Shape lockable apparatus and method for advancing an instrument through unsupported anatomy
Apparatus and methods are provided for placing and advancing a diagnostic or therapeutic instrument in a hollow body organ of a tortuous or unsupported anatomy, comprising a handle, an overtube disposed within a hydrophilic sheath, and a distal region having an atraumatic tip. The overtube may be removable from the handle, and have a longitudinal axis disposed at an angle relative to the handle. The sheath may be disposable to permit reuse of the overtube. Fail-safe tensioning mechanisms may be provided to selectively stiffen the overtube to reduce distension of the organ caused by advancement of the diagnostic or therapeutic instrument. The fail-safe tensioning mechanisms reduce the risk of reconfiguration of the overtube in the event that the tension system fails, and, in one embodiment, rigidizes the overtube without substantial proximal movement of the distal region. The distal region permits passive steering of the overtube caused by deflection of the diagnostic or therapeutic instrument, while the atraumatic tip prevents the wall of the organ from becoming caught or pinched during manipulation of the diagnostic or therapeutic instrument.
1 . (canceled)
2 . A disposable sheath configured to be disposed upon an overtube, comprising:
an outer skin having a distal end, a proximal end, and a length configured to be disposed along an outer surface of the overtube;
a liner disposed within a lumen of the outer skin and having a distal end, a proximal end, and a length configured to be positioned through a lumen of the overtube; and
an atraumatic tip attached to at least one of the distal ends of the outer skin or the liner.
3 . The sheath of claim 2 , wherein the sheath is removable from the overtube.
4 . The sheath of claim 2 , wherein the length of the outer skin extends over a length of the overtube.
5 . The sheath of claim 2 , wherein the outer skin comprises a flexible elastomeric material.
6 . The sheath of claim 5 , wherein the elastomeric material comprises silicone or synthetic rubber.
7 . The sheath of claim 2 , wherein the outer skin has a thickness of less than 0.13 mm.
8 . The sheath of claim 2 , wherein the liner has a thickness of about 0.15 mm.
9 . The sheath of claim 2 , wherein the outer skin and the liner define an annular chamber within which the overtube is inserted.
10 . The sheath of claim 2 , further comprising a kink-resistant coil encapsulated within the liner.
11 . The sheath of claim 2 , wherein the liner is adapted to be lubricious.
12 . The sheath of claim 2 , wherein the liner comprises a hydrophilic coating thereon.
13 . The sheath of claim 2 , wherein the atraumatic tip is disposed at the distal end of the liner.
14 . A disposable sheath configured to be disposed upon an overtube, comprising:
an outer skin having a distal end, a proximal end, and a length configured to be disposed along an outer surface of the overtube; and
a liner disposed within a lumen of the outer skin and having a distal end, a proximal end, and a length configured to be positioned through a lumen of the overtube,
wherein the distal end of the liner is attached to a distal end of the outer skin.
15 . The sheath of claim 14 , wherein the sheath is removable from the overtube.
16 . The sheath of claim 14 , wherein the length of the outer skin extends over a length of the overtube.
17 . The sheath of claim 14 , wherein the outer skin comprises a flexible elastomeric material.
18 . The sheath of claim 17 , wherein the elastomeric material comprises silicone or synthetic rubber.
19 . The sheath of claim 14 , wherein the outer skin has a thickness of less than 0.13 mm.
20 . The sheath of claim 14 , wherein the liner has a thickness of about 0.15 mm.
21 . The sheath of claim 14 , wherein the outer skin and the liner define an annular chamber within which the overtube is inserted.
22 . The sheath of claim 14 , further comprising a kink-resistant coil encapsulated within the liner.
23 . The sheath of claim 14 , wherein the liner is adapted to be lubricious.
24 . The sheath of claim 14 , wherein the liner comprises a hydrophilic coating thereon.
25 . The sheath of claim 14 , further comprising an atraumatic tip attached to at least one of the distal ends of the outer skin or the liner.