Device for sterile coupling of a percutaneous surgical instrument to a rotary drive tool for said instrument having a body and an end provided with a coupling piece which can be driven in rotation with regard to the body, said device comprising:
- a flexible envelope with a first opening of circular shape and with a second opening allowing the drive tool to be introduced into said envelope, the first opening being positioned on a wall of the envelope in such a way that, when the drive tool is located in the envelope, the coupling piece is located opposite said first opening;
- a connector piece having a cylindrical distal portion, for coupling to the percutaneous surgical instrument, and a proximal portion, for coupling to the drive tool, and configured to pass through the envelope via the first, circular opening in such a way that the end of its distal portion is placed outside the envelope, its proximal portion being placed inside the envelope;
- a tubular ring which forms a conduit, in which the body of the rotary drive tool is intended to be inserted, and which is positioned on an inner surface of the envelope opposite the first, circular opening, said ring being rigidly fixed to the envelope via one of its ends, its other end being configured to rigidly connect the envelope to the body of the drive tool, said conduit being configured in such a way that the connector piece, connected to the rotary drive tool, can turn freely about its axis inside the ring and being held in place axially under the action of the coupling piece of the rotary drive tool;
- the rotary drive tool, the envelope, the ring and the connector piece having means which interact in order to form a leaktight barrier in the area of the first, circular opening, said barrier being configured so as not to impede the rotation of the connector piece,
- wherein the ring has a disc-shaped flange situated at the end of the tubular ring via which said ring is fixed on the inner surface of the envelope, the flange having a central opening whose centre is situated on the axis of symmetry of the tubular ring, the ring and the flange being fixed to the inner surface of the envelope in such a way that the centre of the first opening is also aligned with the axis of symmetry of the tubular ring, and
- wherein the first opening of the flexible envelope has a diameter slightly smaller than an external diameter of the cylindrical distal portion of the connector piece, said diameter being defined in such a way that, when the connector piece, connected to the rotary drive tool, is inserted into this first opening from the inside of the envelope, an edge of said first opening deforms and constitutes an annular fold which is directed to the outside of the envelope and which will surround an outer surface of the cylindrical body of the cylindrical distal portion of the connector piece, this annular fold constituting a leaktight barrier in the area of the first opening of the envelope.