Stent placement instrument and method of assembly

An instrument for use by a surgeon to place within and remove from a patient's lumen a stent aligned along an axis, the instrument comprising:

• a thumb loop for manipulation by a surgeon, the thumb loop having an open center into which the surgeon's thumb may fit when it is normal to the axis;
• an arm extending tangentially from the thumb loop, the arm in a plane with the axis, the arm having at least one bore in alignment with the axis;
• a tab extending from the arm along the axis and from the thumb loop so the arm, tab and thumb loop reside substantially in the plane with one another and the axis;
• a finger ring for manipulation by a surgeon, the finger ring centrally open to receive the surgeon's finger;
• a limb extending tangentially from the finger ring and attached thereto, the limb having an axially aligned hole so the hole, finger ring and the limb may be positioned in the plane with the axis;
• a front bracket extending from the tab over and in front of the limb;
• a tube to support the stent located for extending therefrom, the tube for coaxial deposition about the axis, into the bore and the hole, the tube for locating the finger ring forward of the thumb loop for ergonomic use by the surgeon in a sliding action of the finger ring relative to the tube when guided along axis;
• a sheath for sliding along the tube, the sheath extending from the hole along the axis and toward the stent end, the sheath coaxially disposed about the tube;
• a stent end on the tube opposite where the tube fits into the bore, the stent end for engaging the stent with at least one grip carried thereon when the stent is reduced to a diameter to fit within the sheath before and during placement and/or removal from the patient's lumen so the at least one grip is operatively mounted near the stent end for axially locating precisely the stent within the patient's lumen for release;
• a cavity in the sheath beyond the stent end on the tube, the cavity for accommodating the stent being carried along the axis cantilever from the stent end on the tube;
• a support fits coaxially over and about the sheath, the support extending along the sheath from the front bracket so that axial movement of the sheath may be independent of the support;
• a flange is on the support for abutting the front bracket and a tang on the abutted flange resiliently engages the front bracket to restrain axial movement of the flange away from the front bracket;
• a shaft positioned in the plane attached to the front bracket, the shaft generally parallel to the axis, the shaft conjugating with the limb and arm to prevent relative rotary motion between them with respect to the axis;
• an axial control fit within the arm for movement by the surgeon relative to the shaft, the axial control for adjusting the axial position of the shaft relative to the arm for setting the axial position of the shaft with respect to the arm to thereby adjust the instrument for stents of various lengths, the axial control includes a lock for transverse movement by the surgeon relative to the arm and the shaft has settings for cooperative engagement with the lock to define preset adjustment locations for accommodating stents of various lengths;
• a latch on the front bracket to secure the relative axial positions of the limb and the front bracket, the latch to selectively permit the surgeon to move the sheath relative to the tube for loading and thereafter delivering the stent, and
• a catch on the tab to prevent complete release of the stent from the tube without the prior manual release of the catch thus permitting the finger ring to fully approach the thumb loop, the latch includes a spring loaded key on the front bracket and the catch has a spring loaded key on the tab, each spring loaded key is positioned to cooperatively engage a receiving way atop the limb for limiting the axial movement of the finger ring relative to the thumb loop so the axial control, the latch and the catch are all positioned relative to the shaft and the tab and the front bracket, respectively so the instrument may either be disassembled for cleaning and sterilization or assembled and adjusted to a particular stent length.

A method of assembling and disassembling an instrument for use by a surgeon to place a stent within a patient's lumen, the instrument having an axis and a thumb loop, an arm in a plane with the axis and extending tangentially from the thumb loop, a bore in the arm aligned with the axis, a tab extending from the arm along the axis and from the thumb loop, a finger ring for manipulation by a surgeon, a limb having an axially aligned hole and the limb extends tangentially from the finger ring, a front bracket extending from the tab over and in front of the limb, the method comprising the following steps:

• extending a tube to support the stent in coaxial disposition about the axis, into the bore and the hole;
• locating the finger ring on the tube forward of the thumb loop for ergonomic use by the surgeon in a sliding action of the finger ring relative to the tube when guided along axis;
• sliding a sheath extending from the hole and coaxially disposed about the tube;
• accommodating the stent in a cavity within a stent end of the sheath and along the axis;
• conjugating a shaft positioned attached to the front bracket and parallel to the axis with the limb and the arm to prevent relative rotary motion between them with respect to the axis;
• moving an axial control fit within the arm and adjusting the axial position of the shaft relative to the arm for setting the axial position of the shaft with respect to the arm to thereby changing the instrument for stents of various lengths;
• securing the relative axial positions of the limb and the front bracket with a latch on the front bracket and selectively permitting the surgeon to move the tube relative to the sheath for loading and thereafter delivering the stent, and
• preventing complete release of the stent from the tube without the prior manual release of a catch on the tab and thereby permitting the finger ring to fully approach the thumb loop.