Self expandable metallic stents in the upper gastrointestinal tract

Abstract

Background: Open surgery in the upper gastrointestinal tract is associated with high morbidity and mortality especially in case of malignant diseases or infectious conditions. Insertion of self expandable metallic stents (SEMS) is one minimal invasive technique that can be used to relieve obstructive symptoms and to treat perforations within the upper gastrointestinal tract.Aims: To evaluate SEMS based techniques for treatment of perforations and malignant stenoses in the upper gastrointestinal tract regarding clinical outcome and cost-effectiveness. Another aim was to explore if computed tomography (CT) derived tumor size could prognosticate outcome after SEMS treatment in malignant dysphagia and if tumor size could be used as selection criterion for treatment decisions. Material and methods: Clinical outcome of a SEMS based treatment strategy was studied in 22 patients with esophageal perforations. Thirty-five patients with an incurable malignant disease and gastroduodenal obstruction received SEMS or were operated with an open surgical bypass in a non-randomized study with regard to healthcare costs and clinical outcome. SEMS treatment and brachytherapy were compared concerning clinical outcome and healthcare costs in a randomized trial comprising of 60 patients with incurable esophageal cancer. A CT-based technique for tumor size estimation was validated against endoscopically assessed tumor length and volume of surgically removed specimens. Estimated tumor size was analyzed in relation to survival and dysphagia in 82 patients with incurable esophageal cancer.Results: Twenty-one out of 22 esophageal perforations (95%) were sealed and the mortality after SEMS treatment of esophageal perforations was 14%. In patients with gastroduodenal obstruction, dietary intake after SEMS insertion was on a level comparable to that after open surgical bypass, whereas short-term treatment costs were lower for the SEMS strategy. Total lifetime costs were significantly lower for SEMS treatment compared to brachytherapy in patients with incurable esophageal cancer and the differences in clinical outcomes were minimal. There was a significant correlation between tumor volumes assessed by CT and actual tumor volume, as well as between tumor length estimated by CT and endoscopy. Tumor size could not predict outcome after SEMS treatment.Conclusion: This thesis suggests that SEMS insertion is effective in sealing leakages from esophageal perforations and that gastroduodenal SEMS treatment is a feasible and cost-effective treatment option for gastric outlet obstruction. Furthermore, esophageal SEMS insertion show similar clinical outcome as fractionated brachytherapy but SEMS insertion is superior with regard to health care costs. CT derived tumor size could not predict outcome after SEMS treatment.