Status evaluation: Biliary stents

: Large caliber plastic stents (10 to 11.5 French) have become widely accepted as an alternative to surgery in the treatment of many malignant and benign lesions of the biliary tract. Procedure-related early complications occur at an acceptable rate (8 to 10%) and procedure-related mortality is approximately 2%. Late clogging occurs at a mean of 4 to 6 months. This results in the need to change a clogged stent in 20 to 35% of surviving patients with malignant disease. In benign or malignant disease, when long-term stenting is desired, it is generally recommended to prophylactically replace the stent every 4 to 6 months to avoid clogging. While several mechanisms of clogging have been elucidated, research studies have failed to lead to a clinically available improvement in duration of patency. The role of expandable metal stents in the treatment of malignant and benign biliary strictures has not been established. Despite their large internal diameter, they may be associated with late problems related to stent clogging from tumor ingrowth or overgrowth. Technical difficulties and expense, as well as lack of data from prospective randomized trials, limit current recommendation for their use at this time.