Efficacy and safety of standard and anti-reflux self-expanding metal stent: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND Self-expanding metal stents are the main palliative treatment modality for unresectable esophageal cancer. Gastroesophageal reflux is a common adverse outcome after placement of esophageal stent for cancer involving the gastroesophageal junction and the gastric cardia. Anti-reflux stents with valve have been designed to prevent the acid reflux. The superiority of anti-reflux stent over standard stent in preventing gastroesophageal reflux has not been established well. This study compares the anti-reflux stent and the standard stent in terms of their efficacy to prevent acid reflux. AIM To compare the standard and the anti-reflux stents in terms of their efficacy, safety, and complications. METHODS The meta-analysis included 8 randomized clinical trials (RCTs) to compare pooled outcomes of total 395 patients. Primary outcomes include improvement in reflux symptoms and dysphagia score. Secondary outcomes include complications of stent migration, occlusion, and bleeding. RESULTS A total of eight RCTs were included in the meta-analysis. Compared to the standard stent, the anti-reflux stent showed a trend towards reduction in the dysphagia score without reaching a statistical significance [Standardized mean difference (SMD): -0.33 (-0.71, 0.05); P = 0.09, I-2: 37%]. There was no statistical difference in the gastrointestinal reflux (GER) scores between the two types of stents [SMD: -0.17 (-0.78, 0.45); P = 0.008, I-2: 74%]. Compared to standard stent, anti-reflux stent showed no difference in the risk of stent migration [OR: 1.37 (0.66, 2.83); P = 0.40, I-2: 0 %], bleeding [OR: 1.43 (0.40, 5.13); P = 0.59, I-2: 0 %], and obstruction [OR: 1.66 (0.60, 4.60); P = 0.33, I-2: 0 %]. CONCLUSION Traditional self-expanding standard esophageal stent and anti-reflux stent with valve are similar in terms of outcomes and complications.