Study design Randomization is performed preoperatively and stratification is performed intraoperatively, after visualization of the operative field. Patients are randomized to one of three groups: LESS cholecystectomy blind, standard LC, LESS cholecystectomy not blind. Patients are stratified into 3 groups: Nassar grade I, II, III, according to the grade of difficulty of cholecystectomy (Nassar score) assessed at the initial inspection of the operating field.