An implantable surgical ring is configured to be placed around a biological organ forming a bag in order to modify the flow area thereof. The ring includes a flexible strip capable of winding around an axis to form a loop around the organ and which has one ventral surface. The flexible strip is preformed such that the ventral surface is curved around the axis and divided into a plurality of contiguous and intersecting facets. The facets are connected to one another by transition areas forming predefined hinging creases with angle coverage with respect to the axis of no more than 5 degrees, each facet covering an angle sector substantially between 15 degrees and 35 degrees.
