摘要Self expanding metal stents (SEMS) play an important role in the management of malignant obstructing lesions in the gastrointestinal tract.Traditionally,they have been used for palliation in malignant gastdc outlet and colonic obstruction and esophageal malignancy.The development of the polyflex stent,which is a removable self expanding plastic stent,allows temporary stent insertion for benign esophageal disease and possibly for patients undergoing neoadjuvant chemotherapy prior to esophagectomy.Potential complications of SEMS insertion include perforation,tumour overgrowth or ingrowth,and stent migration.Newer stents are being developed with the aim of increasing technical and clinical success rates,while reducing complication rates.Other areas of development include biodegradable stents for benign disease and radioactive or drug-eluting stents for malignant disease.It is hoped that,in the future,newer stents will improve our management of these difficult conditions and,possibly,provide prognostic as well as symptomatic benefit in the setting of malignant obstruction.