The following 11 variables will be evaluated in cholecystitis by univariate analysis: [1] sex, [2] age, [3] regions of stricture, [4] F-CSEMS with high AF AF (axial force), [5] F-CSEMS with high RF, [6] previous biliary stent, [7] gallbladder stone, [8] contrast injection into the gallbladder (GB injection), [9] involvement to the orifice of the cystic duct (OCD), [10] position of distal stent edge, and [11] cystic duct occlusion by F-CSEMS.