from their dysphagia symptoms after placement of an SEMS. Inability to relieve dysphagia with stenting is typically due to technical issues, such as poor stent expansion or malposition. These difficulties may be remedied by removing the stent and replacing it with a more appropriately sized device. In addition, alternative or concurrent therapies such as cryoablation or PDT (described below) may be an option.
The newer generation SEMSs are constructed from various materials that include cobalt alloys (Wallstent, Schneider, Minneapolis, MN), stainless steel (Z-stent, Cook, Bloomington, IN), and a nickel–titanium alloy called Nitinol (Esophacoil, Medtronic, Minneapolis, MN; Ultraflex, Boston Scientific, Natick, MA). These materials are resistant to corrosion and biologically inert.
The wire stents may be woven (Wallstent), knitted (Ultraflex), or bent into a zigzag (Z-stent) or coil (Esophacoil) configuration. Some ...