Hypothesis /Aims SPA technique is a feasible approach to the peritoneal cavity. While performing laparoscopic cholecystectomy the single umbilical access has an overall morbidity comparable to multiport laparoscopy (equivalence study) while it entails a reduced skin-incision's related morbidity rate, a reduced post-operative pain and allows a better cosmetic result. Other considered parameters (operative time, conversion rate and hospital stay) are supposed to be unchanged.