Biliary stent allows the drainage of the bile ducts palliatively or preoperatively in the event of malignant biliary stenosis, and a biliary calibration in the event of benign stenosis. Currently, by expert agreement, the diameter is 10-mm for metal stent. Since 2017, larger stents have been marketed in France and are approved for the biliary drainage of benign and malignant biliary stricture. These new 12-mm diameter stent could reduce the risk of recurrent biliary obstruction (RBO) and therefore increase the stent duration. The aim of our study was to compare whether the permeability of 12-mm diameter stent was better than a conventional 10-mm, covered or uncovered prosthesis depending on the indication.

Inclusion Criteria:

• benign and malignant biliary stricture of the lower or median portion of the main biliary duct with indication of biliary stent placement including pre-operatively drainage
• age≥ 18 years old;
• Karnofsky score ≥ 40.

Exclusion Criteria:

• hilar stenosis;
• coagulation disorder (PT <50%, platelets < 80,000).

From April 2017 to April 2018, at the Paoli Calmettes Institute, 24 patients with benign or malignant biliary strictures were treated by placing a metallic biliary stent, covered or uncovered, KEBOMED HILZO 12mm in diameter (length 4 or 6 cm).

"Control" patients, who had benefited from the placement of a biliary, metallic, covered or uncovered stent, COOK EVOLUTION 10mm in diameter (length 4 or 6 cm) were searched on a database (ConsortConsore®️)extending from January 2016 to March 2018. "Cases" patients were exactly matched in a ratio 1:2 to "control" on the following criteria: age (per decade), sex, pathology responsible for biliary stenosis (i.e., benign or malignant stenosis) and type of stent (i.e., covered/uncovered). When we searched for control patients in our database, the first patient with matching criteria was included.