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Performance of plastic stents used for benign and malignant biliary strictures; experience of single high-volume endoscopy unit.

INTRODUCTION
Plastic biliary stents embedded by endoscopy as definitive or temporary treatment of benign and malignant conditions have been used for over 30 years. These stents are commonly available, inexpensive and easy to implant.


OBJECTIVES
To evaluate the patency duration of plastic stents and assess complications associated with their use, and to determine the time required for the replacement of stents depending on the indication for the biliary stenting.


PATIENTS AND METHODS
This was a retrospective cohort study that included patients with plastic biliary stents implanted from 2012 to 2013 with 5-year follow up in a single tertiary referral gastroenterological center. Performance of stenting was assessed from medical records, direct contact with patients or their family members and information derived from the Central Death Register.


RESULTS
The analysis included 830 procedures of biliary stenting performed in 346 patients. The indications for stenting of the biliary tract were: choledocholithiasis in 120 patients (34.7%), benign stricture in 70 patients (20.2%) and malignant stricture in 156 patients (45.1%). In these conditions the mean duration of stent patency was 110, 106 and 55 days, respectively (P<0.001). Stents implanted for malignant perihilar strictures had significantly shorter functioning time than those used for distal strictures (40 days vs 76 days, P=0.002).


CONCLUSIONS
Patency of plastic stents depends on the underlying disease. In the case of benign biliary diseases it is advisable to replace stents after about 3.5 months. In case of cancer, the time of scheduled stent replacement should depend on prognosis of survival time.