Delivery device and method for indwelling stent
A delivery device includes a handle, a first sheath having a proximal end portion connected to the handle, a second sheath through which the first sheath is inserted, the second sheath translatable relative to the handle in a longitudinal direction of the delivery device, a third sheath through which the second sheath is inserted and a length adjustment mechanism. A distance in the longitudinal direction of the delivery device between a proximal end of the first sheath and a distal end of the third sheath defines a separation distance. The length adjustment mechanism adjusts the separation distance between a first length and a second length. The second length is longer than the first length.
1 . A delivery device, comprising:
a handle;
a first sheath having a proximal end portion connected to the handle;
a second sheath through which the first sheath is inserted, the second sheath translatable relative to the handle in a longitudinal direction of the delivery device;
a third sheath through which the second sheath is inserted;
a length adjustment mechanism;
a protective sheath covering the third sheath and the length adjustment mechanism; and
a lock mechanism configured to reversibly fix a position of the protective sheath relative to the third sheath,
wherein a distance in the longitudinal direction of the delivery device between a proximal end of the first sheath and a distal end of the third sheath defines a separation distance,
wherein the length adjustment mechanism adjusts the separation distance between a first length and a second length,
wherein the second length is longer than the first length,
wherein a distal end of the length adjustment mechanism is fixed to a proximal end of the third sheath, and a proximal end of the length adjustment mechanism is fixed to the handle, and
wherein the protective sheath covers the proximal end of the third sheath, and a proximal end of the protective sheath comes into contact with a distal end portion of the handle.
2 . The delivery device according to claim 1 , wherein the length adjustment mechanism includes a biasing member, and wherein the biasing member variably biases the third sheath relative to the first sheath in the longitudinal direction of the delivery device.
3 . The delivery device according to claim 1 , wherein the length adjustment mechanism is located between the proximal end of the first sheath and the distal end of the third sheath.
4 . The delivery device according to claim 1 , wherein the first sheath has a first length, the second sheath has a second length, and the third sheath has a third length, and
wherein the third length is less than the first length and the third length is less than the second length.
5 . The delivery device according to claim 1 , wherein the first sheath, the second sheath, and the third sheath are configured to be insertable into a channel of an endoscope.
6 . The delivery device according to claim 1 , further comprising:
a stent disposed between an outer circumferential surface of the first sheath and an inner surface of the second sheath,
wherein, in the longitudinal direction of the of the delivery device, the stent is positioned more distal than the distal end of the third sheath.
7 . The delivery device according to claim 6 , wherein the stent includes a plurality of wires, and
wherein each of the plurality of wires includes:
a first plurality of first bent portions in which the wire is bent in a first direction, and
a second plurality of second bent portions in which the wire is bent in a second direction, the second direction opposite to the first direction, and
a plurality of engagement portions in which first bent portions of a first wire of the plurality of wires intersects second bent portions of a second wire of the plurality of wires.
8 . The delivery device according to claim 1 , wherein the length adjustment mechanism includes a spring having a spring force of 3 N or smaller.