Gastric ring with membranous bridge

Implantable surgical ring designed to be closed on itself in order to form a closed loop around a mean axis of extension so that it can grip a biological organ constituting a pocket or a duct in order to modify the section of passage of said biological organ, said ring comprising at least one first gripping pocket and one second gripping pocket which are tiered relative to each other along the mean axis of extension and designed to be filled with a filler fluid so as to provide for the gripping of the biological organ, said first and second gripping pockets respectively having a first peak portion and a second peak portion which project towards the interior of the loop to push against said biological organ, and said first and second peak portions are separated from each other by a separation zone which defines a matter-free clearance zone sufficiently marked to provide for a discontinuity of contact between the biological organ and the surgical ring, between the peak portions, and which comprises a retaining means receding away from said first and second peak portions and designed to limit the penetration depth at which the gripped biological organ is liable to penetrate between said first and second peak portions so as to prevent damage to the wall of the biological organ in the separation zone.